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The interaction between probiotic bacteria and polyphenol antioxidants can potentially enhance animal health. The present study examined the effects of propyl gallate and Lactobacillus plantarum supplementation on the growth, intestinal morphology, antioxidant capacity, and immune functions of Pekin ducks. A total of 128 male Pekin ducks (7-day-old) were allocated to four treatment groups with four replicates of eight birds each. The ducks were fed the corn-soybean based diet (the control), supplemented with either propyl gallate (100 mg/kg), Lactobacillus plantarum (4 × 10 9  CFU/kg), or both, for 5 weeks. Dietary supplementation with propyl gallate and Lactobacillus plantarum had no significant effect on feed intake (P > 0.05), but increased average daily gain (P < 0.05). Lactobacillus plantarum also reduced the feed/gain ratio (P < 0.05). Villus height (VH) in the duodenum and ileum was increased by supplementation, while only propyl gallate supplement increased VH in the jejunum (P < 0.05). Supplementation had no effect on small intestine crypt depth (P > 0.05). Enhanced total superoxide dismutase activity was observed with supplementation (P < 0.05), but no effects were seen on catalase, malondialdehyde, total antioxidant capacity, and glutathione peroxidase values (P > 0.05). Serum immunoglobulin G was increased with Lactobacillus plantarum (P < 0.05), but not with propyl gallate (P > 0.05). No change in IgA and IgM concentrations was observed with supplementation. In conclusion, dietary supplementation with propyl gallate, Lactobacillus plantarum, or both, enhanced the villus height of the small intestines, improving the growth rate of Pekin ducks. The synergistic effects of both propyl gallate and Lactobacillus plantarum on the villus height and serum total superoxide dismutase activity surpassed the individual effects of each supplement in Pekin ducks., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Feed efficiency (FE) is an important economic factor in poultry production, and feed conversion ratio (FCR) is one of the most widely used measures of FE. Factors associated with FCR include genetics, the environment, and other factors. However, the mechanisms responsible for FCR in chickens are still less well appreciated. In this study, we examined the pattern changes of FCR, then delved into understanding the mechanisms behind these variations from both genetic and environmental perspectives. Most interestingly, the FCR at the front section of henhouse exhibited the lowest value. Further investigation revealed that laying rate in the high FCR (HFCR) group was lower than that in the low FCR (LFCR) group (P < 0.05). Cortisol, total antioxidant capacity (TAOC), and IgG levels in the LFCR group were significantly lower than those in the HFCR group (P < 0.05), while BUN level was significantly higher than that in the HFCR group (P < 0.05). We identified a total of 67 and 10 differentially expressed genes (DEGs) associated with FCR in ovarian and small intestine tissues, respectively. Functional enrichment analysis of DEGs revealed that they might affect FCR by modulating genes associated with salivary secretion, ferroptosis, and mineral absorption. Moreover, values for relative humidity (RH), air velocity (AV), PM 2.5 , ammonia (NH 3 ), and carbon dioxide (CO 2 ) in the LFCR group were significantly lower than those in the HFCR group (P < 0.05). Conversely, value for light intensity (LI) in the LFCR group was significantly higher than that in the HFCR group (P < 0.05). Correlation analysis revealed a positive correlation between FCR and RH, AV, PM 2.5 , NH 3 , and CO 2 , and a negative correlation with LI. Finally, the FCR prediction model was successfully constructed based on multiple environmental variables using the random forest algorithm, providing a valuable tool for predicting FCR in chickens., Competing Interests: DISCLOSURES The authors declare no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Public interest in the cannabis plant has increased after its legalization in many countries. Cannabis sativa residues (CR) are a part of the plant waste in the cannabis industry. The CR contain medicinal properties that could be used as a feed additive in poultry production. The trial was conducted to investigate the effects of CR on growth performance, carcass characteristics, intestinal morphology, and blood biochemistry profile of broiler chickens. In a completely randomized design, 256 one-day-old male Ross 308 broilers were randomly allocated to 4 treatments with 8 replicates and 8 birds per replicate. These 4 dietary treatments included a basal diet with 0, 0.5, 1 and 2% CR for 40 d. The results showed that 2% CR supplementation reduced feed intake (FI) in the starter phase (d 3-23, P < 0.05). The birds in the CR groups had lower FI in the finishing phase (d 24-40, P < 0.01) and the whole raising period (d 3-40, P < 0.01) than the control. However, the body weight and carcass yield were not different (P > 0.05). In addition, the CR diet had no adverse effects on the blood biochemistry profile, including total cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total protein, globulin, albumin, and direct bilirubin (P > 0.05). In addition, total bilirubin and malondialdehyde were better in the plasma of CR-supplemented birds than in the control groups (P < 0.05). The observations on intestinal morphology showed that CR supplementation improved the ratio between villus height and crypt depth in the ileum (P < 0.05). In conclusion, CR supplementation can improve intestinal morphology and oxidative stability of broiler chickens. This suggests that CR could potentially be used as an alternative feed additive in broiler production., Competing Interests: DISCLOSURES The authors declare no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: This study investigated the repeatability of feed efficiency and its association with carcass traits in Hanwoo steers during the entire growing and fattening periods., Methods: The growth and intake of thirty-six Hanwoo steers (259±19.7 kg; nine months) were monitored throughout five periods, including two growing periods (GP) and three fattening periods (FP). The steers were fed two types of concentrate mixes with varying nutrient compositions until they reached a target weight of 800 kg for slaughter. For each period, steers were categorized into three classes based on their feed efficiency rankings using residual feed intake (RFI) and feed conversion ratio (FCR). Feed efficiency repeatability was assessed using the Spearman correlation coefficient, decomposition of random errors, and the Theil segregation index (TSI). The Pearson correlation coefficient was used to examine the relationship between feed efficiency and carcass traits., Results: The results demonstrated a significant and high correlation with RFI, but not FCR, during the growing or fattening stages (r>0.5; p<0.01). When steers were classified according to their feed efficiency rankings, 58% of the animals in the high RFI class (low efficient) initially (GP 1) remained in the same class by the last period (FP 3), whereas steers were randomly distributed based on FCR. The repeatability, assessed by the decomposition of random errors, was higher for RFI (0.61) than for FCR (0.15). The TSI also indicated that RFI rankings, rather than FCR rankings, are more likely to be maintained. Moreover, a weak association was observed between feed efficiency and carcass traits., Conclusion: In conclusion, RFI repeatability throughout the GP and FP surpassed that of the FCR, with steers classified as high RFI during the GP more likely to remain in the same class during the FP. Feed efficiency was weakly correlated with carcass traits.

Zinc (Zn) is an important dietary nutrient for the optimum growth performance, feed efficiency, normal metabolism, and fish health. Unfortunately, Zn requirement for mori (Cirrhinus mrigala) is not available. This experiment was designed to assess the impacts of Zn-gluconate levels on growth performance, feed utilization, mineral composition, and enzyme activities of mori and determines the optimum requirement of Zn-gluconate for this species. For this purpose, seven isonitrogenous (29.18%) and isolipidic (10.71%) purified diets were formulated with graded Zn-gluconate levels (0, 10, 20, 30, 40, 50, and 60 mg/kg). A total of 525 juveniles (4.30 ± 0.13 g) were distributed in 21 tanks. All treatments were assessed in triplicates. At the end of the trial (90 days), a progressive increase in final weight (FW) was observed in mori fed with 0-40 mg/kg of Zn-gluconate, remained constant at 50 mg/kg of Zn-gluconate, and significantly decreased at 60 mg/kg of Zn-gluconate. Similarly, weight gain and specific growth rate followed a similar pattern, while weight gain% increased till 40 mg/kg of Zn-gluconate. However, further increase (40-60 mg/kg) had a non-significant effect on weight gain%. Diet supplemented with 40 mg/kg of Zn-gluconate resulted in optimum values for feed intake and feed conversion ratio. Supplementation of Zn-gluconate did not affect dry matter, crude fat, and crude ash at all graded levels. However, whole body crude protein was significant in response to Zn-gluconate supplementation. Furthermore, Zn-gluconate absorption enhanced from 0 to 40 mg/kg of Zn-gluconate and remained constant afterward. Whole body mineral activity also followed a similar pattern. Overall, Zn-gluconate supplementation enhanced (P < 0.05) mineral activity in all parts of the tested parts of mori, including bones, scales, skin, eyes, heart, liver, and kidney. Moreover, the highest (P < 0.05) mineral activity in the skin, heart, liver, and kidney was observed in 60 mg/kg of Zn-gluconate. Supplementation of Zn-gluconate significantly increased the activity of alkaline phosphatase while it reduced thiobarbituric acid reactive substance contents of mori. The optimal dietary requirement of Zn-gluconate was recorded as 43.86 mg/kg through broken-line regression for maximum weight gain% of mori juveniles. Conclusively, 40 mg/kg of Zn-gluconate supplementation significantly enhanced the health of C. mrigala. However, a further increase in Zn-gluconate supplementation from 40 to 60 mg/kg did not significantly improve the above-mentioned parameters., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The development of reuse processes for plant by-products for both animal and human food offers numerous possibilities for quality-of-life improvements that align with a circular economy model. For this reason, we divided this study into two experiments. First, we designed a combined treatment consisting of laccase, ultrasound, and ascorbic acid to hydrolyze rice straw plant fibers and used the resulting feed as the basis for T. molitor diets. Second, we formulated diets with different inclusion levels (0%, 25%, 50%, 75%, and 100%) of rice straw and treated rice straw to assess their impact on larvae growth and diet digestibility. For each treatment, six replicates were employed: four for the growth-performance-digestibility trial and two for complementary uric acid determination tests. The combined laccase enzyme, ultrasound, and ascorbic acid treatment hydrolyzed 13.2% of the vegetable fibers. The diets containing treated rice straw resulted in higher larvae weight and a better feed conversion ratio; however, reaching 100% by-product inclusion values led to similar results between both diets. In conclusion, these treatments improve the potential of low-nutritional-value vegetable by-products as part of a T. molitor diet, opening the possibility of new methodologies for the use of recalcitrant vegetable by-products for insect rearing.

This meta-analysis aims to investigate the effects of residual feed intake (RFI) phenotype on performance, nutrient utilization and meat quality traits in Zebu (Bos indicus) cattle. Twenty-three peer-reviewed publications with 37 treatment means were included in the dataset. Weighted mean difference analysis compared animals categorized into low RFI (more efficient) versus medium or high RFI (less efficient) groups. Data heterogeneity via meta-regression and subgroup analysis, considering variables such as animal age, sex class, experimental duration, RFI group, dietary concentrate, and estimated metabolizable energy intake were also explored. The predominant genetic group of cattle in the dataset was Nellore (89.18%), followed by Brahman (10.81%). More efficient animals (low RFI phenotype) exhibited less dry matter intake (DMI; P < 0.010) than medium or high RFI animals (-0.95 kg vs. -0.42 kg/d). Cattle dietary crude protein and fiber digestibility were consistent across RFI groups (P > 0.05), while dietary ether extract digestibility tended to decrease (P = 0.050) in low RFI animals (-13.20 g/kg DM). Low RFI animals tended to increased (P = 0.065) ribeye area (REA) compared to the high/medium RFI groups, while carcass backfat thickness (BFT) decreased (P = 0.042) compared to high/medium RFI groups. Moreover, there was an increase (P < 0.001) of 0.22 kg in Warner-Bratzler shear force (WBSF) and a reduction (P < 0.001) in the myofibrillar fragmentation index (MFI) in low RFI animals. Meat color parameters (lightness [L*] and yellowness [b*]) and visual marbling scores were consistent (P > 0.05) across RFI groups. In conclusion, Zebu cattle classified as efficient (low RFI) exhibited reduced DMI, which improves their feed efficiency. However, BFT and meat quality parameters such as tenderness (WBSF and MFI) and redness [a*] were compromised by low RFI phenotype, highlighting the challenge of enhancing feed efficiency and meat quality traits in Zebu cattle., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

While the supplementation of methionine (Met) sources in broiler feeds has been established for several decades, there is debate on the nutritional value of the methionine hydroxy analogue of methionine (MHA) relative to DL-Met. Based on a recommendation suggesting that MHA is 65% as effective as DL-Met, many feeding trials have been conducted to challenge this recommendation. A literature search found 25 publications contributing 95 data sets suitable to compute Hedges' g effect sizes used in the meta-analysis. The data had very little heterogeneity of almost zero and the small effect sizes of the DL-Met results were not significantly different from MHA. Data were split in various subgroups, finally suggesting that neither broiler strain (Cobb 500, Ross 308), diet type (corn, wheat based), origin of data (peer-reviewed, grey literature), nor MHA product (MHA-free acid, MHA-calcium salt) impacted the outcome of the meta-analysis. Moreover, distinguishing data in groups with dietary Met+Cysteine (Cys) levels below, at, or above requirement demonstrated that there was no interaction with general Met+Cys supply. It is therefore concluded that MHA products can be replaced by DL-Met in a weight-to-weight ratio of 100:65 in any production condition without compromising broiler performance.

Background: ATPase activity and the antioxidant function of intestinal tissue can reflect intestinal cell metabolic activity and oxidative damage, which might be related to intestinal function. However, the specific influence of intestinal ATPase activity and antioxidant function on growth performance, feed conversion efficiency, and the intestinal microbiota in sheep remains unclear., Results: This study analyzed the correlation between ATPase activity and antioxidant function in the jejunum of 92 Hu sheep and their growth performance and feed conversion efficiency. Additionally, individuals with the highest (H group) and lowest (L group) jejunum MDA content and Na + K + -ATPase activity were further screened, and the effects of jejunum ATPase activity and MDA content on the morphology and microbial community of sheep intestines were analyzed. There was a significant correlation between jejunum ATPase and SOD activity and the initial weight of Hu sheep (P < 0.01). The H-MDA group exhibited significantly higher average daily gain (ADG) from 0 to 80 days old and higher body weight (BW) after 80 days. ATPase and SOD activities, and MDA levels correlated significantly and positively with heart weight. The jejunum crypt depth and circular muscle thickness in the H-ATP group were significantly higher than in the L-ATP group, and the villus length, crypt depth, and longitudinal muscle thickness in the H-MDA group were significantly higher than in the L-MDA group (P < 0.01). High ATPase activity and MDA content significantly reduced the jejunum microbial diversity, as indicated by the Chao1 index and observed species, and affected the relative abundance of specific taxa. Among species, the relative abundance of Olsenella umbonata was significantly higher in the H-MDA group than in the L-MDA group (P < 0.05), while Methanobrevibacter ruminantium abundance was significantly lower than in the L-MDA group (P < 0.05). In vitro culture experiments confirmed that MDA promoted the proliferation of Olsenella umbonata. Thus, ATPase and SOD activities in the jejunum tissues of Hu sheep are predominantly influenced by congenital factors, and lambs with higher birth weights exhibit lower Na + K + -ATPase, Ca 2+ Mg 2+ -ATPase, and SOD activities., Conclusions: The ATPase activity and antioxidant performance of intestinal tissue are closely related to growth performance, heart development, and intestinal tissue morphology. High ATPase activity and MDA content reduced the microbial diversity of intestinal tissue and affect the relative abundance of specific taxa, representing a potential interaction between the host and its intestinal microbiota., (© 2024. The Author(s).)

Humate may be a valuable livestock feed additive, with potential effects on nutrient utilisation and animal performance. Thus, the aim of this study was to investigate the effect of K Humate S 100R supplementation on the feed intake, liveweight gain, and carcass parameters of Angus steers. Within individual pens, 40 weaned steers were allocated to four treatment groups (n = 10/potassium humate K Humate S100R, Omnia Specialities Australia) for 100 days. The treatment groups included Group 1, 35 g K Humate S100R/animal/day; Group 2, 70 g K Humate S100R/animal/day; Group 3, 140 g K Humate S100R/animal/day; and Control Group, which were not supplemented with K Humate S100R (0 g K Humate S100R/animal/day). Chemical and mineral composition of the feed ingredients, dry matter intake (DMI), and average daily weight gains were recorded. The steers were slaughtered as a single group at a commercial Australian abattoir. Standard measures for hot standard carcass weight, eye muscle area, fat depth and coverage, marbling, ossification, meat and fat colour, dressing percentage and loin pH values at 24-hour postmortem were recorded. It was found that the steers allocated to Group 2 had higher DMI (P = 0.003) and feed conversion ratio (FCR) (P < 0.001) compared with those allocated to Group 1 and the Control Group. The MSA marbling score was lowest for steers allocated to the Control Group (P < 0.05) and comparable for those allocated to Groups 1, 2, and 3. Together, these results demonstrate that increased levels of K Humate S100R supplementation improved the carcass quality, via an increase in MSA. However, further research is warranted on the potential effects of humates supplementation on intramuscular fat associated qualities of beef., (© 2024 Australian Veterinary Association.)

The aim of this experiment was to investigate the effects of peppermint essential oil (PEO) and an emulsifier called artifier on growth performance, carcass characteristics, and nutrient digestibility of broiler chickens fed low-energy diets. A total of 240 one-day-old male Ross 308 broiler chickens were divided into five treatments: control, low-energy diet, low-energy diet + 150 ppm PEO, low-energy diet + 300 ppm artifier, and low-energy diet + 150 ppm PEO + 300 ppm artifier. Each treatment was replicated four times in a completely randomized design. The chickens were fed these treatments during the starter, grower, and finisher periods for a total of 42 days. The results indicated that broiler chickens receiving the low-energy diet supplemented with PEO + artifier had similar body weight gain, feed conversion ratio, and breast percentage, but exhibited significantly lower abdominal fat percentage compared to those fed the control diet ( P < 0.05). Furthermore, birds receiving PEO and artifier in low-energy diets, either individually or in combination, demonstrated higher digestibility of dry matter and fat during the starter and grower periods in comparison to those receiving the low-energy diet without any additives ( P < 0.05). Over the entire rearing period, the simultaneous inclusion of 150 ppm PEO and 300 ppm artifier in the low-energy diet resulted in comparable growth performance to the control diet. Additionally, the concurrent use of PEO and artifier in the low-energy diet for broiler chickens led to a decrease in abdominal fat, increased digestibility of fat and dry matter, and enhanced nutrient utilization compared to the control diet., Competing Interests: The authors declare that they have no conflict of interest., (© 2024 The Author(s).)

This investigation was done to determine how much zinc (Zn) the stinging catfish, Heteropneustes fossilis , needs in its diet. Five isonitrogenous (34.5% protein) and isolipidic (6.0% lipid) diets were prepared to contain graded levels of Zn (0, 10, 20, 30, and 40 mg kg -1 ), supplied as zinc sulfate (ZnSO 4 ·7H 2 O), and referred to as Zn0, Zn10, Zn20, Zn30, and Zn40, respectively. A total of 600 fish (initial body weight: 1.41 ± 0.02 g) were stocked in 15 glass aquaria (40 fish/aquarium), each with 180 L water capacity. For ten weeks, each diet was hand fed to three groups of fish twice daily until they appeared satisfied. The highest weight gain and specific growth rate, and lowest feed conversion ratio were recorded in fish fed with a 30 mg Zn kg -1 diet. Zn contents in bone and muscle linearly increased up to 30 mg kg -1 Zn and then remained stable, while iron (Fe) and copper (Cu) contents in bone and muscle had an inverse pattern with the inclusion level of dietary Zn. Increasing dietary Zn levels up to 30 mg kg -1 was found to improve values of hematological parameters such as red blood cell (RBC), white blood cell (WBC), haemoglobin (Hb), and haematocrit (HCT). These values, however, decreased when the dietary Zn level was further increased. The serum alkaline phosphatase level was the highest in fish fed a diet containing 30 mg kg-1 of Zn. Regression analyses based on weight gain, specific growth rate, and bone and muscle Zn concentrations indicated that the optimum dietary Zn requirement for stinging catfish was in a range of 27.4-36.5 mg kg -1 ., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Md. Amzad Hossain reports financial support was provided by University Grants Commission of Bangladesh. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

The present study aimed to compare the growth, meat quality, and production economics of Cherry Valley broiler ducks fed with a commercial diet along with silage from beet pulp or maize. In this study, 180 male Cherry Valley ducks were reared for 49 d. The control group (group C) was fed a commercial diet ad libitum. The experimental groups were fed a restricted amount of commercial diet and ad libitum beet pulp silage (group B) or maize silage (group M). For all groups, the growth performance and meat quality were analyzed, and their production costs were estimated. The beneficial effects of feeding maize silage on the growth rate were observed on d 29 to 49 in group M; moreover, both experimental groups showed lower feed intake than group C (P < 0.05). The feed conversion ratio was lower in the first rearing stage and during the entire experimental period in groups B and M than that in group C. Group M showed a higher European Production Efficiency Factor and European Broiler Index than group C (P < 0.05). The relative weight of the liver was higher in group C than that in the experimental groups (P < 0.05). Group M showed a higher L* value of leg muscles than group C (P < 0.05). Water-holding capacity was higher in leg muscles from ducks fed with silages (P < 0.05). The experimental groups had lower costs of commercial diets. Higher costs were observed for maize silage than for beet pulp silage. Carcass sales yielded the highest profit for group M and the lowest one for group C. Compared with the control group, the silage-fed groups showed a higher estimated profit by PLN 7.94 to 10.68 per duck (P < 0.05). Based on the beneficial production results, notably lower feed conversion ratio, no negative effects on carcass characteristics, and lower production costs, especially maize or even beet pulp silage in broiler duck rearing, could be recommended., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

A novel combination of Butyric and Valeric acid glycerol esters with oregano oil in a dry powder form was evaluated for performance improvements in broilers. The dosing regimen (500 g/Ton feed in starter and grower; 250 g/Ton in finisher feed) was considered low compared to conventional practices using non-esterified Butyric and Valeric short-chain fatty acids (SCFA). Six trials were conducted at various trial facilities in Italy, United Kingdom, Spain, and Poland. Supplemented broilers weighed significantly more than the control birds at 28 days of age (+3.4%; 1459 g vs. 1412 g; p = 0.0006) and at 42 days of age (+2.5%; 2834 g vs. 2763 g; p = 0.0030). Supplementation significantly reduced mortality from 1.9% to 0.8% during the finisher phase (from 29 to 42 days of age); however, average mortality was 3.2% for the whole 42-day growth period and was not affected. Further, supplemented broilers grew more (66.4 vs. 64.5 g/day; p = 0.0005), ate more feed (104.7 vs. 103.1 g/day; p = 0.0473), converted feed significantly more efficiently (1.58 vs. 1.60; p = 0.0072), leading to better EPEF value (410 vs. 389; p = 0.0006) than the control broilers. Meta-analysed trial performance data for novel SCFA formulations such as these are not commonly available, and serve to facilitate efficacy determination from an end-user perspective. The use of short- and medium-chain fatty acid esters in optimal low-dose combinations to reliably augment gut health and performance appears promising in commercial broiler production, and may lead to further improvements in industry practices and reduced antibiotic use.

A meta-analysis was conducted to determine the effects of herbal plant extracts on the growth performance, blood parameters, nutrient digestibility and carcase quality of farmed rabbits. A dataset was created from 33 in vivo studies comprising 121 experimental units. Statistical meta-analysis was performed using a random-effects model and linear-mixed model meta-regression using R software (v. 4.3.0). Our results showed that although supplemental herbs did not affect average daily gain (ADG) and final body weight (BW), they reduced ( P  < 0.01) feed conversion ratio and mortality and increased the digestibility of dry matter (DM) ( P  = 0.014) and crude protein (CP) ( P  = 0.018). The herbal extracts also increased ( P  = 0.037) blood high-density lipoprotein (HDL) and decreased ( P  = 0.004) low-density lipoprotein (LDL). Immunoglobulin M (IgM) was elevated (P = 0.009) by herbal plant extract supplementation, although most blood components were unaffected. The inclusion of herbal plant extract up to 300 g/kg increased ( P  = 0.011) carcase percentage while the weight and percentage of other organs were unaffected. Subgroup meta-analysis further explained the different effect of the type of herbal plant extract. Moringa, olive oil, and pepper were more favourable to increase final BW compared to the other herbs. Interestingly, the majority of herbs showed efficacy in reducing mortality. A majority of the response variables in our meta-analysis showed no dose-response effect except for ADG, mortality, HDL, and LDL which were improved by herbs supplementation. The evidence from the perspective of both meta-analysis and meta-regression shows that the addition of herbs tends to positively affect the parameters for production performance and blood metabolites in farmed rabbits., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

This study aimed to measure the effects of trehalose (Tre) supplementation on the growth, intestinal morphology, gut bacteria, and footpad dermatitis (FPD) of broiler chickens reared at different stocking densities (SD). Four hundred newly hatched Ross 308 male chicks were randomly allocated to four groups of eight, following a 2 × 2 factorial arrangement in a randomized complete block design using two SDs (normal, 11; high, 14 birds/m 2 ) and two diets: basal with and without 0.5% Tre. Tre supplementation was provided during the starter/grower phase, but not the finisher phase. Data were analyzed using a two-way analysis of variance. We observed no significant effects of SD or Tre, individually or combined, on body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) during the starter/grower period. However, high SD decreased both BWG ( P < 0.001) and FI ( P < 0.05), and increased FCR ( P < 0.001), during the finisher period. Whereas Tre reduced FCR ( P < 0.05) as a main effect, no combined effect was observed on FCR. Over the total period, high SD negatively affected BWG and FCR ( P < 0.001), and Tre significantly reduced FCR, with its effect unaffected by SD. No significant effects of SD or Tre were observed on jejunal morphology. The ileal abundance of Clostridium perfringens ( P > 0.05) was not affected by high SD but was significantly reduced by Tre. Neither high SD nor Tre altered Lactobacillus spp. counts; however, high SD increased FPD lesion scores, whereas Tre had no effect. The study showed that Tre supplementation during the starter/grower period improved FCR during the finisher period, possibly by decreasing the abundance of C. perfringens in broiler chickens., Competing Interests: Conflicts of interest: The authors declare that there are no conflict of interests., (2024 Japan Poultry Science Association.)

This study investigated the effects of feather meal (FM) processing methods on production parameters, blood biochemical indices, intestinal morphology, digestive and hepatic enzyme activities, and gastrointestinal tract pH and microflora of broilers. A total of 480-d-old male broilers were used for 42 d in a completely randomized design with eight treatments and five replicates (12 chicks/replicate). Treatments were 1) a control diet (without FM), 2) a diet containing 4% raw FM (RFM), 3) a diet containing 4% processed FM (PFM) by autoclave (Au-PFM), 4) a diet containing 4% fermented FM (FFM) by Bacillus licheniformis (Bl-FFM), 5) a diet containing 4% FFM by Bacillus subtilis (Bs-FFM), 6) a diet containing 4% FFM by Aspergillus niger (An-FFM), 7) a diet containing 4% FFM by B. licheniformis + B. subtilis + A. niger (Co-FFM), and 8) a diet containing 4% PFM by an enzyme (En-PFM). Results showed that in the FFMs the contents of ash, ether extract, total volatile nitrogen, and amino acids including Lys, Met, Thr, Trp, His, Leu, Gly, Ile, Phe, and Tyr increased (P < 0.05), while crude fiber, crude protein, and dry matter content decreased (P < 0.05). Compared with the control, the Co-FFM diet had no significant differences (P > 0.05) in total body weight gain (2,827 vs. 2,791 g/chick), total feed intake (5,018 vs. 4,991 g/chick), European production efficiency factor (375 vs. 377), European Broiler Index (371 vs. 371), and feed conversion ratio (1.77 vs. 1.78 g/g). Feeding FFM decreased (P < 0.05) serum total cholesterol (1.46-fold), triglyceride (1.61-fold), very low-density lipoprotein cholesterol (1.61-fold), and low-density lipoprotein cholesterol (2.27-fold) compared to the control. Also, FFM increased (P < 0.05) villus height (1,045 to 1,351, 661 to 854, and 523 to 620 μm), and villus height to crypt depth ratio (6.15 to 8.45, 4.55 to 7.04, and 4.27 to 5.45), in the duodenum, jejunum, and ileum, respectively, compared to the control. Compared to the control, the Co-FFM diet increased (P < 0.05) protease (34, 39, and 45 %) in the pancreas, duodenum, and jejunum, as well as amylase (73, and 97 %) activities in the duodenum, and jejunum, respectively. Diets containing FFM reduced (P < 0.05) pH in the crop, gizzard, and ileum, and decreased (P < 0.05) Escherichia coli (6.12 to 5.70) count in ileum compared to the control. The Co-FFM diet increased (P < 0.05) lactic acid bacteria count in crop (6.77 to 7.50) and ileum (6.94 to 7.73), also decreased (P < 0.05) coliforms (6.31 to 5.75) count in ileum compared to the control. In conclusion, FM fermentation, particularly Co-FFM, improves the nutritional value of FM, converting it into a decent source of dietary protein for broilers., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The aim of this study was to determine the optimal dietary phosphorus (P) requirement and its effects on growth performance, body composition, mineralization and alkaline phosphate (ALP) activity in silver carp (Hypophthalmichthys molitrix). A total of 360 fish with an average initial weight of 7.0 ± 0.15 g were divided into 18 tanks (70 L capacity each) with a stocking density of 20 fish per tank in triplicate. The fish were fed diets containing six levels of P (3.3, 4.4, 5.5, 6.5, 7.5 and 8.6 g/kg) up to satiation for 90 days twice daily at 09:00 and 16:00. The results showed that fish fed diets containing 6.5 and 7.5 g/kg dietary P had significantly higher (p < 0.05) growth performance in terms of final weight gain, average weight gain (AWG), weight gain% (WG%), protein efficiency ratio (PER) and specific growth rate (SGR) than fish fed other diets. The best value of the feed conversion ratio (FCR) was observed in fish fed the 6.5 g/kg P diet, which was not significantly different from the 7.5 g/kg P diet. Increasing P supplementation above 6.5 g/kg significantly reduced (p < 0.05) the feed intake of silver carp. Whole-body composition analysis indicated that increasing P levels resulted in a decrease (p < 0.05) in crude fat (CF) and an increase (p < 0.05) in crude ash (CA) content, while crude protein (CP) and moisture content remained unaffected (p > 0.05). Fish fed diets containing ≥6.5 g/kg P had significantly higher (p < 0.05) Ca content in the whole body, bones and scales compared to those fed diets containing ≤5.5 g/kg P. A similar trend was observed for P and Mg contents in the whole body, bones and scales. The Zn content tended to decrease (p < 0.05) with increasing P supplementation in the whole body and bones, but fish fed diets containing ≥6.5 g/kg P had significantly higher (p < 0.05) Zn content compared to fish fed diets containing ≤5.5 g/kg P. The Ca/P ratio was significantly affected by P supplementation. Fish fed diets containing ≥6.5 g/kg P had significantly higher (p < 0.05) Ca and P contents in the serum than fish fed other diets. ALP activity increased (p < 0.05) with increasing P levels up to 6.5 g/kg P and decreased (p < 0.05) thereafter. In conclusion, supplementing P up to 6.35 g/kg is recommended for the optimal growth of silver carp., (© 2023 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.)

Tambaqui (Colossoma macropomum) is a species of great cultural and economic importance in aquaculture in the Amazon region. Methionine is considered the first limiting sulfur amino acid in practical fish diets, which encourages investigating its use in diets for tambaqui. This study aimed to verify the digestible methionine plus cystine (Met + Cys) requirement in diets for tambaqui (89.52 ± 0.53 g) for 60 days. The treatments investigated were: 6.50, 7.80, 9.10, 10.40, 11.70, and 13.00 g Met + Cys kg diet -1 . The estimated requirement based on final weight, weight gain, feed conversion ratio, and specific growth rate was 9.04, 8.92, 8.91, and 8.58 g Met + Cys kg diet -1 , respectively, while on body protein deposition, body fat deposition, body ash deposition, and nitrogen retention efficiency was 9.29, 9.20, 9.19, and 8.72 g Met + Cys kg diet -1 , respectively. Linear regression demonstrated that increased digestible Met + Cys in the diet decreased plasma total protein, globulin, and liver total protein levels. Quadratic regression showed that the highest value for liver glycogen was found with a 10.40 g Met + Cys kg diet -1 . Another quadratic regression demonstrated a lower hepatic aspartate aminotransferase (AST) enzymatic activity in fish fed between 7.80 and 11.70 g Met + Cys kg diet -1 . The different treatments did not influence the erythrogram. In conclusion, when considering an integrative view of the results for growth performance, whole-body deposition, and liver parameters without harming the physiological and metabolic status, we recommended choosing a diet with digestible Met + Cys between 8.58 and 9.29 g kg - 1 for tambaqui., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Increased body growth and feed efficiency are important for breeding due to expensive feed costs. This study estimated the genetic parameters for two feed efficiency traits [the feed conversion ratio (FCR) and the residual feed intake (RFI)] and other important economic traits in male Hu sheep using 1642 male Hu lambs. The heritability of the RFI was estimated at 0.31 (±0.10)-0.54 (±0.1) and the heritability of the FCR was 0.05 (±0.07)-0.77 (±0.12). There was a negative genetic correlation between rib-eye muscle area traits and RFI. A positive genetic correlation was found between fat deposition traits and feed efficiency traits. The digestive tract weight decreased with the direction of RFI: however, the FCR showed the opposite: A low FCR was accompanied by a high digestive tract weight. The genetic correlation between feed efficiency (RFI and FCR) and rumen weight was negative. Heritability estimates for feed efficiency generate fluctuations with different experimental intervals. The weight of other traits should be reasonably allocated to avoid losses in production and feed efficiency in the selection of feed efficiency traits. The present study added to our understanding of the genetic parameters of sheep under the condition of house feeding.

Antimicrobial resistance is a significant issue, therefore it's relevant to assess the effects of antibiotics, acidifiers, and probiotic supplementation finding a good alternative to reduce the use of antibiotics in broiler production in rural areas of Bangladesh. Using randomized control trial, this 28-day study evaluated 360 Hubbard Classic broiler chicks divided into four groups: oxytetracycline-treated, acidifier-treated, Lactobacillus-based probiotic-treated, and control (no antibiotics, acidifiers, or probiotics). Each group was replicated three times with 30 birds each with adlibitum feeding. Body weight and feed intake were recorded weekly, and on 28th day, carcass traits and blood lipoprotein levels were evaluated. Results showed that in first and fourth weeks, the body weight gain significantly varied in probiotics and acidifier-treated birds than the control group ( P  < 0.001). The probiotic group had gained considerable increase in body weight (185.0 g vs 161.7 g and 1745.0 g vs 1592.7 g) than the control group. Notably, in the first week, the feed conversion ratio for the probiotic group was 0.76, but the antibiotic group's was 0.96 ( P  < 0.001). The weights of the drumstick (88.33 g) and liver (61.0 g) having probiotic supplements were substantially higher than those in the control group (77.0 g and 51.33 g, respectively) ( P  < 0.001). According to serum lipoprotein analysis, the probiotic and acidifier groups exhibited lower LDL levels (71.1 mg/dl and 69.8 mg/dl, respectively) and higher triglyceride levels (122.9 mg/dl and 135.4 mg/dl). These findings highlight the potential of probiotics and acidifiers as effective antibiotic alternatives, promoting carcass traits and lowering LDL levels in broilers in Bangladesh., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)

The growth performance and survival rates of juvenile striped catfish, Pangasianodon hypophthalmus , reared at various levels of pH and temperature were described in this article. Two rearing trials were conducted separately for pH and temperature where both trials lasted for 35 days. One hundred and twenty juveniles (1.5 ± 0.23 g) were randomly stocked into 12 rectangle glass aquariums ( n = 10 fish/tank; three replicates per treatment) with 100 L of water for each trial. The treatment consisted of four different pH level (7.5, 8.0, 8.5 and 9.0) and four different temperature level (26 °C, 28 °C, 30 °C and 32 °C). The survival of fish was counted at the end of experiments, and the weight of the juvenile was measured once a week. The quantification of feed intake was determined through the measurement of the residual weight of the feeds after the feeding process. Upon the conclusion of the experiment, the data pertaining to weight and feed intake were utilized to calculate the specific growth rate (SGR) and food conversion ratio (FCR) as indicators of growth performance. Additionally, the number of live fish was employed to ascertain the survival rate. The data obtained from the calculation of SGR, FCR and survival rate were next subjected to a normality test, one-way analysis of variance (ANOVA), and a Tukey post-hoc test. The information in this article will help in the business, experimental, and personal usage for P. hypophthalmus juveniles rearing process., (© 2023 Published by Elsevier Inc.)

Understanding the relationships between social stress and the gastrointestinal microbiota, and how they influence host health and performance is expected to have many scientific and commercial implementations in different species, including identification and improvement of challenges to animal welfare and health. In particular, the study of the stress impact on the gastrointestinal microbiota of pigs may be of interest as a model for human health. A porcine stress model based on repeated regrouping and reduced space allowance during the last 4 weeks of the finishing period was developed to identify stress-induced changes in the gut microbiome composition. The application of the porcine stress model resulted in a significant increase in salivary cortisol concentration over the course of the trial and decreased growth performance and appetite. The applied social stress resulted in 32 bacteria being either enriched (13) or depleted (19) in the intestine and feces. Fecal samples showed a greater number of microbial genera influenced by stress than caecum or colon samples. Our trial revealed that the opportunistic pathogens Treponema and Clostridium were enriched in colonic and fecal samples from stressed pigs. Additionally, genera such as Streptococcus , Parabacteroides , Desulfovibrio , Terrisporobacter , Marvinbryantia , and Romboutsia were found to be enriched in response to social stress. In contrast, the genera Prevotella , Faecalibacterium , Butyricicoccus , Dialister , Alloprevotella , Megasphaera , and Mitsuokella were depleted. These depleted bacteria are of great interest because they synthesize metabolites [e.g., short-chain fatty acids (SCFA), in particular, butyrate] showing beneficial health benefits due to inhibitory effects on pathogenic bacteria in different animal species. Of particular interest are Dialister and Faecalibacterium , as their depletion was identified in a human study to be associated with inferior quality of life and depression. We also revealed that some pigs were more susceptible to pathogens as indicated by large enrichments of opportunistic pathogens of Clostridium, Treponema, Streptococcus and Campylobacter . Generally, our results provide further evidence for the microbiota-gut-brain axis as indicated by an increase in cortisol concentration due to social stress regulated by the hypothalamic-pituitary-adrenal axis, and a change in microbiota composition, particularly of bacteria known to be associated with pathogenicity and mental health diseases., Competing Interests: EB was employed by Zoetis Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Nguyen, Martínez-Álvaro, Lima, Auffret, Rutherford, Simm, Dewhurst, Baima and Roehe.)

We investigated the effect of energy levels on growth performance, carcass characteristics, and fatty acid composition of Holstein steers at different slaughter ages. Forty Holstein steers with an average body weight (BW) of 234.21 ± 7.42 kg and 7.78 ± 0.22 months were randomly allocated to two experimental groups; a 22-month-old experimental group and a 24-month-old experimental group. Total digestible nutrients (TDN) for each group were set to 70% (T1) and 72% (T2) during fattening phase and 74% (T3) and 76% (T4) for the finishing phase, respectively. No difference was observed in the final BW between the experimental groups during the fattening phase. However, in the finishing phase, the final BW of T4 (820.31 kg) group was significantly higher than that of T1 (745.57 kg; p < 0.05). The average daily gain (ADG) of T2 group in the finishing phase and overall period were 1.27 kg and 1.26 kg, respectively, which were significantly higher than those of T1 (1.11 kg and 1.12 kg; p < 0.05). The feed conversion ratio (FCR) and TDN conversion ratio of T2 group in the finishing phase also decreased by 10.23% and 7.73%, respectively, compared to those of T1. The cold carcass weight of T4 group was significantly higher ( p < 0.05) than that of T1, whereas back fat thickness, longissimus area, and marbling score were not significantly different among groups. No differences were observed in physicochemical characteristics of the carcass including moisture, crude protein, and crude fat content among groups. However, the composition of fatty acids differed significantly between the groups. The content of C18:0 was significantly lower ( p < 0.05) in T4 than in T1 group, and the content of C18:2 was higher in T4 than in T1 and T3 ( p < 0.05). Therefore, feeding Holstein steers at a high-energy feeding level during the fattening and finishing phases improves ADG and reduces the slaughter age from 24 months to 22 months., Competing Interests: No potential conflict of interest relevant to this article was reported., (© Copyright 2023 Korean Society of Animal Science and Technology.)

Is it possible to reduce feeding costs in rabbit meat production without compromising rabbit health and productive yield? The study tested four feeding strategies: Control group (CC) fed exclusively with concentrate feed; group CT supplemented with whole carrot; group OH supplemented with oat hay; and Group CO supplemented with oat hay and whole carrot. Each feeding strategy was tested in 20 rabbits, randomly allocated in five cages with four rabbits each. The average daily weight gain (ADG), feed conversion ratio (FCR), and the amount of concentrated feed consumed daily were estimated in all experimental groups. Group CC displayed the best ADG (37.1 g/rabbit/day), carrot had no significant influence on ADG (34.2 g/rabbit/day), but oat hay had a negative impact ( p < 0.05), either used alone or in combination with carrot (33.0 and 32.6 g/rabbit/day, respectively). Supplementation with carrot, oat hay, or both increased the FCR ( p < 0.001). Nevertheless, there were no significant differences in final live weight or carcass weight between the rabbits in the different experimental groups. In conclusion, supplementation with oat hay, carrot, or both can be a valid approach to reducing production costs by decreasing concentrate feed without affecting rabbit's health and meat yield. The combined supplementation with oat hay and carrot proved to be the best option in reducing the amount of concentrate feed ingested by rabbits (less than 1107 g/animal), but at current market values, supplementation exclusively with oat hay was the less expensive feeding strategy (less 14% than fed exclusively with concentrate feeding).

1. A study was conducted to evaluate the effects of dietary cholecalciferol (vitamin D 3 ) and 25-hydroxycholecalciferol (25-OH-D 3 ) supplementation on the reproductive performance, egg quality, eggshell ultrastructure, serum hormone level and antioxidant capacity, intestinal morphology and tibia quality of breeder geese during the laying period.2. The trial was designed as a 3 × 3 factorial arrangement with three levels (300, 400 and 500 IU/kg) of vitamin D 3 supplementation and three levels (25, 50 and 75 μg/kg) of 25-OH-D 3 supplementation in a 10-wk feeding trial.3. The results showed that the combined supplementation of 400 IU/kg vitamin D 3 and 50 μg/kg 25-OH-D 3 had a better feed conversion ratio and a higher egg laying rate than the other groups. Vitamin D 3 supplementation significantly increased the rate of qualified eggs for hatching, eggshell strength and thickness, serum testosterone and progesterone levels, serum total superoxide dismutase and glutathione peroxidase activities, tibia ash content and bone mineral density ( P  < 0.05). Dietary 25-OH-D 3 supplementation significantly increased serum glutathione peroxidase activity and duodenal villus height and villus height-to-crypt-depth ratio ( P  < 0.05). The geese receiving 500 IU/kg vitamin D 3 and 75 µg/kg 25-OH-D 3 had the highest tibia calcium and phosphorous content among all groups ( P  < 0.05).4. Feeding 400 IU/kg vitamin D 3 plus 50 µg/kg 25-OH-D 3 gave optimal effects on feed conversion ratio and egg laying rate. This combination could be a nutritional strategy for increasing the laying rate, eggshell quality, serum hormone levels and serum antioxidant function regardless of 25-OH-D 3 supplementation. Supplementation of 50 μg/kg 25-OH-D 3 could be a recommended dose for improving the serum antioxidant capacity and intestinal morphology regardless of vitamin D 3 supplementation.

The study aimed at evaluating the influence of silage type (grass silage-GS, and maize silage-MS) and energy level in the feed portion on animals' performance, carcass value and the quality of Holstein-Friesian bull meat. The animals were reared using intensive (I) feeding, 1.02 feed units for meat production (UFV)/kg dry matter (DM), and semi-intensive (SI) feeding, 0.94 UFV/kg DM. Thirty-two HF bulls with an average live weight of 530 kg were assigned to four feeding groups. The proportions (g/kg DM) of feed in the diets were as follows: group GS-I, GS 500, concentrate 500; group GS-SI, GS 700, concentrate 300; group MS-I, MS 500, concentrate 500; and group MS-SI, MS 700, concentrate 300. After 4 months of the finishing phase, bulls were slaughtered and samples of the longissimus lumborum muscle were collected. The silage type did not affect performance, carcass value or meat quality. However, in the intensive feeding, a 33% increase ( p < 0.01) in daily weight gain and a reduction in the feed conversion ratio compared to semi-intensive feeding were noted. The carcasses of bulls fed intensively received higher scores for conformation and fatness than the carcasses of bulls fed semi-intensively. The meat of I group bulls had a higher intramuscular fat content and received higher juiciness, tenderness, taste and overall acceptability scores.

Access to simple, accurate feed intake models would facilitate decision-making in feedlots as feed costs are a major part of operational expenditure. This study aimed to develop genotype-specific feed intake models for South African feedlot lambs. Four ram and four ewe lambs each of eight genotypes were raised under ideal growth conditions from weaning until 1 year of age. Feed intake and growth were monitored throughout this period. The intake data were then used to fit various models to predict daily feed intake, intake as percentage of body weight, cumulative intake and feed conversion ratio. No satisfactory univariate models could be found for the prediction of daily or percentage intake, but a good fit was found for cumulative intake data (R 2 >0.80, P <0.01). The slope parameters of these linear models show a strong correlation (72%) with feed conversion and can therefore also serve as proxies for feed conversion. A model was also developed that can predict feed conversion ratio with a moderate accuracy (R 2 =0.5, P <0.05) at a given body weight. The cumulative intake model was deemed accurate and simple enough for practical use., (© 2023. The Author(s).)

The plant species Gelsemium elegans Benth. (GEB) promotes pig and sheep growth; however, little is known about its effects in chickens. In this study, a GEB extract (GEBE) was prepared, and its effects on the growth, slaughter, antioxidant performance, meat quality, serum biochemical indices, intestinal morphology, and microflora of yellow-feathered chickens were evaluated. In total, 600 chickens aged 15 days were randomly divided into four groups with five replicates each and fed a basal diet containing 0% (control), 0.25% (0.25 GEBE), 0.75% (0.75 GEBE), or 1.25% (1.25 GEBE) GEBE until 49 days of age. Chickens were then killed, and their meat, organs, and serum and cecal contents were collected. GEBE reduced the feed conversion ratio, particularly in the 0.75 and 1.25 GEBE groups. Furthermore, the GEBE diet improved meat tenderness and reduced the meat expressible moisture content and liver malondialdehyde content, indicating high meat quality. Whereas the 0.25 GEBE diet increased the level of Lactobacillus acidophilus in the cecum, the 0.75 GEBE diet decreased the Escherichia coli level therein. These findings demonstrate that GEBE may improve the meat quality and cecal microbiota of yellow-feathered chickens, providing a basis for identifying candidate alternatives to conventional antibiotics as growth promoting feed additives., Competing Interests: Conflicts of Interest: The authors declare no conflict of interest., (2023 Japan Poultry Science Association.)

&lt;b&gt;Background and Objective:&lt;/b&gt; Probiotic yogurt is beneficial for laying hens because it can improve the animal's hematological status which will improve livestock health, therefore it is hoped that probiotic yogurt can increase the production of laying hens. This research was conducted to determine the lactic acid levels and pH of probiotic yogurt, probiotic yogurt's effect on feed conversion ratio and total production of laying hens. &lt;b&gt;Materials and Methods:&lt;/b&gt; The research was carried out using experimental methods using a Completely Randomized Design (CRD) with 5 treatments and 8 replications so the total sample was 40. The treatment consisted of P0: Basal ration; P1: Basal diet+2% probiotic powder B1 (&lt;i&gt;Bifidobacterium&lt;/i&gt; spp. and &lt;i&gt;L. acidophilus&lt;/i&gt;), P2: Basal ration+3% probiotic powder B1, P3: Basal diet+2% probiotic powder B2 (&lt;i&gt;L. bulgaricus&lt;/i&gt;, &lt;i&gt;S. thermophilus&lt;/i&gt;, &lt;i&gt;L. acidophilus&lt;/i&gt; and &lt;i&gt;B. bifidum&lt;/i&gt;) and P4: Basal ration+3% probiotic powder B2. The data were analyzed using Analysis of Variance (ANOVA) and followed by Duncan's Multiple Range Test. &lt;b&gt;Results:&lt;/b&gt; Lactic acid content in probiotic yogurts B1 is 0.945% and B2 is 0.638%. Based on the results of statistical analysis using the variance test, show that giving probiotic powder to laying hens has a significant effect on the feed conversion ratio and has no significant effect on the production of laying hens. &lt;b&gt;Conclusion:&lt;/b&gt; Based on the results of statistical analysis using the variance test, it shows that giving probiotic powder to laying hens has no significant effect on the production of laying hens during the peak period.

Background: No studies determined the use of spineless cactus cladodes in camel diets., Objectives: The effect of replacing the main energy source in camel diets with fresh spineless cactus cladodes on growth performance was determined. Furthermore, the ability of morphology to predict cladodes yield was determined., Methods: A prediction model of spineless cactus cladode weight based on cladode volume was developed. Three cladodes per plants were randomly selected from 100 plants. Weight and volume were then recorded for each cladode. Sixteen male camel calves (196 ± 18.2 kg live weight and 430 ± 5.55 days of age) were allotted to treatments, control (conventional camel fattening diet based on cotton seed hulls, cereal grains and agro-industrial by-products) or cactus (barley and maize grains in the control diet were replaced totally by fresh cactus cladode on dry matter basis). The study contained a 100-days growth trial and a 21-day digestibility trial (15 days of adaptation and 7 days of faeces collection). Blood samples were collected monthly from each animal., Results: Cactus cladode volume predicted the dry weight with a high accuracy (prediction error = 3.5%). Nutrient intake and nutrient digestibility did not significantly differ among the dietary treatments (p > 0.05). The treatment significantly decreased feed conversion ratio by 1.52 points (p < 0.05). All blood parameters were within the normal range of dromedary camels., Conclusions: Spineless cactus cladode is a potential replacement to the conventional energy sources in dromedary camel diets., (© 2023 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Excreta traits comprise a very important characteristic in breeding that have been neglected for a long time. With the growth of intensive pig farming, plenty of environment problems have been raised, and people have begun to pay attention to pig excreta behaviors from genetics and breeding perspectives. However, the genetic architecture of excreta traits remains unclear. To investigate the genetic architecture of excreta traits in pigs, eight excreta traits and feed conversion ratio (FCR) were analyzed in this study. We performed genome-wide association studies (GWASs) on 213 Yorkshire pigs and estimated genetic parameters for a total number of 290 pigs, comprising 213 Yorkshire, 52 Landrace and 25 Duroc. After analysis, eight and 22 genome-wide significant SNPs were detected for FCR and the eight excreta traits in single-trait GWASs separately, and 18 were detected in a multi-trait meta-analysis for excreta traits, six of which were detected in both the single-trait and the multi-trait GWAS. Eighty, 182 and 133 genes were detected within 1 Mb of the genome-wide significant SNPs for FCR, excreta traits and multi-trait meta-analysis, respectively. Five candidate genes (BCKDC, DBT, ANKRD7, SHPRH and HCRT) with biochemical and physiological effects relevant to feed efficiency and excreta traits might be interesting markers for future breeding. Meanwhile, functional enrichment analysis indicates that most of the significant pathways are associated with the glutathione catabolic process, DNA topological change and replication fork protection complex. This study reveals the architecture of excreta traits in commercial pigs and offers an opportunity for decreasing the pollution from excreta using genomic selection in pigs., (© 2023 The Authors. Animal Genetics published by John Wiley & Sons Ltd on behalf of Stichting International Foundation for Animal Genetics.)

This paper reports on the use of estimates of individual animal feed intake (made using time spent feeding measurements) to predict the Feed Conversion Ratio (FCR), a measure of the amount of feed consumed to produce 1 kg of body mass, for an individual animal. Reported research to date has evaluated the ability of statistical methods to predict daily feed intake based on measurements of time spent feeding measured using electronic feeding systems. The study collated data of the time spent eating for 80 beef animals over a 56-day period as the basis for the prediction of feed intake. A Support Vector Regression (SVR) model was trained to predict feed intake and the performance of the approach was quantified. Here, feed intake predictions are used to estimate individual FCR and use this information to categorise animals into three groups based on the estimated Feed Conversion Ratio value. Results provide evidence of the feasibility of utilising the 'time spent eating' data to estimate feed intake and in turn Feed Conversion Ratio (FCR), the latter providing insights that guide farmer decisions on the optimisation of production costs.

The present study aimed to investigate the relationship between growth performance, body composition, and fat deposition factors, and feed efficiency in growing lambs. We measured average daily feed intake (ADFI) and body weight (BW) from 653 Hu sheep that were fed a pellet diet. The residual feed intake (RFI) not significantly genetic and phenotypic correlated with the metabolic body weight (MBW) and average daily gain (ADG), but it was significantly genetic and phenotypic correlated with ADFI and the feed conversion ratio (FCR) ( p  < 0.01). However, the FCR was significantly associated with growth traits ( p  < 0.01). With the same ADG, body fat deposition was greater in animals with low feed efficiency compared with high feed efficiency. Therefore, excessive fat deposition can affect the feed efficiency of the body, and organ weight and gut-weight have a greater impact on the feed efficiency of lambs. The reticulum stomach and jejunum of lambs with a low RFI were smaller compared with that in the high RFI, indicating that lambs with a low RFI have less intake and a higher absorption rate. Small organs, such as the liver, of lambs with high FE might be associated with low energy expenditure and slow metabolism. This study provides a new perspective to study the biological processes responsible for feed efficiency variation in lambs.

Improving the feed conversion ratio (FCR; the amount of feed consumed relative to the amount of weight gain) can reduce both production costs and environmental impacts of farmed fish. The aim of this study was to investigate what drives FCR to understand how nutrients are retained, as well as the amount of oxygen consumed for digestion, absorption and assimilation (a metabolic process known as specific dynamic action, SDA). Feed-efficient and inefficient Chinook salmon (Oncorhynchus tshawytscha) in fresh water were identified using ballotini beads and X-radiography that tracked individual feed intake across three assessment periods under satiated feeding. This allowed a comparison of physiological traits and body composition between the two FCR phenotypes over two time points as Chinook salmon grew from 305 to 620 g. Fish with higher daily feed intake (DFI) had higher daily weight gain (DWG) as expected. Nonetheless, the relationship between FCR and DFI as well as FCR and DWG was variable between time points. FCR and DWG were not correlated at the first time point and were negatively correlated at the second time point. In contrast, FCR and DFI were positively correlated at the first time point but not the second. Despite this, efficient fish ate smaller meals and retained more protein, lipid and energy in their body tissues. There was no detectable difference in metabolism between the two FCR phenotypes with respect to minimal resting metabolic rate, maximum metabolic rate, aerobic scope, or SDA parameters. In conclusion, FCR is not consistently associated with growth and metabolic differences in freshwater Chinook salmon, but FCR-efficient fish retain more nutrients and consume smaller meals., (© 2022 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

There are an increasing number of studies on the effect of cassava ( Manihot esculenta Crantz) on performance of laying hens with inconsistent outcomes. This study, therefore, used a meta-analytic approach to examine the effect of cassava-based diets on feed intake (FI), feed conversion ratio (FCR) end production data such as hen day egg production (HDEP), egg weight (EW), egg mass (EM), Haugh unit (HU), shell weight (SW) and shell thickness (ST) in laying hens. Two hundred and three studies were identified in a search performed in PubMed, Scopus and Google Scholar databases of which thirteen studies were suitable for the meta-analysis. Subgroup and meta-regression analyses were performed to explore the responses of laying hens to dietary cassava and sources of heterogeneity, respectively using the following moderators: study continent, cassava type, cassava processing methods, inclusion level, layer strain, feeding durations, number of layers and hen's age. Data were pooled using a random-effects model and statistical analyses were performed in OpenMEE software. Results show that cassava increased FI (mean difference MD = 0.97 g/d; 95% confidence intervals (CI) 0.05, 1.90) and reduced egg weight (MD = -0.72 g; 95% CI -1.26, -0.19) and SW (MD = -0.11 g; 95% CI -0.18, -0.04) when compared to control. Laying hens fed cassava diets had HDEP, FCR, EM, ST and HU values that compared favourably with the controls. Subgroup analysis demonstrated that inclusion of cassava at ≤ 25% in layer diets had no deleterious effects on measured outcomes taking cognizance of significant heterogeneity. However, meta-regression results showed that most of the sources of heterogeneity were explained by the studied moderators. In conclusion, ≤25% of cassava (CRM and CPM) can be included in layer diets without adverse effects on feed intake, feed conversion ratio and egg production characteristics, indicating that cassava has a very bright future as an energy source in the diets of laying hens., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. Published by Elsevier Ltd.)

In animal husbandry, feed efficiency is a crucial economic trait. In this study, the general linear model was used to perform association analysis for various genotypes and feed conversion ratio (FCR)-related traits. Reverse transcription-quantitative PCR (RT-qPCR) was used to detect the expression of SHISA3 and RFC3 mRNA levels in 10 tissues from 6 sheep. The results showed that SNPs in the NC&#95;040257.1:c.625 T > C and NC&#95;040261.1:g.9905 T > C were analyzed whether they were associated to feed efficiency parameters in Hu sheep (body weight, feed intake, average daily growth, and feed conversion ratio). NC&#95;040257.1:c.625 T > C was shown to be significantly associated with body weight at 80, 100, and 120 days as well as feed conversion ratio ( P < 0.05), whereas NC&#95;040261.1:g.9905 T > C was found to be significantly associated with average daily weight gain from 80-140 days (ADG80-140) and FCR ( P < 0.05). In Hu sheep, the CC genotypes of SHISA3 and RFC3 were the most common genotypes related to feed efficiency traits. Furthermore, the feed conversion ratio of the combined genotypes TT SHISA 3 -CC RFC 3 , TT SHISA 3 -CT RFC 3 , TT SHISA 3 -TT RFC 3 , CT SHISA 3 -CC RFC 3 and CT SHISA 3 -CT RFC 3 was significantly better than the FCR of CC SHISA 3 -TT RFC 3 . RT-qPCR results showed that the expression levels of SHISA3 were lower in the lung than in spleen, kidney, muscle and lymph ( P < 0.05), and RFC3 was the lung had a highly significant higher expression level than the heart, liver, spleen, and muscle ( P < 0.01). In conclusion, SHISA3 and RFC3 polymorphisms can be used as genetic markers for improving feed conversion efficiency in Hu sheep., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Lin, Wang, Zhang, Huang, Li, Zhang, Zhao, Wang, Zhou, Cheng, Xu, Li, Zhao, Ma, Yang, Huang, Cui, Liu, Zeng, Zhai, Sun, Weng, Wu, Zhang and Zheng.)

Feed efficiency is an important indicator in the sheep production process, which plays an important role in improving economic benefits and strengthening energy conservation and emission reduction. Compared with the rumen, the fermentation of the hindgut microorganisms can also provide part of the energy for the host, and the composition of the hindgut microorganisms will affect the feed efficiency. Therefore, we hope to find new ways to regulate sheep feed efficiency by studying the sheep gut microbes. In this study, male Hu sheep with the same birth date were raised under the same conditions until 180 d old. The sheep were divided into high and low groups according to the feed conversion ratio (FCR) at 80 to 180 d old, and the differences in rectal microorganisms between the two groups were compared. The permutational multivariate analysis (PERMANOVA) test showed that there were differences in microorganisms between the two groups (P < 0.05). Combined with linear fitting analysis, a total of six biomarkers were identified, including Ruminobacter, Eubacterium&#95;xylanophilum&#95;group, Romboutsia, etc. Functional enrichment analysis showed that microorganisms may affect FCR through volatile fatty acids synthesis and inflammatory response. At the same time, we conducted a longitudinal analysis of the hindgut microbes, sampling nine-time points throughout the sheep birth to market stages. The microbiota is clearly divided into two parts: before weaning and after weaning, and after weaning microbes are less affected by before weaning microbial composition., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Pekin ducks are world-famous for its fast growth and have become the majority of breeds rearing in duck industry. Feed conversion ratio (FCR) is an important trait in Pekin ducks breeding and production, and the underlying biological processes are complex. To gain an insight to the possible biological mechanism underlying the FCR in Pekin ducks, an artificial selection population (S) and a natural population (Z7) were used in this study. The FCR of S line decreased from 2.184 ± 0.057 in the first generation to 1.886 ± 0.063 in the eighth generation, which displays significantly low FCR ( p  = 0.0032) than that of the Z7 line (2.23 ± 0.046). Then, 9 samples from eighth generation of S line and 10 samples from Z7 were used for whole-genome resequencing. Analyses of F ST , θπ and XP-EHH revealed 450, 479 and 356 candidate genes, which involved in 1,955, 1,933 and 1,964 candidate divergent regions (CDRs), respectively. And the integration of three approaches resulted in 30 overlapping genes. Functional analysis of 30 candidate genes revealed that variants of KCNQ1 and ADCY7, which were involved in the pancreatic secretion signal pathway, could be important molecular markers for high feed conversion efficiency in S line breeding.

Improving feed efficiency is one of the main goals of chicken breeding and production. The function of the digestive system, where feed is digested and nutrients are absorbed, is closely related to feed efficiency. However, the association between feed efficiency and the development of different digestive organs in chickens remains unclear. Here, we investigated the individual feed efficiency of 207 broilers during the fast-growing period with an electronic feeder and examined the characteristics of 8 organs of their digestive system (the liver, bile, proventriculus, gizzard, duodenum, jejunum, ileum, and cecum) at market age. Both the feed conversion ratio (FCR) and residual feed intake (RFI) were significantly negatively correlated with the gizzard weight (GW) and significantly positively correlated with the relative weight of the liver (RLW). Additionally, we found an obvious negative relationship between the FCR and cecal length (CL). A two-tailed t test further confirmed these correlation analysis results. Specifically, compared to birds with the lowest feed efficiencies, the GW of broilers with the highest feed efficiencies (the lowest FCR or RFI) was 22.74% and 17.97% higher, respectively. The RLW of chickens with the highest feed efficiencies was 10.82 to 13.73% less than that of chickens with the lowest feed efficiencies. In addition, we found that increased CL (5.42-12.09%) was significantly associated with better feed efficiency. Thus, our study showed that the feed efficiency of broilers was related to the development of the gizzard, liver, and cecum. These findings provide new insight into the genetic and physiological regulation of feed efficiency in broilers., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Coccidiosis is an endemic protozoal disease of chickens normally controlled by ionophores. However, coccidiostats are also antibiotics, and evidence of resistance in both coccidia and bacteria may develop and reduce antibacterial activity in humans. This has led to a search for natural coccidiostats, such as green tea., Objectives: To study the effects of supplementing broilers with various levels and types of green tea, in comparison to use of a conventional coccidiostat or a control, unsupplemented diet., Methods: A total of 360 male, day-old Ross 308 broilers (days 1-42) were used to evaluate the gut morphology and performance when challenged with coccidiosis and fed varying dietary levels of green tea powder or extract. Treatments were Negative control (NC, unsupplemented control diet); positive control (PC, control diet + commercial coccidiostat); control diets with 0.2, 0.3 or 0.4 g/kg green tea extract (GTE 0.2, 0.3 and 0.4); and control diets with 1, 2 or 3 g/kg green tea powder (GTP 1, 2 and 3)., Results: Compared with NC, PC and all green tea treatments, but particularly GTE0.4, increased feed intake and growth rate, with the best feed conversion ratio at GTE0.4. As a proportion of carcase weight, higher inclusion rates increased intestine weight and decreased abdominal fat. The duodenum, jejunum and ileum of birds fed green tea, and particularly GTE0.4, had longer, wider villi, and shallower crypts. Epithelium thickness was reduced by green tea and PC, compared to NC. Clostridium perfringens and coliform populations decreased in proportion to green tea inclusion rate and decreased in PC. Lactobacilli increased with green tea and were more for NC than PC. Green tea at the highest concentrations reduced blood glucose and LDL and VLDL cholesterol., Conclusions: Green tea offers a possible replacement for conventional ionophores to control coccidiosis in broiler chickens. The best inclusion rate was 0.4 g/kg., (© 2022 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

In this study, we compared the impacts of Bacillus subtilis PB6 (BS) and bacitracin methylene disalicylate (BMD) on the growth performance, intestinal morphology, expression of tight connection protein, and cecal microbiota community of male ducks through a 42-d trial. Three-hundred and sixty male Cherry Valley meat-type ducklings (1-day-old) were distributed into 3 groups of 6 replicates: CON group (control, basal diet), BMD group (basal diet + 45 mg/kg BMD, active ingredient dose in the feed), and BS group (basal diet + 2 × 10 7 CFU/kg BS in the feed). Results showed that supplementing the diet with BS reduced the average daily feed intake (ADFI) during d 15 to 42 and d 1 to 42 compared with the CON group (P = 0.032). It also reduced feed conversion ratio (FCR) during d 15 to 42 and d 1 to 42 (P < 0.05) relative to the other groups. The ileal villus height (VH) and villus height /crypt depth ratio (V/C) were increased (P < 0.05) in both the BS and BMD groups, and the jejunal VH and V/C ratio were increased in the BS group (P < 0.05). Relative to the CON, BS supplementation was associated with numerical augmentation of goblet cells in the jejunal mucosa and upregulation of jejunal zonula occludens (ZO-1) and ileal mucin2 (P < 0.05) mRNA levels. Analysis showed a negative correlation between FCR (d 0-42) and VH, V/C, and the number of goblet cells in the jejunum (P < 0.05). Additionally, BMD or BS supplementation altered the alpha diversity of colonic microbiota (P < 0.05). Correlation analysis revealed that Butyricimonas, Enterobacteriaceae, Clostridiaceae, and Tannerellaceae were positively associated with the acetic acid and butyrate concentrations (P < 0.05). Taken together, the supplementation of BS in the diet of male ducks was conducive to reducing FCR by meliorating intestinal morphology, upregulating ZO-1 and mucin2 mRNA levels, regulating the abundance of microbiota, and metabolites, and having a greater effect than BMD supplementation., Competing Interests: DISCLOSURES All authors declare that there is no conflict of interest., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

As the northern Largemouth bass (LMB) ( Micropterus nigricans ) industry shifts toward fingerling production, implementing practical feeding strategies to ensure efficient growth during high water temperatures is paramount. Twenty (12.7 ± 0.2 g) (Trial 1) and fifteen (7.2 ± 0.1 g) (Trial 2) LMB fingerlings were stocked in two recirculating systems (each containing nine tanks), acclimated to 30 °C, with one system fed daily rations of 3, 5 and 7% body weight (Trial 1), and the second system fed to satiation daily, every second day, or every third day (Trial 2), for 28 days each. All treatments were triplicated. Multiple growth metrics and lipid composition were analyzed. The 3% treatment yielded the lowest final average weight (36.05 g) and FCR (0.83), with no difference in final biomass in Trial 1 treatments. Fish fed to satiation daily and every second day produced FCRs and biomasses of 0.83 and 356.78 g, and 0.93 and 272.26 g, respectively. There were no differences in total lipid concentration, however, fatty acid profiles differed significantly between all treatments within their respective trials. Feeding LMB fingerlings 3% of total body weight or feeding daily to satiation allows for efficient growth at 30 °C and implements cost-effective feeding strategies.

The effect of hen size and diet nutrient density during early lay on egg production (EP) at 24 and 69 wk of age (WOA) and late lay egg quality and hen health was evaluated. Based on bodyweight (BW) at 18 WOA ISA Brown hens were assigned as heavier (HW; n = 120) or lighter weight (LW; n =120). Sixty birds from each BW group were fed an early-lay diet of higher nutrient density (HND), or lower nutrient density (LND) between 18 and 24 WOA. From 25 WOA all hens received the same early-lay diet and then from 40 WOA the mid-lay diet. Hen average daily feed intake (ADFI), hen-day EP, egg weight (EW), egg mass (EM), and feed conversion ratio (FCR) were assessed at 24 and 69 WOA. Between 66 and 70 WOA eggshell and internal egg quality was evaluated and at 70 WOA BW, liver and bone health were assessed. At 24 WOA BW was highest in HW birds and birds receiving the HND diet (P < 0.01). Concurrently ADFI, and FCR were higher and hen-day EP was lower in HW compared to LW birds (P < 0.05). The HND diet resulted in lower ADFI and FCR at 24 WOA, but higher EW and EM compared to the LND diet (P < 0.01). At 69 WOA HW birds had higher ADFI, EW (P < 0.02) and heavier 70 WOA BW compared to LW hens. The lower FCR of the LW birds at 69 WOA was approaching significance (P = 0.054). Hen weight and diet density did not affect 69 WOA egg production. Between 18 and 69 WOA cumulative FI and EM were higher in HW hens (P < 0.01) than LW hens, as was cumulative FCR (P = 0.053). Hen weight and diet density did not alter 66-70 WOA internal egg quality, but the HND diet generated thicker eggshells and higher eggshell breaking strength (P < 0.05). Seventy WOA liver health, keel curvature and femur breaking strength did not differ. Overall LW hens had lower FCR than HW hens and the early-lay HND diet facilitated improved eggshell integrity during late lay compared to the LND diet., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

To explore the effect of MYOZ1 in the muscle growth and development of meat ducks, MYOZ1 single-nucleotide polymorphism loci were screened at the DNA level in the meat duck population with highest and lowest feed conversion rates. The expression of MYOZ1 was detected using reverse-transcription quantitative polymerase chain reaction. The protein expression of MYOZ1 was detected using Western blotting at the protein level. The results showed that there was a base mutation site at 30 bp and 158 bp in the fourth exon of MYOZ1, which was mutated from C to T (exon4 C30T) and from G to A (exon4 G158A), respectively. The allele frequency of the locus was significantly different between the high and low feed conversion rate groups (p < 0.01). The relative expression of MYOZ1 mRNA in breast muscle tissue of HF ducks was significantly higher than that of LF ducks (p < 0.01). The MYOZ1 protein expression of HF ducks was significantly higher than that of LF ducks (p < 0.01). In general, MYOZ1 has a positive regulatory effect on the muscle growth and development of meat ducks. The results of this study lay a certain theoretical basis for the muscle growth and development of meat ducks.

The objectives of the study were: (a) to study the effect of Haemonchus spp. on the growth performance characteristics of fattening calves, (b) to assess any potential effects on carcass characteristics and (c) to investigate the potential role of climatic conditions in the process of the infection. The study was conducted for 201 days in an intensively managed cross-Limousin herd. The animals were divided into two equal groups: those receiving anthelmintic treatment (AT) and the untreated (C) controls. The same nutritional regime was applied to both groups and the feed consumption was calculated daily. Standard parasitological examinations were performed at weekly intervals. At slaughter, carcasses were weighed and assessed for conformation and fat cover classes. Climatic variables were obtained for the location of the farm and a temperature-humidity index was calculated. Before anthelmintic treatment with ivermectin, there was no difference in parasitic burdens between the two groups: 544 (AT) vs. 554 (C) epg, whilst after it, counts were 0 and 450-700 epg, respectively, with over 96% of larvae identified as Haemonchus spp. and, later, confirmed as Haemonchus contortus . It was concluded that treated animals had a higher average total bodyweight gain, higher feed conversion ratio and carcass yield of superior quality than controls. There was a difference between the two groups in the pattern of reduction of dry matter intake as the temperature-humidity index increased.

Resource efficiency, the ratio of inputs to outputs, is essential for both the economic and environmental performance of any sector of food production. This study quantified the advancement in the feed conversion ratio (FCR) and reduction in nutrient loading from rainbow trout farming in Finland and the degree to which genetic improvements made by a national breeding program have contributed to this advancement. The study combined two datasets. One included annual records on farm-level performance of commercial rainbow trout farms from 1980 onwards, and the other included individuals across eight generations of the national breeding program. The data from the commercial farms showed that from 1980 onwards, the farm-level feed conversion ratio improved by 53.4%, and the specific nitrogen and phosphorus loading from the farms decreased by over 70%. Hence, to produce 1 kg of fish today, only half of the feed is needed compared to the 1980s. The first generation of the breeding program was established in 1992. The FCR was not directly selected for, and hence, the genetic improvement in the FCR is a correlated genetic change in response to the selection for growth and body composition. Since 1992, the estimated genetic improvement in the FCR has been 1.74% per generation, resulting in a cumulative genetic improvement of 11.6% in eight generations. Genetic improvement in the FCR is estimated to be 32.6% of the total improvement in the FCR observed at farms, implying that genetic improvement is a significant contributor to resource efficiency. The use of genetically improved rainbow trout, instead of the base population of fish, reduces feed costs by 18.3% and total production costs by 7.8% at commercial farms (by -0.266€ per kg of ungutted fish). For phosphorus and nitrogen, it can be assumed that the use of fish material with an improved FCR also leads to 18.3% less nitrogen and phosphorus flowing into an aquatic environment. Such improvements in resource efficiency are win-wins for both industry and the environment-the same amount of seafood can be produced with significantly reduced amounts of raw materials and reduced environmental impact., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Feed occupies a significant proportion in the production cost of pigs, and the feed efficiency (FE) in pigs is of utmost economic importance. Hence, the objective of this study is to identify single-nucleotide polymorphisms (SNPs) and candidate genes associated with FE-related traits, including feed conversion ratio (FCR) and residual feed intake (RFI). A genome-wide association study was conducted for FCR and RFI in 169 Yorkshire pigs using whole-genome sequencing data. A total of 23 and 33 suggestive significant SNPs ( P < 1 × 10 -6 ) were detected for FCR and RFI, respectively. However, none of SNPs achieved the genome-wide significance threshold ( P < 5 × 10 -8 ). Importantly, three common SNPs (SSC7:7987268, SSC13:42350250, and SSC13:42551718) were associated with both FCR and RFI. Additionally, the NEDD9 gene related to FCR and RFI traits was overlapped. This study detected novel SNPs on SSC7 and SSC13 common for FCR and RFI. These results provide new insights into the genetic mechanisms and candidate genes of FE-related traits in pigs.

With this study, we aimed to evaluate the effect of two multicomponent feed additives given to animals from 10 to 70 d with milk replacer on the production parameters of reared calves: serum selenium level and histology of duodenum and rumen. The first additive was based on nanosilica (3000 mg) containing pancreatic enzymes (protease (18 mg), lipase (45 mg)), a mixture of fat-coated organic acids (2000 mg) (fumaric, malic, citric, and sorbic acids), and sodium butyrate (10,000 mg) (nanosilica/E/OA/SB), whereas the second was based on the mycelium of L. edodes (7 g) enriched in selenium (0.058 mg/g d.w.) (L. edodes/Se). The study was conducted on 18 male crossbred Holstein dairy calves from birth to 70 days of age, which were randomly assigned to control and experimental groups (six animals in each). From each group, three animals were sacrificed at 70 days of age, and histological analysis of the digestive tract (abdominal rumen and small intestine) was performed. It was observed that the additives used did not have any effect on growth performance and hematological or biochemical parameters. However, higher levels of selenium were found in serum in the calves fed with modified L. edodes mycelium on days 35 and 70 (44.33 and 51.33 µg/L in the control group and 132 and 93 µg/L in the L. edodes/Se group, respectively; p < 0.001). Moreover, we noticed lower average daily milk replacer intake at 35−42 d, which increased significantly from 42 to 70 d in the animals receiving L. edodes/Se.

There is a growing demand for beef products across developing countries. Formulating rations to include locally available waste products has the potential to increase the live weight gain (LWG) of cattle and improve the livelihoods of smallholder farmers; however, upper limit inclusion levels of cassava peel products require investigation. An experiment evaluated the effect of using cassava peel silage (CPS) at the DM inclusion levels of 30, 40, 50, 60 and 70% (with the remainder protein meals and maize stover in the diet) on the LWG of crossbred Limousin × Ongole bulls (269 ± 48.8 kg). Thirty bulls, approximately two years of age, were allocated in a completely randomised block design with six blocks based on initial live weight (LW) and five treatments based on level of CPS. The combination of CPS (with 2% urea of the CPS) and protein meals significantly affected LWG with the highest values obtained at levels of 30 and 50% inclusion of CPS (1.16-1.35 kg/day) (P < 0.05). Polynomial analysis of LWG data revealed the optimal LWG is theoretically achieved at 37% CPS with a LWG of 1.31 kg/day; however, LWG was similar from 30 to 50% inclusion levels and then declined. There was little significant difference at CPS inclusion levels of 30-60%, for DM intake (DMI) which ranged from 2.3 to 2.6% LW, organic matter (OM) digestibility (77.8-81.6%), feed conversion ratio (FCR) (6.56-7.56 kg DM/kg LWG) and feed cost of gain (Indonesia rupiah (IDR)/kg LW 18 612 - 21 398). At a high (70%) level of CPS inclusion, these values were markedly changed when compared to the 30% inclusion level of CPS. Feed treatments did not affect rumen pH, NH 3 -N, concentration or molar percentage of volatile fatty acids or protozoal population (P < 0.05). Rumen pH measured three hours after morning feed ranged from 6.7 to 6.8 and NH 3 -N ranged from 14.1 to 19.3 mg NH 3 -N/dl. It was concluded that inclusion of CPS up to 60% mixed with protein meals and urea and 20% maize stover maximised LWG and profitability of the production system., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)