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Polychlorinated biphenyls (PCBs) are a group of 209 highly stable molecules that were used extensively in industry. Although their commercial use ceased in 1979, they are still present in many aquatic ecosystems due to improper disposal, oceanic currents, atmospheric deposition, and hydrophobic nature. PCBs pose a significant and ongoing threat to the development and sustainability of aquatic organisms. In areas with PCB exposure high mortality rates of organisms inhabiting them are still seen today, posing a significant threat to local species. Zebrafish were exposed to a standard PCB mixture (Aroclor 1254) for the first 5 days post fertilization, as there is a gap in knowledge during this important developmental period for fish (i.e., organization of the body). This PCB mixture was formally available commercially and has a high prevalence in PCB-contaminated sites. We tested for the effects of PCB dosage (control (embryo water only; 0 mg/L), methanol (solvent control; 0 mg/L); PCB 1 (0.125 mg/L), PCB 2 (0.25 mg/L), PCB 3 (0.35 mg/L), and PCB 4 (0.40 mg/L)) on zebrafish survival, rate of metamorphosis, feeding efficiency, and growth. We found significant, dose-dependent effects of PCB exposure on mortality, feeding efficiency, and growth, but no clear effect of PCBs on the rate of zebrafish metamorphosis. We identified a concentration in which there were no observable effects (NOEC), PCB concentration above the NOEC had a significant impact on life-critical processes. This can further inform local management decisions in environments experiencing PCB contamination. [ABSTRACT FROM AUTHOR]

Simple Summary: Enhancing the energy density of lamb diets is a proven method to improve their productivity. While using carbohydrates for this purpose may seem intuitive, it can lead to undesirable shifts in ruminal metabolism, potentially triggering metabolic diseases. Hence, substituting carbohydrates with lipids is favored. Nevertheless, lipids, though effective, can also disrupt ruminal fermentation parameters. Among these lipids, soybean oil stands out for its positive impact on both beef and dairy cattle, leading to improved performance. In our study, we sought to assess the effects of soybean oil supplementation on performance, digestibility, feeding behaviour, and blood metabolites of feedlot lambs. Our findings indicate that the inclusion of soybean oil resulted in a linear reduction in nutrient intake, consequently lowering the average daily gain of the lambs. Additionally, soybean oil supplementation induced selective feeding behaviour among the lambs. Based on our observations, we recommend incorporating soybean oil into lamb diets at a maximum inclusion rate of 41 g/kg DM to optimize production parameters. The strategy implemented to adapt lambs to increasing levels of high-fat diet mitigated the detrimental effects of lipids on the rumen, with high-density energy intake being the constraining factor on performance. The objective of the current study was to evaluate the effects of soybean oil inclusion in diets on feeding behaviour, digestibility, performance, and blood metabolites of feedlot lambs. Forty non-castrated Santa Inês lambs with a mean age of 5 months and initial body weight of 34.88 ± 3.19 kg were used in a 40-day feeding trial. The lambs were distributed in five experimental diets with the inclusion of increasing soybean oil (SO) levels: 0, 30, 60, 90, and 120 g/kg DM. The SO inclusion promoted a linear reduction in DM intake (p < 0.001), crude protein (CP, p < 0.001), non-fibrous carbohydrates (NFC, p < 0.001), and total digestible nutrients (TDN, p = 0.004). There was an increasing quadratic effect on the intake of ether extract (EE; p = 0.002) and decreasing for neutral detergent fiber (p = 0.005). The soybean oil inclusion promoted the greater apparent digestibility of CP (p = 0.016), EE (p = 0.005), NDFom (p < 0.001), and TDN (p < 0.001); on the other hand, the apparent digestibility of NFC (p = 0.005) was decreased. The average daily gain decreased (p < 0.001) with SO inclusion. The SO inclusion increased feeding time (p = 0.004), reduced the efficiency of DM rumination (p = 0.001), and reduced the concentration of blood N-ureic (p < 0.001). Considering the productive parameters, SO can be included in diets and it is recommended that we include SO of up to 41 g/kg DM in diets for fattening lambs as the ideal maximum level. The strategy implemented to adapt lambs to increasing levels of high-fat diet mitigated the detrimental effects of lipids on the rumen, with high-density energy intake being the constraining factor on performance. [ABSTRACT FROM AUTHOR]

Simple Summary: This study evaluated the effect of dietary supplementation with organic silicon on the growth performance, blood biochemistry, digestive enzymes, morphohistology, intestinal microbiota and stress resistance in juvenile hybrid Tilapia (Oreochromis mossambicus × Oreochromis niloticus). It is concluded that organic silicon had no negative effects on the physiology and metabolism of the fish. The results showed that up to 50 mg·kg−1 of organic silicon can be applied to the diet of red Tilapia, improving digestive, metabolic and growth performance. The interactions between zootechnical performance, physiological digestive and metabolic capacity in hybrid red Tilapia still deserve further exploration. In recent decades, interest has been aroused worldwide in the use of silicon in nutrition; however, information on its effect on nutrition and metabolism of fish is limited. The objective of the research was to evaluate the effect of dietary supplementation with organic silicon on the growth performance, blood biochemistry, digestive enzymes, morphohistology and intestinal microbiota and stress resistance in hybrid Tilapia (Oreochromis mossambicus × Oreochromis niloticus). Methodologically, six levels of organic silicon (DOS) [control (0), 10, 20, 30, 40 and 50 mg·kg−1] were used to feed juvenile fish (initial weight 7.51 ± 0.25 g) grown for eight weeks in 18 aquariums (15 fish/aquarium). The results indicated that growth performance showed differences (p < 0.05) for specific growth rate, feed conversion and survival. Triglycerides, cholesterol and glucose, transaminases and digestive enzymes were significantly influenced by DOS levels. The histological study confirmed that the administered diets did not cause damage and induced significant morphological changes in the proximal intestine. The 16S rRNA gene sequencing analysis of the gut microbiota showed a high diversity and richness of OTU/Chao-1, with Fusobacteria, Proteobacteria, Bacteroidetes and Acidobacteria predominating in the DOS treatments compared to the control (p < 0.05). Induction of hypoxia stress after the feeding period showed a significant relative survival rate of 83.33% in fish fed 50 mg·kg−1. It is concluded that the DOS treatments performed better than the control treatment in most of the variables analysed. DOS had no negative effects on the fish. The results showed that up to 50 mg·kg−1 DOS improved digestive, metabolic and growth performance in hybrid Tilapia. [ABSTRACT FROM AUTHOR]

Turbidity can be a result of suspended natural particles, such as sediment, or anthropogenic particles such as microplastics. This study assessed whether Daphnia magna, a pelagic filter feeder known to ingest suspended particles, have an altered response to equally turbid environments caused by the presence of either suspended bentonite or suspended polyethylene microplastics. Compared to controls, daphnids exposed to suspended bentonite maintained their feeding efficiency and increased their digestive activity, as measured by mandibular movement, peristalsis, and expulsion, to pass bentonite through the digestive tract. The same effects were not seen in microplastic‐exposed individuals, in which feeding efficiency was decreased and only peristaltic movement was increased but without a coordinated increase in expulsion, suggesting that microplastics do not have the same ability as bentonite to pass through the digestive tract. This study highlights the need to discern the identities of particulates contributing to turbid environments as different particles, even of the same size, can have different effects on filter feeders, which inherently ingest suspended particles. [ABSTRACT FROM AUTHOR]

Polychlorinated biphenyls (PCBs) are a group of 209 highly stable molecules that were used extensively in industry. Although their commercial use ceased in 1979, they are still present in many aquatic ecosystems due to improper disposal, oceanic currents, atmospheric deposition, and hydrophobic nature. PCBs pose a significant and ongoing threat to the development and sustainability of aquatic organisms. In areas with PCB exposure high mortality rates of organisms inhabiting them are still seen today, posing a significant threat to local species. Zebrafish were exposed to a standard PCB mixture (Aroclor 1254) for the first 5 days post fertilization, as there is a gap in knowledge during this important developmental period for fish (i.e., organization of the body). This PCB mixture was formally available commercially and has a high prevalence in PCB-contaminated sites. We tested for the effects of PCB dosage (control (embryo water only; 0 mg/L), methanol (solvent control; 0 mg/L); PCB 1 (0.125 mg/L), PCB 2 (0.25 mg/L), PCB 3 (0.35 mg/L), and PCB 4 (0.40 mg/L)) on zebrafish survival, rate of metamorphosis, feeding efficiency, and growth. We found significant, dose-dependent effects of PCB exposure on mortality, feeding efficiency, and growth, but no clear effect of PCBs on the rate of zebrafish metamorphosis. We identified a concentration in which there were no observable effects (NOEC), PCB concentration above the NOEC had a significant impact on life-critical processes. This can further inform local management decisions in environments experiencing PCB contamination.

The "messy" feeding behaviour of spiny lobsters remains an obstacle for formulated feed development. This study examined the relationship between feeding efficiency and feed waste by juvenile spiny lobster, Sagmariasus verreauxi, fed different formulated pellet diameters or lengths across two separate experiments. Feed texture (hard and dry pellet, HDP; soft and moist pellet, SMP) was also examined. Juvenile lobsters were fed experimental feeds at 0.5% BW daily over a 6 h duration. The resulting feed waste was categorised as either feeding-related waste (FRW) or non-feeding-related waste (NFRW). For all feed types, the FRW increased with increasing pellet diameter and pellet length. The increase in FRW corresponded with a decrease in NFRW, particularly for HDP, resulting in no difference in total feed waste in any treatment investigated. Thus, even with improved feeding efficiency with small feed dimensions, feed intake was not improved. Feed leaching rate decreased with increasing pellet size, suggesting a more rapid decline in feed attractiveness for smaller pellets. This finding indicates that currently a counteractive interaction exists between pellet size and feed attractiveness and suggests improving attractiveness would further enhance feeding. Future research should aim at optimising feed dimensions simultaneously to support efficient feeding whilst enhancing attraction/gustatory stimulations. [ABSTRACT FROM AUTHOR]

Simple Summary: Agriculture accounts for 92% of the global freshwater footprint (WF), of which more than a quarter is used in livestock production for feed, mixing feed, watering animals and agricultural activities. This study shows that replacing maize silage with triticale silage in the diet of beef calves results in a relevant reduction in water consumption per cattle per day, without changing growth performance. It also shows how feed choice can help improve the water balance of livestock production, and thus reduce the pressure that the sector puts on water resources. In this study, we have included the water footprint (WF) in the process of optimizing animal feed rations. The global footprint of cattle production accounts for the largest share (33%) of the global water footprint of livestock production. Using two homogeneous groups of Limousine × Podolian young bulls, two different diets were compared: corn silage feeding (CSF), with a corn silage-based diet; and triticale silage feeding (TSF), with a triticale silage-based diet. Silage constituted about 41% and 46% of the feed composition (for CSF and TSF, respectively). Diets were characterised by the same energy and protein content. Despite the lower WF in the TSF group than in the CSF group (7726 vs. 8571 L/day/calf respectively), no significant differences were found in animal performances (i.e., daily weight gain and final weight), feed conversion or income over feed costs. These results show that simple production decisions can have a significant impact on water resource. Therefore, the use of triticale silage should be further promoted, especially in world regions with limited water resources where low WF feed formulation is more strategic than elsewhere. [ABSTRACT FROM AUTHOR]

Suspension feeding via setae collecting particles is common within Crustacea. Even though the mechanisms behind it and the structures themselves have been studied for decades, the interplay between the different setae types and the parameters contributing to their particle collecting capacities remain partly enigmatic. Here, we provide a numerical modeling approach to understand the relationship among the mechanical property gradients, the mechanical behavior and the adhesion of setae, and the feeding efficiency of the system. In this context, we set-up a simple dynamic numerical model that takes all of these parameters into account and describes the interaction with food particles and their delivery into the mouth opening. By altering the parameters, it was unraveled that the system performs best when the long and short setae have different mechanical properties and different degrees of adhesion since the long setae generate the feeding current and the short ones establish the contact with the particle. This protocol can be applied to any system in the future as the parameters (i.e., properties and arrangement of particles and setae) can be easily altered. This will shed light on the biomechanical adaptations of these structures to suspension feeding and provide inspiration for biomimetics in the field of filtration technologies.

The radula, a chitinous membrane with teeth, is the molluscan autapomorphy for food gathering and processing. Even though this structure is studied for decades, the interplay between the structure and the particular food or/and the substrate remains mostly enigmatic. Here, we provide a numerical model approach to understand the relationship between structure, feeding efficiency, and partial work performed by the system. This first simple dynamic numerical radular model interacts with the food particles and the uneven substrate. This protocol can be applied to any system in the future, as the parameters (interaction between structures, adhesion, size of food particles, attachment angle of teeth to membrane, etc.) can be easily altered. This will shed light on the biomechanical adaptations of this feeding structure (e.g., wear and failure prevention) to the specific environment. [ABSTRACT FROM AUTHOR]

With the development of aquaculture,the demand for aquatic products in our country is increasing year by year,and the majority of aquaculture means is follow traditional artificial experience. Artificial feeding has some problems,such as inaccurate control of feeding quantity,low degree of automation and large labor cost. Therefore,a precise and intelligent feeding method is needed to improve the utilization rate of bait. The six-axis sensor is used to analyze the surface wave of the fish pond,and the feeding state function curve is obtained through the sensor. The principal component analysis is used to select representative characteristic parameters and compare the contribution rate of characteristic parameters at different intervals. The results showed that the analysis results with an interval of 60 seconds were more close to the actual situation. Six parameters with higher contribution rate were selected as indicators to determine whether to continue feeding. If two characteristic parameters were lower than the set threshold for three consecutive times, feeding was considered to be over. The feeding method based on the study on the feeding rules of fish schools makes the feeding process more in line with the feeding needs of fish schools. The utilization rate of bait reaches more than 85%,saves the breeding cost and reduces the pollution. The results show that this method can realize precise feeding of fish swarm,and provide reference for realizing automatic feeding of fish swarm. [ABSTRACT FROM AUTHOR]

There is concern that microplastics can act as a vector for cadmium (Cd), altering the bioavailability and subsequent toxicity of Cd to ecologically important species such as Daphnia magna. The toxicity of Cd to D. magna has been well described; however, what is not known, and what the present study addresses, was how the addition of polyethylene microplastic altered Cd toxicity. Using high‐throughput feeding assays and size assessments, the present study quantified effects of exposure to Cd, microplastic, or their mixture on daphnids from neonate to adult. Exposure to Cd inhibited feeding efficiency, while exposure to microplastic inhibited growth rates of juveniles. Daphnia magna coexposed to Cd and microplastic showed significant decreases in both feeding and prereproductive growth rate. There were no differences in life‐history traits across any treatments. The alterations of feeding and growth while maintaining reproductive endpoints (time to first brood, reproductive frequency, the number of neonates released at each reproductive event, and the size of neonates produced) might be the result of a shift in energy allocation away from somatic growth, allowing individuals to maintain reproductive output despite lower nutritional reserves. Our findings suggest that cocontamination of microplastic and Cd has additive effects on feeding and growth rates, resulting in a greater energy allocation shift. Environ Toxicol Chem 2023;42:1401–1408. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Maintaining a mosquito colony for rearing is essential in research, and the rearing of mosquitoes in the laboratory requires blood as a protein source for females to produce eggs. The use of live animals for blood-feeding imposes ethical considerations and entails an additional laboratory for rearing the live animals. In this study, we have established an artificial blood-feeding system for Aedes aegypti that took into consideration the effects of four factors on blood-feeding - namely, egg source colony, blood source, age of females, and heating intervals. For the quality control tests, all parameters tested did not significantly differ between colonies after 14 generations. In terms of egg source, more adult females significantly fed from pig blood (PB) colonies (78%) than live mice (LM) colonies. In terms of blood source, more adult females (85%) fed on immobilized LM than in the artificial blood-feeding system with PB as a blood source. In terms of age, 3- and 5-d-old females showed the highest % blood-feeding (75-78%), fecundity, fertility, and recoveries compared to when females were fed very young at 1 d old and quite old at 7 d old. Among the heating intervals tested, re-heating PB every 60 min for 4 h showed the highest % of females fed (66%). All four factors significantly explain the variation in the % blood-feeding efficiency of female mosquitoes and, therefore, important factors to consider in mosquito colony maintenance. We also conclude that the established artificial blood-feeding system can be used for rearing Ae. aegypti. The results of the study may encourage laboratories in other institutes that conduct mosquito colony maintenance to seek inexpensive, effective, and locally-available artificial blood-feeding systems. [ABSTRACT FROM AUTHOR]

Simple Summary: As one of the essential mineral elements, manganese (Mn) is involved in maintaining the growth and physiological function of fish species. An optimal dietary level of manganese accelerated the growth, lipid metabolism, Mn accumulation, and antioxidant capacity of coho salmon. The dietary Mn requirement for post-larvae coho salmon was 17.35 mg kg−1 and 19.75 mg kg−1 according to the SGR and FCR, respectively. An optimal dietary level of manganese had a positive effect on the antioxidant capacity by scavenging free radicals in fish bodies. In addition, dietary Mn improved lipid metabolism, and the signaling pathway of PI3K/AKT/mTOR may be involved in regulating the activity of lipid metabolism enzymes. In this study, post-larval coho salmon Oncorhynchus kisutch (initial weight 0.37 ± 0.03 g) were fed with 6 experimental diets with increasing manganese (Mn) content (2.4, 8.5, 14.8, 19.8, 24.6, and 33.7 mg kg−1) for 12 weeks. Our results indicated that the feed conversion rate (FCR), specific growth rate (SGR), condition factor (CF), crude protein, moisture, crude lipid, ash, whole-body Mn, and vertebral Mn were affected by the elevation of Mn content in the diet. The activities of hepatic GSH-PX, Mn-SOD, and CAT were enhanced with increasing Mn content in the diet and reached the highest value at 19.8 mg kg−1 Mn. However, the level of hydrogen peroxide (H2O2), superoxide anion (O2·−), and malondialdehyde (MDA) was reduced with increasing Mn content in the diet. In addition, the activity of hepatic lipase (HL) and lipoprotein lipase (LPL) was increased with the elevation of dietary Mn content and reached a peak value at 14.8 mg kg−1 Mn. The activity of fatty acid synthetase (FAS) and the content of nonesterified fatty acid (NEFA) were increased following the elevation of Mn content from 2.4 to 19.8 mg kg−1 in the diet. The results indicated that the appropriate dietary Mn supplementation improved the feeding efficiency, lipid metabolism, and antioxidant capacity of coho salmon. The dietary Mn requirement for post-larval coho salmon was 17.35 mg kg−1 and 19.75 mg kg−1 based on the SGR and FCR, respectively. An optimal dietary level of Mn enhances hepatic lipid metabolism, and the signaling pathway of PI3K/AKT/mTOR may be involved in regulating the activity of enzymes related to lipid metabolism. [ABSTRACT FROM AUTHOR]

This study aimed to measure the potential and basal feed introduction (corn stover, gliricidia leaves, Panicum maximum) with the addition of Indigofera zollingeriana, which is expected to increase the goat performance. Fifteen goats aged 9-12 months, with an initial weight of ±20 kg were randomly assigned in completely randomized design (CRD) to one of three treatments and five replications. The treatment were P1 = 60% basal feed + 40% Indigofera zollingeriana, P2 = 70% basal feed + 30% Indigofera zollingeriana, P3= 80% basal feed + 20% Indigofera zollingeriana. We assessed the study outcomes as follows: daily weight gain (DWG), dry matter intake (DMI), feed efficiency and physiological responses. Data was statistically analyzed with Analysis of Variance (ANOVA) and Duncan’s multiple range test. ANOVA test showed that the treatments significantly affected (p0.05) affect rectal temperature and heart rate. Mean rectal temperature and heart rate were 38.2-39.8°C and 80-90 beats per minute, respectively. In conclusion, the administration of 60% basal feed (20% corn straw, 20% gamal leaves and 20% Panicum maximum) and 40% Indigofera zollingeriana could improve the goat’s performance.

Nutrient accumulation is crucial in insect diapause preparation because insufficient nutrient accumulation can shorten the diapause period, interfere with diapause development completion, and decrease the probability of surviving the overwintering period. The amounts of lipids and carbohydrates stored in diapausing pupae of Hyphantria cunea (Drury) (Lepidoptera: Erebidae, Arctiinae) are greater than those in the non‐diapausing pupae. In this study, we tested the hypothesis that diapause‐destined (DD) and non‐diapause‐destined (NDD) larvae of H. cunea have different nutrient accumulation patterns in penultimate and final instars. The body mass, as well as lipid, carbohydrate, and soluble protein contents, and the efficiency of converting digested food and ingested food into body matter were greater in the DD penultimate and final instars than in the NDD penultimate and final instars. Larger amounts of lipids, carbohydrates, and proteins were absorbed by DD penultimate and final instars and the final instar development period in the DD larvae was prolonged relative to NDD larvae. The activities of fatty acid synthase and glycogen synthase of DD penultimate and final instars were significantly higher than those of NDD larvae. These results suggest that the changes in nutrient accumulation patterns between DD and NDD larvae occur in penultimate and final instars, and that the DD larvae increase their nutrient accumulation during diapause preparation by the combined effect of extending their final‐instar development period and improving their digestive efficiency; they increase their lipid and carbohydrate stores by increasing the activities of fatty acid synthase and glycogen synthase in the fat body. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the effect of residual feed intake (RFI) on the histological, physical and mechanical characteristics of the sheep skin confined in full sun or shade. Dorper sheep (n = 64), male, with an initial bodyweight of 17.8 ± 2.43 kg was confined for 40 days to determine the RFI. After classification, 30 animals with positive RFI and 30 animals with negative RFI were selected, which were distributed in 2 confinement environments. This was a factorial arrangement of 2 (groups of animals—positive RFI and negative RFI) × 2 (environments—full sun and shade), with 15 animals for each combination of factors. The sheep remained in confinement for 60 days. After slaughter, skins were divided in half, and fragments were collected from the right portion for histological sections. The left part of each skin was subjected to tanning. Interaction effect RFI × environment was found in the evaluation of leather fragments in the horizontal direction on elongation at break, leather thickness and tear strength (p < 0.05). An isolated effect of the environment was found on elongation at break of leather fragments in the evaluation on the vertical direction (p = 0.01) and on the number of secondary follicles during the histological evaluation of the dorsal and lateral regions of the skin (p < 0.05). An effect of the interaction RFI × environment was observed for the thermostatic layer of the hip region (p = 0.03). Sheep with positive RFI and kept in confinement in full sun have a leather with greater elongation at break and tear strength, important aspects in determining the quality of the product by the leather industry. [ABSTRACT FROM AUTHOR]

Little is known about the foraging behavior of top predators in the deep mesopelagic ocean. Elephant seals dive to the deep biota-poor oxygen minimum zone (OMZ) (>800 m depth) despite high diving costs in terms of energy and time, but how they successfully forage in the OMZ remains largely unknown. Assessment of their feeding rate is the key to understanding their foraging behavior, but this has been challenging. Here, we assessed the feeding rate of 14 female northern elephant seals determined by jaw motion events (JME) and dive cycle time to examine how feeding rates varied with dive depth, particularly in the OMZ. We also obtained video footage from seal-mounted videos to understand their feeding in the OMZ. While the diel vertical migration pattern was apparent for most depths of the JME, some very deep dives, beyond the normal diel depth ranges, occurred episodically during daylight hours. The midmesopelagic zone was the main foraging zone for all seals. Larger seals tended to show smaller numbers of JME and lower feeding rates than smaller seals during migration, suggesting that larger seals tended to feed on larger prey to satisfy their metabolic needs. Larger seals also dived frequently to the deep OMZ, possibly because of a greater diving ability than smaller seals, suggesting their dependency on food in the deeper depth zones. Video observations showed that seals encountered the rarely reported ragfish (Icosteus aenigmaticus) in the depths of the OMZ, which failed to show an escape response from the seals, suggesting that low oxygen concentrations might reduce prey mobility. Less mobile prey in OMZ would enhance the efficiency of foraging in this zone, especially for large seals that can dive deeper and longer. We suggest that the OMZ plays an important role in structuring the mesopelagic ecosystem and for the survival and evolution of elephant seals.

Abstract Behavioral lateralization, which is associated with the functional lateralization of the two brain hemispheres, commonly exists in animals and can provide an individual with benefits such as enhanced cognition and dual tasking. Lateral bias in limb use, as a type of behavioral lateralization, occur in many species, but the reasons for the coexistence of left‐ and right‐biased individuals in a population remain poorly understood. We examined the footedness of male yellow‐bellied tits (Pardaliparus venustulus) when they used feet to clamp mealworms against a perch, and tested its association with other fitness‐related behavioral traits (i.e., feeding efficiency, exploration tendency, and escape performance). We expected differently footed individuals to have respective advantages in these behaviors and thereby coexist (“respective advantage” hypothesis). We found their footedness repeatable, and there was no population‐level bias. While no associations of feeding efficiency and exploration tendency with footedness were detected, the right‐footed individuals were found to be harder to catch than the other individuals. Future studies need to investigate the reasons for the right‐footed individuals' superior escape performance. Moreover, the escape advantage for being right‐footed and the lack of population‐level bias in footedness in male yellow‐bellied tits suggest that the benefits related to left footedness also remain to be explored.

The accumulation of nutrients during diapause preparation is crucial because any lack of nutrition will reduce the likelihood of insects completing diapause, thereby decreasing their chances of survival and reproduction. The fall webworm, Hyphantria cunea, diapause as overwintering pupae and their diapause incidence and diapause intensity are regulated by the photoperiod. In this study, we test the hypothesis that photoperiod influences energy reserve accumulation during diapause preparation in fall webworm. We found that the body size and mass, lipid and carbohydrate content of pupae with a short photoperiod during the diapause induction phase were significantly greater than those of pupae with a relatively short photoperiod, and the efficiency of converting digested food and ingested food into body matter was greater in the short-photoperiod diapause-destined larvae than the relatively short-photoperiod diapause-destined larvae. We also observed higher lipase and amylase activities in short-photoperiod diapause-destined larvae relative to the counterparts. However, no obvious difference was found in protein and protease in the pupae with a short photoperiod during the diapause induction phase and short-photoperiod diapause-destined larvae compared with the counterparts. Therefore, we conclude that the energy reserve patterns of diapausing fall webworm pupae are plastic and that short-photoperiod diapause-destined larvae increase their energy reserves by improving their feeding efficiency and increase their lipid and carbohydrate stores by increasing the lipase and amylase activities in the midgut. [ABSTRACT FROM AUTHOR]

The potential of Panagrolaimus sp. nematode as a live prey was assessed in longfin yellowtail Seriola rivoliana larval rearing. Larvae were reared from 3-11 days post-hatching (dph) in a 2000 L tank and fed on copepods and rotifers. On 12 dph, larvae were transferred to eight 200 L tanks at a density of 12 larvae L-1 to start the feeding trial, consisting of two treatments (Artemia or nematodes) using four replicates each. Rotifers were offered on 12 dph with a "co-feeding" from 14 to 16 dph (rotifer/enriched Artemia or rotifer/nematode). Only Artemia or nematodes were supplied from 17 to 19 dph. Feeding incidence was 80-90% on 14 dph, but more larvae were capturing rotifers than Artemia or nematodes. Artemia consumption increased more than nematodes at 19 dph, though it was not significantly different. Significantly lower enterocyte and villus heights in the posterior intestine were observed at 19 dph in larvae fed on nematodes but only in enterocyte height in the anterior one. No significant differences were observed between treatments in total larval length and body depth on 16 dph, but a significantly higher total length in the nematode one was present on 19 dph. A significantly higher survival was observed in treatment Artemia compared to nematodes. These preliminary results showed a lower nutritional condition in larvae fed nematodes; however, technical improvements need to be performed to increase Panagrolaimus sp. availability to larvae in the water column. [ABSTRACT FROM AUTHOR]

The source of maternal energy supporting reproduction (i.e., stored or incoming) is an important factor determining different breeding strategies (capital, income or mixed) in female mammals. Key periods of energy storage and allocation might induce behavioral and physiological shifts in females, and investigating their distribution throughout reproduction helps in determining vulnerable phases shaping female reproductive success. Here, we examined the effects of reproductive state on activity budget, feeding behavior, and urinary C-peptide (uCP) levels, a physiological marker of energy balance, in 43 wild female Assamese macaques (Macaca assamensis). Over a 13-month study period, we collected 96,266 instantaneous records of activity and 905 urine samples. We found that early lactating females and non-gestating–non-lactating females follow an energy-saving strategy consisting of resting more at the expense of feeding and consuming mostly fruits which contributed to enhancing their energy intake and feeding efficiency. We found an opposite pattern in gestating and late lactating females who feed more at the expense of resting and consume mostly seeds, providing a fiber-rich diet. Storing food into cheek pouches increased throughout gestation while it decreased all along with lactation. Lastly, we found the highest uCP levels during late gestation. Our results reflect different feeding adaptations in response to the energetic costs of reproduction and suggest a critical role of fat accumulation before conception and metabolizing fat during gestation and lactation. Overall, our study provides an integrative picture of the energetics of reproduction in a seasonal species and contributes to our understanding of the diversity of behavioral and physiological adaptations shaping female reproductive success. Significance statement: To offset their substantial energetic investment in reproduction, mammalian females may modify their behavior and the way they extract energy from their environment. In addition, as a result of heightened energy expenditure, female reproduction might trigger physiological shifts. To date, most studies investigated the energetic costs of female reproduction using either a behavioral or a physiological approach. To arrive at a more comprehensive picture, we combined behavioral data with a physiological marker of energy balance, i.e., urinary C-peptide, in a seasonal primate species in its natural habitat. Our results indicate that throughout the reproductive cycle, behavioral and physiological adaptations operate concomitantly, inducing modifications in female activity budget, feeding behavior, and suggesting shifts in fat use. Overall, our results illustrate the relevance of combining data on behavior and hormones to investigate breeding strategies in coping with the energetic costs of reproduction. [ABSTRACT FROM AUTHOR]

Objective The aim of this research was to evaluate the effect of different concentrate levels in diets based on cactus Opuntia Stricta (Haw.) Haw cladodes on the performance of lactating Girolando cows. Methods The experiment involved 10 Girolando multiparous dairy cows at 512.6 kg of body weight (BW) and producing 13.2 kg milk/d, allocated into two 5×5 Latin squares. The experimental treatments consisted of control diet composed by cactus Nopalea cochenillifera. Salm-Dyck. cladodes (Nopalea), forage sorghum silage and concentrate at 20% on dry matter (DM) basis, and four concentrate levels diets (20%, 24%, 28%, and 32%) plus cactus Opuntia stricta (Haw.) Haw. cladodes (Opuntia) and forage sorghum silage. Results Regarding cows fed control diet, the nutrients intake were greater than for cows fed with cactus Opuntia and concentrate. Regarding concentrate levels, intakes of DM, organic matter (OM), crude protein (CP), non-fiber carbohydrates (NFC), and total digestible nutrients of cows increased linearly. Organic matter, CP, and NDF digestibilities were similar in between to control diet and cactus Opuntia-based diets. The digestibility of NFC increased linearly when the concentrate was inserted. The N balance was the same for control diet and cactus Opuntia-based diets, irrespective the concentrate levels. Conclusion For cows producing 14 kg/d with 3.5% of fat, it is recommended 32% of concentrate to be included in cactus Opuntia-based diets, and the increase in concentrate level promotes a linear increase in milk yield.

The experiment was conducted to evaluate the ingestive behavior of buffalo fed sugarcane with different levels of concentrate. Twenty four Murrah buffaloes with body weight of 219±23 kg and nine months old were assigned to completely randomized design. Animals were placed in individual pens where they received diets ad libitum, twice a day. The experimental period has divided into 30 d for adaptation and 84 d for observations and samples collection. Four treatments were used: 1) 80% sugarcane (SC) + 20% concentrate (C); 2) 60% SC + 40% C; 3) 40% SC + 60% C; 4) 20% SC + 80% C. The diets were isoproteics and urea/ammonium sulfate was used at 9:1 ratio to correct the protein level of sugarcane. The evaluated variables were time spent feeding (TSF), ruminating (TSR), idle (TSI), dry matter intake (DMI), feeding efficiency of dry matter (FEDM), rumination efficiency of dry matter (REDM), number of meals, duration of meal and duration of breaks between meal. A regression analysis was performed using the MIXED procedure. DMI was positively affected (P0.05) on TSF. However, the TSR and number of meals decreased linearly (P

The effects of invaders on native species are usually tested using species mean trait values over long time scales. However, considering individual variation over short timescales can help us better understand the interaction between invaders and native species. We compared trophic traits of the non-native guppy (Poecilia reticulata) and the native Brazilian poeciliid Phalloceros harpagos using experiments simulating the early stages of an invasive process. We used short-term mesocosms to simulate an early invasion scenario, where the two species were placed together, and a pre-invasion scenario, where species were kept separated, and analyzed interspecific and intraspecific trophic variability. We also compared the foraging efficiency of species in laboratory experiments. We found no differences on the mean diet of both species between pre and early invasion treatments. At the individual level, in the early invasion scenario, individuals of both species reduced their trophic niche as a probable effect of the presence of the heterospecific. Phalloceros harpagos had higher consumption rates than guppies indicating greater efficiency in feeding on invertebrates. Our results suggest that non-native species were not intrinsically better consumers of high-quality resources. Instead, intraspecific variation might be playing an overlooked role in shaping interactions between species during the early stages of invasion. [ABSTRACT FROM AUTHOR]

The level of dentition asymmetry in snail‐eating snakes may reflect their prey choice and feeding efficiency on asymmetric land snails. The three species of Pareas snakes (Squamata: Pareidae) in Taiwan, which form partially sympatric distribution on the island, provide a potential case to test the hypothesis of niche partitioning and character displacement with regard to dentition asymmetry and specialisation in feeding behaviour.In this study, behavioural experiments confirmed that P. formosensis feeds exclusively on slugs, whereas P. atayal and P. komaii consumed both. However, P. atayal more efficiently preys on land snails than P. komaii, exhibiting a shorter handling time and fewer mandibular retractions.Micro‐CT and ancestral character reconstruction demonstrated the lowest asymmetry in P. formosensis (the slug specialist), the highest dentition asymmetry in P. atayal (the land snail specialist) and flexibility in P. komaii (the niche switcher): increased dentition asymmetry when sympatrically distributed with the slug eater (character displacement), and decreased asymmetry when living alone (ecological niche release).Ecological niche modelling showed that the distribution of P. formosensis is associated with the presence of slugs, while that of P. atayal could be explained by the land snails.Combining the results from morphology, phylogeny, behavioural experiments and ecological niche modelling, we showed that competition in the sympatric region might have facilitated character displacement among congeners, while the absence of competition in allopatric region has led to ecological niche release. [ABSTRACT FROM AUTHOR]

ABSTRACT: Host genetics and diet can exert an influence on microbiota and, therefore, on feeding efficiency. This study evaluated the effect of genetic line (fast-growth and high-resistance) in Pacific white shrimp ( Litopenaeus vannamei ) on the hepatopancreatic microbiota and its association with the feeding efficiency in shrimp fed with diets containing different protein sources. Shrimp (2.08 ± 0.06 g) from each genetic line were fed for 36 days with two dietary treatments (animal and vegetable protein). Each of the four groups was sampled, and the hepatopancreatic metagenome was amplified using specific primers for the variable V4 region of the 16S rRNA gene. The PCR product was sequenced on the MiSeq platform. Nineteen bacterial phyla were detected, of which Proteobacteria was the most abundant (51.0 – 72.5 %), Bacteroidetes (3.6 – 23.3 %), Firmicutes (4.2 – 13.7 %), Actinobacteria (1.9 – 12.1 %), and Planctomycetes (1.3 – 9.5 %). Diet was the most influential factor in the taxonomic composition of the microbiota, while genetic line was not a strong influential factor. The results suggest that the taxonomic profile of the bacteria colonizing shrimp hepatopancreas was determined by the diet consumed, similar to what occurs in the intestine. Shrimp in the fast-growth line had greater feeding efficiency regardless of the diet supplied. Finally, the results suggest that Proteobacteria influenced ( p < 0.05) the feeding efficiency of shrimp fed with a vegetable diet. Nevertheless, further studies are required to explore how shrimp genetic line–diet interaction influences microbiota for probiotic development and functional food formulation for farmed shrimp according to the genetic line.

As extreme climate events become more frequent and intense, short-term temperature responses of ectothermic organisms can lead to decreased performance and survival. However, organisms may acclimate to these conditions through behavioural and physiological mechanisms as exposure time increases. We used a reciprocal temperature (16 °C and 24 °C) transplant experiment to determine how feeding rate and body size of an apex soil mite predator (Stratiolaelaps scimitus) (formerly Hypoaspis miles) consuming prey (Carpoglyphus lactis) (dried-fruit-mite) changed along a gradient of acclimation time (1, 3, and 7 days, with control). In the control treatments, mites reared at 24 °C fed more, but were smaller than mites reared at 16 °C. When transferred to new temperature conditions, predators that experienced cooling events had reduced feeding efficiencies driven by decreased feeding performance, despite an absence of metabolic costs, while under warming events, predators also had reduced feeding activity, but feeding increased with acclimation time. Yet predators lost more weight the longer they were exposed to warming, and continued to experience reduced feeding efficiencies (i.e., lack of weight gain after feeding); this result suggests increased metabolic costs at higher temperatures and provides a mechanism for community downsizing under warming. Overall, our results suggest that ectothermic predators can acclimate to warming events with increased exposure time, but both warming and cooling events decrease overall performance. [ABSTRACT FROM AUTHOR]

Behavioral lateralization, which is associated with the functional lateralization of the two brain hemispheres, commonly exists in animals and can provide an individual with benefits such as enhanced cognition and dual tasking. Lateral bias in limb use, as a type of behavioral lateralization, occur in many species, but the reasons for the coexistence of left‐ and right‐biased individuals in a population remain poorly understood. We examined the footedness of male yellow‐bellied tits (Pardaliparus venustulus) when they used feet to clamp mealworms against a perch, and tested its association with other fitness‐related behavioral traits (i.e., feeding efficiency, exploration tendency, and escape performance). We expected differently footed individuals to have respective advantages in these behaviors and thereby coexist ("respective advantage" hypothesis). We found their footedness repeatable, and there was no population‐level bias. While no associations of feeding efficiency and exploration tendency with footedness were detected, the right‐footed individuals were found to be harder to catch than the other individuals. Future studies need to investigate the reasons for the right‐footed individuals' superior escape performance. Moreover, the escape advantage for being right‐footed and the lack of population‐level bias in footedness in male yellow‐bellied tits suggest that the benefits related to left footedness also remain to be explored. [ABSTRACT FROM AUTHOR]

The effect of essential oil of Origanum vulgare L. a medicinal plant was studied on toxicity, physiology and biochemical characteristics of diamondback moth Plutella xylustella L. in controlled condition. The LC10, LC30 and LC50 values were estimated 0.234, 0.710 and 1.528 percent (v/v) respectively for 3rd instar larvae. Repellency of essential oil under LC10 and LC30 concentrations was 22.8 ± 6.64 and 49.8 ± 6.95 percent respectively. Effect of plant essential oil on feeding efficiency was also evaluated under LC10 and LC30 concentrations. Approximately Digestibility (AD), Efficacy of Conversion of Ingested Food (ECI), Efficacy of Conversion of Digested Food (ECD), Relative Consumption Rate (RCR) and Relative Growth Rate (RGR) of the treated larvae showed a significant difference compared with the control. The effectiveness of plant essential oil on digestive enzymes under LC50 concentration for the survivors after 24 and 48 h after treatment was analyzed. Total protein and triglycerides were decreased significantly compared with the control. Activity of alkaline phosphatase and protease in treated larvae decreased compared with the controls. The lipase was increased 24 h after treatment compared with the control. Significant differences in detoxifying enzymes such as glutathione S-transferase and esterase were noted compared to controls. It is concluded that the essential oil used in the present experiment shows toxicity in higher doses. It is also concluded that the essential oil used did show considerable changes in repellency, feeding efficiency, reduced larval weight and changes in biochemical properties which may nominate it for further investigation in key insect pests.

The aim of this study was to evaluate the feeding behavior of sheep fed sugarcane silage enriched with increasing levels of detoxified castor bean meal. Twenty-four non-castrated male Santa Inês sheep with an average body weight of 25.34 kg and four months of age, were distributed in four treatments - 0, 7, 14 and 21% of the natural matter of detoxified castor bean meal in sugarcane silage. There was a linear increase (p < 0.05) in time spent eating and feeding and rumination efficiency (g MS and NDF/h) with the inclusion of castor bean meal in silage. However, there was a linear decreasing response for time spent resting (p < 0.05). Time spent ruminating, number of boluses per day and numbers of chews per day per bolus were not affected (p > 0.05) by the inclusion of castor bean meal. The addition of detoxified castor bean meal to sugarcane silage reduces time spent eating and increases feed and rumination efficiency in sheep.

How predators maximize energetic gains while minimizing the costs associated with exploiting heterogeneous prey remains a difficult ecological principle to test in natural systems.Deep‐diving, air‐breathing predators face conflicting demands of oxygen conservation to extend dive time and oxygen usage from the exercise required to find and capture prey. How predators balance these opposing factors is additionally complicated by prey patches that are heterogeneous spatially, temporally and in quality.Tags deployed on foraging fin whales revealed that deeper dives consisted of higher feeding rates (lunges/hr), as generally predicted by optimal foraging theory. By simultaneously measuring prey density and distribution in the local environment, we show that whales increased their dive depths in order to forage on the densest prey patches.Despite the increased travel time needed to find deeper prey during a breath‐hold dive, the increase in feeding rates of fin whales and modelled prey consumption quadrupled compared to shallow foraging. Because the cost of transport is low at this extreme in body size, we posit that feeding on the deep prey patches significantly increases the energetic efficiency of foraging.Given the increasing recognition that anthropogenic disturbance can curtail deep foraging dives in many cetacean species, endangered fin whales may be susceptible to significant energetic losses that may impact individual fitness and population health in some areas. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Two trials were conducted with 48 newly weaned piglets (28 d old) each 8.6 ± 0.05 kg to study how Laminaria japonica plants (LJ) affect zootechnical performance, feed conversion and the apparent total tract digestibility (ATTD) of crude nutrients. All basal diets consisted of cereals, soybeanmeal, skim milk powder and premixes according to recommendations (no growth promoters or enzymes). For Trial 1, piglets from 16 litters (50%male-castrated, 50% female) were assigned to three treatment groups (n = 16) in a completely randomised block design. Groups received either 2.5% supplementation with sun dried (SD) or drum dried (DD) LJ powder or 2.5% of diatomaceous earth (control). For Trial 2, piglets from 12 litters received either 5% of diatomaceous earth (control) or one of three mixtures of diatomaceous earth + DD LJ powder (3.3%+1.7%, 1.7%+3.3% or 0.0%+5%; n = 12). Data collection included zootechnical performance, faecal consistency, blood plasma urea (Trial 1 and 2) and ATTD (Trial 2). Metabolisable energy (ME) of DD LJ and diets in Trial 2 was estimated using digestible nutrients. Statistical analysis included two-way ANOVA (treatment, block) and mixed linear regression. During both trials, LJ at dosages =2.5% significantly reduced feed:gain ratio compared to control (p = 0.0001, = 0.01 for Trial 1, Trial 2) irrespective of the drying method. ATTD from Trial 2 significantly increased digestibilities of dry matter (DM) and crude ash (CA) (p = 0.01) and significantly decreased digestibilities of organic matter and crude fibre in animals fed =3.33% DD LJ (p = 0.01). Fractional digestibility of the DD LJ resulted in limited ME of ~9.3 ± 2.5 MJ/kg DM. Dietary conversion ratios of ME and digestible DM of DD LJ diets from Trial 2 decreased linearly with increasing algal supplementation (R2 = 0.93, 0.94 and pslope = 0.002, 0.002 for MCR, DCR). In conclusion, dried LJ powder was included up to 5% into diets without impairing zootechnical performance. The improved feed conversion in the presence of LJ was partly due to slightly higher ME within the algae diets compared to control. However, piglets receiving LJ during Trial 2 needed significantly lower dietary ME and digestible DM to maintain growth performance. Thus, LJ exerted a performance enhancing effect on weaned piglets. The precise mode-of-action is yet unclear. [ABSTRACT FROM AUTHOR]

Objective: The aim of this research was to evaluate the effect of different concentrate levels in diets based on cactus Opuntia Stricta (Haw.) Haw cladodes on the performance of lactating Girolando cows. Methods: The experiment involved 10 Girolando multiparous dairy cows at 512.6 kg of body weight (BW) and producing 13.2 kg milk/d, allocated into two 5×5 Latin squares. The experimental treatments consisted of control diet composed by cactus Nopalea cochenillifera. Salm- Dyck. cladodes (Nopalea), forage sorghum silage and concentrate at 20% on dry matter (DM) basis, and four concentrate levels diets (20%, 24%, 28%, and 32%) plus cactus Opuntia stricta (Haw.) Haw. cladodes (Opuntia) and forage sorghum silage. Results: Regarding cows fed control diet, the nutrients intake were greater than for cows fed with cactus Opuntia and concentrate. Regarding concentrate levels, intakes of DM, organic matter (OM), crude protein (CP), non-fiber carbohydrates (NFC), and total digestible nutrients of cows increased linearly. Organic matter, CP, and NDF digestibilities were similar in between to control diet and cactus Opuntia-based diets. The digestibility of NFC increased linearly when the concentrate was inserted. The N balance was the same for control diet and cactus Opuntia-based diets, irrespective the concentrate levels. Conclusion: For cows producing 14 kg/d with 3.5% of fat, it is recommended 32% of concentrate to be included in cactus Opuntia-based diets, and the increase in concentrate level promotes a linear increase in milk yield. [ABSTRACT FROM AUTHOR]

The experiment was conducted to evaluate the ingestive behavior of buffalo fed sugarcane with different levels of concentrate. Twenty four Murrah buffaloes with body weight of 219±23 kg and nine months old were assigned to completely randomized design. Animals were placed in individual pens where they received diets ad libitum, twice a day. The experimental period has divided into 30 d for adaptation and 84 d for observations and samples collection. Four treatments were used: 1) 80% sugarcane (SC) + 20% concentrate (C); 2) 60% SC + 40% C; 3) 40% SC + 60% C; 4) 20% SC + 80% C. The diets were isoproteics and urea/ammonium sulfate was used at 9:1 ratio to correct the protein level of sugarcane. The evaluated variables were time spent feeding (TSF), ruminating (TSR), idle (TSI), dry matter intake (DMI), feeding efficiency of dry matter (FEDM), rumination efficiency of dry matter (REDM), number of meals, duration of meal and duration of breaks between meal. A regression analysis was performed using the MIXED procedure. DMI was positively affected (P<0.05) by concentrate levels. The treatments had no effect (P>0.05) on TSF. However, the TSR and number of meals decreased linearly (P<0.05) as the dietary levels of concentrate increased. TSI, duration of meal and duration of breaks between meals increased linearly (P<0.05). Increasing levels of concentrate up to 80% in sugarcane based diets influence directly the feeding behavior of buffaloes resulting in fewer daily meals and more time in the trough, improving the feeding and rumination efficiencies. [ABSTRACT FROM AUTHOR]

Lucerne has multifunctional value: it is a source of a high-protein forage for farm animals and valuableraw materials for pharmaceutical industry. The purpose of this work was studying of features of intra population variability of a lucerne with a mf-mutation on a complex of the qualitative signs, valuable as for the forage production as well as for the pharmaceutical industry. In the years 2016-2018, researchers of the 30 breed population, received as a result of an individual selections from a breed lucerne Krasnoyaruzhskaya 1 on the basis of a high expression of a mutation of multifoliolation (mfmutation). The high variability of a population of the lucerne in the posterity of the second generation on the basis of expressiveness of the mf-mutation was established. The breed population was distributed by the index of an expression of the mf-mutation as follows: the group with low expressiveness of the sign included 52.8% of numbers, 9.9% of the numbers had the index of an expression up to the standard, 36.3% of the breed population exceeded the standard for 9.3-62.7%. As a result of researches the direct correlation between degree of an expression of the mf-mutation and the feeding efficiency of a lucerne is not revealed. There was established the breed population SP-11 at which the high expression of the mf-mutation and high efficiency of the elevated phytoweight against the background of the low maintenance of saponin and antotcyanin. The population of SP-11 will be included in the selection program for the creation of the lucerne breeds with a high fodder quality. The breed population SP-23, SP-24, SP-28 has a high expression of the mf-mutation, high efficiency of the elevated phytoweight against the background of the high content of the biologically active agents (saponins and antocyanins). These forms will be included in the selection program for creation of breeds of a lucerne with the high content of biologically active agents for the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

The nutritional energy requirements of animals for maintenance and weight gain, such as the energy partition of the diet, were determined in different feeding plans. Fifteen F1 Holstein × Gyr, non-castrated male bovines with a mean initial liveweight of 302 kg were used. The diets were corn silage and concentrate, formulated to enable gains of 100, 500 and 900 g/day, called low, medium and high weight gains, respectively. Tests of digestibility and metabolism were conducted to determine energy losses through faeces, urine and methane emissions. Heat production was determined using respirometry chamber. Net energy for maintenance was calculated as the antilogarithm of the intercept of the regression of the logarithm of the heat production, as a function of the metabolisable energy intake. Retained energy was obtained by subtracting the heat production from the metabolisable energy intake. With the increased consumption of dry matter, there was an increase in faecal and urinary energy loss. Retained energy increased linearly with the metabolisable energy intake. The net energy for gain in the diet did not differ among the treatments, such as the efficiency of use of metabolisable energy for weight gain kg (0.34). The net energy for maintenance was 312 kJ/kg LW0.75, and the metabolisable energy for maintenance was 523 kJ/kg LW0.75. The daily methane production (g/day) increased with the dry matter level and the daily loss represented 5.31% of the gross energy consumption. The determination of the nutritional energy requirements for bovines of different genetic groups and under different feeding conditions allows the appropriate adjustment of feed formulation for each animal category. Knowledge of the energy partition of the diet and methane production allows the development of appropriate nutritional strategies respecting the environment. [ABSTRACT FROM AUTHOR]

A fully random design was used to distribute 200 Cobb 500 chickens. They were one day old, looked healthy and had an average weight of 37.34 ± 0.44 g. It consisted in five groups with four replicas having 10 chickens each. During the 42 experimental days, the birds received a traditional zootechnical management including commercial isoproteic diet (20% raw protein) and an isocaloric diet (3,100 kilocalories (kcal)/kilogram (kg)). On day 15, the herd was subject to a feeding restriction program (PRA) according to these treatments (T): T0 ad libitum consumption of concentrated food (CF) for 24 hours (h), T1 removal of the CF for 12 h (20:00-8:00), T2 removal of AC for 14 h (18:00-8:00), T3 16 h with not access to the CF (16:00-8:00), and T4 lack of AC for 18 h (14:00 y 8:00). After day 30, the birds returned to the free consumption of CF. The total weight gain (TWG), daily weight gain (DWG), food consumption (FC), dietary conversion factor (DCF), channel performance (CP), and mortality (M) were taken as response variables. The statistical analysis showed that the PRA had a significant effect on the (P>0.05) on the production indicators evaluated in T0, T1, T2 and T3. However, the CF was significantly lower (p<0,05) in T3 and T4 as compared to the other treatments. In addition, only T4 showed a lower DCF (p<0,05) as compared to the other treatments. It is concluded that a PRA of 18 hours from 15 to 30 days of age favors the sustainability criteria as it does not impact negatively the bird productivity. [ABSTRACT FROM AUTHOR]

The feeding conversion and efficiency of Oreochromis aureus (Cichlidae) hybrids with balanced food of different protein percentage in closed system in Trujillo, La Libertad, Peru was investigated in the Aquaculture laboratory of the National University of Trujillo in 2018. Four 500 l tanks were used with potable water, air system, 100 W thermostat, 60 W recirculation system and 20 L biological mechanical filters. In June 2018, 50 hybrid "blue tilapia" fingerlings were acclimatized in 30 minutes and entered 49 days in quarantine supplying all units with balanced food of 45 and 40% of protein. Then, two treatments and their respective replicas were applied, T1 and R1: 35% and T2 and R2 of 28% in 135 days of rearing. In the research, the feeding conversion and efficiency ranges fluctuated between 1.30 and 2.14; and from 71.43 to 46.60% respectively. It is concluded that the best feeding conversion and efficiency in O. aureus was obtained in T1. [ABSTRACT FROM AUTHOR]

The selection of animals with greater feed efficiency has unknown parasitological and physiological parameters when confined in full sun or shade. Thus, we aimed to assess the effect of residual feed intake (RFI) and the confinement environment on the hematological, parasitological and physiological parameters in male Dorper sheep (n = 60; 30 with positive RFI and 30 with negative RFI) distributed in 2 confinement environments (full sun and shade), in a 2 × 2 factorial scheme, with 15 animals for treatment. Animals kept in the shade showed an increase (P < 0.05) of erythrocytes, hemoglobin and albumin. Animals kept in full sun showed higherOocysts gamma glutamyltransferase, direct bilirubin, transaminase aspartate and respiratory rate (P < 0.05). There was a higher incidence of Eimeria spp oocysts in RFI negative animals (P < 0.05). Positive RFI animals increased respiratory rate (P < 0.05). The RFI did not influence the blood parameters of Dorper sheep, however, it had an effect on respiratory rate and presence of Eimeria spp. oocysts. Thermal environment promoted changes in blood parameters and the physiological parameters of Dorper sheep. • Feed efficiency and thermal environment can influence the animal's health. • Negative residual feed intake Dorper sheep has a higher incidence of Eimeria spp. • Negative residual feed intake Dorper sheep have a lower respiratory rate. • Confinement in full sun promoted changes in hematological parameters. • Confinement in full sun increase respiratory rate and rectal temperature. [ABSTRACT FROM AUTHOR]

The salicylic acid analog BTH (benzo-(1,2,3)-thiadiazole-7-carbothioic-acid S-methyl ester) induces systemic acquired resistance by promoting plant resistance against numerous plant pathogens and some insect pests. The objective of the research was to evaluate the activation of plant defenses with BTH on melon (Cucumis melo L., Cucurbitaceae) and its effects on the herbivore Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) and on the aphid predator Chrysoperla carnea (Stephens, 1836) (Neuroptera: Chrysopidae). Under laboratory conditions, plants were sprayed with BTH (50 g/ha) zero (B0), four (B4), and seven (B7) days prior exposure to insects. B0 treatment resulted in 100% mortality of aphid nymphs and disrupted adult feeding behavior (recorded by electrical-penetration-graphs technique), by prolonging the time to reach the phloem, requiring more probes to first salivation and reducing ingestion activities. There were no effects on feeding behavior of A. gossypii fed on B4 plants but on its life history because fewer nymphs were born, intrinsic rate of natural growth decreased, and mortality increased. There were no effects on biological parameters of aphids reared on B7 plants. Prey consumption by C. carnea larvae when predated A. gossypii fed on BTH-treated plants was not different among treatments. Therefore, BTH enhances the suppression of A. gossypii in the short term, without negative effects on the predatory larva C. carnea, which makes this plant strengthener a useful tool to be considered in integrated pest management programs.

Growth, feeding efficiency, carcass traits, and meat quality (including as measured by sensory analysis) were examined in four cattle breeds differing by age at maturity and purpose of production. A total of 40 bulls of Aberdeen Angus (AA), Gascon (GS), Holstein (HO), and Fleckvieh (FL) breeds were fattened under identical housing and feeding conditions until slaughter at a similar age of 17 months. Whereas no breed difference was found in growth rate, dry matter intake was higher in AA and HO than in GS and FL ( P  < 0.001). The highest residual feed intake indicating the lowest feeding efficiency was observed in HO ( P  < 0.001). The highest killing-out and total lean meat proportions were found in GS, the lowest in HO and intermediary in AA and FL ( P  < 0.01). Lower shear force values indicating more tender meat were measured in grilled meat samples of AA than in HO ( P  < 0.05), with GS and FL being intermediary. Meat from AA and HO had highest concentrations of dry matter and intramuscular fat ( P  < 0.001). Most sensory attributes were rated higher in AA compared to the other breeds ( P  < 0.001). GS samples received the second-best scores ( P  < 0.001) for tenderness and residue. The study revealed clear differences among breeds in most of the traits examined that may be of value for beef producers. Whereas purebred GS bulls were superior in slaughter and carcass traits, eating quality characteristics were rated highest in AA. [ABSTRACT FROM AUTHOR]

Artificial diets that devoid of insect components have been widely developed for predatory insects, but often yield disappointing results. Carotenoids play vital roles in insects and generally must be acquired from diet, but their supplementation in insect artificial diets has been rarely concerned. Here, we tried to evaluate the function and application prospect of carotenoids in artificial diet of Harmonia axyridis . Firstly, the physical form of component pork liver in artificial diet was improved using fine powder to replace the homogenate, and the survival of infant larvae was greatly increased. Then, four β-carotene-amended artificial diets were developed (0, 0.3, 3 and 30 μg/g (β-carotene/pork liver powder), indicated as AD-A, AD-B, AD-C and AD-D respectively) to evaluate their feeding efficiency for H. axyridis , and the aphid Myzus persicae was used as control. The larval survival on AD-D was equal to that on aphids, and was significantly higher than those on other artificial diets. However, H. axyridis feeding on artificial diets, whichever of the concentration of β-carotene, had significantly longer pre-imaginal development time and obtained smaller newly emerged adults than those on M. persicae . Overall, AD-D showed to be the optimal diet. Finally, the performance of AD-D-fed H. axyridis was evaluated on the target pest M. persicae . Compared to aphid-fed lady beetles, the fourth instar larvae raised with AD-D had similar number of aphid consumption and both showed preference for non-parasitized aphid than newly parasitized by Aphidius gifuensis ; the adults produced fewer eggs but had undifferentiated pre-ovipostion period and egg hatch rate. In conclusion, supplementation of β-carotene could increase the efficiency of artificial diet. On M. persicae , H. axyridis developed from AD-D had outstanding performance which was applicable for releasing in biological control. Our results highlight the importance of carotenoids in artificial diet and might provide a new approach for developing artificial diets. [ABSTRACT FROM AUTHOR]

Thyroid hormones are known for their stimulation of feed efficiency and growth performance in different farm animals. More interestingly, the level of thyroid hormones is influenced by selection for growth in some animal species. Therefore, it was the aim of the current study to investigate whether a correlation exists between the blood triiodothyronine (T3) level and some production traits (daily feed intake, average daily gain, and feed conversion ratio). To test this hypothesis, six male goat kids (21.9 ± 2.4 kg; 5 months old) belonging to Aardi, Damascus, and their cross breed (two kids from each genotype) were used in the current study. The obtained results revealed a positive linear correlation of plasma T3 level with both average daily feed intake and average daily gain with correlation coefficients of 99% and 97%, respectively (P = 0.001). On the other hand, feed conversion ratio was negatively correlated to the plasma T3 level with a correlation coefficient of 81% (P = 0.05). The obtained results indicate the possible use of blood T3 level for the prediction of feed intake, daily body weight gain, and feed conversion ratio in addition to the possible use of blood T3 level as a criterion of breeding selection for growth performance in the future. [ABSTRACT FROM AUTHOR]

The effects of tank color on the growth, stress responses, and skin color of snakeskin gourami (Trichogaster pectoralis) were investigated in this study. Fish with initial body weights of 5.03±0.00 g were reared in five experimental tank colors (white, red, green, blue, and black) for 8 weeks. Each tank color was tested in triplicate with an initial stocking density of 15 fish per tank. Fish were fed with commercial sinking pellets at 4% of the average body weight per day. Growth performance, feed utilization efficiency, stress indicators (hematocrit, blood glucose, plasma cortisol levels), and skin color parameters were investigated. The fish reared in blue tanks had a significantly higher average final body weight (9.73 ± 0.14 g) and significantly lower average feed conversion ratio (3.42 ± 0.12) than the fish reared in black tanks (P < 0.05). The fish reared in black tanks exhibited higher average hematocrit (36.63 ± 1.11%), blood glucose (48.33 ± 1.45 mg dL−1), and plasma cortisol (9.00 ± 0.56 μg dL−1) levels than those reared in the other tank colors. However, the blood glucose levels in only the fish reared in black tanks were significantly higher than those in the fish reared in the other tank colors. The fish skin color ranged from very pale (high skin lightness) in the white tanks to very dark (low skin lightness) in the black tanks, and 80% of the variation in skin lightness were explained by the tank lightness. The use of a blue tank resulted in normal skin color; hence, blue tanks will not affect the customer acceptance of the fish. Our study revealed that blue is the most appropriate tank color for culturing snakeskin gourami. [ABSTRACT FROM AUTHOR]

Cheilomenes sexmaculata F. (Coleoptera: Coccinellidae) is an effective biological control agent against aphids. This study observed its feeding efficiency in the grub stages, and adult male and female during March and April on aphid Aphis craccivora Koch in broad bean Vicia faba. The first to fourth instar grubs were observed in April to predate on aphids to an extent of 13.2± 0.18, 42.2± 1.98, 61.8± 1.31 and 164.2± 4.94 aphids, respectively). Male and female adults fed on 1011.4± 0.25 and 1201.2± 0.88 aphids, respectively. [ABSTRACT FROM AUTHOR]

Artificial selection towards a desired phenotype/trait has modified the genomes of livestock dramatically that generated breeds that greatly differ in morphology, production and environmental adaptation traits. Angus cattle are among the famous cattle breeds developed for superior beef quality. This paper aimed at exploring genomic regions under selection in Angus cattle that are associated with meat quality traits and other associated phenotypes. The whole genome of 10 Angus cattle was compared with 11 Hanwoo (A-H) and 9 Jersey (A-J) cattle breeds using a cross-population composite likelihood ratio (XP-CLR) statistical method. The top 1% of the empirical distribution was taken as significant and annotated using UMD3.1. As a result, 255 and 210 genes were revealed under selection from A-H and A-J comparisons, respectively. The WebGestalt gene ontology analysis resulted in sixteen (A-H) and five (A-J) significantly enriched KEGG pathways. Several pathways associated with meat quality traits (insulin signaling, type II diabetes mellitus pathway, focal adhesion pathway, and ECM-receptor interaction), and feeding efficiency (olfactory transduction, tight junction, and metabolic pathways) were enriched. Genes affecting beef quality traits (e.g., FABP3, FTO, DGAT2, ACS, ACAA2, CPE, TNNI1), stature and body size (e.g., PLAG1, LYN, CHCHD7, RPS20), fertility and dystocia (e.g., ESR1, RPS20, PPP2R1A, GHRL, PLAG1), feeding efficiency (e.g., PIK3CD, DNAJC28, DNAJC3, GHRL, PLAG1), coat color (e.g., MC1-R) and genetic disorders (e.g., ITGB6, PLAG1) were found to be under positive selection in Angus cattle. The study identified genes and pathways that are related to meat quality traits and other phenotypes of Angus cattle. The findings in this study, after validation using additional or independent dataset, will provide useful information for the study of Angus cattle in particular and beef cattle in general. [ABSTRACT FROM AUTHOR]

Investigations of host plant selection in herbivorous arthropods have emphasized the importance of oviposition site selection by adults; however, a more complete picture of this process requires additional consideration of the factors influencing host plant choice during the immature feeding stages. We conducted a series of larval choice experiments to examine both the innate and induced preferences of larvae of the Silver-spotted skipper ( Epargyreus clarus L.) on three commonly used hosts ( Wisteria, Robinia, and Pueraria). Late instar E. clarus larvae reared on each of the three host plants displayed an overall pattern of innate preferences that correlated well with larval performance measures and reflected differences in foliar nutrient concentrations. Larval preferences were also influenced by rearing host species, indicating a role for feeding-induced preferences. When larvae reared on low-quality Wisteria for the first four instars were switched to higher quality Pueraria for the final instar, they developed more quickly and attained significantly higher pupal mass than larvae maintained on Wisteria throughout development. Similarly, larvae switched from Pueraria to Wisteria for the final instar suffered increased development time and produced significantly smaller pupae than those maintained on Pueraria throughout. Thus host-switching, particularly during the more mobile final instars, appears to offer larvae an opportunity to recoup fitness losses associated with early development on a low-quality host. For an equal amount of consumption, larvae feeding on Pueraria gained 50% more mass than those feeding on Wisteria, reflecting measured differences in foliar nitrogen concentration; despite these overall differences in quality, larval growth efficiency was similar among hosts. Especially in the age of common exotic plant introductions, a full understanding of the behavioral component of host selection by herbivorous insects requires appreciation of the dynamic role that immatures can play in host selection and use. [ABSTRACT FROM AUTHOR]

Inactivating mutations in the melanocortin 3 receptor ( Mc3r ) have been described as causing obesity in mice, but the physiologic effects of MC3R mutations in humans have been less clear. Here we review the MC3R polymorphisms and mutations identified in humans, and the in vitro , murine, and human cohort studies examining their putative effects. Some, but not all, studies suggest that the common human MC3R variant T6K + V81I , as well as several other rare, function-altering mutations, are associated with greater adiposity and hyperleptinemia with altered energy partitioning. In vitro , the T6K + V81I variant appears to decrease MC3R expression and therefore cAMP generation in response to ligand binding. Knockin mouse studies confirm that the T6K + V81I variant increases feeding efficiency and the avidity with which adipocytes derived from bone or adipose tissue stem cells store triglycerides. Other MC3R mutations occur too infrequently in the human population to make definitive conclusions regarding their clinical effects. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao. [ABSTRACT FROM AUTHOR]