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We studied the effect of lighting during 19 days of incubation on embryonic bone characteristics, gene expression, thyroid hormones, and glucose in Cobb broiler hatchlings. Eggs (2160) were incubated under darkness (control) and green and white lighting (16D:8L and 12D:12L). On 19th day, tibiotarsal length increased under eight hours of white light, and femoral ossified length was longer under eight hours of white and green light. In femur, expression of Alp, Col10a1, and Spp1 increased by 12 h white and 8 h green lighting, and Bglap expression decreased under white. In tibiotarsus, expression of Alp decreased by 8 h lighting (green or white) while Bglap increased by 12 h lighting (green or white). Tibiotarsal expression of Col10a1 increased by 12 h lighting (white and green), and in 8 h green lighting, and Spp1 expression was higher under light illumination. The hatchling blood triiodothyronine concentration in 8 h green lighting was higher than that in control, whereas, thyroxine concentration was lower under 12 h white lighting compared with other treatments. Femoral organic matter to mineral (OM:M) ratio and calcium concentration were higher in the eight-hour white light group than in the control, but tibiotarsal OM:M ratio and calcium and phosphorus concentrations were higher under 12 h white light. The findings indicated that lighting during incubation may impact, both positively and negatively, bone morphology and gene expression. More studies are needed to find the most beneficial lighting system during incubation in chickens. [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate the nitrogen requirements of Holstein suckling calves at 2, 6 and 8 weeks of age. Newborn healthy calves, randomly divided into 2 groups (n=16 per group), were fed with either a starter based on corn or barley. The calves received pasteurized cow's milk in accordance to the herd schedule. The calves were housed in individual metabolic cages and urinary and fecal nitrogen contents were measured in samples collected for four days at 2, 6 and 8 weeks of age. Nitrogen requirement was estimated using the regression analysis. Nitrogen requirement for maintenance at week 2 significantly (P=0.037) differed between the starters, but not at 6 and 8 weeks. However, the nitrogen requirement for maintenance at 8 weeks of age tended to be differ between male and female calves (P=0.075), but not at weeks 2 and 6. Daily nitrogen requirements for maintenance based on the metabolic weight decreased as the calves aged. Nitrogen requirement for growth was affected by the type of grain in the diet at weeks 2 (P=0.068), 6 (P<0.05) and 8 (P<0.05). No effect of sex was found on nitrogen requirements for growth (P>0.05). [ABSTRACT FROM AUTHOR]

Adding corn silage (CS) instead of alfalfa hay (AH) to the finely ground starter diet would improve calf performance if feed intake or feed efficiency is increased. We investigated the effects of replacing AH with CS in the starter diet on nutrient intake, digestibility, growth performance, rumen fermentation and selected blood metabolites in Holstein calves. Newborn male calves (n = 30; 3 days of age; 40.2 ± 1.28 kg BW) were assigned randomly to three groups receiving starter diets containing chopped AH (10% dry matter (DM) basis; AH diet), CS (10% DM, CS diet) or their combination (each at 5% level; AHCS diet). The starter diets had the same nutrient composition but differed in DM content (91.2%, 87.5% and 83.8% for AH, AHCS and CS, respectively). The calves were weaned on day 50, and the study continued until day 70. Nutrient intake, BW (at weaning and at the end of the study) and body measurements were not affected by the diet. During the post-weaning period, average daily gain tended to be greater on CS than on AH diet. Feed efficiency was greater in CS than in AH or AHCS calves during the post-weaning period. Digestibility of neutral detergent fiber was greater in AHCS and CS compared with AH during the post-weaning period. Concentration and profile of volatile fatty acids and ruminal fluid pH were not affected by the diet. Replacing AH with CS in the starter diet had no effect on feed intake, growth performance and general health of the calves. These results indicate that AH and CS can be used interchangeably in dairy calf starter diets until 70 days of age, allowing dairy producers more choices in selecting the feed ingredients. [ABSTRACT FROM AUTHOR]

The association of birth type (single vs. double) and pregnancy type (single vs. double) with lactation performance and lactation curve was investigated in Holstein cows in Iran. Data of 243298 lactations on 138021 cows in 261 herds collected during January 2000 to December 2012 were used. The average twinning rate was 3.64% and ranged from 1.44% (primiparous) to 5.41% (multiparous). Factors associated with twining were calving season, calving year, herd, and parity. The rate of twinning increased from 2.49% in 2000 to 3.42% in 2012. The probability of twinning was higher in multiparous cows than that in primiparous [Odds ratio (OR) (95% confidence interval (CI))= 3.64 (3.44-3.84) for multiparous vs. primiparous cows]. The probability of twin pregnancy was higher in cows previously delivering twins than that in those delivering singles [OR (95% CI)= 3.17 (3.02-3.34) for cows delivering twins vs. cows delivering singles]. The lactation curve for cows delivering singles in previous gestation and pregnant with twins in subsequent gestation tended to be lower and flatter. The incidence of twin pregnancy was increased as the cow reached its peak yield earlier, and produced more milk at peak lactation. Primiparous cows delivering singletons in their previous gestation and having twins in their subsequent gestation produced more 100-d, 200-d and 305-d milk than those pregnant with singletons. Multiparous cows that delivered singleton in previous gestation and were pregnant with twin in the subsequent gestation, produced more milk during the first 100-d and 200-d of lactation than those pregnant with singles. [ABSTRACT FROM AUTHOR]

BMP15 and GDF9 are two oogenesis specific genes play a pivotal role in female fertility in mammals and potential for improvement of prolificacy in marker-assisted selection. The aim of present research was to investigate the variation and association between BMP15 and GDF9 polymorphism and litter size in Markhoz goats. The sequence variability of the different amplified fragments utilized for genotyping was further investigated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequencing. Sequencing technology allowed the detection of two nucleotide variations: A both non-functional mutation (G/A) transition at nt 1026 known as P3) and a synonymous mutation at 1049 position which for the first time was found at the BMP15 gene. Also, GDF9 gene exhibited a polymorphism on BcnI site (1159 bp) within exon 2 of amplified PCR products (glutamine/proline). Our analysis using general linear model (GLM) statistical methods showed litter size was significantly influenced by genotypes of GDF9 (P<0.01). Heterozygous genotype showed higher litter size than homozygous genotypes (P<0.01). The conformation of this founding would need large sample size and test to screen in other indigenous goats. [ABSTRACT FROM AUTHOR]

The objectives were to estimate (co)variance components and genetic parameters for lactation curve traits in Holstein dairy cows in Iran. The used data were records on Holstein cows collected during January 2003 to December 2012 by the Animal Breeding Center of Iran (Karaj, Iran). In order to describe the lactation curve, an incomplete gamma function was fitted to 691200 test-day records on 96263 lactations, 377696 test-day records on 52168 lactations, and 182143 test-day records on 24951 lactations for the first three parities, respectively. Lactation curve traits that were analyzed included a scaling factor associated with initial yield, the inclining and declining slopes of the curve, peak time, peak yield, 305-d milk yield and a lactation persistency measure derived from the incomplete gamma function. The estimated heritability of lactation curve traits for the first, second and third lactation ranged from 0.012 to 0.29, 0.017 to 0.15, and 0.02 to 0.13, respectively. Genetic correlations among lactation curve traits for the first, second and third lactation ranged from -0.68 to 0.99, -0.84 to 0.98 and -0.90 to 0.94, respectively. The estimated repeatability of lactation curve traits ranged from 0.07 to 0.40. The moderate to large positive genetic correlations of 305-d milk yield with initial yield, peak yield and lactation persistency suggest that one of these traits could be used as a selection criterion to improve all four traits. However, the peak yield and 305-d milk yield were more heritable than lactation were persistency and initial yield. [ABSTRACT FROM AUTHOR]

Experiments were conducted to determine the effect of lime pre-treatment on the chemical composition and in vitro rumen degradability of date palm leaves (DPL). Lime pre-treatments, with or without oxygen supply, were applied for 1, 2 and 3 weeks at 25 and 40 °C. Lime was neutralized by the Calcium-Capturing-by-Carbonation process. Delignification and in vitro rumen gas production were significantly influenced by duration, temperature and oxygen. At 40 °C, oxygen presence stimulated more delignification and subsequently increased in vitro rumen degradability. Lime pre-treatment with 0·2 g calcium hydroxide (Ca(OH)2)/g dry biomass for 3 weeks at 40 °C in the presence of oxygen resulted in a 3-fold increase in gas production after 24 h of incubation, compared with untreated biomass. Lime treatment of DPL with aeration resulted in higher lignin removal and subsequent rumen degradability than without aeration. A techno-economic analysis is needed to select the most efficient and economically feasible pre-treatment procedure. [ABSTRACT FROM PUBLISHER]

Published data on the effects of essential oils (EO) on in vivo nutrient digestibility in sheep are contradictory. In 2 experiments, the effect of thymol and carvacrol on nutrient digestibility was studied in sheep fed with high (70%) or low (52%) concentrate diets, using incomplete Latin Square designs. The essential oils were mixed with the concentrate portion of the diet at the rate of 0.0, 0.3, or 0.6 g per kg dry matter (DM) diet. Supplementation of thymol had no significant effect on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and acid detergent fiber (ADF). The main effect of thymol on neutral detergent fiber (NDF) and ether extract (EE) digestibility and on nitrogen balance (NB) was significant (P<0.05), but within each level of dietary concentrate no significant differences were observed for these measurements. Overall, ruminal ammonia concentration was higher (P<0.05) in both HCD and LCD lambs receiving 0.3 mg thymol per kg diet. Supplementation of carvacrol had no significant effect on nutrient digestibility. The main effect of carvacrol on ruminal ammonia levels and NB was significant, but within each level of dietary concentrate no significant differences were observed in ammonia levels and NB. Inclusion of 0.3 g/kg diet DM of carvacrol or thyme was more effective than 0.6 g/kg diet DM in terms of NB but neither dose affected nutrient digestibility. Future research should determine the long-term effects of essential oils on digestibility and performance in sheep, before recommendation can be made for their use under practical husbandry conditions. [ABSTRACT FROM AUTHOR]

The present experiment aimed at increasing orange peel and sugar beet pulp protein content through solid-state fermentation by Trichoderma reesei and Trichoderma viride. In vitro digestibility and changes in the chemical composition of the fermented products were determined after seven days of fungal cultivation using gas production tests. The cultivation of T. reesei and T. viride on orange peels decreased neutral detergent soluble content (P<0.01) and increased cellulose, hemicellulose and lignin contents (P<0.01). Changes in fiber fractions were found to be more pronounced with T. viride. The cultivation of T. reesei and T. viride on sugar beet pulp increased neutral detergent soluble content (P<0.01) and decreased cellulose and hemicellulose contents (P<0.01). These changes were more pronounced with T. reesei. The cultivation of T. reesei or T. viride on orange peels or sugar beet pulp increased crude protein content (P<0.01) compared with the unfermented materials; however, the increase was more pronounced for orange peels fermented with T. viride when corrected for weight loss (P<0.05). After 24 and 48 h of incubation, significant decreases in cumulative gas production (P<0.01) were observed in fermented sugar beet pulp and orange peels compared with the unfermented materials. Fungal treatment of orange peels and sugar beet pulp reduced the digestibility of in vitro organic matter, metabolizable energy and average fermentation and gas production rates (P<0.01). The data showed that seven days of solid-state fermentation of orange peels and sugar beet pulp by T. reesei or T. viride can increase their crude protein content. [ABSTRACT FROM AUTHOR]

Genetic and non-genetic correlations of the average somatic cell score (SCS) at different stages of lactation (100, 150, 200, 305 and 365 days in milk) with lactation performance were estimated based on the first lactation records of Iranian Holstein calving during 2000 to 2009. (Co) variance components were estimated using derivative-free REML based on multiple traits animal models. The estimated genetic correlations between average of first 100 days in milk SCS (SCS100) and milk100, fat100, milk305, fat305 and protein305 were 0.14, 0.19, 0.11, 0.15 and 0.17, respectively. The corresponding environmental correlations were -0.13, -0.03, -0.18, -0.10 and -0.13, respectively. The estimated genetic correlations of the average SCS during the first 150 days in milk (SCS150) with milk100, fat100, milk305, fat305 and protein305 were 0.14, 0.19, 0.11, 0.15 and 0.17, respectively. The corresponding environmental correlations were -0.13, -0.03, -0.18, - 0.10 and -0.13, respectively. The estimated genetic correlations of the average SCS during 305 days in milk with milk, fat and protein yield, and fat and protein percentages were 0.12, 0.11, 0.18, -0.05 and -0.08, respectively. The estimated genetic correlation between SCS100 or SCS150 with average SCS over longer stages of lactations (SCS305 and SCS365) was 0.99 ± 0.01. These results indicate that recording SCS data over shorter period of lactation is an alternative approach to reduce the costs of SCS data collection and therefore to expand the SCS recording in the country by increasing both the number of herds and cows involved. [ABSTRACT FROM AUTHOR]

In this study, 65,971 lactations on 41,842 cows in 64 herds were used to determine the association between dry period length (DPL) and lactation performance, lactation curve, calf birth weight, and the incidence of calving difficulty during the subsequent parity in Holstein dairy cows in Iran. The length of the dry period was classified into 7 categories: 0 to 35 d, 36 to 50 d, 51 to 60 d, 61 to 70 d, 71 to 85 d, 86 to 110 d, and 111 to 160 d. Cows with the standard DPL (51 to 60 d) produced more 305-d milk, fat, and protein over the next lactation compared with those with shorter dry periods. Shorter dry periods (0 to 35 d and 36 to 50 d) were associated with lower initial milk yield, steeper inclining and declining slopes of the lactation curve, and higher milk persistency compared with dry period length of 51 to 60 d. Peak lactation was achieved later in cows with 0- to 35-d and 36- to 50-d dry period length than in those with dry period length of 51 to 60 d. We also observed a relationship between DPL and calf birth weight: smaller calf birth weight was recorded with a dry period of 51 to 60 d compared with longer dry periods. The incidence of calving difficulty did not differ in cows with 51- to 60-d dry period compared with cows with 0- to 35-d and 36- to 50-d dry periods. In conclusion, the results of this study did not support previous findings that suggested a shorter dry period could be beneficial to dairy production. [ABSTRACT FROM AUTHOR]

This study was carried out to investigate the relationship between early lactation curve parameters and calving interval in Holstein cows of Iran. In order to describe the lactation curve, the incomplete gamma function was fitted to 5,754,428 test-day milk records corresponding to 766,108 lactations on 315,634 cows in 2,448 herds. Cows with higher milk yield during early lactation had shorter calving intervals; however, longer calving intervals increased the 305-d milk production (P<0.01). Cows with higher yield at the beginning of lactation, steeper ascending, and steeper descending slope had shorter calving intervals (P<0.01). Calving interval was increased by 2.73 (±0.12) d for every extra kg of milk at peak lactation (P<0.01). The calving interval was directly impacted by the persistency of milk yield, but milk yield persistency was reduced in cows with shorter calving intervals (P<0.01). [ABSTRACT FROM AUTHOR]

Based on the findings of a recent study suggesting a decreased cold-induced ascites incidence in broiler progeny from hyperthyroid (HYPER) breed-er hens, and a controversy on the effects of hyperthy-roidism on immunocompetence, the present study was conducted to determine the probable adverse effect of induced maternal hyperthyroidism on immune function in progeny chicks. Breeder hens (n = 88) were ran-domly allotted to the control or HYPER groups and received common or thyroxine (T4-added (1 mg/L) water, respectively. The hens were artificially insemi-nated, and hatching eggs (n = 924) were incubated. Thereafter, the male hatchlings fn = 288) were reared for 42 d, and several cellular and humoral immune responses were evaluated at standard or low ambient temperature. Prevaccination antibody titers to New-castle disease, infectious bronchitis, and infectious bur-sal disease virus were higher in HYPER chicks during 1 wk of age, although not different in their dams. For primary response to SRBC administered at 7 d of age, HYPER chicks recorded higher total, IgM (d 14), and IgG (d 21) anti-SRBC antibody titers. Higher cuta-neous basophilic hypersensitivity response in HYPER chicks (d 10) was not observed at 35 d of age. Carbon clearance assay showed no difference, but in vitro lym-phoproliferative response to concanavalin A was higher in 19-d-old HYPER chicks, independent of tempera-ture treatment. An increase in lymphocyte percentage coincided with a decreased heterophil percentage and heterophil to lymphocyte ratio (d 14) in the HYPER group. The weight of lymphoid organs in progeny was not influenced by the oral exposure of dams to extra T4. Independent of T4 treatment, cold exposure was generally associated with decreased immune functions at early stages. The data suggested that oral exposure of broiler breeder hens to 1 mg/L of T4 not only had no adverse effect on immune function, but also modulated early adaptive immune responses in progeny chicks for which the causal mechanisms remain to be unraveled. [ABSTRACT FROM AUTHOR]

The induction and regulation of broodiness is of the most important role of prolactin in avian species. The promoter region of the prolactin gene is an appropriate model for studying tissue-specific and hormonally-regulated activation of gene transcription. In this study, the association between prolactin promoter region alleles and egg production in Fars native chickens was investigated. In total, 100 laying hens, randomly selected from the flock of the Breeding Center for Fars Native Chicken, were genotyped for two single nucleotide polymorphisms (C-2161G and C-2402T), one 24-bp insertion-deletion at the site -358. The observed genotypic frequencies in the C-2161G site were CC (0.437), CG (0.435) and GG (0.101). Two alleles were found for the SNP of C-2402T with frequency of 0.34 for T and 0.66 for C. The 24-bp insertiondeletion at the site -358 was shown to be polymorph in the studied sample, with the observed genotyping frequency of 0.417 in II, 0.457 in ID and 0.126 in DD. Significant relationship was found between the SNPs and insertion-deletion genotypes with egg production (P<0.01). [ABSTRACT FROM AUTHOR]

Genetic, environmental, and phenotypic correlations among average somatic cell score (SCS) at different stages of lactation and conformation traits were estimated. Data consisted of the lactational average of SCS at 150 (SCS150) and 305 (SCS305) d in milk and 19 conformation traits recorded on 57,154 primiparous Holstein cows, that calved from 1996 to 2009 in 119 herds in Iran. Variance components were estimated using the restricted maximum likelihood procedure based on multiple-trait animal models. Udder depth (-0.32), fore udder attachment (-0.22), and udder width (0.34) showed moderate genetic correlation with SCS150. Heart girth (0.17), body depth (0.14), chest width (0.26), and angularity (0.19), showed modest genetic correlation with SCS150. The estimated heritabilities for SCS150 and SCS305 were 0.06 and 0.08, respectively. The heritability of the conformation traits ranged from 0.09 to 0.29. Genetic and environmental correlations between SCS150 and SCS305 were very high (means ± SE; 0.99 ± 0.01 and 0.89 ± 0.01, respectively), which indicates that recording SCS over a shorter period of lactation is an alternative approach for involving many herds in SCS data collection. The low heritability of SCS indicated that indirect selection for some of udder and body traits might be helpful to reduce the SCS. Additionally, selection for udder traits may help reduce SCS in developing countries where SCS data are sparsely recorded. [ABSTRACT FROM AUTHOR]

Because of a paucity of information on the effect of tomato pomace in male chickens, a study was undertaken to determine the influence of dietary inclusion of dried tomato pomace (DTP) on seminal characteristics in Iranian native breeder roosters. Fifty-four roosters (24 wk old) were randomly allotted to 3 treatment groups and received either a basal diet with-out DTP (T0), or a diet containing 15% (T15) or 30% (T30) DTP for an 8-wk-long experimental period. Se-men samples were obtained weekly by abdominal mas-sage to evaluate the seminal characteristics. Dietary inclusion of DTP increased sperm concentration, ac-companied by a decreased seminal volume (P ≤ 0.05). The percentage of live sperm in ejaculate was increased in T15 and T30 groups, but sperm forward motility was not affected by DTP inclusion. A decreased percentage of abnormal sperm and improved membrane integrity (as determined by the hypoosmotic swelling test) were observed in T15 and T30 groups. Lower concentration of thiobarbituric acid reactive substances (as an index of sperm membrane lipid peroxidation) was recorded in roosters fed DTP. A diet x time (wk) interaction was also found for most of seminal characteristics, except for the sperm forward motility (P ≤ 0.05). The results indicated that dietary inclusion of DTP up to 30% im-proved seminal quality attributes within 4 to 5 wk in roosters; however, the underlying mechanism(s) war-rants further study. [ABSTRACT FROM AUTHOR]

A hypothesis was tested that providing the breeder hens with exogenous thyroxine (T4) would help their offspring to better survive the ascites-inducing condition during the growing period. In total, 132 broiler breeder hens were randomly assigned to one of 3 treatments: control (CON), hypothyroid [HYPO; 6-N-propyl-2-thiouracil (PTU)-treatedj, and hyperthyroid (HYPER; T4-treated). The hens were artificially inseminated, and the hatching eggs (n = 1,320) were incubated. No eggs in the HYPO group hatched. The 1-d-old male chicks (n = 288) from other groups were reared for 42 d under standard or low ambient temperature to induce ascites. Blood samples were drawn from the hens, embryos, and broilers for determination of T4 and triiodothyronine (T3). The hematocrit was also determined in broilers. The PTU-treated hens had an increased BW along with lower plasma T3 and T4 concentrations. Plasma T4 was higher in the HYPER hens compared with CON hens, but T3 concentration was not different between these groups. The fertility rate was not affected by either hypoor hyperthyroidism. The embryos in the HYPO group had lower plasma T3 and T4 concentrations at d 18 of embryonic development and internal pipping. Higher plasma T4 was recorded in the HYPER birds ut internal pipping, although plasma T3 concentration was not affected at this stage. Maternal hyperthyroidism decreased the overall incidence of ascites in the cold-exposed chickens (10.0 vs. 33.4% for HYPER and CON groups, respectively). Although the effect of maternal PTU or T4 treatment on plasma thyroid hormones and on the right ventricle-to-total ventricular weight ratio in the broilers was not significant, the cold-exposed healthy CON chicks showed higher hematocrit values, compared with the HYPER birds. It was concluded that maternal hyperthyroidism could decrease the incidence of cold-induced ascites in broiler chickens; however, probable causal mechanisms remain to be elucidated. [ABSTRACT FROM AUTHOR]

The effect feeding olive-pulp silage (OPS) for 120 days on several blood attributes was studied using 16 rams allotted to two diets consisting of 70% corn silage or 70% OPS. Olive-pulp silage feeding resulted in lower serum total protein, alanine aminotransferase, calcium and phosphorus levels and higher glucose concentration compared to the corn silage diet. Body weight and other blood attributes were not affected by OPS feeding. Feeding a diet containing 70% OPS at the maintenance level had no apparent detrimental effect in mature rams. [ABSTRACT FROM AUTHOR]