Journal of Livestock Science and Technology
Volume:10 Issue: 2, Dec 2022

The inhibin α (INHA), inhibin βA (INHBA) and bone morphogenetic protein 15 (BMP-15) were investigated as candidate genes for reproductive traits in four Iranian sheep breeds (Bahmaei, Lak Ghashghaei, Lori-Bakhtiari and Karakul). Based on the ovine sequences of BMP-15, INHA and INHBA genes, three pairs of primers were designed to identify single nucleotide polymorphisms (SNPs) in exon 2 of BMP-15, INHA and INHBA in multiparous ewes by DNA sequencing. Two SNPs were detected in exon 2 of the ovine BMP15 gene at positions 367 and 430, which lead to amino acid substitutions at position 231 and 252 in the BMP15 protein sequence, respectively. Substitution of Leucine to Proline at position 252 is predicted to affect the protein function. A synonymous mutation was found in the amplified fragment of exon 2 at position 752 in ovine INHBA gene. In addition, the c752C>T mutation was only found in heterozygous condition in only one Lori-Bakhtiari ewe, while other breeds were in wild type genotype for c752C>T mutation. The INHA gene was shown to be highly polymorphic. A total of 7 SNPs including 6 nucleotide substitutions and one insertion were found in the amplified fragment of the INHA locus. The insertion mutation was found in two animals of Bahmaei and Karakul breeds. Interestingly, homozygous condition for the mutant alleles in all identified SNPs in BMP15, INHA and INHBA loci was absent in these breeds. Generally, these breeds showed different genetic structures with regard to the identified SNPs in BMP15, INHBA and INHA genes. However, further research with larger sample size and phenotype data on reproductive performance is required to investigate the definitive effect of the identified mutations in this study.

The current study aimed to investigate the effects of different sources of organic iron (native product in comparison to foreign ones) in the milk on plasma mineral concentration (Fe, Cu, Ca, P, and Zn), body weight, starter intake, feed conversion ratio (FCR), health condition, body measurements, and fecal score. Female calves (n=36) were randomly allocated to 3 groups (12 calves per treatment) and fed control milk (no iron supplement) (C), a low dose of iron (LF) consisting of 400 mg of Fe supplementation with the purity of 10% iron (native) and high dose of iron (HF) which had 200 mg of Fe supplementation with 20% purity (foreign). All animals were kept in individual pens and had ad libitum access to starter feed and water during the experimental period. From the first day of age to weaning (56 days), starter intake was measured daily. Body weight, skeletal measurements, fecal score, and health parameters were monitored weekly until weaning age. Calves that received the iron supplements had higher plasma Fe concentration, average daily gain (ADG) and starter intake, in contrast, they had low Cu, Ca, and P content and FCR than the control group. Supplementing milk with iron resulted in improved health status. Results showed that native Fe had the same impacts as the foreign product. There were no notable effects of treatment on skeletal parameters, fecal score, heart rate, respiratory rate, and rectal temperature. According to this experiment, applying iron supplements in diets requires taking into account the iron supply via other sources such as milk and or solid feeds. According to this experiment, although calves’ health and performance improved regardless of iron sources, the amount of iron supplied through other sources such as milk or solid feed should also be considered, when using iron supplements in the diet.

The present study was conducted to study the efficiency of substituting conventional gonadotropin-based technique with clomiphene citrate (CC) on reproductive parameters and hormonal changes in sheep during the breeding season. For this this purpose, 30 Afshari ewes (3-4 years, 55 ± 1.3 kg BW, BCS 3.04±0.3) were treated with intravaginal CIDR for 14 days and the divided into three groups: one group was considered as the control, the other groups received eCG (300 IU, intramuscularly) and CC (600 mg, oral), respectively. Blood samples were taken from three days before until three days after CIDR removal. Reproductive parameters were calculated after parturition. Fecundity and multiple lambing were numerically higher in the eCG group; however, there was no significant difference in reproductive performance between treatments. Estradiol and progesterone concentrations showed similar trends between treatments. Results of this study showed that CC was not a reliable substitute for eCG to increase the ovulation rate in sheep.

In the current study, a meta-analysis was carried out by merging outcomes resulting from 26 published studies in various breeds of sheep to assess the influence of the FecB gene on litter size by applying the additive, recessive, dominant, and co-dominant genetic models. The model with random effects was used for data analysis according to the Cochran Q test and I2 quantity statistical measures. Standardized mean difference (SMD) was applied to measure the size effects of ' +' and B alleles of FecB on the litter size. The significant effect (P<0.01) of FecB genotypes on the litter size was identified under the additive (SMD = 0.511), dominant (SMD = 0.469) and recessive (SMD = 0.255) models. An increase in the litter size by approximately 0.47 lambs (Dominant model) was associated with the first copy of the FecB gene and 0.25 lambs (Recessive model) with the second copy of FecB. The findings of the current study supported the idea that BMPR1B would fundamentally influence the litter size in sheep. Subsequently, it may be utilized in marker-assisted selection programs to improve the genetic merit of litter size in the future. Introgression this gene through crossbreeding programs in low prolific breeds may improve reproductive performance.

The effects of in ovo feeding (0 and 1g/L) and dietary feeding (0 and 1g/kg diet) of betaine on hatchability, performance, body temperature and blood parameters of broiler chicks under heat stress condition, were investigated using 600 fertile eggs (Ross 308) for in ovo injection at 17.5d of incubation. After hatching, 192 male chickens were divided into four groups: 1- In ovo feeding of non-betaine solution and post-hatch diet without betaine, 2- In ovo feeding of non-betaine solution and post-hatch dietary feeding 1g per kg of betaine, 3- In ovo feeding of 1g per L betaine solution and post-hatch diet without betaine, and 4- In ovo feeding of 1g per L betaine solution and post-hatch dietary feeding 1g per kg of betaine. The chicks were exposed to heat stress from 7-28d for 4h/d. The results showed that body weight of hatched chicks and the hatched chick body weight to initial egg weight ratio, was significantly increased by in ovo feeding of betaine (P<0.05). The effects of in ovo feeding and dietary feeding of betaine resulted in higher feed intake (P<0.05) and daily weight gain (P<0.01) and improved feed conversion ratio (P<0.05) for 7-21d. Birds that received dietary betaine had more carcass, breast and leg weight than chickens receiving betaine-free diet at 28d (P<0.05). The experimental treatments had no significant effect on carcass yield at d 42. During heat stress between 14 and 21d age, the group that did not receive betaine (in ovo or dietary) had the highest cloacal temperature (P<0.01). The concentration of high-density lipoproteins, triglycerides and cholesterol in the blood of chickens that received betaine-free diet was significantly higher than other groups (P<0.05). In general, dietary betaine feeding improved the performance and carcass parameters and decreased blood lipids and cloacal temperature of chicks under heat stress conditions. However, these effects were not observed from days 28 to 42, which were free of heat stress.

The main purpose of this study was to assess live yeast and hydrolyzed yeast effects on blood biochemical parameters, colostrum quality and performance of dairy cows during transition period. Fifteen pregnant Holstein dairy cows were randomly divided into three groups during three weeks pre- and post-parturition. Cows were assigned to treatments as: 1) control group fed basal diet, 2) cows fed basal diet plus 6.0 g/d/head live yeast and 3) cows fed basal diet plus 20 g/d/head hydrolyzed yeast as on top. Live yeast supplementation resulted in higher dry matter intake and milk production compared with hydrolyzed yeast and the control group. Cows received live yeast had the highest milk fat percentage and those in the control group had the lowest lactate dehydrogenase and alkaline phosphatase activities and those received hydrolyzed yeast had the highest IgG and lactoferrin in the colostrum. Cows received live yeast had the highest serum albumin and those in the control group had the lowest serum albumin. Cows received hydrolyzed yeast had the highest globulin among treatments. There was no difference among treatments for blood triglyceride, cholesterol, non-esterified fatty acids and beta-hydroxy butyric acid. Cows in the control group had the highest aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase activities in the serum. Live yeast and hydrolyzed yeast supplementation reduced aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase in the serum. Cows receive hydrolyzed yeast had higher IgG level in the serum. Dietary supplementation of live yeast could improve feed intake and milk yield post parturition, but hydrolyzed yeast enhance immunity components of colostrum. Pre-parturition, supplementation of 20 g/d/head hydrolyzed yeast in the diet of dairy cows recommended for enhancing immunity status of cow and her newborn and post-parturition, supplementation of 6.0 g/d/head live yeast recommended for better production performance.

This research was conducted to evaluate the nutritional value of different varieties of barley (Turkmen, Reyhan and Gorgan), triticale (Juvanilo, Rondo and Massa) and oat (Wild and Canadian) grains. The chemical composition of the samples was determined using the standard methods of AOAC. Gas production (GP) test was performed to estimate the in vitro fermentation parameters. In vitro digestibility was determined by the batch culture procedure. The carbohydrate fractions of the Cornell Net Carbohydrate and Protein System (CNCPS) were also measured. Crude protein (CP) content was more in triticale and barley than oat grains (P<0.01). Triticale grains had higher contents of neutral detergent fiber (NDF), acid detergent fiber (ADF), and lower lignin compared to barley and oat grains (P<0.01). The amounts of GP potential and fermentation parameters were higher in triticale and barley than oat grains (P<0.01). Partitioning factor (PF, P<0.01), microbial biomass (MB, P<0.05) and efficiency of microbial biomass (EMB P<0.01) were more in different varieties of triticale and barley than oat varieties. According to CNCPS, carbohydrate portions and total carbohydrate content in triticale and barley grains were higher than in oat grains (P<0.01). The highest and lowest contents of none- fiber carbohydrates (NFC), starch, and soluble sugars were observed in triticale and oat varieties, respectively. Totally, triticale and barley grains had a better nutritional value than oat grains. Triticale grains were as good as barley grains in most aspects, while being superior in some traits.

A feeding experiment was performed to determine the effect of limestone particle size on apparent (AIDC) and true (TIDC) ileal digestibility coefficients of calcium (Ca) in broilers and pullets. With this motivation, four dietary treatments were developed based on a 2×2 factorial arrangement, that included two limestone particle sizes (fine vs. coarse) and two bird types (broilers vs. pullets). Each treatment was replicated six times (eight birds/replicate). Two corn-based diets containing limestone with either fine (<0.5 mm) or coarse (1-2 mm) particles as the sole Ca source were developed and fed to broilers and pullets from 16 to 20 days of age. A Ca-unsupplemented diet was used to determine the ileal endogenous Ca losses. Titanium dioxide was incorporated in all diets as an indigestible marker. Digesta were collected on day 20 from all birds per pen. The AIDC of Ca was determined by marker and the TIDC values were determined by correcting for endogenous Ca losses. Endogenous Ca losses were obtained to be 420 and 696 mg/kg of dry matter intake for broilers and pullets, respectively. Broilers consumed more feed (P=0.001) and had higher body weight gain (P<0.05) than the pullets. Broilers had higher AIDC and TIDC of Ca than pullets (P<0.001). Coarse limestone particles increased the AIDC and TIDC of Ca regardless of bird type. Feeding coarse limestone increased the Ca concentration in the gizzard content of broilers but not in pullets, resulting in a significant (P<0.05) interaction between limestone particle size and bird type. Regardless of bird type, increasing limestone particle size enhanced AIDC and TIDC of Ca in limestone.