Association of the calpastatin genotypes, haplotypes, and SNPs with meat quality and fatty acid composition in two Iranian fat- and thin-tailed sheep breeds

Trajectory of livestock genomics in South Asia: A comprehensive review

Livestock plays a central role in sustaining human livelihood in South Asia. There are numerous and distinct livestock species in South Asian countries. Several of them have experienced genetic development in recent years due to the application of genomic technologies and effective breeding programs. This review discusses genomic studies on cattle, buffalo, sheep, goat, pig, horse, camel, yak, mithun, and poultry. The frontiers covered in this review are genetic diversity, admixture studies, selection signature research, QTL discovery, genome-wide association studies (GWAS), and genomic selection. The review concludes with recommendations for South Asian livestock systems to increasingly leverage genomic technologies, based on the lessons learned from the numerous case studies. This paper aims to present a comprehensive analysis of the dichotomy in the South Asian livestock sector and argues that a realistic approach to genomics in livestock can ensure long-term genetic advancements.

Transcriptome Analysis of the Liver and Muscle Tissues of Dorper and Small-Tailed Han Sheep

It is well known that Dorper (DP) is a full-bodied, fast-growing and high dressing percentage breed, while the production performance of Small-tailed Han sheep (STH) is not so excellent, in contrast to DP. Therefore, in this study, a comparative transcriptomic analysis of liver and muscle tissues from DP and STH breeds was carried out to find differentially expressed genes (DEGs) that affect their growth and meat quality traits. The results showed that the total number of DEGs was 2,188 in the two tissues. There were 950, 160 up-regulated and 1,007, 71 down-regulated genes in the liver and muscle, respectively. Several DEGs such as TGFB1, TGFB3, FABP3, LPL may be associated with growth and development in DP. Also, several GO terms were found to be associated with muscle growth and development, such as developmental growth (GO:0048589), and myofibril (GO:0030016). Further validation of eight genes (6 up-regulated, and 2 down-regulated) was performed using quantitative RT-PCR. These findings will provide valuable information for studying growth and development as well as meat quality traits in sheep.

The use of mutton in sausage production

The work analyzes the quality of sausage with mutton. The proportion of individual commodities was as follows 40% sheep thigh, 40% pork shoulder, and belly 20%. The protein content in pork shoulder was 20.11 g.100g-1 in sheep thigh 23.65 g.100g-1 and sausage 19.89 g.100g-1. Of the monitored amino acids, the highest content was in lysine, in the sausage was 1.9 g.100g-1 and of the raw materials in the belly 2.1 g.100g-1. We also found a higher proportion of leucine 1.7 g.100g-1 in both sausage and sheep thighs. The arginine content in the sausage was also high 1.39 g.100g-1. We found a high content of palmitic acid in the pork shoulder of 24.38 g.100g-1 FAME. The content of palmitic acid in sheep meat was 24.32 g.100g-1 FAME and in sausage 24.16 g.100g-1 FAME. The content of stearic acid in the pork shoulder was 10.89g.100g-1 FAME, in the sheep thigh 10.64g.100g-1 FAME, in the belly 11.07 g.100g-1 FAME, and the sausage 10.92 g.100g-1 FAME. The MDA content in sheep meat was 0.185 mg.kg-1, in pork shoulder 0.141 mg.kg-1, in pork belly 0.22 mg.kg-1 and in sausage on the day of production 0.45 mg.kg-1. On the 30th day, the MDA content was in the sausage 0.78 mg.kg-1. The high MDA content of the sausage was probably most influenced by the technological process, as all raw materials, because there was a lower MDA content.

Single Loci and Haplotypes in CAPN1 and CAST Genes are Associated with Growth, Biometrics, and in Vivo Carcass Traits in Santa Inês Sheep

µ-calpain (CAPN1) and calpastatin (CAST) genes play key roles in protein turnover. The present study aimed to identify the variants in these genes associated with growth and ultrasound carcass traits in Santa Inês sheep. A sample of 192 no full sibling Santa Inês lambs was used. Fragments of the CAST and CAPN1 genes were amplified and next-generation sequencing was performed in the MiSeq platform. Variants in the CAPN1 and CAST sequences were then detected using bioinformatic tools. Withers and croup heights, body length, thoracic and croup widths, thoracic and leg girths, body depth, carcass fat score, rib eye area, fat thickness, body weights were recorded at weaning and at 140 days post-weaning, and average daily gain post-weaning was calculated. Both single-locus and haplotype association analyses were performed with the model as follows: farm (2 levels), year (4 levels), the month of birth (12 levels), and the covariate age of the animal. The fragments amplified included 4,514 bp between the 20th and 23rd exons of CAST as well as 3,927 bp between the 12th and 21st exons of CAPN1. In these regions, 58 (CAST) and 45 (CAPN1) variants were identified. In the CAST gene, the single-locus analysis revealed 22 suggestive additive effects (P<0.05) on several growth and carcass traits. Moreover, haplotype substitutions were associated with rib eye area (–0.689±0.290), average daily gain (–23.6±10.4), thoracic girth (–2.72±1.27), body length (–3.38±1.49), and leg girth (–2.84±1.37). Regarding the CAPN1 gene, the single-locus analysis identified seven suggestive additive effects, while only one haplotype replacement effect on fat thickness (–0.0143±0.0053) was detected. The results of the present study suggest that variants in the CAPN1 and CAST genes are associated with growth and ultrasound carcass traits in Santa Inês sheep, which may be a source of information to improve knowledge regarding the genetic control of these traits.

Review on Genomic Regions and Candidate Genes Associated with Economically Important Production and Reproduction Traits in Sheep (Ovies aries)

Sheep (Ovis aries) is one of the most economically, culturally, and socially important domestic animals. They are reared primarily for meat, milk, wool, and fur production. Sheep were reared using natural selection for a long period of time to offer these traits. In fact, this production system has been slowing the productivity and production potential of the sheep. To improve production efficiency and productivity of this animal through genetic improvement technologies, understanding the genetic background of traits such as body growth, weight, carcass quality, fat percent, fertility, milk yield, wool quality, horn type, and coat color is essential. With the development and utilization of animal genotyping technologies and gene identification methods, many functional genes and genetic variants associated with economically important phenotypic traits have been identified and annotated. This is useful and presented an opportunity to increase the pace of animal genetic gain. Quantitative trait loci and genome wide association study have been playing an important role in identifying candidate genes and animal characterization. This review provides comprehensive information on the identified genomic regions and candidate genes associated with production and reproduction traits, and gene function in sheep.

Determination of optimum carcass weight for meat quality and fatty acid composition in fat-tailed male and female Chall lambs

The aim of this study was to determine the optimum carcass weight for meat quality and fatty acid composition in fat-tailed Chall lambs. Thirty lambs (15 male and 15 female) were allotted to three carcass weight groups: (1) light carcass weight (LCW 10-15 kg), (2) moderate carcass weight (MCW 15-20 kg), and (3) heavy carcass weight (HCW 20-25 kg). Back fat thickness and intramuscular fat (IMF) content were greater (P < 0.05) for HCW and female groups than their counterparts, respectively. Drip loss was lower (P < 0.05) for female and HCW lamb groups than male and LCW group, respectively. Female and LCW lambs had lower (P < 0.05) shear force compared with their corresponding male and HCW groups. Meat from LCW and MCW lambs had higher lightness (L* value; 43.6, 43.5 vs. 39.9), while redness (a* value; 13.6, 13.9 vs. 15.4) was greater for HCW and female (13.7 vs. 14.9) lambs compared with their counterparts (P < 0.05). The MCW lambs produced meat with higher overall acceptability compared with other two groups (P < 0.05). The HCW lambs contained lower polyunsaturated fatty acids (PUFA), polyunsaturated fatty acids to saturated fatty acids (P:S) ratio, and n-3 PUFA compared with LCW group (P < 0.05). Results show that as the animal grow faster and achieved HCW, the IMF content also increased mainly as storage triglyceride, while functional fats consisting long-chain omega-3 did not increase proportionately. In addition, the study also demonstrates that using IMF for predicting or assessing meat quality aspects such as juiciness and flavor or the nutritional value of meat relating to health claimable fatty acids would not be appropriate.