The implications of various gene variant combinations on breeding values for Awassi ewe milk production

Background and Aim: Milk production is an important factor to consider in selecting Awassi sheep. This trait is influenced by various genes that can be managed to boost production. The breeding values (BVs) for milk production in Jordan’s Awassi sheep flocks have been established. This study determined how combined gene variants of BLG, PRL, CSN3, CSN1S1, and CSN2 affect the estimated BVs (EBVs) for milk production in Awassi sheep. Materials and Methods: Milk and blood samples were collected from 391 Awassi sheep, which was then subjected to molecular analysis through sequencing in order to identify potential alleles and genotypes that could be linked to the EBVs of milk. Results: The predicted BVs for milk were significantly influenced by PRL and CSN3 gene variants. Through performing the act of epistasis, the i nteractions of BLG with CSN3 and –CSN1S1 greatly impacted EBVs for milk production. Likewise, the three-way interaction among PRL, CSN3, and CSN1S1, as well as the combined effect of CSN3 with CSN1S1 and CNS1 significantly improved BVs for milk production. When the breeding selection program incorporates the polymorphisms of these genes, gains in milk production can be obtained. Conclusion: Alleles within the examined genomic areas are crucial for evaluating BVs and maximizing genetic gain in milk production

Association between the prolificacy of Romanov sheep breed and fecundity gene, growth differentiation factor 9 gene and prolactin gene genotypes

Prolificacy data of Romanov sheep breed were retrieved from Sekhra Station (Jordan) through five parities. The data were used for studying the effect of Fecundity (FecB), Growth Differentiation Factor 9 (GDF9) and Prolactin genes on the prolificacy of Romanov ewes. GDF9, FecB and Prolactin genes genotypes were investigated in Romanov ewes by using the PCRRFLP technique. The Mixed Model of SAS software was used for analyzing the data. The different gene genotypes and the parity were inserted in the Model as fixed effects while the dams were inserted as Random. Fecundity gene was observed to be monomorphic, the wild type genotype of Fecundity gene was found in the Romanov ewes. Prolactin and GDF9 genes were observed to be polymorphic in Romanov. The results revealed non-significant differences in the prolificacy of the ewes that carry AA and BB of Prolactin gene genotypes. The GDF9 gene genotypes showed significant (P<0.0001) differences in prolificacy. The homozygous MM genotype ewes produced 0.792 more lambs born per lambing than the heterozygous NM genotype. Selection based on GDF9 mutation may help in improving the prolificacy of Romanov sheep

Female reproductive tract anatomy of the endangered Arabian oryx (Oryx leucoryx) in Jordan

Female reproductive anatomy of the Arabian oryx is unknown. In this study, reproductive tracts of seven female Arabian oryx (aged 2 to 7 years) were examined to characterize their reproductive anatomy. Observations and measurements were obtained in situ from dead animals during necropsy. Animals were allocated into two groups: cycling (n=3; follicles or corpora lutea present) and not-cycling (n=4; follicles or corpora lutea absent). Different reproductive tract segments for each animal in both groups were measured using a digital caliper. The mean, SD and range for each reproductive tract segment were generated and compared between groups. Female oryx reproductive anatomy share some anatomical characteristics with that of domestic ruminants except that the oryx uterus has no distinct uterine body and the cervix has two internal openings for each respective uterine horn. In addition, there were more than 8 rows of caruncles within each uterine horn. There were significant differences in the length and width (P&lt;0.05), but not in height, of both the right and left ovaries between cycling and not-cycling animals (P&gt;0.05). Posterior and anterior vaginal lengths varied between cycling and not-cycling groups (P&lt;0.05). Length of right and left oviducts, left and right uterine horns, cervix and vulva did not vary between cycling and not-cycling groups (P&gt;0.05). Defining this unique morphology of female Arabian oryx reproductive anatomy will help in the development of appropriate reproductive techniques in order to propagate this endangered species and control its reproduction

The effects of Saccharomyces cerevisiae supplementation on intake, nutrient digestibility, and rumen fluid pH in Awassi female lambs

Aim: The aim of this study was to evaluate the effect of feeding low (LO)- or high (HI)-fiber diets supplemented with Saccharomyces cerevisiae (SC) on nutrient intake, digestibility, nitrogen balance, rumen fluid pH, and serum concentrations of glucose and urea nitrogen in Awassi female lambs in a 2×2 factorial arrangement of treatments. Materials and Methods: Experimental diets were as follows: (1) LO-fiber diet with no SC supplementation (-LO), (2) LO-fiber diet supplemented with SC (+LO), (3) HI-fiber diet with no SC supplementation (-HI), or (4) HI-fiber diet supplemented with SC (+HI). Eight female lambs were used in a replicated 4×4 Latin square design with 15-day experimental periods (10-day adaptation period and 5-day collection period). Results: A fiber×SC interaction (p≤0.05) was detected for dry matter (DM) and crude protein (CP) intake among diets showing greater DM and CP intake for +LO diet compared to +HI group supplemented with SC, whereas -LO and -HI were intermediate. A fiber×SC interaction (p=0.05) was also detected for the neutral detergent fiber (NDF) intake among diets. Intake of NDF was greater for the -HI diet compared with +LO and -LO diets. Similarly, NDF intake was greater for +HI diet than -LO diet. A tendency (p=0.07) for a fiber×SC interaction was detected for acid detergent fiber (ADF) intake among diets as well. ADF intake tended to be greater for HI-fiber diets. No difference was observed in the rumen fluid pH for lambs fed with the different diets. No fiber×SC interactions were detected for the digestibility of DM, CP, NDF, and ADF among dietary treatments. Digestibility of DM was greater (72.9 g/100 g vs. 67.1 g/100 g; p=0.0002) for LO versus HI fiber. However, NDF and ADF digestibilities were greater (60.8 and 61.9 g/100 g vs. 55.8 and 52.7 g/100 g for NDF and ADF digestibility, respectively; p≤0.01) for the HI-fiber than the LO-fiber diets. Conclusion: Results obtained in the current study indicate that SC supplementation has a minimal effect on the performance of Awassi female lambs fed with varying fiber levels

Growth Performance and Meat Characteristics of the First Awassi–Rambouillet Callipyge Backcross

The Awassi breed is desirable due to its resilient traits, but shows poor lean meat content on the carcass; the callipyge mutation may enhance growth and meat characteristics. The first backcross of callipyge Awassi&ndash;Rambouillet (CRAW) lambs was generated by mating Awassi ewes with heterozygous F1 (50 % Awassi and 50 % Rambouillet) rams for the callipyge mutation. A fattening trial with carriers of CLPG (CRAW), non-carriers (RAW), and Awassi (AW) ram lambs was conducted for 94 days and growth and meat characteristic parameters were recorded. Final body weight, average daily gain (ADG), feed conversion ratio, and dry matter intake, but not initial body weight, were greater in CRAW and RAW lambs as compared to AW lambs; hot and cold carcass, dressing percentage, and shoulder, rack, and loin weights were greater in CRAW vs. AW but not RAW lambs. Leg cuts were heavier in CRAW vs. both RAW and AW lambs; intermuscular and subcutaneous fat percentages were greater in CRAW as compared to AW but not RAW lambs. Non-carcass components showed kidney fat, kidney, liver and testes weights higher in CRAW lambs as compared to AW lambs, but these parameters were similar to those of RAW lambs. There were no differences in fat tail weight. Further, CRAW lambs had higher shear force and water holding capacity than RAW and AW lambs, while cooking loss was the lowest in CRAW lambs. In conclusion, the callipyge mutation with 25% Rambouillet genes can provide efficient improvements in growth and meat characteristics, with the exception of tenderness in Awassi sheep

Effect and Interaction of β-Lactoglobulin, Kappa Casein, and Prolactin Genes on Milk Production and Composition of Awassi Sheep

A participatory animal-breeding program was applied to 9 commercial Awassi sheep flocks in Jordan. This study aimed to assess the influence of Beta-lactoglobulin (&beta;-LG), Prolactin (PRL), and Kappa casein (CSN3) genes, genotypes and their interaction on milk production and composition traits of 167 genotyped Awassi ewes via Polymerase Chain Reaction (PCR) followed by sequencing. Allele frequencies for the two variants were 0.42 and 0.58 for &beta;-LG, 0.82 and 0.18 for PRL, and 0.92 and 0.08 for CSN3. No association was found among &beta;-LG and CSN3 polymorphic genotypes with milk production traits. However, ewes with PRL AA genotype showed higher milk production, &beta;-LG AB was associated with lowest fat%, high solid not fat (SNF)%, protein%, and lactose%. &beta;-LG BB was associated with highest milk density. PRL, &beta;-LG, and CSN3 polymorphic genotypes were differentially associated with milk production and component traits. Furthermore, &beta;-LG &times; PRL interaction showed the highest milk production and fat%; &beta;-LG &times; PRL recorded the highest SNF%, protein%, lactose%, and milk density, while the PRL &times; CSN3 had the highest fat% and SNF%. The enhancing effects of these gene interactions can be incorporated in Awassi breeding programs to improve milk production and composition

Polymorphism of prolactin, growth differentiation factor 9, and calpastatin genes and their effects on weight traits in Awassi lambs

Objectives: This study was conducted to determine the correlation among prolactin gene (PRG), growth differentiation factor 9 (GDF-9), and calpastatin (CAG) genes polymorphism with growth traits in Awassi lambs. Materials and Methods: Records of 779 Awassi lambsfrom 264 dams and 15 sires were used. The sex, type of birth (single versus twins), weight at birth, average daily gain (ADG), and the adjusted weight at 60 days of age were determined for each animal. Blood samples were collected from all lambs to determine PRG, GDF-9, and CAG polymorphism using polymerase chain reaction-Restriction fragment length polymorphism. Results: Three PRG genotypes (AA, AB, and BB) were determined with a frequency of 0.88, 0.05, and 0.07, respectively. The frequency of each allele was 0.84 and 0.16 for A and B alleles, respectively. For GDF-9, there were only two genotypes detected (AB and BB) with a frequency of 0.96 and 0.04, respectively. The frequency of each allele was 0.92 and 0.08 for A and B alleles, respectively. For CAG, two genotypes were also detected (AB and BB) with a frequency of 0.92 and 0.08, respectively. The frequency of each allele was 0.96 and 0.04 for A and B alleles, respectively. A significant (p &#8804; 0.04) effect of PRG genotype on birth weight was detected but this effect was not significant on ADG and weight at weaning. There were no associations between any of the pre-weaning growth traits and GDF-9 and CAG variants. Conclusion: The results of this study show that PRG could be used to select dams with a high frequency of dystocia to reduce birth weight of newborn lambs and therefore conserve the dams reproductive functions and improve lamb survivability. [J Adv Vet Anim Res 2019; 6(1.000): 86-91

Duplication in ECR near HMX1 and a SNP in GATA6 Genes Regulate Microtia in Awassi Sheep

Microtia and anotia are hereditary traits characterized by an underdevelopment or complete absence of the outer ear. These congenital malformations observed in many species can exist as part of various syndromes or as an isolated trait as seen in the fat-tailed Awassi sheep breed. Our study aims to identify the genetic mutations causing microtia in Awassi sheep by DNA sequencing. DNA was extracted from blood samples randomly collected from 84 Awassi sheep (16 earless, 41 short ear and 27 normal ear) across different farms. GATA6 exons 1, 2, 4, 6 and 7, CLRN1 intron 3, DCC intron 2, ECR near HMX1 and the intergenic region between GATA6 and MIB1 genes were screened, amplified and sequenced. Allele and genotype frequencies were calculated by direct counting. Association was performed using chi-squared test for goodness-of-fit. Results showed mutations in only two genes significantly associated with microtia in Awassi: duplication in part of ECR near HMX1 (6:114293121-6:114293196) and a SNP at GATA6 exon 7 (23:34498242). Association results revealed that the ECR locus accounts for the microtia phenotype, while GATA6 exon 7 acts as a modifier gene. Genetic screening for these loci can be used to improve selection against microtia in Awassi sheep

Relationships between Hha1 Calpastatin Gene Polymorphism, Growth Performance, and Meat Characteristics of Awassi Sheep

Advances in molecular genetics have allowed the identification of genes that can enhance livestock production. The aim of this study was to investigate possible relationships between the calpastatin (CAST) Hha1 gene polymorphisms and growth performance, carcass characteristics, and meat quality in Awassi sheep. A total of 87 blood samples were collected from two-week-old Awassi ram lambs. The amplification of the CAST Hha1 gene yielded a fragment of 622 bp. Three CAST genotypes were found in Awassi sheep: MM for two fragments (385 bp and 281 bp), MN for three fragments (622 bp, 385 bp, and 281 bp), and NN for only one fragment (622 bp). The M and N allele frequencies of the CAST Hha1 genotypes were 0.765 and 0.235, respectively, while the genotypic frequencies of MM, MN, and NN were 0.586, 0.356, and 0.057, respectively. Based on CAST Hha1 gene polymorphisms, three groups of lambs (MM: n = 8; MN: n = 6; and NN: n = 3 genotypes) were subjected to a fattening period of 70 days to investigate growth performance and meat characteristics. Only the final body weight and longissimus muscle width were significantly different between the three genotypes, while no significant differences were detected in any other carcass characteristics and meat quality parameters. In this study, new variants were observed in CAST using the Hha1 restriction site, potentially assisting in Awassi sheep breeding and selection programs to improve final body weight and longissimus muscle width

Growth performance and meat characteristics of the first filial Awassi Rambouillet callipyge ram lambs

Aim: This study was designed to introduce the callipyge (CLPG) and 50% of Rambouillet sheep genes to improve meat quality and quantity of Awassi (AW) sheep. Materials and Methods: The CLPG mutation was introduced into the AW sheep through frozen semen of homozygous Rambouillet rams for the CLPG mutation. Four ram lambs from the first-generation Rambouillet callipyge Awassi (F1-RCA) and five from pure AW were recruited for a fattening trial conducted in individual pens using standard ration, following which ram lambs were slaughtered for carcass and meat evaluation. Results: Final body weight, dry matter intake, average daily gain, and feed conversion ratio were significantly higher in F1-RCA than AW. Hot and cold carcass weights and the other carcass cuts' weights, except for the fat tail, were heavier in F1-RCA than AW. There was no difference in dressing percentage between the two genetic groups (p>0.05). All non-carcass components' weights, except spleen, kidney, and testis, were higher in F1-RCA. Total lean, total bone, and intermuscular fat weight were greater in F1-RCA, but bone-to-lean ratio was lower in F1-RCA when compared with AW (p0.05) were observed in all meat quality parameters for muscle longissimus with the exception of pH, redness color, and tenderness that were lower (p<0.05) in F1-RCA than AW. F1-RCA lambs had larger longissimus muscle area (30.9 vs. 16.9 cm2) and less leg fat depth (11.1 vs. 17.4 mm). Conclusion: The implications of this research show the potential of 50% of Rambouillet genes and the CLPG mutation to improve growth and meat characteristics in AW-Rambouillet crosses and can be used further to develop a meat-type AW with improved productivity and muscle mass