PSVIII-10 Genome-wide CNV analysis unravels a deletion associated with parasite resistance in Florida native sheep

Florida Native sheep is an indigenous breed from Florida and expresses superior parasite resistance. Previous candidate and genome wide association studies with Florida Native sheep have identified single nucleotide polymorphisms with additive and non-additive effects associated with parasite resistance. However, the role of other potential DNA variants, such as copy number variants (CNVs), controlling this complex trait have not been evaluated. The objective of the present study was to investigate the importance of CNVs on resistance to natural Haemonchus contortus infections in Florida Native sheep. A total of 200 sheep were evaluated in the present study. Phenotypic records included fecal egg count (FEC, eggs/gram), FAMACHA score, and packed cell volume (PCV, %). Sheep were genotyped using the GGP Ovine 50K SNP chip. The copy number analysis was used to identify CNVs using the univariate method. A total of 170 animals with CNVs and phenotypic data were used for the association testing. Association tests were carried out using single linear regression and Principal Component Analysis (PCA) correction to identify CNVs associated with FEC, FAMACHA, and PCV. To confirm our results, a second association testing using the correlation-trend test with PCA correction was performed. Significant CNVs were detected when their adjusted p-value was < 0.05 after FDR correction. A deletion CNV in chromosome 21 was associated with FEC. This DNA variant was located in intron 2 of RAB3IL gene and overlapped a QTL associated with changes in eosinophil number. Our study demonstrated for the first time that CNVs could be potentially involved with parasite resistance in this heritage sheep breed.

PSVIII-8 Genetic parameters for parasite resistance in an endangered and heritage sheep breed from Florida

The Florida Native Sheep is one of the oldest sheep breeds in the United States. This heritage breed from Florida, naturally adapted to humid and hot climate conditions, is one of the most parasite resistant breeds from the Southern US. However, only approximately 1,000 individuals remain alive in the world. Therefore, conservation efforts and breeding programs are critical for survival of this breed. The objective of this research was to estimate genetic parameters for parasite resistance and body condition score in Florida Native sheep. The pedigree file contained 695 animals born between 2018 and 2020 and included 279 individuals with genotypes (38,429 SNP after quality control). The dataset contained 365 animals with phenotypic records at 38 days post-infection (natural Haemonchus contortus infection) for fecal egg count (FEC), blood packed count volume (PCV), FAMACHA score (FAM), and body condition score (BCS). Genetic parameters were estimated using a multi-trait model with a Bayesian implementation in the GIBBS3F90 program. Heritabilities were 0.38 0.07, 0.47 0.05, 0.27 0.04, and 0.52 0.07 for FEC, PCV, FAM, and BCS. Genetic correlations among parasite resistance traits were high and favorable: -0.82 0.06 (FEC-PCV), 0.83 0.07 (FEC-FAM), and -0.94 0.03 (PCV-FAM). Genetic correlations among parasite resistance traits and BCS were -0.42 0.11 (FEC-BCS), 0.75 0.09 (PCV-BCS), and -0.82 0.05 (FAM-BCS). Genetic progress for parasite resistance is possible in Florida Native sheep. The FAMACHA score is a phenotypic parameter easy to record in sheep; therefore, genetic selection for this trait can be effective to improve the remaining traits.

334 Effect of Dietary Supplementation of Peanut Skins with and Without Polyphenols on the Performance, Rumen Fermentation and Carcass Characteristics of Florida-native Sheep

The objective of this study was to evaluate the effects of dietary supplementation of peanut skins (PS) with and without polyphenols on the performance, rumen fermentation, and carcass characteristics of Florida-Native Sheep. Thirty-three intact lambs were randomly blocked by body weight (BW) (33.5 ± 0.1 kg; 11 lambs per treatment) and distributed in three isonitrogenous (17.1%) and isocaloric (2.5 Mcal/kg) diets: 1) Control diet, 2) Diet + 20% of intact peanut skins (IPS) and, 3) Diet + 20% of treated PS without polyphenols (TPS) for 42 d + 7 days of adaptation. Then, lambs were slaughtered to evaluate carcass characteristics and rumen fermentation. Dry matter intake (DMI), BW, and blood samples were collected and analyzed using the effects of treatment, week, interactions, and the random effect of animals. Dietary IPS and TPS did not (P > 0.05) affect DMI (1.14, 1.15 vs 1.04 kg/d) and final BW (35.9, 35.8 vs 36.8 kg) compared to the control. Dietary TPS reduced (P < 0.01) blood glucose levels compared to IPS and control (67.9 vs 74.6, 75.7 mg/dL) but IPS had lower (P = 0.03) blood urea nitrogen than TPS and control (5.79 vs 6.0, 6.32 mmol/L). Both IPS and TPS decreased (P < 0.01) total volatile fatty acid concentration (37.9, 14.2 vs 45.8 mmol/L) and increased rumen pH (7.1, 6.9 vs 6.7) compared to the control. Carcass weight was similar between treatments, TPS reduced (P = 0.01) dressing percentage compared to IPS and control (42.6 vs 45.2, 46.6%), both IPS and TPS reduced liver weight compared to control (230, 223 vs 302 g). Conversely, IPS and TPS increased (P < 0.01) alpha-tocopherol concentration (3.73, 4.0 vs 1.24 mg/g) in lean meat compared to control. This study showed that IPS increased the incorporation of antioxidants in meat without affecting animal performance.

SNPs in Sheep: Characterization of Lithuanian Sheep Populations

In Lithuania, there are two recognised native sheep breeds: old native Lithuanian Coarsewooled and Lithuanian Blackface. In addition, in 2005, primitive Heidschnucke-type Skudde sheep were imported to Lithuania and were argued to possibly represent a lost Lithuanian sheep type. The aim of the study was to investigate the genetic variation in the two Lithuanian native sheep breeds, compare them with the imported Skudde sheep and establish the historical patterns of admixture and the genetic relatedness of Lithuanian sheep to British, Central European and Nordic sheep breeds included in the SheepHapMap study. In total, 72 individuals, representing two Lithuanian native and imported Skudde sheep breeds, were genotyped using a Neogen 12K Illumina Infinium chip. The population analysis was carried out by model-based clustering, principal component analysis and neighbour net analysis, and showed similar patterns for the Lithuanian sheep populations. Lithuanian Coarsewooled and Skudde in Lithuania have unique divergence and possibly some shared ancestry, while the Lithuanian Blackface conforms to a modern synthetic breed. The study clearly showed that the Coarsewooled and the Skudde breeds are distinct from each other. Historical data strongly suggest that the Coarsewooled breed represents a local breed, while the Skudde origin is less directly linked to the geographical area of modern-day Lithuania. Within the modern-day Lithuanian context, the Lithuanian Coarsewooled sheep is very important historical sheep type for conservation.

THE COMBINED EFFECT OF SUCKLING SYSTEM AND WEANING WEIGHT ON MILK TRAITS OF NATIVE SHEEP

Data of the current stud, were collected on 32 Iraqi native sheep aged 2-5 years maintained on commercial flock. At lambing, the 32 ewes were divided into two equal groups, lambs in the 1st group were left with their dams till weaning and then were milked twice daily till they dry off (Continuous), whereas the 2nd group, lambs were separated at night for 12 hr. and the ewes were milked once daily at morning (Restricted). Then each main group was subdivided into two group to be weaned their lambs when they reached 3 or 4 times of their birth weight (WB1 and WB2). Results revealed that ewes of restricted suckling produced significantly (P < 0.05) more post weaning (80.80 vs.49.44 L), total milk yield (135.01 vs. 109.94 L) and sealable milk (99.86 vs. 49.44 L) and had significantly longer lactation period (169.3 vs. 140.2 days) compared ewes in continuous suckling. Also, results obtained indicate that daily gain in weight averaged 0.23 kg from birth to weaning and from birth to marketing and 0.24 kg from weaning to marketing and neither suckling system nor weaning weight affected these trait significantly. It can be concluded that restricted suckling resulted in an increase in sealable milk without any adverse effect on growth of lambs.

Sheep genetic resources in Bulgaria with focus on breeds with coloured wool

This review describes sheep genetic resources in Bulgaria with coloured wool and evaluates the country’s potential for coloured wool production. In 2018, Bulgaria counted 125,422 animals belonging to 18 native sheep breeds, six of which are in danger of extinction. Native sheep breeds in Bulgaria can be divided into three groups depending on the fleece colour of the animals: i) sheep breeds with fully pigmented fleece in all animals; ii) sheep breeds with animals with fully pigmented fleece or fully white fleece; iii) sheep breeds with spotted coloured fleece. Colouration in populations of the native Bulgarian sheep breeds can be explained by the phenotypic expression of several alleles of coat colour genes: ExtensionD, Agoutia and Pigmented headT , while white colour is due to the presence of the dominant Agoutiwt allele.Based on the relative share of the animals with coloured wool, the country’s potential for annual coloured wool production from native breeds was estimated at a minimum of 133,791 kg of unwashed wool. Recent tendencies in lifestyle changes of the Bulgarian people are gradually leading to increased interest in naturally coloured wool products, which may benefit the conservation of endangered native breeds by promoting relevant breeding programmes.