The goals of the current work were to analyse the population structure of 11 Spanish ovine breeds and to detect genomic regions that may have been targeted by selection. A total of 141 individuals were genotyped with the Infinium 50 K Ovine SNP BeadChip (Illumina). We combined this dataset with Spanish ovine data previously reported by the International Sheep Genomics Consortium (N = 229). Multidimensional scaling and Admixture analyses revealed that Canaria de Pelo and, to a lesser extent, Roja Mallorquina, Latxa and Churra are clearly differentiated populations, while the remaining seven breeds (Ojalada, Castellana, Gallega, Xisqueta, Ripollesa, Rasa Aragonesa and Segureña) share a similar genetic background. Performance of a genome scan with BayeScan and hapFLK allowed us identifying three genomic regions that are consistently detected with both methods i.e. Oar3 (150–154 Mb), Oar6 (4–49 Mb) and Oar13 (68–74 Mb). Neighbor-joining trees based on polymorphisms mapping to these three selective sweeps did not show a clustering of breeds according to their predominant productive specialization (except the local tree based on Oar13 SNPs). Such cryptic signatures of selection have been also found in the bovine genome, posing a considerable challenge to understand the biological consequences of artificial selection.
In this research the meat quality of the two canary sheep local breeds, Canaria breed (CB) and Canaria Hair breed (CHB), was evaluated, making groups of 10 males and females from each, slaughtered at live weights of 9.78 ± 0.49 kg, 15.8 ± 0.66 kg and 24.9 ± 0.76 kg. The breed affected to meat and fat colour at 24 h after slaughter. Meat of CB showed more redness and more chroma values. Fat of CB showed greater lightness. Related to the physio-chemical analysis of the meat, CB showed higher water-holding capacity, shear force and intramuscular fat content that CHB; however, CHB showed higher protein and ash percentages that CB. In relation to fat quality, CB presented higher MUFA percentage and CHB had higher PUFA percentage. CHB showed the lower atherogenic and thrombogenic indexes. Slaughter weight affected the pH, meat and fat colour and also all physio-chemical parameters, except shear force and collagen content and the fatty acid profile. Males had higher moisture content, soluble collagen and PUFA, while females had higher MUFA. The breed effect on meat quality was shown mainly in lambs slaughtered at 10 kg. Owing to their fatty acid profile, the healthiest meat was from lambs slaughtered at 25 kg.
ARTICLE HISTORY
Semi-arid conditions can adversely affect livestock productivity and change certain physiological parameters. The relationship between hair coat and thyroxine levels in Morada Nova ewes was evaluated through environmental factors, such as air temperature, relative air humidity, radiant and Black Globe Humidity Index to gain a better understanding of thermoregulation mechanisms in these animals. Measurements were taken from July to January in 383 Morada Nova ewes. The variables studied included rectal temperature (RT), respiratory rate (RR), coat thickness (CT), hair length (HL), hair diameter (HD), hair density (D) and thyroid hormones. The data underwent multivariate statistical analyses and a significant inverse relationship was found between coat traits and Thyroxine (T 4 ). The animals that exhibited greater HL, coat density and CT showed lower T 4 concentrations. Coat traits showed a strong interaction with physiological mechanisms and can be considered relevant in maintaining homeostasis. Hair traits play an important role in this process, since T 4 reduction was stronger in animals that showed difficulties in eliminating heat, which were the ones that had greater HL, hair density and HD. By contrast, animals with a hair coat more favourable to heat losses had higher levels of thyroid hormones.
ARTICLE HISTORY
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