Temperament can be defined as the emotional variability among animals of the same species in response to the same stimulus, grouping animals by their reactivity as nervous, intermediate, or calm. Our goal was to identify genomic regions with the temperament phenotype measured by the Isolation Box Test (IBT) by single-step genome-wide association studies (ssGWAS). The database consisted of 4317 animals with temperament records, and 1697 genotyped animals with 38,268 effective Single Nucleotide Polymorphism (SNP) after quality control. We identified three genomic regions that explained the greatest percentage of the genetic variance, resulting in 25 SNP associated with candidate genes on chromosomes 6, 10, and 21. A total of nine candidate genes are reported for the temperament trait, which is: PYGM, SYVN1, CAPN1, FADS1, SYT7, GRID2, GPRIN3, EEF1A1 and FRY, linked to the energetic activity of the organism, synaptic transmission, meat tenderness, and calcium associated activities. This is the first study to identify these genetic variants associated with temperament in sheep, which could be used as molecular markers in future behavioral research.

Sorghum dried distillers’ grain with soluble (S-DDGS) has not been utilized as supplement in lamb growing and finishing diets under grazing conditions in summer. The hypothesis was that the performance of post-weaning lambs grazing Paspalum notatum (PN) INIA Sepé supplemented with an energy-protein diet (whole sorghum grain [SG], and soybean meal [SM]) is not reduced by the inclusion of 40% S-DDGS. During 82 days, in summer, 42 Merino Dohne male lambs (130 ± 7.6 days of age, 32 ± 2.4 kg of body weight [BW], and 2.2 ± 0.2 body condition score [BCS]) were evaluated, in a completely random experimental design with three treatments and two replicates each (n = 14 each one). All lambs grazed PN INIA Sepé and in two treatments they were daily supplemented (1.7% BW) with different components. The treatments were: PN (control group, no supplementation), SGSM (70% SG, 30% SM) and DDGS (45% SG, 40% S-DDGS, and 15% SM). Supplemented lambs had higher (P<0.0001) body weight gain (BWG), final BW and wool growth (140 and 126 g/a/d, 43.5 and 42.4 kg; 1814 and 1892 µg/cm2/d for DDGS and SGSM, respectively) than control lambs (40 g/a/d; 35.5 kg; 1353 µg/cm2/d) (P<0.0001), without differences between supplemented groups. Gastrointestinal nematodes infestation (GIN) was affected by the treatments on day 69, where supplemented animals showed lower infestation levels than control lambs (P=0.0024). The inclusion of S-DDGS in the supplement did not reduce the productive performance of the lambs when the concentration of crude protein and energy remained constant.

Temperament can be defined as the emotional variability among animals of the same species in response to the same stimulus, thus being able to group animals by reactivity as nervous, intermediate or calm. The main objective for this study was to identify genomic regions with the temperament phenotype measured by the Isolation Box Test (IBT) by single-step genome wide association studies (ssGWAS). The database used consisted of 4,317 animals with temperament records, and 1,697 genotyped animals with 38,268 effective SNP after quality control. We identified three genomic regions that explained the greatest percentage of the genetic variance, resulting in 25 SNP associated with candidate genes on chromosomes 6, 10 and 21. A total of nine candidate genes are reported for the temperament trait, which are: PYGM , SYVN1 , CAPN1 , FADS1 , SYT7 , GRID2 , GPRIN3 , EEF1A1 and FRY , linked to energetic activity of the organism, synaptic transmission, meat tenderness and calcium associated activities. This is the first study to identify these genetic variants associated with temperament in sheep, leading the opportinuty to potential applications of these molecular markers in future behavioral research.