Structural equation models for slaughtering weight prediction for broilers.

The aim of this research was to determine the effect of gut health parameters on the flock's final weight of broilers and to calculate an accurate equation to estimate this weight with information available at 7, 14, and 21 days, in field conditions. Gut health parameters (gizzard erosion, coccidiosis, feed passage, and redness, gut tone, consistency of content, and presence of mucus for each part of the small intestine [duodenum, jejunum, and ileum], and color, consistency, and presence of gas for caeca content) were evaluated at 7 and 14 days. Other parameters evaluated for impact on flock final weight were body weight and mortality, both at 7, 14, and 21 days; stocking density; litter reuse; and downtime period. Structural equation model evaluation of the data showed that stocking density and litter reuse did not affect (P > 0.05) flock final weight, while downtime period, body weight (14 and 21 days), and mortality (14 and 21 days) directly affected (P ≤ 0.05) the flock final weight. Gut health parameters did not directly affect the flock's final weight; however, they affected body weight and mortality at 14 days, thus showing an indirect effect on the flock's final weight. It was also possible to determine two accurate equations to estimate the flock's final weight using information available at both 14 (R2 = 0.56) and 21 (R2 = 0.77) days.

Genes and SNPs Involved with Scrotal and Umbilical Hernia in Pigs.

Hernia is one of the most common defects in pigs. The most prevalent are the scrotal (SH), inguinal (IH) and umbilical (UH) hernias. We compared the inguinal ring transcriptome of normal and SH-affected pigs with the umbilical ring transcriptome of normal and UH-affected pigs to discover genes and pathways involved with the development of both types of hernia. A total of 13,307 transcripts was expressed in the inguinal and 13,302 in the umbilical ring tissues with 94.91% of them present in both tissues. From those, 35 genes were differentially expressed in both groups, participating in 108 biological processes. A total of 67 polymorphisms was identified in the inguinal ring and 76 in the umbilical ring tissue, of which 11 and 14 were novel, respectively. A single nucleotide polymorphism (SNP) with deleterious function was identified in the integrin α M (ITGAM) gene. The microtubule associated protein 1 light chain 3 γ (MAP1LC3C), vitrin (VIT), aggrecan (ACAN), alkaline ceramidase 2 (ACER2), potassium calcium-activated channel subfamily M α 1 (KCNMA1) and synaptopodin 2 (SYNPO2) genes are highlighted as candidates to trigger both types of hernia. We generated the first comparative study of the pig umbilical and inguinal ring transcriptomes, contributing to the understanding of the genetic mechanism involved with these two types of hernia in pigs and probably in other mammals.

Genome Association Study for Visual Scores in Nellore Cattle Measured at Weaning.

BACKGROUND: Genome-wide association studies (GWAS) are utilized in cattle to identify regions or genetic variants associated with phenotypes of interest, and thus, to identify design strategies that allow for the increase of the frequency of favorable alleles. Visual scores are important traits of cattle production in Brazil because they are utilized as selection criteria, helping to choose more harmonious animals. Despite its importance, there are still no studies on the genome association for these traits. This study aimed to identify genome regions associated with the traits of conformation, precocity and muscling, based on a visual score measured at weaning. RESULTS: Bayesian approaches with BayesC and Bayesian LASSO were utilized with 2873 phenotypes of Nellore cattle for a GWAS. The animals were genotyped with Illumina BovineHD BeadChip, and a total of 309,865 SNPs were utilized after quality control. In the analyses, phenotype and deregressed breeding values were utilized as dependent variables; a threshold model was utilized for the former and a linear model for the latter. The association criterion was the percentage of genetic variance explained by SNPs found in 1 Mb-long windows. The Bayesian approach BayesC was better adjusted to the data because it could explain a larger phenotypic variance for both dependent variables. CONCLUSIONS: There were no large effects for the visual scores, indicating that they have a polygenic nature; however, regions in chromosomes 1, 3, 5, 7, 14, 15, 16, 19, 20 and 23 were identified and explained a large part of the genetic variance.