It was analyzed the existence of genotype × environment interaction for weaning weight in populations of Angus from Brazil and Uruguay by using records of 73,205 animals (10,257 from Uruguay and 62,948 from Brazil) belonging to 33 and 161 farms and 13 and 34 regions in Uruguay and Brazil, respectively. It was used the one- and two-trait animal model analyses considering weight at weaning of each country as different characters. Coefficients of direct and maternal additive-genetic correlation estimated by two […]

Records of test-day milk yields of the first three lactations of 25,500 Holstein cows were used to estimate genetic parameters for milk yield by using two alternatives of definition of fixed regression of the random regression models (RRM). Legendre polynomials of fourth and fifth orders were used to model regression of fixed curve (defined based on averages of the populations or multiple sub-populations formed by grouping animals which calved at the same age and in the same season of the […]

The objective of this study was to evaluate the effects of culture time and sex of nuclei donor cells on embryo and fetal development after nuclear transfer. Thus, bovine oocytes were matured, enucleated and reconstructed with somatic cells from an adult animal. After fusion and chemical activation, the reconstituted zygotes were cultured in Charles Rosenkranz 2 (CR2) on a granular monolayer cell at 38.8ºC in a humidified atmosphere 5% CO2 in air for seven days, and transferred to synchronized receptors. […]

The objective of this study was to map quantitative trait loci (QTL) in chromosomes 9, 10 and 11 of swines (Sus scrofa) and to associate their effects on traits of carcass, carcass cuts, organs and guts, performance and meat quality. Samples of DNA of animals from a F2 population originated from crosses between Piau breed males and Landrace õ Large White õ Pietrain females were used. A total of 13 microsatellite loci were used to build link maps of the […]

It was evaluated in this work the effect of calving sub-season on the pregnancy rate of 7,726 multiparous Hereford beef cows grazing on natural pastures in southern Brazil, from 1994 to 2007. Calving sub-season periods were divided in 20-day intervals from August 12th to 31st; from September 1st to 20th; from September 21st to October 10th; from October 11th to 31st; from November 1st to 20th. Calving in each sub-season and pregnancy rate (PR) were analyzed by the Chi-square test. […]

Records of Large White breed animals were used to estimate variance components, genetic parameters and trends for the character total number of born piglets (TNBP) as measure of litter size. For obtaining variance components and genetic parameters, it was used the Restricted Maximum Likelihood Method using MTDFREML software. Two mixed models (additive and repeatability) were evaluated. The additive model contained fixed effect of the contemporary group and the following random effects: direct additive genetic and residual effect for the first […]

Lactation curves were fitted from 1,340 lactations of F1 Holstein-Gyr, Holstein-Guzerat, Holstein-Nellore and Holstein-Undefined Zebu crossbred cows from two farms with milk controls carried out every 14 days. Nutritional management was based on pastures in the summer, and corn silage and sugar cane with urea during winter and concentrated rations in the milking, according to the production. Incomplet Gamma function was used for estimating parameters of curves, production during lactation peak and of the time from the beginning of lactation […]

Additive genetic, dominance and recombination effects in breedings among Santa Inês (SI), Brazilian Somali (So), Dorper (Do) and Poll Dorset (Po) breeds were estimated for growth, reproductive and maternal hability traits. Data were obtained from Gaasa e Alimentos LTDA, a company that participates on the Programa de Melhoramento Genético de Caprinos e Ovinos (GENECOC) coordinated by Embrapa Caprinos. Initially, 3,573 records were analyzed using the MIXED procedure of the statistical package SAS (1999). The analyses were carried out considering the […]

The aim of this study was to evaluate the effects of short term non-protein nitrogen feeding at different periods of the oestrus cycle in superovulated cows, without previous adaptation, on yield, quality and development degree of recovered embryos. A total of sixty-eight Nelore cows were distributed in three groups: the control group (C) and two groups with urea supply before (UB; urea supply from day -5 to day 0) and after (UA; supply from day 0 to day 5) artificial […]

The aim of this study was to establish the morphologic and endocrine characteristics of luteal dynamics in goats. It was used Toggenburg female goats that showed natural estrus in a 48-hour interval. After estrus, ultrasonographic evaluations of the ovaries were daily performed during 21 days using a portable device (5MHz probe). Blood sample was collected for plasma progresterone (P4) determination. Corpora lutea were detected for the first time on day 5 and progressively increased in size until D9 (1.26 ± […]