The objective of this study was to evaluate the productivity efficiency indicators of cows selected for post-weaning weight, with emphasis in the calf-cow weight ratios, in a controlled herd (NeC), unselected for post-weaning weight, selection (NeS) and conventional (NeT). The analysis involved 3929 and 3906 calves weights at the 120 (P120) and 210 (P210) days of age, respectively. The cow weights at those ages were also considered, and the recorded numbers were 3824 (PV120) and 3777 (PV210), respectively, for 120 […]

The objective of this work was to evaluate the effect of some environmental factors on days open (DO) and days dry (DD), as well as to estimate genetic parameters for these traits in Holstein breed cows. A total of 6,485 records of DO and DD were used. The database were analyzed using a model that included the fixed effects of dairy group farmers, calving year, calving season, production level (PL), genetic group (GG), calving age class (CA) and the first […]

In the present work, 180 Nellore females from eight herds were analyzed for TEXAN15, BM1224 and CSFM50 microsatellites and for the restriction fragments polymorphism (RFLP) at the locos k-casein, b-lactoglobulin and growth hormone (GH). Excepted for GH, all markers were polymorphic in the studied sample. The values of heterozigozity, gene diversity, polymorphic information content (PIC) and paternity exclusion probability (PE) were estimated. The highest PIC (0.685) and PE (0.521) values were obtained for microsatellite BM1224.

The objective of this study was to evaluate the viability of using partial records of milk yield instead of the production accumulated at 305 days of lactation to obtain the predicted breeding values (BV). Sires and cows ranked by BV using accumulated milk yield records at 90(T90), 150(T150) and 210(T210) days of lactation were compared with BV estimated by using production up to 305 days (T305). An animal model was used to estimate the animals BV including herd-year, season and […]

The objective of the experiment was to evaluate, during the growth phase, the dry matter intake, weight gain and feed to gain conversion of young bulls and steers, castrated at eight month, from two breeding systems, straightbred (Charolais – C and Nellore – N) and crossbred (1/2 CN, 1/2 NC), as well as to measure the resulting heterosis. The animals were confined from nine to twelve months and fed a 15% crude protein diet and a 70:30 forage to concentrate […]

Data of 109.200 lactations were used to verify the effects of heterogeneity of variance on genetic evaluation of cows and bulls of Holstein breed raised in Brazil. Total milk production adjusted for adult age was used to classify the herds among three classes of phenotypic standard deviation: Low (<1427 kg), medium (between 1427 kg and 1625 kg) and high (>1625 kg) classes. Records from the first lactation were analyzed for total milk production adjusted for adult age (TOTAJU) and for […]

The performance of two broiler breeder lines, developed by Federal University of Viçosa – UFV (M1 and F1) was tested against two mainly trade mark lines (C1 and C2), using methods of multivariate analysis for the evaluation of the genetic divergence. Four important economic traits were evaluated: age at sexual maturity (IMS), egg number (NO), average egg weight (PO) and body weight (PM), during three periods of the productive life of the birds: initial (25th to 32nd week of age), […]

The experiment was carried out to evaluated the reproductive traits of crossbred goats submitted to the semi-arid Notheast climate conditions. Data from 657 does kept in a native pasture and fed corn and soybean meal based diet, during the dry season, and 945 kids milked up 24 hours, were analyzed. The means for the does prolificacy and at kidding weight were respectively 1.69+.03 and 36.38+.03 kg for ½ Pardo Alpina (PA) + ½ Moxotó (MO), 1.59+.05 and 36.24+0.58 kg for ¾ […]

Informations of 7986 births of animals from a Nellore cattle herd, from 1960 to 1993, were used to estimate (co) variance components, heritabilities and genetic correlations of weaning weight (W240), yearling weight (W365), age at first calving (AFC), first calving interval (CI1), reproductive efficiency (RE), longevity (LONG), calculated as years of permanence of cow in herd and weaning weight of the first calf of cow (W240C). The analysis were performed using the MTDFREML software, estimating the (co) variance components by […]

The objective of this work was to study the effects of the injection of 10 mg buserelin (GnRH) in the presence of an ovarian follicle with ³ 10 mm diameter associated to a dose of 500 mg of cloprostenol six days later, or with two doses of 500 mg of cloprostenol (PGF2a) at the 12th and 26th days postpartum about the follicular dynamic and the reestablishment of cyclic ovarian activity in crossbred Holstein-Zebu cows. Fifteen crossbred Holstein-Zebu cows were randomly […]