Records of start of breeding season and subsequent calving, from 1,247 Nelore females raised at Sertãozinho Experimental Station (IZ ¾ SP, Brazil), selected for high (selection and traditional lines) and for average (control line) yearling weights were used to compute days to calving and to study the effect of selection for yearling weight on reproductive performance. Data sets of heifers, and cow and heifers were analyzed with and without non-calvers females. There were no significant differences among the performance of […]

Thirty six Nellore bulls, with 240 kg initial live weight (LW), were used and distributed in eight treatments, with four different concentrate levels in the diets (20; 40; 60 and 80%) and two crude protein (CP) levels (15 and 18%) with four reference bulls. After the slaughter, the carcass dressing percentage, the basic cuts percentages, the carcass length, the loin eye area, the subcutaneous fat thickness, and the carcass muscle, fat, bone, protein, ether extract, water percentages, the organs and […]

The research was carried out in Felixlândia Experimental Farm ¾ MG ¾ EPAMIG, from July to October 1997, to determine the effect of concentrate supplements on cuts percentage and percentage of bone, muscle and fatty tissues in the carcass of the twenty crossbred Limousin-Nelore males aging 22-23 months and average slaughter weight of 459 kg were used. These animals were previously submitted to supplementation treatments in Brachiaria decumbens postponed pasture during dry season for 112 days. The treatments were: T1 […]

The objective of this study was to evaluate the nutritive value of the diet by cows grazing in natural pastures, in a typical area of Nhecolândia sub-region, Pantanal, during two hydrological years: from October 1997 to September 1999. Grazed forage species samples, representative of the animals’ diet, were collected manually in each month. All forage samples were analyzed for crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and lignin (LIG). Near infrared spectrofotometry (NIRS) was used to […]

The experiment evaluated the performance of beef heifers submitted to three alternatives of autumn-winter feeding systems, during 88 days, and after this period on improved pastures all together until the end of theirs first mating season, with 14-15 months of age. The systems were: Pasture- continuous grazing on cultivated annual ryegrass (L. multiflorum Lam); supplementation- continuous grazing on natural pasture plus energy and protein supplementation; feedlot – feedlot, with sorghum silage plus non- proteic nitrogen (NNP). After this period, all […]

The objective of the experiment was to evaluate the carcass and meat characteristics of two year old steers, produced by the mating of 1/2 Nellore 1/2 Charolais cows with Charolais bulls and by mating 1/2 Charolais 1/2 Nellore cows with Nellore bulls. Eighty 3/4 Nellore 1/4 Charolais (NC) and 136 3/4 Charolais 1/4 Nellore steers were used. The data were collected from September 1986 to December 1998. In the statistical model were included the contemporary group effect, age of dam […]

Methods of standardization of body weight for 205, 365 and 550 days of age were compared. It was used information of animals of the Nellore breed, raised in the Northeast Brazil, and controlled by the Brazilian Zebu Breeders Association (ABCZ). The following methods were compared: MET1 – used by ABCZ; MET2 – individual curves of linear regression for each animal; MET3 – individual curves of quadratic regression; MET4 – individual Brody curve; MET5 – used by the Program of Genetic […]

The objective of this study was to investigate, via simulated data, the effect of heterogeneity of residual variance among contemporary groups (CG) on genetic evaluation of beef cattle, and to compare a weighted genetic evaluation procedure (R¹Ise2) with one that assumes homogeneity of variances (R = Ise2). Different data sets of postweaning weight gain, adjusted to 345 days, were simulated with and without heterogeneity of residual variance, using a phenotypic variance of 300 kg2 and a true heritability of 0.4. […]

The experiment was conducted to evaluate the average daily liveweight gain (ADLG), number of animal.days/ha (AD/ha) and liveweight gain/ha (LG/ha), in a Tanzaniagrass pasture deferred in different sward heights in the autumn and after managed in different sward height conditions, during the winter period. A completely randomized design was used. The treatments were four levels of sward height: T1=20, T2=40, T3=60 and T4=80 cm. However, the average sward height levels maintained in a pasture was used for the statistical analysis, […]

An experiment was conducted to evaluate the effect of dietary lysine levels and sex on breast yield and breast meat quality. Two thousand Ross day-old chicks were reared in a 2×2 randomized factorial design (two sex and two dietary lysine levels). Birds fed starter diets (1 – 21 days), growing (22 – 42 days) and finishing (42 – 49 days) with 100% of NRC (1994) lysine requirement, or 110% in the starter and growing and 120% in the finishing diets. […]