Predicted transmitting ability (PTA) of milk yield of 529 sires using animal model (MA), sire model (MT) and herdmate contemporary comparison method (MCR) were calculated and compared by means of correlation’s rank and values, reliability, differences among PTA and percent of coincidence in the selection of the best bulls. Two sets of data were considered one contained up to five lactation per cow and other with production data at first lactation. Data of 12,762 lactations of 5757 Gyr and crossbred […]

Data of 36,755 first lactation of Holstein cows, daughters of 866 sires, distributed in different states from 1980 to 1993, were stratified in herds according to the phenotypic standard deviation of the milk yield adjusted for adult age, in three levels: low (11,713 lactations), medium (12,764 lactations) and high (12,278 lactations). The total milk production adjusted for adult age and adjusted for adult age and for 305 days of lactation, within each class, and the base 10 logarithm transformations, square […]

Previous and present days open were fit simultaneously as fixed effects in a sire model for 305 day milk production (L305) containing yet the fixed effects of herd-year-season, level of Holstein blood, age of cow as covariant (up to 3rd degree) and the random effects of sire and cow. A relationship matrix including the bull, his sire and his dam was used. The same model without age of cow was used for 305-day mature age equivalent milk yield (PROAJU). The […]

The objective of this work was to estimate minimum sample size (n) of animals to detect significant differences (D) among monthly replicate evaluations of scrotal circumference from animals of the Nellore breed, from 10 to 30 months of age, considered as 21 evaluation conditions or repeated measurements (treatments). The value of n that allows to detect the D among means when each subject is observed for t > 2 treatments, was obtained by means of the Statistical Analysis System – […]

The data used in this study are results of the evaluations of crosses among European breeds and Nellore breed. The data regarding to the weaning weight of 883 calves resulted from six mating groups involving crosses of Simental, Charolais and Chianina breeds with Nellore, backcrosses and pure Nellore, were used. The weaning weights were adjusted for cow and calf ages and contemporary group (formed by the combination of year and season of birth and sex) to estimate direct and maternal […]

Data simulated with five levels of pedigree errors (0, 5, 10, 15 and 20%) and three heritabilities (.10, .30 and .60) were used to verify the effect of pedigree errors on the selection during 10 generations. The largest phenotypic values and efficiency on the individual selection, in overall, were obtained by BLUP without errors, followed by those with 5, 10, 15 and 20% of error. The average superiority in genetic gain of the BLUP per generation, in the various error […]

Simulated populations were used to verify the effect of errors in the selection of males in the estimates of genetic gains along ten generations of selection, using BLUP. Five levels of errors in the selection of males (0, 5, 10, 15 and 20%) and three heritabilites (.10, .30 e .60) were used. Twenty males and 200 females were selected by BLUP. After the selection of 20 males in each generation, 1, 2, 3 and 4 sires were changed by others […]

With the objective to determine the combining ability of broiler matrix lines by means of factor analysis, single crosses (full diallel) within female lines (PP, KK and VV) were used. The evaluated traits were egg numbers from the 24th-32nd(P1), 32nd-40th(P2), 40th-48th (P3), 48th-56th (P4), 56th-64th (P5), 22nd-66th (P6), 32nd-66th (P7)), 40th-66th (P8), 48th-66th(P9), 24th-40th (P10), 24th-48th (P11)) and 24th-56th (P12) week of age. In the factor analysis, two factors were used, with the meaning biological factor defined after the factor […]

This study was conducted using data from single crosses(partial diallel) of 9 male lines – group 1 – (LL, TL, ZL, TT, LT, ZT, ZZ, LZ, TL), 9 female lines of group 2 (PP, KP, VP, KK, PK, VK, VV, PV, KV), to evaluate general combining ability of productions traits of broiler lines using principal components analyses The eleven production traits analyzed, were,: fertility at 32nd,38th, 42nd and 49th weeks of age, hatchability at 32nd, body weight at day of […]

Two experiments were carried out to evaluate the effects of three grazing frequencies (28, 38 and 48 days) on forage mass, dry matter (DM) accumulation rate and leaf:stem ratio in Tanzania and Mombaça, from September 1995 to May 1996 period. A split plot experimental design was used, with grazing frequency as main plots and period of the year as subplots. The forage mass per grazing was greater when the grazing frequency was small, however did not have an effect on […]