The objective of this study was to evaluate two grazing intervals (IG) for elephant grass (Pennisetum purpureum Schum cv. Cameroon) pasture: one variable, determined by the entry of animals to the paddocks when 95% of active photosynthetic radiation was intercepted by the sward, and fixed 26-day grazing interval. Eight dairy cows were used, averaging 124 days lactation, 516 kg body weight and 17.5 kg daily milk production at the beginning of the trial. The experimental period was 80 days divided […]

The objective of this study was to evaluate the influence of body condition at birth on Alpine goat productive parameters in early lactation. Sixty-eight females were assigned to three groups according to the body condition score (BCS) – low (1.00 – 2.75); intermediate (2.75 – 3.50) and high (3.50 – 5.00) and evaluated from kidding to the eighth week of lactation. The feed intake and milk production were recorded on a daily basis and the body weight, body condition score […]

The objective of this study was to evaluate the correlations between rainfall data and goat productive traits in Alpine X Gurgueia breeds goats, raised in a intensive regime in the Ocidental Cariri, a semi-arid microclime of Paraíba State, Brazil. Birth weight, milk production and mortality of kids to 90 days of age and rainfall data from the Carnauba Farm were used. The rainfall data were transformed in Logx. The birth weight, milk production and mortality correlated reasonably correlated with the […]

To assess the reproductive performance of beef cows submitted to estrus induction/synchronization, 42 Aberdeen Angus cows with body condition 3 (1-5 scale) under extensive management were used. The milk production was estimated through the weight-suckling-weight method. For gynecological examinations, ultrasound equipment and trans-rectal palpation were used. The milk production level (above and below the average production of cows), pregnancy, prebreeding reproductive condition (CRPA), surface anoestrus (uterine tone, follicles > 10 mm and absence of CL) and deep anoestrus (no uterine […]

Records from 2.440 first lactations of Gir cows, calving between 1990 and 2005, were used for estimating genetic parameters of test-day milk yield (TDMY) and accumulated 305 day milk yield (M305) in univariate and bivariate animal models analyses. The model for TDMY included the contemporary group (CG) defined by the combination of herd, year and season of test day, the class of age of cow at calving and the linear covariate of days in milk (linear regression) as fixed effects […]

The objective of this trial was to evaluate the effect of starch sources and processing used in diets on performance and nitrogen metabolism of lactating Holstein dairy cows fed sugar cane as forage. Five multiparous lactating Holstein cows, cannulated in the rumen and proximal duodenum, were used in a 5 × 5 Latin square. Cows were fed a 40:60 forage concentrate ration (40% fresh sugar cane and 60% concentrate) and differ only on processing or mainly starch source: cracked corn; […]

Seventy and six lactating crossbred sows of medium genetic potential with initial weight of 207.0 ± 32.0 kg and reproductive cycles order of 3.53 ± 2.11 were used to evaluate digestible threonine levels in the lactation phase. The animals were allotted to a randomized blocks experimental design with four treatments (0.589, 0.627, 0.665, and 0.703% of digestible threonine) and nineteen replications, in which each experimental unit was onsisted by a female. There was no effect of digestible threonine levels on […]

The objective of this research was to evaluate the effects of fat supplementations as calcium salts of palm oil (PF), whole rice bran + rice oil (WRBO) and whole rice bran + bovine tallow (WRBT) on dry matter intake, productive efficiency and energy balance of dairy cows in the beginning of the first third period of lactation. Control diet contained 2.9% EE, while the diets GP, FAIO and FAIS contained 5.13; 5.29 and 5.16% EE, respectively. Pure bred Jersey cows […]

Data comprising 39,578 test-day records of 3,766 first lactation Holstein cows calving from 1994 to 2002 was used to estimate genetic parameters for test-day yields (TDY) and 305-day milk yield (MY305) and to compare two selection criteria. Variance components were estimated by restricted maximum likelihood using univariate and bivariate animal models. The TDY models included the additive genetic random effect and the fixed effects of contemporary groups and the regressions of calving age (linear and quadratic effects) and days in […]

Production of low cost milk is the most relevant aspect in dairy goat systems. Therefore, studying the behavior of the lactation curve of dairy goats is important to implement animal breeding programs as well as for plan and introduce new management tools. The objective of this study was to select among mathematical models published in the literature the one that best describe the lactation curve of dairy goats. A dataset constituted of 23,502 observations of milk yield from 748 lactations […]