The objective of this trial was to investigate the effects of partial replacement of sorghum silage and soybean meal with whole cottonseed on microbial protein synthesis and efficiency and nitrogen metabolism in lactating Holstein cows receiving forage cactus based diets. Five animals were randomly assigned to a 5 × 5 Latin square design and were fed diets containing (% of DM): 0.0, 6.25, 12.50, 18.75, and 25.00% of whole cottonseed. Inclusion of whole cottonseed in the diet did not affect […]

The objective of this trial was to investigate the daily variation in the urinary excretions of creatinine and nitrogen compounds in dairy heifers. It was also of particular interest to determine whether or not estimation of microbial protein synthesis is affected by the number of urinary sampling days. Eleven dairy Holstein heifers averaging 287 ± 49 kg of body weight (BW) in the beginning of the trial were used. Samples of urine were collected during six consecutive days using N. […]

The objective of this trial was to investigate the daily variation in the urinary excretions of creatinine, urea and purine derivatives (PD) as well as the plasma concentration of urea-N (PUN) in steers. Four castrated Holstein steers averaging 445 kg of body weight (BW) in the beginning of the trial were used in a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Animals were fed two levels of urea (0 and 100%) and […]

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 […]

The objective of this trial was to evaluate the effects of three different dietary levels of urea on milk yield and composition. Nine lactating Holstein cows were randomly assigned to three replicated 3 x 3 Latin squares with three periods of 21 days each. Treatments were: A) control diet formulated to meet 100% of the requirements of crude protein (CP), rumen undegradable protein (RUP) and rumen degradable protein (RDP) according to the NRC (2001) model by feeding soybean meal and […]

The objective of this experiment was to evaluate the influence of different rates of weight gain (low: 340 ± 32 g/day or moderate: 490 ± 29 g/day) of heifers, from birth until seven months of age, and the type of pasture after calving, as cows, on the biologic efficiency of cows and their calves until weaning at 217 days. After calving, the animals were maintained on native pasture (NP) or cultivated pasture (CP). During lactation, cows with low preweaning rate […]

The objective of this experiment was to study the development of external body components and that of discarded fat in feedlot finished crossbred cows from the second (G2 – 3/4Charolais (C) 1/4Nellore (N) and 3/4NC) and third (G3 – 5/8CN and 5/8NC) generations of a Charolais ´ Nellore rotational crossbreeding program slaughtered with 465 (T465), 507 (T507) and 566 kg (T566) of body weight. At the beginning of the trial, age, body weight and body condition score averaged, respectively, 8.5 […]

The objective of this experiment was to evaluate the effects of diets with corn silage or with sugar cane + sunflower seed and influence of sexual categories of fedlot young cattle on the performance and economic results of this production system. Thirty animals of Canchim breed (10 young bulls, 10 castrated males and 10 females) averagfing 15 months old and 289 kg BW were housed in individual stalls, for 105 days and weighted in the beginning of the experiment and […]

The objective of this trial was to evaluate performance, thermal comfort and behavior of crossbred Holstein x Zebu dairy calves kept in different housing systems during the dry season (26/04/2002 to 30/08/2002). Twenty-four calves were raised from birth to 70 days of age in one of the following housing systems: (1 – hutches; 2 – shadecloth; or 3 – with no shelter. Calves raised with no shelter showed higher rectal temperatures and respiratory rates in the afternoon. It was also […]

With the objective of evaluating different levels of IGF-I on the hepatical and intestinal indicators of cellular activity in newborn calves, 42 pregnant Holstein cows were randomly assigned to two groups: a) control: injection of vitamin E or b) rbST: injection of growth hormone (rbST). Injections started 35 days pre-partum and were repeated every 14 days until parturition. Newborn calves were randomly assigned to a 2 x 3 factorial arrangement of treatments (two mother groups and three different ages). After […]