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An experiment was conducted to compare different oilseeds in substitution of ground corn in fattening lambs’ diet, evaluating ingestive behavior, apparent diet digestibility, performance and carcass characteristics. Twenty-four crossbred lambs, 3 month-old and initial body weight of 25.97 ± 0.75 kg, were kept in individual pens. They received one of the following diets: control (no oilseeds, 3.01% Ether Extract - EE), with cottonseed (6.86% EE), sunflower seed (6.93% EE), or soybean (4.75% EE). All diets contained 23.63% of coast cross hay and 76.37% of concentrate. After 84 days of feedlot, the animals were slaughtered and the carcasses evaluated. The dry matter intake and daily weight gain of animals fed with control diet was higher than with oilseeds (P≤0.05). Final body weight and carcass weight were higher (P≤0.05) with control (42.42 kg and 19.27 kg, respectively) than sunflower diet (34.85 kg and 16.05 kg, respectively). Neutral detergent fiber (NDF) digestibility was reduced (P≤0.05) when the animals received cottonseed (50.34%) than soybean (71.07%); sunflower (67.07%) and control (66.50%) diets did not differ among others. Lower (P≤0.05) ether extract digestibility was observed for the control diet (73.67%). There were no differences (P≥0.05) in the ingestive behavior, however, the inclusion of cottonseed or sunflower negatively affected (P≤0.05) the rumination efficiency of NDF. Cottonseed, sunflower and soybeans should not be included in high concentrate diets for fattening lambs.

The pregnancy rate (PR) is extremely important for the productive efficiency of beef cattle and bull fertility can influence the PR of cows in natural mating. The objective of this study was to evaluate the relationship of andrological traits, especially scrotal circumference (SC), of Nellore bulls (Bos indicus) selected for breeding based on greater postweaning weight gain with the PR of naturally mated Nellore cows in a 90-day breeding season. Records of 7,171 entries into the breeding season of 1,923 cows exposed to 216 bulls in 368 mating batches in the field (single bull) from 1995 to 2014, as well as records of SC, were evaluated. Scrotal circumference was pre-adjusted for bull age (2.67±0.62 years) at the start of the breeding season using a linear regression model and was divided into three classes: class 1: SC < 35 cm; class 2: 35 ≥ SC < 37 cm; class 3: SC ≥ 37. More than half the observations of SC were in class 2 and 74.52% of the exposures to bulls resulted in pregnancy, with a minimum rate of successful pregnancy of 0% and a maximum rate of 100% in the 368 mating batches. Thirty-three of the 216 bulls had records of andrological traits [SC, sperm volume, motility, vigor, concentration and morphology (major and minor defects)]. The class of intermediate SC values (class 2: 35 ≥ SC < 37 cm) was associated with a higher relative risk of pregnancy success. In the sample of the 33 bulls, PR showed a moderate positive correlation (r = 0.66) only with sperm concentration. The weak association between andrological traits of bulls and PR might be due to the fact that the sample of bulls evaluated in this type of study will be always biased. In other words, only bulls that enter the breeding season are considered, which correspond to a small percentage of all males born. Consequently, the variation observed in these bulls does not represent the variation in SC, seminal traits and, possibly, reproductive fitness of all bulls born. In addition, PR is the result of the expression of many factors that affect cows and bulls differently and that are likely to have a subtle individual influence on this outcome.

Pasture management can affect plant growth and interfere with the performance of the animals or the productivity of the production system. Marandu palisade grass swards subjected to year-round grazing by crossbred heifers were evaluated. Three stocking systems were tested: 1) a grazing cycle of 28 days (T28d); 2) when the sward reached a pre-grazing height of 30 cm (T0.3m), and 3) when the sward reached a pre-grazing height of 30 cm under irrigation (T-irrig0.3m). Heifers from treatments T28d and T0.3m were supplemented with dry matter at 1% of BW during winter. Statistical was a completely randomized block split-plot design. The light interception was higher (P