ABSTRACT We evaluated performance, non-carcass components, and carcass characteristics of crossbred Texel lambs in different categories of residual intake and gain (RIG). We assessed 77 crossbred (¼ Pantaneira and ¾ Texel) non-castrated animals in two study phases. The first phase included 47 lambs with an initial average weight of 29.9±5.5 kg, and the second phase included 30 lambs with initial average weight of 22.4±3.3 kg. Dry matter intake (DMI) and average daily gain (ADG) were evaluated for 70 days. Animals […]

ABSTRACT The objective of this study was to evaluate the associations between feed efficiency and feeding behavior, growth and carcass traits in Senepol cattle. A total of 137 animals were evaluated. Of these animals, 36 males were evaluated in a second test, totaling 173 records (initial age of 466±96 days and initial weight of 426±104 kg). Residual feed intake (RFI) was calculated as the difference between observed and expected dry matter intake, estimated by regression of dry matter intake on […]

This study was conducted to determine optimum test duration for measuring performance, feed intake and feed efficiency. Sixty young Nellore bulls were submitted to feeding performance test and fed in individual pens to determine feed intake and performance over 112 days. Body weight was determined every 28 days, after fasting of water and feed for 16 hours. Changes in variance, relative variance and Pearson and Spearman correlations among data from shortened test periods (28, 56 and 84 days) and full […]

Two Nellore herds were compared, one selected for greater postweaning weight and the other, control, selected for average postweaning weight, to evaluate the effects of 29 years of selection on feed efficiency. Sixty Nellore males (41 selected and 19 control) averaging 205 kg and 267 days of age were evaluated in individual pens during performance test. Performance and dry matter intake were used to determine the following feed efficiency traits: feed conversion; residual feed intake; residual gain; partial growth efficiency; […]

The objective of this study was to assess the bionutritional efficiency of crossbred F1 Red Angus × Nellore (½ RA ½ N) and F1 Blonde D’Aquitaine × Nellore (½ BA ½ N) young bulls finished on feedlot and slaughtered at 480, 520 and 560 kg body weight. A completely randomized experimental design in a 2 × 3 (genetic group × slaughter weight) factorial arrangement with six replicates was used. The ½ BA ½ N young bulls showed higher kidney, pelvic […]

Providing feed is a major input cost in beef production, hence improvements in the efficiency of feed utilisation will reduce the cost of production. Residual feed intake (RFI) is a measure of feed efficiency, and is defined as the difference between an animal’s actual feed intake and its expected feed intake based on its size and growth. It is independent of the level of production, and the lower the value the more efficient the animal is. This paper examines the […]