摘要
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 average daily gain and metabolic body weight (BW0.75), and the animals were classified as negative (high efficiency) and positive RFI (low efficiency). The mean RFI was -0.838±0.078 and 0.797±0.075 kg DM day-1 for negative and positive RFI animals, respectively, with a difference of 1.63 kg dry matter day-1. The dry matter intake of negative RFI animals, expressed as kg day-1 and percentage of mean body weight, was 11.3% and 13.1% lower than that of positive RFI animals. Negative RFI animals spent less time at the feed bunk and ingested less dry matter per visit than positive RFI animals, but did not differ in terms of chest girth, scrotal circumference, or hip height. However, negative RFI animals had lower rump fat deposition (7.13±0.477 mm) than positive RFI animals (7.83±0.473 mm). The Spearman correlation between RFI estimated in the first and second tests was 0.69, indicating that RFI is consistent when evaluated during two different periods of the life of the animal. Senepol animals with low residual feed intake (high efficiency) deposit less subcutaneous rump fat, but this reduction is not accompanied by a reduction in backfat thickness and longissimus muscle area
摘要译文
本研究的目的是评估饲料效率与Senepol牛的摄食行为，生长和胴体性状之间的关系。共评估了137只动物。在这些动物中，36名男性在第二次测试中被评估，总共173条记录（初始年龄为466±96天，初始体重为426±104kg）。剩余采食量（RFI）计算为观察到的和预期的干物质摄入量之间的差异，通过干物质摄入量对平均日增重和代谢体重（BW0.75）的回归估计，并且动物被分类为阴性（高效率）和阳性RFI（低效率）。对于阴性和阳性RFI动物，平均RFI分别为-0.838±0.078和0.797±0.075kg DM day-1，相差1.63kg干物质日-1。负RFI动物的干物质摄入量，以kg day-1和平均体重百分比表示，比阳性RFI动物低11.3％和13.1％。与RFI正向动物相比，负面RFI动物在饲料铺位上花费的时间更少，每次访问摄入的干物质也少，但胸围，阴囊周长，或臀部高度。然而，阴性RFI动物的臀部脂肪沉积（7.13±0.477mm）低于阳性RFI动物（7.83±0.473mm）。在第一次和第二次测试中估计的RFI之间的Spearman相关性为0.69，表明在动物生命的两个不同时期评估时RFI是一致的。具有低残留饲料摄入量（高效率）的塞内泊尔动物沉积较少的皮下臀部脂肪，但这种减少并没有伴随着背thickness厚度和最长肌面积的减少
GUIMARAES, ;ré Lasmar et al.. Phenotypic association between feed efficiency and feeding behavior, growth and carcass traits in Senepol cattle.[J]. Revista Brasileira de Zootecnia, 2017,46(1): 47-55