Inclusion of copaiba oil (Copaifera sp.) as additive in supplements for cattle on pasture

SUMMARY This study analyzed the effect of including copaiba oil as an additive for cattle supplemented on pasture, during the dry season. Four crossbred steers, castrated, with 245 ± 25 kg, aged about 18 months, fitted with permanent rumen cannula; were randomly assigned to a 4×4 Latin square. All animals were housed in individual paddocks (0.3 ha), uniformly covered with Brachiaria brizantha cv Marandu, with through and drinking fountain; and were given a concentrate at 500g/100 kg BW containing 380 g/kg crude protein (%DM). The copaiba oil was added to the supplement as a spray, in the proportions of 0, 0.5; 1.0 and 1.5 g/kg DM intake. Spraying supplementation was performed daily at the time of supply of the supplement. Data of intake and digestibility of nutrients, ruminal pH; ruminal ammonia nitrogen, and microbial protein synthesis were tested by analysis of variance and polynomial regression, adopting a significance level of 5%. The inclusion of copaiba oil quadratically affected total dry matter intake (P=0.030) and CP digestibility (P=0.043), without altering ruminal metabolism (P>0.05) and microbial protein synthesis (P>0.05) of the animals kept on pasture.摘要 本研究分析了旱季期间，在牧场放牧肉牛的补饲日粮中添加苦配巴油（copaiba oil）作为添加剂的效果。选取4头去势杂交肉牛，初始体重245±25 kg，月龄约18个月，安装永久性瘤胃瘘管，采用4×4拉丁方（Latin square）试验设计随机分组。所有试验牛均饲养于面积0.3公顷的单栏圈舍，圈舍内均匀覆盖马兰多臂形草（Brachiaria brizantha cv Marandu），配备饲槽与饮水装置；按照每100 kg体重饲喂500 g浓缩补料的比例进行补饲，该浓缩补料的粗蛋白（crude protein, CP）含量为380 g/kg干物质（dry matter, DM）。苦配巴油以喷雾方式添加至补饲日粮中，添加比例分别为0、0.5、1.0和1.5 g/kg干物质采食量。每日在供给补饲日粮时进行喷雾添加操作。针对养分采食量、养分消化率、瘤胃pH、瘤胃氨氮以及微生物蛋白合成量等数据，采用方差分析与多项式回归进行统计检验，显著性水平设定为5%。苦配巴油的添加量对总干物质采食量（P=0.030）与粗蛋白消化率（P=0.043）产生了二次效应，而对放牧肉牛的瘤胃代谢（P>0.05）与微生物蛋白合成量（P>0.05）无显著影响。