Cortese Martina, Segato Severino, Andrighetto Igino, Ughelini Nicola, Chinello Maria, Schiavon Eliana, Marchesini Giorgio
Departement of Animal Medicine, Production and Health, University of Padova, 35020 Legnaro (PD), Italy.
Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Legnaro (PD), Italy.
Animals (Basel). 2019 Nov 1;9(11):906. doi: 10.3390/ani9110906.
This study aimed to evaluate the effect of decreasing dietary crude protein (CP) on the performance of finishing Charolais bulls in the Italian rearing system. Animals were fed two diets, differing only in the CP level (low protein (LP), 13.5% CP versus control (CON), 15.0% CP). Dry matter (DM) intake (DMI) and animals' weights were recorded to obtain average daily gain (ADG) and feed conversion rate (FCR). Feed and fecal samples were collected to evaluate digestibility of diet components. Daily cost of the ration (DRC), feed cost per kg of daily weight gain (CDG) and daily gross margin (DGM) were calculated to analyze the possible benefits of decreasing the protein level. Meat quality analyses were also conducted. Higher DMI (10.6 versus 10 kg/d; < 0.05) and ADG (1.47 versus 1.36 kg/d; < 0.05) were observed for CON. No differences in FCR or digestibility were found. Even if the DRC was lower ( < 0.05) for the LP diet (2.26 versus 1.97 €; CON versus LP), no difference was reported for CDG and DGM. Meat lightness and redness were significantly lower and higher in the LP, respectively To conclude, the CP requirement in these rearing conditions appeared to be higher than 13.5%.
本研究旨在评估在意大利饲养体系中降低日粮粗蛋白（CP）水平对夏洛莱育肥牛性能的影响。给动物饲喂两种日粮，仅CP水平不同（低蛋白（LP）日粮，CP含量为13.5%，对照（CON）日粮，CP含量为15.0%）。记录干物质（DM）摄入量（DMI）和动物体重，以获得平均日增重（ADG）和饲料转化率（FCR）。采集饲料和粪便样本，以评估日粮成分的消化率。计算日粮的每日成本（DRC）、每千克日增重的饲料成本（CDG）和每日毛利润（DGM），以分析降低蛋白质水平可能带来的益处。还进行了肉质分析。CON组的DMI（10.6对10千克/天；P<0.05）和ADG（1.47对1.36千克/天；P<0.05）较高。FCR或消化率未发现差异。即使LP日粮的DRC较低（P<0.05）（2.26对1.97欧元；CON对LP），但CDG和DGM未报告差异。LP组肉的亮度显著较低，红色度显著较高。总之，在这些饲养条件下，CP需求量似乎高于13.5%。
