Livestock Farm Complex, College of Veterinary Science, Sri Venkateswara Veterinary University, Proddutur, Andhra Pradesh, India.
Department of Animal Nutrition, NTR College of Veterinary Science, Sri Venkateswara Veterinary University, Gannavaram, Andhra Pradesh, India.
PLoS One. 2019 Aug 13;14(8):e0220252. doi: 10.1371/journal.pone.0220252. eCollection 2019.
The contemporary environmental-stewardship programmes primarily aimed at curbing the global warming potential by adopting a multidisciplinary approach. Manipulating the feeding strategies has great potential in reducing the environmental footprints of livestock production. This study intends to assess the effect of soybean meal (SBM) replacement with varying levels of coated urea (SRU) on both zoo-technical (nutrient digestibility, heat increment, and physio-biochemical parameters) and environmental attributes. The coated urea was used to replace the SBM at 0, 25, 50, and 75 percent levels. Eight adult rams (43.02 ± 0.76) maintained in a conventional shed were used in a replicated 4 x 4 Latin square design. Not all the physiological parameters viz. rectal temperature, pulse rate, and respiratory rate were affected (P>0.05)f by varying levels of SRU incorporation. The SRU fed animals had higher (P<0.05) crude protein digestibility compared to SBM fed animals; however, the replacements did not affect the nutrient digestibility coefficients of DM, OM, NFC, NDFap, ADF, and hemicellulose components. The SRU did not affect various biochemical parameters such as serum glucose, total protein, albumin, globulin, urea, creatinine, ALT, AST, Ca, P and T3, and T4 levels; however, post-prandial serum urea N (SUN) values showed a diurnal quadratic pattern (P<0.05) with a dose-dependent relationship. Further, the SBM replacements had no effect on the calcium excretion, while the SRU incorporation decreased the faecal phosphorous content, thereby abating the eutrophication phenomenon. Although the SBM replacements did not affect in vivo water variables and faecal solid fractions, they managed to decrease the land and virtual water requirement along with global warming potential (GWP) of the entire trial. The GWP-perceptual map unveils the fact that replacement of conventional feed ingredients with NPN compounds aids in eco-friendly livestock production. Further, the conjectural analysis of the carbon footprint methodology revealed that agricultural by-products consideration could cause a huge increase in the GWP share of feed consumed, thus compelling the importance of research pertaining to feed production perspective as equal as ruminal methane amelioration.
本研究旨在评估不同水平包被尿素（SRU）替代豆粕（SBM）对动物生产的营养消化率、热增耗和生理生化参数的影响。采用四因素拉丁方设计，选用 8 只成年公羊（43.02±0.76），在常规畜舍中进行试验。结果表明，不同水平 SRU 对直肠温度、脉搏率和呼吸率等生理参数无显著影响（P＞0.05）。与 SBM 组相比，SRU 组的粗蛋白消化率更高（P＜0.05）；但替代水平并未影响 DM、OM、NFC、NDFap、ADF 和半纤维素的养分消化率。SRU 对血清葡萄糖、总蛋白、白蛋白、球蛋白、尿素、肌酐、ALT、AST、Ca、P 和 T3、T4 等生化参数无显著影响；但餐后血清尿素氮（SUN）值呈昼夜二次曲线（P＜0.05），且与剂量呈正相关。此外，SBM 替代对钙排泄没有影响，而 SRU 减少了粪便磷含量，从而减轻了富营养化现象。虽然 SBM 替代对体内水变量和粪便固体分数没有影响，但降低了土地和虚拟水需求，同时降低了整个试验的全球变暖潜势（GWP）。GWP 感知图揭示了用非蛋白氮化合物替代常规饲料成分有助于生态友好型畜牧业生产的事实。此外，对碳足迹方法的推测性分析表明，农业副产品的考虑可能会导致饲料消耗的 GWP 份额大幅增加，因此必须重视饲料生产方面的研究，与瘤胃甲烷减排同等重要。
