Department of Food Science and Nutrition, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al-Khoud, P. O. Code,123, P. O. Box 34, Al-Khoud, Muscat, Oman.
Department of Animal and Veterinary Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, P. O. Code 123, P. O. Box 34, Al-Khoud, Muscat, Oman.
Trop Anim Health Prod. 2024 Aug 3;56(7):229. doi: 10.1007/s11250-024-04071-2.
Holocellulose (HC) fraction extracted from date-pits was evaluated as a novel feed additive for ruminant feeding. This study was performed to investigate the effectiveness of the HC additive on rumen fermentation, methane (CH) production, and diet degradability over 24 h of in vitro incubation. Three independent incubation trials were conducted over three consecutive weeks, employing the same in vitro methodology to assess four treatment doses in a completely randomized design. The experimental diet incorporated four increasing doses of HC, containing HC at 0 (HC0), 10 (HC10), 20 (HC20), and 30 (HC30) g/kg dry matter (DM). In vitro gas production (GP) and CH production, volatile fatty acids (VFAs) concentration, protozoa accounts, degraded organic matter (DOM), metabolizable and net energy (ME and NE), and hydrogen (H) estimates were measured. No significant differences in ruminal pH were observed as the HC doses gradually increased. All incremental doses of HC additive over 24 h resulted in a linear increase in GP (P < 0.001), DOM (P < 0.001), total VFAs (P = 0.011), and propionate (P < 0.001) concentrations, as well as estimated energy (ME and NE) (P < 0.05) and microbial protein (P = 0.017) values. However, the inclusion of increasing doses of HC in the diet displayed linear reductions in the net CH production (ml/kg DOM; P = 0.002), protozoa abundance (P = 0.027); acetate (P = 0.029), and butyrate (P < 0.001) concentrations, the acetate-to-propionate ratio (P < 0.001), and the estimated net H production concentration (P = 0.049). Thus, the use of date-pits HC additive generated positive ruminal fermentability, including increased total VFAs and a reduction in the acetate-to-propionate ratio, leading to decreased CH output over 24 h of in vitro incubation. Hence, HC could be considered a potent feed additive (at up to 30 g/kg DM), demonstrating promising CH-mitigating competency and thereby enhancing energy-use efficiency in ruminants.
从枣核中提取的全纤维素（HC）被评估为一种新型的反刍动物饲料添加剂。本研究旨在通过 24 小时体外孵育试验，研究 HC 添加剂对瘤胃发酵、甲烷（CH）生成和饲料降解率的影响。在三个连续的星期内进行了三次独立的孵育试验，采用相同的体外方法，在完全随机设计中评估了四个处理剂量。实验日粮中添加了四种递增剂量的 HC，分别为 0（HC0）、10（HC10）、20（HC20）和 30（HC30）g/kg 干物质（DM）。测量了体外产气量（GP）和 CH 生成、挥发性脂肪酸（VFAs）浓度、原生动物计数、降解有机物（DOM）、可代谢和净能（ME 和 NE）以及氢（H）估计值。随着 HC 剂量逐渐增加，瘤胃 pH 无显著差异。HC 添加剂的所有递增剂量在 24 小时内均导致 GP（P<0.001）、DOM（P<0.001）、总 VFAs（P=0.011）和丙酸（P<0.001）浓度、估计能量（ME 和 NE）（P<0.05）和微生物蛋白（P=0.017）值线性增加。然而，日粮中添加递增剂量的 HC 会导致净 CH 生成（ml/kg DOM；P=0.002）、原生动物丰度（P=0.027）、乙酸（P=0.029）和丁酸（P<0.001）浓度、乙酸/丙酸比（P<0.001）和估计的净 H 生成浓度（P=0.049）线性降低。因此，使用枣核 HC 添加剂可提高瘤胃发酵性，包括增加总 VFAs 和降低乙酸/丙酸比，从而降低 24 小时体外孵育的 CH 产量。因此，HC 可被认为是一种有效的饲料添加剂（最高可达 30g/kg DM），具有降低 CH 排放的潜力，从而提高反刍动物的能量利用效率。
