Ngo Thi Thuy, Bang Nguyen N, Dart Peter, Callaghan Matthew, Klieve Athol, McNeill David
School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia.
Faculty of Animal Science, Vietnam National University of Agriculture, Hanoi 131000, Vietnam.
Animals (Basel). 2021 Dec 4;11(12):3455. doi: 10.3390/ani11123455.
This study examined whether the probiotic strain H57 (H57) affects ruminal fermentation parameters that exercise post-ingestive feedback appetite control mechanisms. A 4 × 4 Latin square design was used to separate pre- and post-ingestive effects of H57 in four rumen-fistulated steers. The steers were offered a set amount of feedlot pellets, inoculated with H57 or without H57 (control, C). Half of the total amount of pellets fed were introduced intra-ruminally (r), and then the remaining pellets were orally consumed (o) to make four feeding treatments: H57r/H57o, H57r/Co, Cr/H57o and Cr/Co. Rumen fluid was sampled at 2, 4 and 6 h after feeding. Preference behaviour was tested immediately after the 6 h rumen fluid sampling by simultaneously offering the steers 4 kg of each of H57 and C pellets in adjacent troughs for 5 min. Steers preferred the pellets with added H57 over the C pellets (56:44; < 0.001) and their preferences were not affected by the treatment protocol imposed to separate post- from pre-ingestive effects ( > 0.05). Steers fed H57 pellets had higher ruminal pH, molar proportions of iso-butyrate and iso-valerate ( < 0.05) and tended to have greater ruminal ammonia concentrations compared to those fed C pellets ( < 0.1). However, post-ingestive signals did not affect diet preference more than pre-ingestive signals.
本研究考察了益生菌菌株H57是否会影响瘤胃发酵参数，这些参数会影响采食后反馈性食欲控制机制。采用4×4拉丁方设计，在四头瘤胃造瘘的肉牛中区分H57的采食前和采食后效应。给肉牛提供一定量的育肥牛颗粒料，分别接种H57或不接种H57（对照，C）。所喂颗粒料总量的一半经瘤胃内注射（r），然后其余颗粒料经口服摄入（o），从而形成四种饲喂处理：H57r/H57o、H57r/Co、Cr/H57o和Cr/Co。在采食后2、4和6小时采集瘤胃液。在6小时瘤胃液采样后，立即通过在相邻料槽中同时给肉牛提供4千克添加H57的颗粒料和对照颗粒料5分钟，来测试偏好行为。肉牛更喜欢添加H57的颗粒料而非对照颗粒料（56:44；<0.001），并且它们的偏好不受为区分采食后和采食前效应而施加的处理方案的影响（>0.05）。与饲喂对照颗粒料的肉牛相比，饲喂添加H57颗粒料的肉牛瘤胃pH值、异丁酸和异戊酸的摩尔比例更高（<0.05），并且瘤胃氨浓度有升高趋势（<0.1）。然而，采食后信号对日粮偏好的影响并不比采食前信号更大。
