Scoley Gillian, Gordon Alan, Morrison Steven
Agri-Food and Biosciences Institute, Hillsborough, BT26 6DR, Northern Ireland, UK.
Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, UK.
Animals (Basel). 2019 Oct 2;9(10):760. doi: 10.3390/ani9100760.
This study aimed to examine the use of non-invasive monitoring technologies as a means of capturing behavioural, physiological and health responses of calves allocated to different nutritional regimes. Seventy-four Holstein Friesian calves were individually penned and allocated to receive either high (HML) or conventional (CML) milk replacer (MR) levels between 5-70 days of age. Additionally calves were allocated to one of four forage treatments: (i) chopped straw offered between 14-70 days of age (CS14), (ii) chopped straw offered between 56-70 days of age (CS56), (iii) grass silage offered between 56-70 days of age (GS56), and (iv) no forage in the pre-wean period (NF). A representative sample of calves from each treatment were fitted with activity sensors and heart rate monitors throughout the experimental period to examine lying behaviour and heart rate variability, respectively. Thermal images of the eye and rectal area of each calf were taken 5 days/week between 5-77 days of age. Faecal and respiratory scoring of each individual calf was carried out on a daily basis throughout the experimental period. Milk replacer feeding level had limited effects on measures of calf health, although HML calves tended to have an increased likelihood for receiving treatment for scour than CML calves. Daily lying time (min/d) was lower in HML calves following reduction in MR feeding frequency at 43 days of age and weaning at 71 days of age when compared with CML calves. Additionally, HML calves displayed a lower heart rate variability following weaning, this suggestive of increased stress load. There were limited effects of forage treatment, however, CS14 calves displayed a greater daily lying time following MR step-down at 68 days of age, this potentially indicating increased rumination. Results of the present study highlight the benefits of using remote monitoring technologies as a means of detecting behavioural and physiological changes as a result of nutritional management strategy in individually housed dairy calves.
本研究旨在探讨使用非侵入性监测技术，作为获取不同营养方案下犊牛行为、生理和健康反应的一种手段。74头荷斯坦弗里生犊牛被单独圈养，并在5至70日龄期间分别给予高（HML）或常规（CML）水平的代乳粉（MR）。此外，犊牛被分配到四种草料处理之一：（i）在14至70日龄期间提供切碎的稻草（CS14），（ii）在56至70日龄期间提供切碎的稻草（CS56），（iii）在56至70日龄期间提供青贮牧草（GS56），以及（iv）断奶前不提供草料（NF）。在整个实验期间，从每个处理中选取代表性的犊牛样本，分别佩戴活动传感器和心率监测器，以检查躺卧行为和心率变异性。在5至77日龄期间，每周5天对每头犊牛的眼睛和直肠区域进行热成像。在整个实验期间，每天对每头犊牛进行粪便和呼吸评分。代乳粉的饲喂水平对犊牛健康指标的影响有限，尽管HML组犊牛患腹泻接受治疗的可能性往往高于CML组犊牛。与CML组犊牛相比，HML组犊牛在43日龄时代乳粉饲喂频率降低以及71日龄断奶后，每日躺卧时间（分钟/天）较低。此外，HML组犊牛断奶后的心率变异性较低，这表明应激负荷增加。草料处理的影响有限，然而，CS14组犊牛在68日龄代乳粉减量后，每日躺卧时间更长，这可能表明反刍增加。本研究结果突出了使用远程监测技术作为检测个体圈养奶牛犊营养管理策略导致的行为和生理变化的一种手段的益处。
