A preliminary investigation of the feeding behaviour of dairy goat kids reared away from their dams on a computerised ad libitum milk feeding system

Most commercial dairy goat famers use ad libitum milk feeding set-ups that allow constant, unrestricted milk access to artificially rear goat kids. No detailed information on how kids use these ad libitum milk systems exists and characterising this would help target future research and improve management. The aim was to describe and characterise the individual and group milk feeding behaviour of 16 castrated male dairy breed goat kids from 22 to 56 days of age, in two pens fed from a computerised milk feeder supplying one teat per pen. Solid feed and water intakes were measured from 15 to 70 days of age and Average Daily Gain (ADG) calculated. Repeated measures mixed models produced weekly estimated marginal means of milk feeding variables. Factors influencing ADG were investigated using residual maximum likelihood analysis. Spearman's rank correlations investigated the relationship between pen-level feeding behaviour variables and age. Meal criterions were created by fitting a mixture of Gaussians to determine a threshold value. On average it took 7.8 days before kids were reliably suckling alone (range 2-15 days). Each day kids spent on average 24.3 +/- 1.80 min feeding and consumed 1968 +/- 99.6 ml of milk. Mean individual daily milk consumption increased with age (p < 0.001; 1623 ml/day week four to 2222 ml/day week 8), as did milk intake per meal (p < 0.001). The number of daily rewarded milk station visits averaged 8.4 +/- 0.14 (range 2 - 19). Daily milk meals and time spent milk feeding was not impacted by age (p 0.666; p 0.095). ADG was not associated with age (p 0.226; weekly average 0.19 - 0.22) and was most impacted by an interaction between daily milk intake and week (p < 0.001). All solid feed and water intakes were positively correlated with age during the milk-feeding period (p < 0.001) and increased steeply when weaning occurred at the industry average of 56 days old. Each kid consumed 5.9 +/- 0.28 meals per day (1.4 +/- 0.9 visits to the teat per meal), which lasted 4.1 +/- 0.22 min and resulted in a consumption of 342.8 +/- 20.7 ml. There was little evidence of close consecutive feeding, 57% within the 'social' meal Gaussian-defined time criteria were individual feeds, only 21% consisted of two kids, 10% three and 12% four or more kids, however, 74% of milk intake occurred during meals with > 2 kids. This study showed that a computerised milk feeder can provide data on goat kid feeding which can be used as a baseline for future research.