Impact of enhanced compared to restricted milk feeding on the behaviour and health of organic dairy calves

Abstract

Experimental studies have shown positive welfare effects of enhanced milk feeding of calves. However, there is limited evidence from studies carried out under commercial management conditions including organic farming with a prolonged whole milk feeding period. In a multi-farm study, we investigated effects of an increased level of milk feeding (10–12 l/d, ≙ 14–16% of the calves’ body weight, ‘MilkPlus’ (MP)) compared to the still wide-spread restricted milk feeding (6–8 l/d, ≙ 10–12% of body weight, ‘Control’ (C)) between weeks 3–13 of life. In total 111 female calves were alternatingly allocated to the treatments MP or C on each of the 10 dairy farms (nine certified organic, one near-organic) in Austria (Fleckvieh; 4 farms) or Germany (Holstein Friesian; 6 farms) that originally applied restricted milk provision by bucket-feeding. Data were recorded during the milk feeding period in weeks of life 3/4, 7/8, 11/12 ( ± 2 days) as well as after weaning in week 15/16. It comprised welfare measures relating to behaviour, observed from video-recordings (manipulating other calves, manipulating objects, vocalisation, duration of contact with solid feed; observation time: 320 min per day distributed over 16 h), to health (clinical scoring), and to performance (weight gain). MP calves tended to have higher body weights at the end of the milk feeding period (weeks of life 11/12: MP 111.0 kg, C 104.4 kg) and shortly after weaning (weeks of life 15/16: MP 138.7 kg, C 131.1 kg; pgroup*time point =0.095) and had higher daily weight gains during the milk feeding period (week 3/4–7/8: MP 939 g/d, C 818 g/d; week 7/8–11/12: MP 1082 g/d, C 956 g/d; p = 0.025). C calves manipulated other calves more frequently only in week 3/4 (MP 2.6, C 4.5 times per 320 min, p < 0.001). Clinical health and manipulation of objects showed no association to milk amounts, but the latter decreased when feeding duration of solid feed increased (p < 0.001). C calves spent more time with solid feed during the milk feeding period (week 7/8: MP 9.8% of observed time, C 12.0%, week 11/12: MP 14.4%, C 17.7%; p = 0.008). MP calves vocalised more after weaning (MP 1.6, C 0.5 times per 320 min, p < 0.001), though time spent with solid feed and weight gain (MP 983 g/d, C 995 g/d) were then similar between treatments. We conclude that twice-daily (teat-)bucket feeding of enhanced milk amounts under commercial organic or near-organic conditions had limited positive welfare effects.