Intake, milk yield, and lying behavior of dairy cows fed on two hay diets at dry-off: A case study in Brazil

Abstract

Dry-off involves a series of changes to the cows’ routine to achieve cessation of lactation. One of these methodologies includes a change in diet, typically to a feed that is lower in energy. Although this is effective in reducing milk production, it has potential negative welfare effects. The objective of this case study was to investigate the effect of two hay diets on dry matter intake, milk yield (MY), lying behavior, and vocalizations of dairy cows at dry-off on a farm in Brazil. Sixteen Holstein dairy cows were assigned to one of two dietary treatments: diet 1 = Vaquero (Cynodon dactylon) or diet 2 = Tifton 85 (Cynodon spp.). Cows were monitored for 3 days before dry-off and 5 days after. Baseline results are presented as mean ± SEM or mean and 95% confidence interval. Before provision of hay diets (day −2 to day 0), each cow was consuming 8.9 ± 0.5 kg/d of dry matter of total mixed ration, MY was 9.5 ± 0.3 kg/d, and they were lying down for 10.9 ± 0.7 h/d, over 7.8 (6.2-9.8) bouts/d. Regardless of treatment, compared with baseline, MY (mean ± standard error of the difference) decreased by 5.2 ± 0.3 kg/d on day 1 and a further 1.0 ± 0.3 kg/d on day 5. Similarly, lying time and bouts were not affected by treatment, but they did change compared with baseline, likely because of an effect of the skipped milking schedule. Highly variable vocalization data prevented modeling of this variable. In conclusion, low-producing dairy cows at dry-off could be fed either diet to reduce milk production, without negatively affecting feed intake or lying behavior.