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Timing of ration delivery regulates periprandial eating behavior of dairy cows
Chronophysiology of eating behavior and feed intake control is a state-of-the-art science. The objective was to determine effects of feeding time and dietary forage to concentrate ratio on periprandial and 24-h patterns of feed intake in lactating cows. Four tie stall-housed multiparous (body weight = 652 ± 14 kg, body condition score = 2.87 ± 0.14, days in milk = 83 ± 22) and 4 primiparous (body weight = 667 ± 110 kg, body condition score = 3.19 ± 0.66, days in milk = 81 ± 23; mean ± SD) Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of feeding time and diet type. A higher (HC, forage to concentrate ratio = 38.5:61.5) or a lower (LC, forage to concentrate ratio = 50.6:49.4) concentrate total mixed ration (TMR) was delivered at either 2100 h or 0900 h. The study consisted of four 21-d periods, each with 14-d of adaptation and 7-d of sampling. A metabolic acquisition system was used to monitor continuous feed intake electronically. Mixed Models used to analyze the data included fixed effects of feeding time, diet, parity, and their interactions, and random effects of period and cow within parity plus residuals. Provision of the TMR at 2100 h vs. 0900 h increased feed intake within 3-h post-feeding, from 26% to 37% of total daily intake (P < 0.05). In cumulative terms, the amounts consumed between 0 and 6 h and 0 and 9 h post-feeding were similar between the 2 groups. Parity and diet did not interact with feeding time on circadian patterns of feed intake (P> 0.10). Despite altering the post-feeding patterns of intake, provision of TMR at 2100 h vs. 0900 h did not affect total daily dry matter intake (19 kg/d). Findings demonstrate that altering eating time can alter periprandial patterns of feed intake in lactating cows. Feeding time is established as a management orchestrator of periprandial feeding behavior in once-daily fed dairy cows.
Keywords: eating time, intake pattern, dairy cow