Effects of extended voluntary waiting period from calving until first insemination on body condition, milk yield, and lactation persistency

A 1-yr calving interval (CInt) is usually associated with maximized milk output, due to the calving-related peak in yield. Extending CInt could benefit cow health and production efficiency fewer transition periods per unit of time. can affect lactation performance by days dry year, delayed pregnancy effect on yield, greater solid yield late lactation. This study first investigated effects 3 different voluntary waiting (VWP) from until insemination body weight, condition, persistency. Second, individual characteristics early were identified that contributed persistency cows VWP. Holstein-Friesian dairy (n = 154) within 1 herd blocked for parity, season, expected Cows randomly assigned blocks VWP (50, 125, or 200 d: VWP50, VWP125, VWP200, respectively) monitored through complete 6 wk subsequent lactation, culling. Minimum mean (384 vs. 452 501 d VWP50 VWP125 VWP200) increased increasing VWP, but maximum was equal Fat- protein-corrected (FPCM) analyzed weekly. Milk FPCM also expressed day CInt, compare yields Persistency determined between 100 as well dry-off. Values are presented least squares means ± standard error mean. During 44 did not both primiparous multiparous cows. The CInt. Multiparous had similar VWP50. VWP200 lower compared (27.2 30.4 kg/d). last before dry-off, which their udder period after calving. better (−0.05 −0.07 Body weight among groups. a higher condition score mo dry-off next be extended 50 125 without an daily interval. 200-d reduced 50-d