Edvardsson Rasmussen A, Holtenius K, Båge R, Strandberg E, Åkerlind M, Kronqvist C
Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Box 7024, 750 07 Uppsala, Sweden.
Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Box 7024, 750 07 Uppsala, Sweden.
J Dairy Sci. 2023 Apr;106(4):2510-2518. doi: 10.3168/jds.2022-22773. Epub 2023 Feb 22.
Extending the voluntary waiting period (VWP) for primiparous cows can have a positive impact on fertility without a negative impact on milk production per day in the calving interval (CInt). We investigated the effect of extended VWP during first lactation on milk yield (MY) during 2 consecutive lactations in primiparous cows. The study involved 16 commercial herds in southern Sweden. A total of 533 Holstein and Red dairy cattle (Swedish Red, Danish Red, Ayrshire) dairy cows were randomly assigned to a conventional 25 to 95 d VWP (n = 252) or extended 145 to 215 d VWP (n = 281). Data on calvings, inseminations, and test-day yields were retrieved from the Swedish Milk Recording System. Cows with VWP according to plan and completing 1 or 2 CInt with a second or third calving were included in the data analysis. Whole lactation and 305-d energy-corrected milk (ECM) yield were higher for the extended VWP group than the conventional VWP group in both the first lactation (12,307 vs. 9,587 and 9,653 vs. 9,127 kg ECM) and second lactation (12,817 vs. 11,986 and 11,957 vs. 11,304 kg ECM). We found no difference between the VWP groups in MY per day during the first CInt or during the first and second CInt combined, although MY per day during the second CInt was around 1.5 kg higher for cows with extended VWP than for cows with conventional VWP. Thus extended VWP for primiparous cows can be used as a management tool without compromising MY.
延长初产母牛的自愿等待期（VWP）对繁殖力有积极影响，且对产犊间隔（CInt）内的日均产奶量没有负面影响。我们研究了初产母牛首次泌乳期间延长VWP对连续两个泌乳期产奶量（MY）的影响。该研究涉及瑞典南部的16个商业牛群。总共533头荷斯坦和红奶牛（瑞典红牛、丹麦红牛、艾尔夏牛）被随机分配到常规的25至95天VWP组（n = 252）或延长的145至215天VWP组（n = 281）。从瑞典牛奶记录系统中检索产犊、授精和测定日产奶量的数据。按照计划有VWP并完成1个或2个产犊间隔且进行第二次或第三次产犊的母牛被纳入数据分析。在第一个泌乳期（12,307对9,587以及9,653对9,127千克能量校正乳）和第二个泌乳期（12,817对11,986以及11,957对11,304千克能量校正乳），延长VWP组的全泌乳期和305天能量校正乳产量均高于常规VWP组。我们发现，在第一个产犊间隔期间或第一个和第二个产犊间隔合并期间，VWP组之间的日均产奶量没有差异，尽管延长VWP的母牛在第二个产犊间隔期间的日均产奶量比常规VWP的母牛高约1.5千克。因此，延长初产母牛的VWP可作为一种管理工具，而不会影响产奶量。
