Purpose of this study was to investigate the relations of dry period lengths (DPL) with subsequent lactation (305-d) milk yield (MY) and reproductive performance of Holstein cattle. Data were obtained from 800 Holstein cows raised in a private dairy operation and which were in different parity (2 nd , 3 rd and ≥4 th). DPL was classified in 5 categories as; ≤40, 41-50, 51-60, 61-70 and ≥71 days. The differences in lactation milk yields of experimental DPL groups were not significant. The highest MY (7808.6±135.1 Lt) was obtained from ≥71 days DPL group and the lowest MY (7529.4±159.8 Lt) was obtained from ≤40 days DPL group. DPL had significant effect on the number of inseminations resulted in pregnancy (P<0.01). The greatest pregnancy ratio (53.0%) in the first insemination was obtained from ≤40 days DPL group and the lowest pregnancy ratio (30.8%) was obtained from 61-70 days dry period group. There was a positive correlation (0.056) between DPL and 305-d MY and a highly significant positive correlation (0.141) between DPL and the number of insemination resulted in pregnancy. Present findings revealed that longer DPL might have positive effects on lactation MY, but shorter DPL practices might have better outcomes for pregnancy ratios of the first insemination for this farm.
This study was conducted to investigate the effects of dry period length (DPL) on survival rate, gender, growth performance, mortality of Holstein calves. Data belonged to 800 Holstein cows in different parities (2nd, 3rd and ≥4th) and 800 calves delivered by these cows. DPL were classified in 5 categories (≤40, 41-50, 51-60, 61-70, ≥71 days). Calves were weighed and body dimensions (body length, wither height, hearth girth) at birth and 6th months of age. There were significant relationships between DPL and calf gender (P
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.