Journal article

Publication year: 2022

Pages: 6858-6869

Journal: Journal of Dairy Science

Volume number: 105

Issue number: 8

ISSN: 0022-0302

eISSN: 1525-3198

Open access status: Gold

DOI Link: https://doi.org/10.3168/jds.2021-21526

Publisher: Elsevier

Abstract: 
The objective of this prospective cohort study was to evaluate the association between the prepartum days in the close-up group (DINCU) and milk yield, milk components, reproductive performance, and cull-ing risk in the subsequent lactation for Holstein dairy cows. Dry cow feeding management of 20 farms was evaluated during 2 farm visits. All farms were feeding an acidogenic diet in the close-up group. Data from 14,843 cows were collected for 365 d following the sec-ond farm visit. Data sets of 13,314 cows were available for final statistical analysis after exclusion of cows with missing information about gestation length, cows with a gestation length shorter than 262 d or longer than 292, cows with 0 DINCU, and cows with >42 DINCU. At enrollment, 3,871 and 9,443 of those animals were nulliparous and parous cows, respectively. Continuous data such as energy corrected milk (ECM), the ratio of fat and protein, and somatic cell score (SCS) at first test day were analyzed using linear mixed models. Binary data such as stillbirth, culling within 60 DIM, and pregnancy within 150 DIM were analyzed using logistic regression models. Based on their different physiology, separate models were built for nulliparous and parous cows. All results displayed are the predicted least squares means from the multivariable analyses. A significant association between DINCU and milk yield at first test day was observed for nulliparous and par-ous cows. Nulliparous cows with 7, 21, or 35 DINCU had a first test day ECM of 31.8, 33.3, and 35.5 kg, respectively. Parous cows with 7, 21, or 35 DINCU had a first test day ECM of 42.8, 45.6, and 44.6 kg of ECM, respectively. In nulliparous cows, there was a tendency for an association between DINCU and the ratio of fat and protein at first test day. In parous cows, however, a Berlin, Berlin, Germany significant association was observed. Parous cows with 7, 21, or 35 DINCU had a ratio of fat and protein of 1.31, 1.35, and 1.37, respectively. There was a signifi-cant association between DINCU and SCS at first test day in nulliparous and parous cows. In nulliparous cows with 7, 21, or 35 DINCU, SCS was 2.39, 2.49, and 2.85, respectively. In parous cows with 7, 21, or 35 DINCU, SCS was 2.46, 2.53, and 2.78, respectively. No associa-tions were observed between DINCU and occurrence of stillbirth and DINCU and the risk of pregnancy within 150 DIM. The multivariable model predicted a tendency for an association between DINCU and the risk of be-ing culled within 60 DIM in parous cows. Particularly, 0 to 6 DINCU were associated with a substantially increased risk of being culled. In conclusion, a short stay in the close-up group should be avoided to improve milk yield at first test day and to minimize culling risk for parous cows. A long stay in the close-up group (>30 d) was associated with reduced milk production and an increased ratio of fat and protein in milk of parous cows and increased SCS of nulliparous and parous cows.

Harvard Citation style: Venjakob, P., Neuhaus, L., Heuwieser, W. and Borchardt, S. (2022) Associations between time in the close-up group and milk yield, milk components, reproductive performance, and culling of Holstein dairy cows fed acidogenic diets: A multisite study, Journal of Dairy Science, 105(8), pp. 6858-6869. https://doi.org/10.3168/jds.2021-21526

APA Citation style: Venjakob, P., Neuhaus, L., Heuwieser, W., & Borchardt, S. (2022). Associations between time in the close-up group and milk yield, milk components, reproductive performance, and culling of Holstein dairy cows fed acidogenic diets: A multisite study. Journal of Dairy Science. 105(8), 6858-6869. https://doi.org/10.3168/jds.2021-21526