Effects of early lactation milking frequency in an automated milking system on cow performance

Authors: KAMMANN, ERIN - UNIVERSITY OF WISCONSIN; French, Lizzy; JOZIK, NATALIE - UNIVERSITY OF WISCONSIN; Li, Wenli; PRALLE, RYAN - UNIVERSITY OF WISCONSIN

Submitted to: Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2024
Publication Date: 8/6/2024
Citation: Kammann, E.M., French, E.A., Jozik, N.S., Li, W., Pralle, R.S. 2024. Effects of early lactation milking frequency in an automated milking system on cow performance. Animals. 14(16). Article 2293. https://doi.org/10.3390/ani14162293.
DOI: https://doi.org/10.3390/ani14162293

Interpretive Summary: We investigated the productive and metabolic impact of three versus six milkings per day (MPD) during early lactation on cows managed in an automatic milking system (AMS). Mature cows (third and greater parity) milked six MPD had greater milk fat production (4 to 29 days in milk; DIM) and milk production (30 to 90 DIM) than mature three MPD cows. However, the mature six MPD cows had metabolic indications of a greater postpartum nutrient deficit and risk of metabolic illness. Our findings suggest a need to strategically manage the MPD or nutrition of mature dairy cows in an AMS.

Technical Abstract: Our study objective was to investigate the effects of early lactation milking frequency on cows milked via an automated milking system (AMS). Multiparous Holstein cows blocked by parity and due date were randomly assigned to fetch schedule treatments (n=8 per treatment): three (3X) or six times (6X) per day. All cows had three milkings per day (MPD) through three days in milk (DIM). From four to 29 DIM (experiment phase, EXP), 3X cows were limited to three MPD while 6X cows were allowed six MPD. After EXP, all cows were allowed six MPD but fetching was reduced to twice per day from 30 to 90 DIM (carryover phase, CO). Bodyweight, milk yield, and feeding data was measured via the AMS. Weekly composite milk samples from all milkings within a 24 h period were collected and analyzed by a commercial lab. Coccygeal blood was sampled at 3, 8 ± 1, and 13 ± 1 DIM; concentrations of alanine transaminase (ALT), aspartate transaminase (AST), cholesterol, glucose, ß-hydroxybutyrate (BHB), and fatty acids (FA) were quantified. A greater MPD was achieved for 6X cows compared to 3X cows (5.0 ± 0.2 vs 3.1 ± 0.1 MPD) for EXP, but similar during the CO. Daily milk yield was non-separable during the EXP while 6X cows in their third or greater lactation group (3+ LG) had greater milk yield than 3X cows of the same LG during the CO. Milk fat content and 4% fat-corrected milk yield were both greater for 6X cows in 3+ LG during the EXP compared to 3X cows in 3+ LG. Pellet provisioned controlled during the EXP with both treatments having the same amount of pellet available until 21 DIM, when pellet provisioned was based on milk yield and continued through the CO. During the CO pellet provisioned was greater for 6X, 3+ LG cows compared to 3X, 3+ LG cows. Of the analytes analyzed, differences were found for ALT, AST:ALT, BHB, and FA indicating that 6X, 3+ LG cows were experiencing metabolic disorders. Greater early lactation MPD in AMS may shift cow nutrient partitioning to support greater production in 3+ parity cows.