Activity and rumination of Holstein and crossbred cows in an organic grazing and low-input conventional dairy herd.

Holstein and crossbred dairy cows from an organic grazing and low-input conventional herd were evaluated for activity and rumination across 4 yr (January 2014 to December 2017). Data were from two herds, an organic grazing (ORG) and a low-input conventional (CONV) that were managed similarly at the University of Minnesota West Central Research and Outreach Center, Morris, MN. Breed groups and total cows across the 4-yr study in the analysis for both herds were Holstein (HO, n = 114), 1964 HO genetic line (H64, n = 83); crossbreds sired by Montbéliarde, Viking Red, and HO (MVH, n = 248), and Normande, Jersey, and Viking Red (NJV, n = 167). During the summer grazing season (May to October) ORG cows were on pasture and supplemented daily with 2.72 kg of corn per cow, and CONV cows were fed a total mixed ration (TMR) in an outdoor confinement dry-lot. During the winter season (November to April) ORG and CONV cows were fed a TMR consisting of corn silage, alfalfa haylage, corn, soybean meal, and minerals in an outwintering lot and a compost barn. Activity (reported in activity units by daily and bihourly periods) and rumination, (min/d and min/2 h) from SCR DataFlow II software, were monitored electronically using HR-LD Tags (SCR Engineers Ltd, Netanya, Israel) for the 4-yr period. Daily activity was greater for 2016 and 2017 (P < 0.05) than for 2014 and 2015 for the ORG and CONV herds. Daily rumination varied by year, and 2015 and 2016 were lower (P < 0.05) than 2014 and 2017 in both herds. The HO and crossbred cows were not different (P > 0.05) for activity in both the ORG and CONV herds. The H64 cows had lower (P < 0.05) rumination than the other breed groups in the ORG and CONV herds. For ORG primiparous cows, the H64 cows had lower rumination than MVH cows, and the ORG multiparous H64 cows had lower (P < 0.05) rumination than HO and MVH breed groups. For CONV primiparous cows, the HO cows had greater (P < 0.05) rumination the other breed groups, and the CONV multiparous HO, MVH, and NJV cows had greater (P < 0.05) rumination than the H64 cows. Results from this study suggest that activity and rumination are different between breeds in the experimental low-input dairy herds.