Freestall housing during the dry period altered lying time but did not affect milk quality or energy balance compared to pasture

Abstract Text: The objective was to determine changes in behavior and performance of cows housed in freestalls or pasture during a 60-d dry period.  Non-lactating Holstein cows were assigned to either deep bedded sand freestalls (n = 14) and grassy pasture (n = 14) at stocking densities below industry recommendations using rolling enrollment. At dry off, cows were equipped with an accelerometer to determine daily lying time (h/d), lying bouts (bouts/d), and steps (steps/d).  Data were divided into four periods relative to calving: FO (d -60 to -15), CU (d-14 to -1), CA (d 0), and PP (d 1 to 14).  Cows were scored for BCS (1 = thin, 5 = obese), hygiene (1 = clean, 5 = dirty), locomotion (1 = normal, 5 = severely lame), and weighed one week before dry off, at dry off, at calving, and on d 7 and d 14 postpartum.  All cows commingled following calving in a pen identical to the freestall housing treatment. Blood samples were analyzed cow-side for BHBA on d 0, 2, 5, 8, 11, and 14.  Milk samples collected at the AM milking on d 0, 1, 2, 7, and 14 were analyzed for SCC, fat, and protein.  On day 0, colostrum volume and quality were assessed.  Data were analyzed with the MIXED procedure of SAS with model effects for day, treatment, and the interaction of day and treatment.  Cows housed in freestalls laid down longer during FO (11.9±0.3 vs. 10.2±0.3 h/d, P<0.01) and CU (12.6±0.3 vs. 10.3±0.3 h/d, P<0.01) periods. Freestall cows had fewer lying bouts during the CA (11.6±0.8 vs. 15.8±0.8 bouts/d; P<0.01) period with no other periods differing. Freestall cows took fewer steps during FO (1,844.5±165.1 vs. 2,909.4±202.0 steps/d; P<0.01), CU (1,714.6±177.0 vs. 2,648.8±214.9 steps/d; P<0.01), and CA (2,015.8±204.2 vs. 2,874.3±245.6 steps/d; P<0.01) periods.  Overall, milk fat was greater for freestall cows (4.9±0.2 vs. 4.1±0.2%, respectively; P<0.01).  Lower locomotion scores tended to be associated with freestall housing compared to pasture (1.4±0.1 vs. 1.8±0.1, respectively; P=0.06).  No differences in BHBA, colostrum amount and quality, hygiene, SCC, milk protein, BCS, or weight existed between housing treatments (P>0.22).  Freestall housed cows were less active (fewer steps and greater lying times) throughout the dry period, however, this did not affect colostrum or energy balance postpartum.  The more important factor (lying time versus moderate exercise) needs to be established for improved management of dry cows.

Keywords: dairy cattle, dry cow housing, behavior