Provision of shelter during the prepartum period: Effects on behavior, blood analytes, and health status in dairy cows in winter.

This study aimed to assess the effect of shelter provision during the prepartum period on lying, ruminating, and feeding behavior in outdoor-housed dairy cows exposed to winter weather conditions in a temperate climate. We also aimed to determine whether shelter provision during the prepartum period influenced blood analytes related to energy metabolism, body cleanliness, and health status. In this study, 2 cohorts of 12 multiparous Holstein prepartum cows were tested in winter. Twenty-five days before their expected calving date, the cows in each cohort were paired and randomly assigned to an open paddock without shelter or to one with access to an artificial shelter until calving. Shelter use, lying time, number of lying bouts, duration of lying bouts, rumination time, and feeding time were continuously recorded during the 3 wk before calving. Cows were assessed weekly for body cleanliness throughout the 3-wk prepartum period. A blood sample was taken from the coccygeal vein of each cow at wk -3, -2, -1, 1, 2, and 3 relative to calving date, and were assayed for nonesterified fatty acids (NEFA), ß-hydroxybutyrate, and haptoglobin concentrations. Cases of clinical health disorders after calving were also recorded. The cows spent 60% of their daily time in the shelters, and for 75% of that time they were lying down. Cows with access to shelter during the prepartum period lay down around 3.2 h/d more than cows without shelter on wk -3 and -2 relative to calving. The cows with shelter access spent less time feeding during the morning (wk -3: 29.7 min; wk -2: 12.1 min; wk -1: 17.3 min) and afternoon (wk -3: 18.2 min; wk -2: 21.9 min) than cows without shelter access. As well, cows with shelter access showed a higher body cleanliness score (∼92 vs. ∼48%) and lower NEFA concentrations (wk -2: 0.27 vs. 0.44 mmol/L; wk -1: 0.46 vs. 0.64 mmol/L) in the precalving period, and lower haptoglobin concentrations in the first week postpartum (0.34 vs. 0.79 mg/mL) than cows without shelter access. We observed no treatment differences in daily rumination time, ß-hydroxybutyrate concentrations, or postpartum health disorders. Despite the small number of dairy cows used in this study, these findings suggest that having access to a shelter during the prepartum period increases lying time, improves body cleanliness, and reduces adipose mobilization. Therefore, it is important to provide a protected area for the welfare of prepartum dairy cows exposed to winter climate conditions.

Milk production responses and rumen fermentation of dairy cows supplemented with summer brassicas.

Forage brassicas, such as summer turnip (ST; Brassica rapa) and forage rape (FR; Brassica napus), are used as supplementary crops during summer. However, studies with lactating dairy cows fed these forages are limited and report inconsistent productive responses. The aim of this study was to determine dry matter intake, rumen fermentation and milk production responses of dairy cows in mid-lactation supplemented with and without summer ('ST' or 'FR') brassicas. Twelve multiparous lactating dairy cows were randomly allocated to three dietary treatments in a replicated 3 × 3 Latin square design balanced for residual effects over three 21-day periods. The control diet consisted of 16.2 kg DM of grass silage, 2.25 kg DM of commercial concentrate and 2.25 kg DM solvent-extracted soybean meal. For the other two dietary treatments, 25% of the amounts of silage and concentrates were replaced with FR or ST. The inclusion of forage brassicas had no effects on milk production (24.2 kg cow/day average) and composition (average milk fat and protein 43.2 and 33.6 g/l, respectively). Dry matter intake was 0.98 kg and 1.12 kg lower for cows supplemented with FR and ST, respectively, resulting in a greater feed conversion efficiency (1.35 kg milk/kg DM for ST and FR v. 1.27 kg milk/kg DM for the control diet). Intraruminal pH was lower for cows supplemented with ST compared to the control diet; however, it did not decrease below pH 5.8 at any time of the day. After feeding, the concentrations of total short-chain fatty acids (SCFAs) in rumen contents increased with ST supplementation compared to the control diet. Inclusion of FR in the diet increased the molar proportion of acetate (68.5 mmol/100 mmol) in total SCFA at the expense of propionate, measured 6 h after feeding of the forage. The molar proportion of butyric acid was greater with ST and FR supplementation (13.1 and 12 mmol/100 mmol, respectively) than in control cows. The estimated microbial nitrogen (N) flow was 89.1 g/day greater when supplementing FR compared to the control diet. Based on the haematological measures, the inclusion of summer brassica forages did not affect the health status of the animals. These results indicate that mid-lactation dairy cows fed brassicas are able to maintain production despite the reduced intake, probably due to improved rumen fermentation and therefore nutrient utilization.

Claw horn lesions in mid-lactation primiparous dairy cows under pasture-based systems: Association with behavioral and metabolic changes around calving.

The objectives of this study were to describe the lying behavior of primiparous dairy cows under pasture-based systems during the pre- and postcalving period and characterize the association of lying behavior and analytes related to energy metabolism during this period with claw horn disruption lesion development later in lactation. Our convenience sample included 39 primiparous Holstein cows from 3 commercial farms that were assessed for body condition score (BCS; 5-point scale, 0.25-point increments) and had blood collected at wk -3, -2, -1, 1, 2, and 3 relative to calving date. Blood samples were assayed for nonesterified fatty acids, ß-hydroxybutyrate (BHB), and cholesterol concentrations. Electronic data loggers (HOBO Pendant G Acceleration, Onset Computer Corporation, Bourne, MA) recorded lying behavior at 1-min intervals from 3 wk before calving to 3 wk after calving. Starting at 4 wk after calving and until 16 wk after calving, cows were examined for claw lesions at approximately 4-wk intervals. Sole lesions and white line lesions were scored on a 0 to 10 scale. Of the 39 primiparous cows, 19 cows scored 0 at all exams during the entire study period and 20 cows had at least 1 severe lesion (score ≥4) between 8 and 16 wk after calving. Time spent lying before calving averaged 10.3 ± 0.3 h/d, but declined to 7.3 ± 0.3 h/d after calving (least squares means ± standard error). At calving, we noted an increase in the number of lying bouts (12.9 ± 0.45 bouts/d) compared with the pre- and postcalving averages of 11.6 (±0.53) and 9.1 (±0.47) bouts, respectively. Cows that developed claw lesions later in mid lactation spent less time lying down than cows without lesions during wk 3 after calving compared with healthy cows (7.29 ± 0.22 vs. 8.51 ± 0.16 h/d). Lesion cows had fewer lying bouts per day, and these bouts were of longer duration than no-lesion cows after calving. Increased odds of lesion were found to be associated with shorter lying times and fewer number of lying bouts during wk 3 (odds ratio = 1.23). Nonesterified fatty acids (747 ± 58 vs. 990 ± 86.85 µmol/L) and BHB (0.77 ± 0.06 vs. 0.60 ± 0.04 mmol/L) concentrations during wk 1 were greater in cows that developed claw lesions relative to cows that did not develop lesions. The BHB concentrations also remained higher in wk 2 for cows that developed claw lesions (0.63 ± 0.04 vs. 0.46 ± 0.03 mmol/L) compared with cows that did not develop any lesions. Cows that developed lesions experienced greater losses in BCS from wk -3 to 3 than cows without lesions (0.74 ± 0.01 and 0.61 ± 0.01 BCS change, respectively). In summary, changes in lying behavior and energy metabolic status after calving were associated with claw horn disruption lesions in mid-lactation primiparous cows under pasture-based systems.

Lying behavior and postpartum health status in grazing dairy cows.

Many cows have difficulty making the transition from pregnancy to lactation, as evidenced by the high incidence of disease that occurs in the weeks after calving. Changes in lying behavior can be used as an indicator of illness, yet no work to date has evaluated this relationship in dairy cows on pasture. The objectives of this study were to describe the lying behavior of grazing dairy cows during the first 3 wk after calving and determine the relationships between transition diseases and lying behavior. Our convenience sample included 227 multiparous and 47 primiparous Holstein cows from 6 commercial farms. Cows were recruited as they calved during the spring calving period. Electronic data loggers (Hobo Pendant G Acceleration, Onset Computer Corp., Pocasset, MA) recorded lying behavior at 1-min intervals. Diseases were recorded up to 21 d in milk, and cows were subsequently categorized into 3 health categories: (1) healthy, not lame and had no other signs of clinical (retained placenta, milk fever, metritis, mastitis) or subclinical (ketosis, hypocalcemia) postpartum diseases; (2) lame, identified as being clinically or severely lame with no other signs of clinical or subclinical postpartum disease; and (3) sick, diagnosed as having one or more clinical postpartum diseases (with or without a subclinical disease) but not lame. This last group was further divided into 2 groups: those that were diagnosed with a single clinical health event and those diagnosed with more than one clinical event. Lying behavior differed between primiparous and multiparous cows; primiparous cows divided their lying time into more bouts than did multiparous cows (9.7 ± 0.54 vs. 8.4 ± 0.26 bouts/d) and spent less time lying down than multiparous cows (7.5 ± 0.38 h/d vs. 8.5 ± 0.19 h/d). Lying behavior was also affected by illness; primiparous cows that developed more than one clinical disease, excluding lameness, spent more time lying, and tended to have longer lying bouts in the days following calving compared with healthy cows; multiparous severely lame cows spent more time lying down (1.7 h longer per day) compared with multiparous cows that were nonlame. Clinically lame cows had fewer lying bouts per day and these bouts were of longer duration than healthy nonlame cows. In summary, changes in lying behavior after calving were associated with postpartum health status in grazing dairy cows.