Abstract #M81

Section: Animal Health
Session: Animal Health I
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall B
# M81
Effect of calving stress on feed intake of dairy cows soon after calving.
M. Reshalaitihan*1, K. Matsuki2, T. Sato2, M. Hanada2, 1United Graduate School of Agricultural Science, Iwate University, Morioka, Iwate, Japan, 2Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.

Several studies reported that dry matter intake (DMI) after calving was lower and the degree of calving difficulty was higher in primiparous cows compared with multiparous cows. These results suggest that primiparous cows might experience more stress around calving than multiparous cows. This study was done to compare calving stress around calving between primiparous and multiparous cows and to investigate the effect of the stress on DMI in dairy cows soon after calving. Fifteen primiparous and 15 multiparous Holstein cows were used. The cows were offered a total mixed ration (TMR) restrictedly (80% of energy requirements) and hay ad-libitum before calving and were offered another TMR and hay ad-libitum after calving. DMI was measured from 1 to 6 d after calving. Blood was taken at −33, 0.5, 3 and 7 d after calving to measure metabolites. Urine was collected at −11, −8, −4, 0.25, 4, 8 and 13 d after calving to measure cortisol concentration. BW was measured once a week and milk yield was measured every day after calving. One-way ANOVA followed by LSD multiple comparisons tests were used to compare individual parameters among the groups. Average DMI for 6 d after calving was lower in primiparous cows (88 g/BW0.75/d) than in multiparous cows (112 g/BW0.75/d, P < 0.01). Highest urinary cortisol was observed at 0.25 d after calving in both cows and there was no significant difference between primiparous and multiparous cows (P > 0.10). However, urinary cortisol was higher in primiparous cows than in multiparous cows at 4 d after calving (P < 0.01). Pearson correlations were performed to investigate the relationship between the parameters. Average DMI for 6 d after calving was negatively related to the urinary cortisol at 4 d after calving (P < 0.01) and positively related to average milk yield for 6 d after calving (P < 0.01) and serum Ca at 3 d after calving (P < 0.01). To identify the effect of these 3 factors on the DMI, a multiple regression analysis was performed and a significant multiple regression equation was obtained (r2 = 0.67, P < 0.01). The standardized partial regression coefficients of the equation were −0.43 for the urinary cortisol, 0.52 for the milk yield and 0.44 for the serum Ca.

Key Words: cortisol, intake, transition dairy cow