Effect of prepartum dry matter intake on liver triglyceride concentration and early lactation.

Depression in feed intake during the final week before calving was hypothesized to be a major factor in the etiology of fatty liver development near parturition. Eleven cows were allowed to eat for ad libitum intake prior to calving (control), and 11 cows were maintained at the same level of DMI recorded during d 21 to 17 prior to calving by force feeding the feed refusals via rumen cannulas. Feed intake by control cows decreased 28% during the final 17 d prior to calving. Lipid triglyceride increased 227 and 75% for control and force-fed cows between d 17 prior to parturition and d 1 following calving. Dry matter intake prior to calving was correlated negatively with liver triglyceride immediately after calving (r = -.80). Plasma glucose concentrations for control and force-fed cows were 63 and 76 mg/dl 2 d prior to calving and also were related closely to liver triglyceride immediately after calving (r = -.50). By d 28 after calving, there were no differences in liver triglyceride between treatments. Cows that were force-fed prior to calving tended to yield milk with greater fat percentage (4.22 vs. 3.88%) and to yield more 3.5% FCM (46.1 vs. 41.7 kg/d) during the first 28 d postpartum.