A dry cow’s protein and energy needs rise during the last three weeks of gestation due to the growth of the calf and udder, as well as the synthesis of colostrum. During this period, widely referred to as closeup, dry matter intake drops by nearly 30 percent.
Intake plummets near calving
Most of this reduction, however, occurs during the last week of gestation, as reported by University of Wisconsin researchers. In their experiment, feed intake three weeks before calving was around 1.7 and 2 percent of body weight in heifers and cows, respectively. It dropped further to 1.3 and 1.4 percent the day before calving.
Intake reduction coupled with higher nutrient demands result in a negative energy balance that is more pronounced towards the end of gestation. The magnitude of the energy shortage depends on the cow’s milk production potential and the adequacy of its feeding program. Even with energy-dense rations this deficit can continue for several weeks and has been associated with immune suppression, health disorders around calving and longer calving to first service intervals.
Creates health hurdles
Research has suggested that cows with lower intakes are predisposed to suffer metabolic problems and infections right after calving. In a trial conducted at the University of British Columbia, cows diagnosed with an acute uterine infection had consumed less feed 12 to two days before calving than those not affected.
In a posterior experiment at the same university, the risk of uterine infection rose between 1.6 and 1.7 times for every 10 minutes less cows spent daily at the feedbunk during the last week of gestation. In addition, for every 2.2 pounds’ reduction in intake, the risk of metritis tripled. The incidence of subclinical ketosis showed a similar pattern, with double the risk for every 2.2-pound drop in intake or every 10-minute reduction in time spent at the feedbunk.
Continue reading this article published in Hoard’s Dairyman.
