More than 250 people attended the Dairy Cattle Reproductive Council meeting in Kansas City, Mo., last week to discuss dairy cattle reproduction. Elliot Block, PhD, Arm & Hammer Animal Nutrition, discussed the effects of protein during the prepartum period and how it influences reproductive diseases.

“Parameters for reproductive outcome are better with higher protein prepartum,” he said. “It has positive effects on first serve conception rate, fewer days open and a reduction in ketosis.” Block said in one study the postpartum level of clinical ketosis went from 31% to zero between the low protein group and high protein group, respectively.

Feeding fat has benefits
Prepartum fat feeding also seems to benefit dairy cows. Block said in one study one group was fed .5 pound/day supplemental fat four weeks prepartum and were shifted to 1 pound/day of fat postpartum, one group was fed .5 pound/day of fat at calving shifting to 1 pound/day after a one-week adjustment, another was fed .5/pound/day 28 days postpartum and shifted to 1 pound/day after a one-week adjustment, and a control group was fed no fat.

Block noted that the cows that were not fed fat had higher levels of plasma fibrinogen during first 28 days postpartum. However, cows fed any fat had better first service conception rates than cows fed no fat.

A study looked at cows fed oleic acid, linoleic acid or EPA & DHA vs. cows fed no fat. Cows that were fed omega-3 or omega-6 (linoleic) fatty acids had significantly larger follicles, which, Block said, indicates a healthier ova, and the size of the follicle is related to the quality of the embryo produced. Cows fed higher levels of omega-6 had higher messenger RNA for prostaglandin synthesis. Bock says this is worth further investigation.

21-day transition period
Block also spoke about the benefits of a 21-day transition period which research is showing to be ideal. A study of 890 cows showed that the longer they were in transition pens, predicted milk yield went up. Cows in transition groups more than 20 days had significantly lower culling and death up to 160 days in milk. Block says most culling and death occurs in the first 60 days.

Another study (Corbett, 1999) looked at number of days in the transition pen versus metabolic disease. The study showed that cows in pens shorter periods of time had higher milk fever, retained placenta and uterine infections than those in pens greater than 15 days. “Twenty-one days for the transition period seems very reasonable,” Block said. “There is no harm in keeping them in longer, but there are negative effects if they are in for shorter periods of time.”