Calf and mother

What mama eats now will affect calves for the rest of their lives

December 13, 2019 3:26 p.m.

By Lance Kennington, PH.D., animal nutritionist, CHS

We have now entered the very crucial time of the year when the mineral needs of the cow herd are of maximum importance. Most calving will begin in the next 30 to 60 days and the mineral requirements of the cows are at a heightened state. The fetus is growing at, or near, one pound per day and this is the last time to build proper trace mineral status in the calf until he is able to consume feedstuffs or free-choice mineral well after birth. The early diet of the calf is milk, and it is nearly devoid of trace minerals.

The second, and perhaps most important, function of proper mineral nutrition for the pre-calving cow is building high quality colostrum. What happens in the first 24 hours impacts the rest of a calf’s life. In order to have high quality colostrum and to subsequently maximize passive immunity, it is imperative that ranchers provide, and insure intake of, a high quality chelated mineral program.

Scientists with the USDA experiment station at Clay Center, Nebraska, monitored health events and growth performance in a population of range beef calves in order to identify associations of production factors with baby calf passive immune status.

Blood samples were collected at 24 hours after calving from 263 crossbred calves to determine the amount of passive maternal immunity that had been obtained from colostrum. The baby calves were classified with “inadequate” or “adequate” passive immune status based on that blood sample at 24 hours of age. Growth performance and health events in the study population were monitored from birth to weaning, and after weaning throughout the feedlot phase.

The lowest levels of passive immunity were observed among calves that were sick or died prior to weaning. Calves with inadequate passive immunity had a 5.4 times greater risk of death prior to weaning, 6.4 times greater risk of being sick during the first 28 days of life, and 3.2 times greater risk of being sick any time prior to weaning when compared to calves with adequate passive immunity. Based on 24-hour proteins (most of which are antibodies or immunoglobulins) in the blood, the risk of being sick in the feedlot was also three times greater for the inadequate calves versus adequate calves. Passive immune status was also indirectly associated with growth rates through its effects on calf health. Sickness during the first 28 days of life was associated with a 35-pound lower expected weaning weight. If those calves with inadequate immunity contracted respiratory diseases while in the feedlot, they would gain almost 0.09 pound less per day than those with adequate immunity.

Remember that most of the transfer of antibodies from colostrum to the calf happens in the first six hours. The first day sets the stage for the rest of a calf’s life.

Lastly, one must always remember that the mineral program during the period of calving through breeding is very important for maximizing first service and total conception rates. Each cycle a cow doesn’t breed will decrease weaning weight by 50 pounds and each cow that ends up open would have bought a lot of high-quality mineral.

In many situations, mineral supplementation may be the most neglected program on the ranch. Increased genetic potential for performance requires the need to maximize nutritional inputs in order to maintain economic sustainability. A proper mineral program that is designed to balance the inadequacies of forage is the cheapest supplement that a rancher will buy.