The last trimester of pregnancy is a critical period for determining the profitability of a cow-calf operation. Approximately 75% of fetal growth occurs during the final 90 days of gestation and the cow herself is preparing for the challenges of the calving process. Unquestionably, the calving day is the most traumatic of the year for the cow. Sometimes, the process of making colostrum, or the calf’s first meal, gets lost in the crush of all the metabolic processes occurring as the big day of calving approaches, yet colostrum quantity and quality may determine calf livability and health for the rest of its life into the feedlot or breeding herd.
Calves are born with an immature immune system and a sterile digestive tract ready to be populated by both slow-growing beneficial microflora and fast-growing pathogens. Into the potentially death causing gap in the calf’s self-defense steps colostrum. Colostrum is a critical source of a range of antibodies or immunoglobulins (Ig), energy, amino acids, and importantly, growth factors for the digestive tract and body.
Further, the calf’s digestive tract enables the absorption of important Ig in the first 6-12 hours of life and then Ig absorption quickly declines to no uptake. Calf researchers often emphasize not only colostrum consumption within even the first two hours of life, but also a colostrum with a high concentration of Ig. While measuring colostrum quality and consumption may be relatively easy for dairy producers; colostrum consumption, timing, and quality are essentially unknown with beef calves. Therefore, cow-calf producers should consider the critical factors to increase colostrum quality and quantity.
- Environment: Heat, cold, and other environmental factors affect nutrient intake, metabolism, and nutrient allocation. The cow prioritizes nutrients to staying alive, and colostrum production is usually the last priority for nutrient allocation.
- Immune system status: Unresolved inflammation from disease, environment, stress, mycotoxins, and other factors suppress the immune system’s ability to respond to vaccinations and diverts nutrients from more useful purposes, such as preparing for calving and preparing the calf’s first meal: colostrum.
- Energy: Environmental conditions, the cow’s age, and inflammation status determine energy allocation, and then fetal development receives priority usage for energy-over-colostrum production Monitoring cow-body condition, and adjusting energy feeding accordingly, is the best way to assure sufficient energy is available for colostrum production.
- Protein: Protein, or more appropriately amino acid, nutrition is critical for supporting immune function, fetal growth, and colostrum production. Generally, a 9-11% CP and 60% TDN diet will result in sufficient ruminal bacteria growth to meet the cow’s amino-acid needs.
- Minerals: Macro and micro minerals are often overlooked for their importance as key factors in nutrient utilization, metabolism, and immune function. Appropriate mineral supplementation may be the best ROI decision for the cow-calf producer.
- Vitamins and antioxidants: Similar to minerals, vitamins, and antioxidants are critical for metabolism and immune support to enable colostrum production.
The calf’s first meal, colostrum, is a major determinant of calf survival and health, and may have lasting effects into feedlot performance or future retainment as a herd replacement. Simple management and nutritional decisions during the last pregnancy trimester impact colostrum quality and quantity and may be among the best ROI decisions for the cow-calf producer.
Author: Larry Roth, Ph.D., PAS Vice President of Nutrition Agrarian Solutions • [email protected]