Bryan McMurry, with Cargill Animal Nutrition, earned his Masters Degree in Animal Breeding and Genetics, and a PhD in Animal Science from Texas A&M University. The short, simple answer to this question is of course, the cow. That’s her job. As cattlemen, taking care of the cow is our job. The answer to taking care of the cow is neither short nor simple.
The calf depends entirely on the cow from conception until weaning and given the proper environment she is capable of providing nearly everything the calf needs. If we understand the cow’s needs we can provide for the needs of both her and the calf.
We take care of the calf through our management of the cow. Our entire management efforts center on providing the inputs required for the cow to do her job. Not providing these inputs diminishes her chances of successfully playing her role in the cow/calf production system. The role of the cow specifically, and cow/calf production systems in general, is to profitably turn forage (plant matter) into beef (animal protein) through the production of calves.
Like every living thing, the cow needs water, which is the most important nutrient. Water is essential to maintaining all bodily functions and if limited results in lower productivity and performance. Clean water should be provided ad libitum. Production systems that rely on surface water are at the mercy of adequate runoff from rainfall to provide the cow’s drinking water. The quality of surface water can vary greatly, especially during times when the quantity is limited. It is important to understand water quality through occasional testing. Well water should also be tested at least once for elements that can cause health or nutritional issues. Critical elements found in water that, if excessive, can cause health or nutritional problems are sulfur, iron, nitrates, sodium and heavy metals.
The nutritional status of the cow throughout the year is critical for success. The majority of the nutrients are most economically derived from grazed forage. Therefore our entire management plan should focus on providing a sufficient quantity of grazed forage of a quality closest to the cows’ requirements.
The cow’s requirements vary throughout the year as she moves through the four phases of production; calving to breeding, late lactation, mid gestation, and pre-calving.
Likewise, the quality of the forage, and level of nutrients available to the cow, varies throughout the year and are categorized into four growth stages; early vegetative, late vegetative, mature, and dormant. From a nutritional perspective we manage cattle to ensure that when the cow’s requirements are highest, calving to breeding, she has the highest quality forage, the early vegetative stage, available to her. Therefore the timing of calving is critical in providing the needed nutrients at the lowest cost, meeting the cow’s requirements to ultimately care for the calf.
The nutritional care of the calf is primarily delivered through milk. Milk constitutes nearly all of the calf’s nutrient supply for the first four months of its life. Cows genetically capable of supplying high quantities of milk mobilize body fat to ensure that the milk production is adequate, even when high quality forage is available to them. Body conditioning scoring (BCS) is how we assess the amount of body fat available for mobilization during early lactation. In addition to providing energy for milk production, higher body condition scores (BCS 5 and 6) at calving result in higher reproductive performance than cows with lower scores (BCS 4 or less).
Managing cow BCS is how we begin taking care of the calf, even before it’s born. During mid-gestation the cow’s nutritional requirements are at their lowest of the production cycle. This is the most opportune time to replace body condition lost during lactation before the cow’s requirements increase substantially in the pre-calving phase. The pre-calving phase, the sixty days prior to calving, is when approximately seventy percent of fetal development occurs. By ensuring that the cows are in good body condition and that the diet meets their increasing nutritional requirements, we’re indirectly taking care of the prenatal calf. The calf’s neonatal vigor, the ability to quickly rise and nurse, and health status are impacted by the nutritional status of the cow during the pre-calving phase.
The nutritional status of the cow pre-calving, along with a complete cow vaccination program, determines the quality of colostrum or first milk provided to the calf. Colostrum provides the sole source of antibodies, providing passive immunity from pathogens until the calf’s active immune system begins functioning. The health of the neonate calf is entirely dependent on how well we take care of the cow pre and post calving.
The first time we routinely directly intervene in the care or the calf is when we vaccinate to prevent common infectious disease. These vaccinations are administered after the calf develops a functioning immune system, about three months of age, and before weaning. By three months of age the passive immunity provided by the colostrum is no longer providing immunity and it is time to directly intervene.
Putting it All Together
The way we manage the above factors begins with the establishment of the production calendar. For the herd the calendar begins with the birth of the first calf, which in most cases should be about thirty, but not more than sixty days before forage is in the early vegetative stage of growth. The cow’s nutrient requirements are highest in the third month after calving, coinciding with her peak milk production. Maximum forage quality and quantity begins about a month after first green up. Cows calving thirty days before green up are peaking in their milk production at the time when the forage is most capable of meeting the higher protein and energy requirements, and the calf is of sufficient size to handle the volume of milk. The critical nutrients lacking at this time are mineral elements, both macro and micro minerals. A high quality, weatherized, loose mineral designed for the region offered free-choice is essential in filling the mineral shortcomings in the forage. Mineral supplementation should continue through the grazing season.
After weaning the cow’s nutrient requirements drop to the lowest levels during the production cycle. Even though the mature forage is of relatively lower quality than earlier in the season, this is the best time for the cow to regain body condition due to her low nutrient requirements. Late season, mature forage is often capable of meeting the cow’s protein and energy requirements, while dormant forage is more often marginal. If the grazed forage contains a minimum of 7% crude protein and 45 – 48% total digestible nutrients (TDN) the only supplementation required is mineral until about sixty days prior to calving.
The cow’s nutrient requirements increase substantially during the pre-calving period, driven by the developing fetus and associated tissues. It is important to make sure we are meeting the cow’s requirements during this period to ensure proper fetal growth, maintain the cow’s body condition and promote the production of high quality colostrum. Dormant or lower quality forages won’t meet the requirements during this period. Supplemental feed is often required during the pre-calving phase and a high quality, free-choice mineral is essential. As the cows calve, the entire process begins anew.
So, who takes care of the calf? If we do a good job of taking care of the cow, meeting her needs pre and post calving, she can raise and wean a quality calf.