Weight gain of the calf is influenced by the persistence of lactation and by forage consumption by the calf. Persistence of lactation is dependent upon forage availability and quality and is influenced by the genetic potential of the cow. Cows with high milk production potential will respond more to intensively grazed pastures managed for high quality. Cows with lower milk production potential might best be used in a system that utilizes a higher percentage of forage since their nutrient requirements are lower, reducing the demand for higher quality forage. Additionally, cows with high milk production potential probably should be calved in the spring or late winter, whereas cows of average milk potential might best be calved in the fall.
All herds have cattle with different nutrient requirements.
Monitoring the condition scores of cows is important in determining the nutritional requirements of animals. It is probably good economical management to allow cows to lose weight at certain times of the year if the weight can be replaced with good pasture at another time without interfering with the reproduction of the cow. This is particularly useful with two calving seasons when dry cows can follow lactating cows. Other examples include first-calf heifers followed by mature cows or the most productive cows followed by lower potential cows. Another strategy is creep grazing which gives calves access to higher quality forage than the cow.