Young stock is the future of a dairy herd. Therefore, the transition period for first lactation animals is critical to the future success of a high-quality dairy. Essential factors of a good heifer transition program include early development of heifers, calving at an appropriate age and body condition, and reducing stress before, during and after calving.
Development of replacement heifers begins at birth. Of initial importance is prompt delivery of high-quality colostrum and separation from the mother cow. Replacement heifers should be raised in a clean, dry, well-ventilated environment with milk feedings of 2 or more quarts of high-quality milk replacer or waste milk fed at least twice a day. Increasing the amount and frequency of feeding will lead to a better-developed heifer calf that will make a better growing breeding animal and future cow. Heifer calves should also be offered calf starter from a young age to develop the rumen appropriately. All calves need access to fresh water in a bucket or bottle.
Once a replacement heifer has been weaned and moved to group housing, she needs an appropriate ration to encourage growth and reproductive development. Successful herdsmen will work closely with their nutritionist to ensure that a growing heifer’s energy and protein needs are met. With many farms starting to breed heifers at 13-14 months of age, this early development is critical to a heifer becoming a productive member of the dairy herd. After a heifer is confirmed pregnant, she should be fed to support the pregnancy and continue her growth.
Ideally, heifers should calve at approximately 22-24 months of age and 80-85% of mature body weight. Calving in heifers at this age and bodyweight will allow them to be more profitable over their lifetime. Before calving, heifers should be eating a close-up dry cow ration and preferably be housed separately from multiparous dry cows. If they cannot be housed independently, heifers should be moved into the dry-cow pen at 60 days before calving. This gives the heifers time to adjust to competing with older cows and lessens the risk of metabolic issues post-calving. Like with all dairy cows, calving should occur in a clean and dry environment, and the calf should be removed soon after birth.
It is essential to monitor fresh heifers for signs of metabolic disease such as ketosis and milk fever. And it is also imperative to watch for reproductive issues such as retained placenta or metritis. Mastitis can also negatively affect fresh first lactation animals, making monitoring milk for signs of infection, flakes, clots, and color change of utmost importance. Milk from first lactation animals with mastitis should be cultured and an appropriate treatment course determined with the assistance of the herd veterinarian. After calving, it is beneficial to continue to house first lactation animals separately from multiparous animals. This helps ensure adequate bunk space and less competition during the transition period. Housing fresh heifers separately also allows the herdsman to better monitor for any fresh cow diseases. If fresh heifers need to be housed with mature cows, stocking density should be 90% or less in a pen, based on feed bunk space.
Success in the first lactation transition period positions a dairy for success throughout the life of the cow. Managing early heifer development, age and bodyweight at first calving, and stress in the periparturient period supports a profitable dairy well into the future.