Group Raising of Dairy Calves on Well-Managed Pasture
Bill Murphy, Joshua Silman, Mike Eastman, Henry Forgues, Travis Forgues
Duration: 1994 - 1997
Raising calves individually in barns or hutches is too labor-intensive and expensive for pasture-based dairy farmers striving for high profitability and quality of life. It also may result in unhealthy adult cows that cant efficiently use forage, because rations high in grain may not sufficiently stimulate rumen development in calves. Heifers raised on pasture tend to have larger rumens, which enable them to hold and process more feed than those raised on low-bulk feeds in confinement. The relative size of a calfs rumen at 3 to 4 months of age remains constant for the rest of its life. Raising calves separately also doesnt provide them with the social interaction they need to behave and graze well as mature cows in herds on pasture-based dairies.
One way to get healthy cows that have fully developed rumens and know how to graze well in a herd is to raise them from birth in groups on well-managed pasture, preferably with a nurse cow that teaches calves how to graze. If calves start early on pasture, they can live on pasture forage alone after they are about 60 days old.
Some questions still need to be answered to eliminate unnecessary costs of raising
replacement heifers on pasture, such as: How much energy and protein supplement should be
fed calves raised on pasture? We did two
experiments to answer part of this question.
In 1994 on his farm near Hinesburg, Mike Eastman raised 20 Holstein and crossbred calves from 2 days of age on pasture under management intensive grazing. The group of calves grazed a Kentucky bluegrass-white clover pasture that had not been plowed for at least 30 years, so the sward was very dense. He kept the sward short, with a pregrazing mass of 2100 lb DM/acre (4 inches tall) and a postgrazing mass of 1400 lb DM/acre (2 inches tall). Keeping the sward short and leafy is important for little calves to be able to eat well. Mike moved the calves to fresh forage every 3 days. Calves were fed about 2 gallons of milk/calf/day using barrels with New Zealand nipples, and 2 lb 19% Calf Starter BT/calf/day free-choice.
At weaning (about 60 days old) we separated the calves by weight and breeding into two groups of 10 each and fed one group 2 lb and the other group 4 lb of 19% Calf Starter BT/calf/day free-choice in tubs on the ground. We treated all calves with fenbendazole wormer at weaning and again 1 month later. We weighed the calves every 2 weeks. Grazing management continued the same, moving the calves every 3 days.
The calves gained the same (1.5 lb/calf/day) after weaning until end of the grazing season (mid-October) regardless of supplement level, indicating that the lower amount would be adequate on this kind of high-quality pasture. Until heifers are sexually mature they shouldnt gain more than 1.5 lb/day; otherwise their potential for producing milk decreases.
Unfortunately, we werent able to repeat the experiment on this farm to see if calves would gain the same without supplement. We attempted to repeat it in 1995, but deer kept passing through the pasture at night, causing the calves get excited and mix the two groups together. Mike purchased a different farm in 1996, and the new lessee of this farm didnt want to conduct this research.
We repeated the experiment in 1997 on the Forgues farm near Alburg. Henry and Travis Forgues raised 18 crossbred calves on pasture in the same way as on Mikes farm, except that they moved the calves to fresh forage every day. The pasture was only about 6 years old, following 15 years of corn and alfalfa cropping with herbicides, so its still developing into a dense sward. It consisted mainly of Kentucky bluegrass and white clover, with other plants such as orchardgrass, dandelion, chicory, lambsquarter,pigweed, and foxtail. The pasture was less dense and was grazed taller than on Mikes farm: 6-8 inches tall at start of grazing, grazed down to 3-4 inches tall. The calves were fed the same amount of milk using barrels with New Zealand nipples, and the same amount of supplement until weaning as in the first experiment.
At weaning (60 days old) we separated the calves by breeding and weight into 2 groups of 9 each and fed one group 0 lb and the other group 2 lb of 19% Calf Starter BT/calf/day. All calves were dewormed with fenbendazole at 4 and 8 weeks after turnout on pasture. We weighed the calves once a month. Grazing management continued the same, moving the calves to fresh forage every day.
The calves gained 0.6 (no supplement) or 0.9 (supplemented) lb/calf/day after weaning until the end of the grazing season (mid-October). These calves gained less than usually desired, were smaller and bred later (16-20 months old) than conventional standards. The Forgues, however, are trying to develop a herd of smaller animals to reduce cow body maintenance costs; they concluded that, for their purposes, supplementation after weaning was not worth the expense.
These studies indicate that calves can be raised very well in groups on pasture with 2 lb or less protein supplement/calf/day after weaning. Two pounds was an adequate level of supplementation with a high-quality sward,but could not make up for efficiencies of a low-quality sward to achieve high weight gains, if desired. Pasture quality is the most important aspect of raising calves on pasture. A short, dense, leafy sward is ideal for calves to eat all they need of excellent-quality forage that results in high weight gains.