The Summer Dairy Research Updates, presented in various locations around the state, included the latest data from several Cornell dairy research trials.
New York state dairy farmers had the opportunity to hear the latest PRO-DAIRY research updates on several topics of interest which may assist them in increasing herd health and profitability. The Summer Dairy Research Updates, presented in various locations around the state, included the latest data from several Cornell dairy research trials.
One of the presentation sites, in Amsterdam, New York, included an tour of the host farm, Stony Brook Dairy. Several dozen dairy farmers from the surrounding communities gathered for a tour of this dairy, whose milking herd averages about 460 cows, with 525 mature cows, plus calves and replacement heifers in this closed Holstein herd. The herd has reached its optimal size, and is no longer growing. Heavy culling of open cows, cows with health issues and poor performance, and a zero-tolerance policy of mastitis are some of the ways in which this farm focuses on increasing efficiency and profitability without herd growth.
The farm features a automated calf feeders and group calf housing, and recent additions to old heifer facilities, which have improved respiratory concerns in the herd. The milking herd is housed in a three row, free stall facility. The double 10 parallel milking parlor can milk 100 cows per hour. Milking is performed three times per day, including overnight.
The farm is calving at 20 or 21 months, and 40 to 50 percent of heifers are confirmed pregnant with their second calf by 24 months, farmer/owner Paul Bargstedt said. This attention to reproduction is one of the primary factors helping to reduce the cost of raising replacement heifers.
Cost of Rearing Heifers
“There are many ways to get you to successful reproduction,” Dr. Julio Giordano, DVM, Assistant Professor, Cornell University Dairy Cattle Biology & Management said. Giordano presented the latest data from his recent study on dairy cow reproduction and its impact on reducing replacement heifer rearing costs.
His research involved three New York farms, and studied three different approaches to managing heifer breeding. The least intensive method involved prostaglandin injections, followed by estrus detection (ED) and artificial insemination (AI); the mid-intensity program involved Presynch protocols (to synchronize ovulation) followed by EDAI plus 5d-Cosynch; and the most intensive used a 100 percent TAI protocol. All farms had heifers enrolled in all three programs.
Giordano’s studies did not stop after the first breeding attempt. Open heifers were rebred via EDAI and 5d-Cosynch in all protocols. Any open at 31 days were bred with the same timed AI program used for the 100 percent TAI group. As expected, the most aggressive 100 percent TAI approach resulted in 100 percent of heifers bred within one day, on all farms.
The other approaches varied in success rates depending on how well the farm staff detected heat. For farms with high heat detection rates, the least intensive method resulted in only one percent of the cows open at 31 days. On the farm with very poor heat detection rates, this least aggressive method resulted in 47 percent of the heifers being open at 31 days. The mid-range intensity synchronization program resulted in more cows requiring TAI on all farms, with 19 percent of cows open at 31 days.
The study found little statistical cost difference between the low and mid-intensity programs. On average, the high-intensity TAI added $40.00 – $60.00 per cow to rearing costs, Giordano said. The heifers in the study, on average, did not make more money than it cost to rear them, after accounting for feed costs, fixed costs, shots, pregnancy checks, and the value of the calves born, and all other various expenses.
New York dairy farms have also been participating in a large-scale study to help determine what, if any, benefits are associated with supplementing fresh cows with oral calcium. In the study, 1,000 cows – both first lactation and older cows – were randomly given Quadrical boluses, and reproduction and milk production were studied.
Results show that some cows with normal calcium levels, but who received supplementation, had some negative health effects, including higher levels of mastitis in first lactation animals, or metritis in older animals. Some animal groups did demonstrate slight positive effects from calcium supplementation. Fat heifers had slightly better reproduction rates and small gains in milk production were seen in those with prolonged gestation.
The national average rate of milk fever, due to low calcium levels, is about five percent. But forty-seven percent of cows on their second or subsequent lactations have subclinical calcium levels, according to Dr. Robert Lynch, DVM, Dairy Herd Health and Management Specialist.
“Downer cows need serious intervention,” Lynch said. However, “we’re supplementing everything and maybe need to decrease this tendency.”