Research using standard diets for dairy heifer calves
Raising replacement dairy heifers is challenging but also provides some excellent opportunities to be assured quality replacements are continuously available for the dairy herd. They need to be managed to ensure they come into the milking herd as soon as possible and become healthy, high producing cows for the future profitability of the dairy operation. The first two months of life is the most sensitive rearing period for the young calf. With biological, environmental and nutritional stressors, the success of this first rearing phase depends on calf managers paying special attention to detail, including choosing a quality milk and calf starter nutrition program.
Recent evaluations of calf feeding philosophies comparing conventional vs. intensive feeding has been the subject of much interest by dairy farmers and specialized calf raisers. Over the past two years the research team1 at the Southern Research and Outreach Center (SROC) in Waseca have evaluated both milk replacer (varying protein, fat sources, levels and supplements) and calf starter (physical form and composition) options with over 900 heifer calves from three southern Minnesota commercial dairy herds. Since April 2004, these calves came to SROC at 2 to 4 days of age and were custom raised in the calf and heifer facility up to 6 months of age. Calves were picked up twice weekly from three dairy farms and housed in individual 4 ft x 8 ft pens for 56 days in a naturally ventilated, curtain side-wall frame-steel building. Calves between 75 and 110 pounds were assigned to a number of nutritional management projects evaluating milk replacer and calf starter programs.
The majority of projects had a similar standard control program to which all other options were compared. The standard control was feeding a 20:20 medicated all-milk protein milk replacer (MR) at 1.25 pounds per day (in equal feedings twice daily reconstituted to 12.5% solids with water) for 35 days and once daily with 0.625 pounds per day from day 36 to weaning at 42 days. A texturized 18% crude protein (CP) calf starter was offered free choice with fresh water available at all times. Performance from 177 calves on the control diets representing seven projects is summarized in the table below. A total of 927 calves have been used in these seven projects. Calf performance indicates that the standard control diets with an 18% CP starter and a medicated 20:20 MR resulted in very good calf performance. Use of a non-medicated MR with custom raised calves reduced overall performance due mainly to lower starter intake under more stressful summer temperatures which affected calf health. Increasing the amount of medicated 20:20 MR to 1.5 pounds per day and calf starter to a 20% CP or protein level in the MR to 24:20 during the winter months resulted in similar calf performance to the average of the other calf groups.
The study provided a useful base for assessing liquid and dry feeding program options for calves. The use of intensive vs. standard SROC feeding programs did provide a 21-pound gain and over 2% frame size advantage to 56 days with higher feed but slightly reduced treatment costs. An overall systems evaluation of the economic benefit to growth ratio should be assessed by including the post-weaning calf performance after calves have been transferred to group feeding pens. The choice to the calf raiser is a balance of options and economics.
What is important to emphasize is that the benchmark for a conventional program is shown by our data. The calf raiser has a number of options for calf feeding programs up to 60 days of age to use intensive, modified intensive or other liquid feeding options to meet specific growth and economic goals. Optimizing growth and health of calves during this period has a profound affect on subsequent heifer performance. The key is to maintain consistency of nutritional management and provide the most beneficial balance between calf performance and economic efficiencies that best fits the needs of the individual operation.
The bottom line-producers need to establish goals for their calf programs. Once that is done, options can be designed to meet these goals.
Published in Dairy Star September 23, 2006