When I tour a calf barn along with dairy producers, I often ask them what their main goal in raising baby calves to weaning? Many people respond that they wish to double the newborn’s bodyweight by weaning. My first thought is that this objective is truly challenging from any angle.
To start, I calculate the average daily gain (ADG) that a typical neonate Holstein calf needs to verify if such calf barn ambition is probable in the first place. Therefore, a 95-lb. calf needs to gain 1.7 lbs./head/dairy to achieve a 190-lb. weaning-weight, given an eight-week (56 day) period. Now that I got my head wrapped around this idea (which I believe is certainly achievable), I outline a successful accelerated plane of nutrition and management for these high performance calves.
As backup, I refer to the dairy scientists of Iowa State University, which states that the traditional way of feeding milk/milk replacer at a rate of 1.25-1.5 per cent of the calf’s bodyweight only supplies enough energy and protein; to support neonate maintenance requirements with little left over to allow for modest growth rates. Whereas feeding milk/milk replacer at 2.0-2.5 per cent of their bodyweight allows identical calves to achieve “doubling birthweight” growth.
Higher protein milk replacer
Their research shows dairy calves grown on 28 per cent protein – 16 per cent fat milk replacers fed at approximately 900-1,000 grams per day can achieve desired daily growth rates of 1.0 kg per head, compared to 0.25- 0.5 kg per day on a standard 20 per cent protein – 20 per cent fat milk replacer diet fed at about 600-700 grams per day. These scientists point out most of this weight gain on test subjects is desirable skeleton and lean tissue growth, rather than fat deposition. Once these calves are weaned, they can easily be turned onto a conventional heifer ration.
To illustrate this point, here is a comparison of an Iowa State University 56-day trial (see table)which compares the calf growth rates of a conventional and accelerated milk feeding programs:
Other conventional science proves dairy producers should introduce a nutritious and palatable grain-based calf starter to four-day old calves. By three to four weeks of age, pre-weaned calves should be eating an appreciable amount (500-600 g), which yields fermentation nutrients such as butyrate, which stimulates rumen papillae growth and metabolic activity. As a result in a short period, there becomes enough rumen digestion to help the pre-weaned calf meet its own energy requirements from dry feed as well as to facilitate weaning from milk or milk replacer.
Scours a concern
In addition, it has been my concern that newborn calves of less than three weeks of age consuming a lot of milk/milk replacer in these “double birthweight” milk-feeding programs are very susceptible to nutritional scours.
When nutritional diarrhea strikes pre-weaned calves, it is seen as bright yellow, cream color or nearly white liquid; all signs that a recently consumed milk/milk replacer meal was poorly digested). Not only does such poor milk digestion lead to poor absorption of essential nutrients the calf requires to live and grow, but also these unabsorbed nutrients in the calves’ gut tend to draw retained water from the calf’s tissues and into the gut lumen, which amplifies scouring.
I added my own price inputs (bold and italicized) in the above table as: $75/20 kg bag of 20 – 20 – 20 standard milk replacer, $85 for a 20 kg bag of accelerated 26 – 26 – 16 milk replacer and $20 per 20 kg bag of a 21 per cent textured calf starter. I speculate advocates of accelerated calf feeding programs might say the respective $110 higher total cost to raise a pre-weaned dairy calf to weaning is offset by well-established economic benefits of future milking performance; first-lactation 305-d actual milk production is shown to be five to 15 per cent higher compared to conventional-reared herd-mates.
Rather than be an advocate of “double birthweight” programs, I am more of assistant to dairy producers, who are interested. I recommend: first measure birth weight of newborn calves, measure milk/milk replacer and calf starter consumption. Finally, measure 56-day weaned weights. These are important numbers and should be tied to both present and future performance benefits and profit.