Calf nutrition key
to replacement heifer success By Michael Cox
‘A good start is half the battle,’ is a saying that certainly rings true for early calf nutrition. As replacement heifer calves are a limited resource of future high genetic-merit cows in the milking string, producers should strive to provide good quality nutrition to get calves off to the best possible start in life.
Excellent calf nutrition begins first and foremost with colostrum. High quality ‘liquid gold’ colostrum is crucial for passive immunity transfer of immunoglobins from dam to calf. Research studies from around the world regularly state that 50 per-cent of calf mortality in year one occurs during the first six weeks after birth. Colostrum is key to reducing future illness and mortality in youngstock. An NAHMS 2007 study shows less
than 15 per-cent of dairy farms test for colostrum quality. So how do we know if our colostrum is up to scratch? A Brix refractometer or a digital refractometer is a useful tool to help identify good and poor-quality colostrum. Antibody IgG levels of 50mg per mL or more is considered good quality. On a Brix refractometer, this colostrum will give a reading of 22 percent or greater. An alternative method for testing colostrum quality and intake is to perform a total protein blood count on calves between one and four days old. 5.2g per dL or greater of total blood protein indicates first-rate passive transfer of immunoglobins. In Ireland, dair y men have seen widespread improvements in calf performance by implementing a ‘Colostrum 1,2,3 Program.’ Colostrum 1,2,3 is a nationally
publicized program that involves three steps; Step 1 – 1st milk only. Milk from the first milking only is to be used as colostrum. Milk from subsequent milkings will contain massively reduced levels of antibodies and is not suitable as a first feed for newborn calves. Step 2 – Two hours. Time is of the essence when feeding newborn calves colostrum. The gut wall of the calf has a time-limited window to absorb immunoglobins, after which it seals up and become impermeable to the beneficial IgGs. Colostrum should be fed to calves via stomach tube within the first two hours after birth. S te p 3 – T h r e e l ite r s . Depending on the breed type/size of the calf, a minimum of three liters of colostrum should be fed. * Continued on page 14
Michael Cox is a freelance writer for American Dairymen. His background is in Animal Science, where he graduated from University College Dublin Ireland with a First Class Honors degree in 2016. He is currently involved with a dairy business in Missouri, managing a 750 cow grass-based grazing farm and am also a research scholar with University of Missouri- Columbia.