Managing Calf Health Through Nutrition
Posted: October 14, 2009
Calf health as reflected in morbidity and mortality is a consistent and major issue facing the dairy farmer. Data from Europe and the US clearly show that dairy calf mortality remains above 5-8%, representing a significant economic impact on the dairy farm economy. In addition, morbidity remains high which adds to the economic burden through added labor and health supply costs; and over 50% of this morbidity is related to neonatal scours. When calf health is discussed, we must begin with the nutrition of the dam and the related influence on the body tissues of the calf at birth and the nutrient value of colostrum. Research has shown that various aspects related to dry cow nutrition can affect the calf at birth. Most notably minerals fed to dry cows such as Se, Cu, and Zn can greatly influence the calf at birth as well as the colostrum. Health issues related to anemia and white muscle disease that were once common problems in newborn calves are rarely a problem now in well managed farms due to dietary supplementation of the dry cow.
An important calf health issue that also must be considered is colostrum management. There are many research publications clearly showing the significant effects of timing, quality, and quantity of colostrum fed and its impacts on morbidity, mortality, growth, age at calving, and culling of dairy heifers. Failure of passive transfer (FPT) of colostrum maternal immunoglobulins occurs in a high percentage of calves in the US and other countries, due to the way colostrum feeding is managed on dairy farms. The correlation with mortality is very strong and this along with morbidity represents a serious economic loss to dairy farmers.
Recent studies show that colostrum as fed on dairy farms often is not adequate in immunoglobulin and nutrient levels; and is often high in bacteria, all of which need to be improved with management on the farm. Methods to increase immunoglobulin levels in colostrum are limited due to the genetics of the cow (dam) and physiological con- ditions of the cow at calving time. Recent work at Penn State and the University of Minnesota has been conducted to improve immunoglobulin absorption by the small intestine of the newborn calf. Heat treating colostrum (60oC for 30 to 60 minutes) is one of the methods recently demonstrated that significantly improves immunoglobulin absorption without increasing the viscosity of the colostrum or impacting the nutritional or immunological value.
Calf nutrition related to basic feeding also can be addressed in relation to health. Levels of nutrients and types of feeding systems impact health. Both low and high levels of milk/milk replacer feeding have been shown to impact calf health and growth. Feeding less than 10% of body weight (BW) per day of liquid feed will result in low rates of BW gain and in situations with added stress, may predispose calves to increased morbidity. Altering diet nutrient levels have not been shown to affect immunity unless the nutrient levels are extremely low or high. We now often recommend feeding 12% of birth body weight in milk or milk replacer per day for adequate growth. Dietary supplements have been shown to impact calf health. In a non-antibiotic situation, many supplements have been tried with minimal success.
Oligosaccharides are one class of compounds have been shown by researchers at Penn State as well as others, to positively affect calf health by reducing the incidence and severity of diarrhea in calves. More recently, nucleotides have been used in neonate milk replacers for many species with great success. In a study done at Penn State, it has been shown that added nucleotides increase small intestinal DNA content, significantly increase abundance of nucleoside transporter mRNA, improve small intestine villi size, and improve microbial populations in the gut. Probiotics have also been studied by many researchers and it has been shown that these can alter intestinal microbial populations to a more positive group of bacteria and can also enhance the immunity of the calf.
Nutrition has many effects on the health of the calf and improvements must be considered to reduce the high incidence of morbidity and mortality as found on dairy farms around the world.Jud Heinrichs, Professor of Dairy and Animal Science, Department of Dairy and Animal Science