Proper Nutrition for Broodmares, Foals and Weanlings

Producing strong, healthy, structurally correct foals is the goal of every horse breeder.

To ensure that goal is met, nothing is more critical than providing excellent nutrition throughout every stage of growth and development.

In an effort to make the latest nutritional advice available to the equine industry, Hilltop Farm of Colora, Maryland, has published 'Comprehensive Preventative Medicine for the Mare and Foal Highlighting Nutritional Management and Developmental Orthopedic Disease.' This manual is a compilation of papers by leading researchers including Dr. Harold Hintz, long-time professor at Cornell University, and Dr. Joe Pagan, founder and president of Kentucky Equine Research, Inc.

Broodmare Nutrition

Pagan stated that broodmare nutrition must match the mare's needs at each stage: barren/early pregnancy, late pregnancy, and lactation. During early pregnancy, the mare's needs resemble those of a barren mare and can usually be met by good pasture.

After the seventh month of pregnancy, demands for energy, minerals, vitamins, and protein increase and mares should be supplemented to meet these needs, but overfeeding to the point of obesity should be avoided. During the last several weeks of pregnancy the mare's ration should be increased to around 6.35 kilograms of grain per day, the amount needed to carry the mare and foal through the demands of lactation.

As the foal nears weaning age, the mare's ration can slowly be tapered to a maintenance level.

Calcium requirements

Regarding calcium requirements of pregnant mares, Hintz pointed out that the trend has been toward increasing this important mineral in the ration. The NRC Subcommittee on Horse Nutrition raised its recommendations for calcium levels in broodmare diets at every revision, essentially doubling the requirement from its earliest estimates.

Hintz cited a recent study by Martin et al. that examined serum concentrations of calcium and parathyroid hormones when mares were fed diets containing lower or higher calcium concentrations. The results showed less disruption of serum calcium and parathyroid hormone in the mares fed higher concentrations of calcium. Data from a number of other independent sources support th increases in NRC calcium recommendations, and estimates by French and German equine nutritionists are similar to current NRC figures.

Hintz referred to a South African study in which groups of broodmares were fed one of four diets ranging from a low-protein hay supplemented with low-quality protein pellets to a higher-protein lucerne hay supplemented with fish meal, a good source of lysine and methionine. Birth weights of foals in all four groups were similar, but foals from high-protein mares showed increased growth planes compared to those from low-protein mares. Additionally, high-protein mares gained weight during lactation, while low-protein mares lost weight during the same period.

The balance between calcium and phosphorus is important in preventing abnormalities in the developing skeleton, according to Hintz. Nutritional secondary hyperparathyroidism, a condition in which calcium is removed from the bones to maintain the necessary plasma level, can be prevented by educating horse owners about the importance of adequate dietary calcium and proper calcium/phosphorus ratios.

Weaning Age

Lawrence et al. from the University of Kentucky conducted a study on the effect of weaning age on foal growth and radiographic bone density. A report was included in the proceedings of the 1997 Equine Nutrition and Physiology Society's symposium. The study looked at fifteen foals of Quarter Horse or Thoroughbred breeding.

The foals were put into two groups balanced by breed, gender, and birth month, factors that have been shown to affect growth parametres, and were weaned at either 140 or 182 days of age. All foals were weighed and measured at three-week intervals before weaning, at weaning, a week after weaning, and at three-week intervals after weaning.

Rate of gain, bone density, and skeletal growth were recorded, and analysis of variance was used to determine the effect of weaning age. The researchers found that average daily gain was depressed in both the early-weaned and late-weaned groups, but gain returned to pre-weaning rates by six weeks after weaning for both groups. Wither height and bone density did not appear to vary between the groups.

These data indicate that there is no growth advantage for foals allowed to nurse until six months of age, and likewise no growth disadvantage for foals weaned at four and a half months.

By Kentucky Equine Research - Last updated 16 November 2012