PG . 42
HORSE HEALTH NEWS
MINERALS AND MARES
ARTICLE BY : DR JENNIFER STEWART BVSC BSC PHD EQUINE VETERINARIAN , CEO JENQUINE AND CONSULTANT NUTRITIONIST EQUINE CLINICAL NUTRITION
LATE GESTATION - such an exciting time with our anticipation and the foetus both growing rapidly . The last trimester is the 8th-11th month of pregnancy for mares . Most of the foal ’ s bone calcium is deposited in the last 2 months of gestation and the foal is building it ’ s liver stores of minerals needed for healthy bone growth after foaling . These minerals are low in mares ’ milk and without liver reserves , the risk of developmental orthopaedic diseases in young horses is increased .
To support the rapidly growing foetus , it ’ s important that adequate levels of minerals are provided in the late pregnant mare ’ s diet . Good pasture is the cornerstone and major source of minerals in the mare ’ s diet . But pastures vary in nutrients levels from season to season and also from year to year . In the early 1980 ’ s researchers found that the calcium intake of mares on studs in Victoria was below requirements in winter and spring when few pastures contained calcium-rich legumes . During the last 3 months of pregnancy and lactation , most forages do not provide sufficient calcium or other trace minerals to meet the mare ’ s needs . Lucerne and clover hays are usually higher in calcium than phosphorus , but levels of minerals vary
greatly from different hay crops . Droughtaffected pastures are an even poorer source of minerals , providing negligible amounts of calcium , magnesium and phosphorus . When pastures ( and the hay made from them ) mature , additional calcium , magnesium , phosphorus , protein and energy are usually required to support pregnancy and lactation .
CALCIUM :
Calcium and magnesium are critical for bone and cartilage development and mares need additional dietary intake to meet the increased bone growth of the foetus . As the mare diverts calcium to the growing foal , her blood calcium level falls and blood calcium levels are lower in pregnant mares compared to non-pregnant mares . During late pregnancy , the mare draws
AUSTRALIAN QUARTER HORSE ASSOCIATION - www . aqha . com . au