The Influence of High Planes of Nutrition on Skeletal Growth and Development of Weanling Horses

Abstract

Effects of high dietary levels of energy, protein and Ca and deficient levels of Ca on skeletal growth and development in the equine were studied in two experiments. The weanlings were fed grain-based diets. In Exp. 1, Group 1 (Ctl) received all nutrients at NRC recommended levels for growth; Group 2 (HE) received 150% of their digestible energy (DE) requirement; Group 3 (LC) received 150% of DE and 35% of Ca requirements. In Exp. 2, Group 1 (Ctl) again received all nutrients at NRC recommended levels for growth; Group 2 (HEP) received 150% of DE and 275% of CP requirements; Group 3 (HEPC) received 150% of DE, 275% of CP and 500% of Ca requirements. In addition, all groups had access to pasture. The HE treatment resulted in greater (P less than .10) increases in BW and total cortical width. However, LC weanlings had lower (P less than .10) gains in third metacarpal length and radiographic bone density. Cumulative increases in BW and wither height were greater (P less than .10) for the HEP and HEPC weanlings than for the Ctl weanlings. Increases in third metatarsal length also were greater (P less than .10) for HEP weanlings than for Ctl weanlings. Higher planes of nutrition increased body weight gains and growth rate of several long bones. However, skeletal development (e.g., cortical area) may be compromised by a high rate of growth.

Energy intake and growth of weanling horses in a cold loose housing system

“…in Sweden and Finland, the nutrient requirements commonly used are SLU (2004) and MTT (2006) requirements, of which the SLU requirements include guidelines for feeding horses in a cold environment. Feeding of growing horses according to the requirements is important, since imbalanced nutrition may cause weight loss or weight gain, retard or increase growth rate, weaken the bones and increase the risk of developmental orthopaedic diseases (Thompson et al 1988, Donabédian et al 2006, NRC 2007. In practice, balancing nutrient intake is difficult for horse breeders because they do not often know the nutrient concentrations of the feeds they use and do not take into account differences in nutrient requirements for growing horses of various ages in the feeding strategies (Gibbs and Cohen 2001).…”

Protein, amino acid and energy requirements of weanling foals and yearlings

“…Also Savage et al (1993) reported skeletal abnormalities in foals fed excess energy (129%o /VBC-I989) (81 MJ DE). On the other hand, Thompson et al, (1988) found no detrimental effcets on growth or bone development due to high energy (159% /VRC-1978) (97.5 MJ DE) or protein (275% /VBC-1978) intakes, although there was a decrease in mineral deposition into bone. The accelerated growth causing skeletal abnormalities is largely due to high intake of carbohydrates, which in turn causes hormonal changes stimulating a rapid growth of cartilage, resulting in improper cadilage maturation (Glade et al 1984).…”

Developmental orthopedic disease

“…Dietary energy intake and its impact on the incidence of OC have been in the focus of interest for several decades. It was speculated that skeletal development was impaired by the high growth rate, especially in those cases in which the protein intake was also low ( Thompson et al 1988). It was speculated that skeletal development was impaired by the high growth rate, especially in those cases in which the protein intake was also low ( Thompson et al 1988).…”