BORON SUPPLEMENTATION TO A SEMI-PURIFIED DIET FOR WEANLING PIGS IMPROVES FEED EFFICIENCY AND BONE STRENGTH CHARACTERISTICS AND ALTERS PLASMA LIPID METABOLITES

Authors: ARMSTRONG, TODD - NORTH CAROLINA STATE U; SPEARS, JERRY - NORTH CAROLINA STATE U; CRENSHAW, THOMAS - UNIVERSITY OF WISCONSIN; Nielsen, Forrest - Frosty

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2000
Publication Date: 10/1/2000
Citation: Armstrong, T.A., Spears, J.W., Crenshaw, T.D., Nielsen, F.H. 2000. Boron supplementation of a semi-purified diet for weanling pigs improves feed efficiency and bone strength characteristics adn alters plasma lipid metabolites. Journal of Nutrition. 130:2575-2581.

Interpretive Summary: Boron has recently gained prominence as an element of possible nutritional importance for growth and development of higher animals. This possibility has come from findings from zebrafish and frogs. Support for the nutritional importance of boron for humans would be stronger if higher animals were also shown to require or benefit from consuming specific physiological amounts of boron. Thus, two experiments were performed with pigs, animals whose physiology is close to that of humans. In the first experiment, boron supplementation to a natural diet luxuriant in boron did not have much effect on pigs. This finding suggests that the pigs were getting adequate amounts of boron from the natural diet. In the second experiment, the pigs were fed a semi-purified diet that was lower in boron than the natural diet. With the semi-purified diet, boron supplementation in amounts found in natural diets improved weight gain per amount of feed consumed, increased plasma cholesterol and triglyceride concentrations, decreased the per cent of lipids in bone, and improved the maximum bending force of a long bone (femur). The findings show that boron supplementation to a diet low in boron elicited biological responses of physiological importance to the pig. The findings also support the concept that boron is a nutritionally beneficial or essential element for higher animals and that this element may be of practical nutritional importance for good energy metabolism and bone health.

Technical Abstract: Two experiments were conducted to determine the effects of dietary boron (B) supplementation on animal performance, plasma mineral concentrations, plasma metabolites, and bone characteristics in young pigs. In experiment 1, 48 weanling pigs (21 d of age) were allotted to pens, that were randomly assigned to one of three dietary treatments: 1) control (natural ingredient basal diet; 6.7 mg B/kg diet), 2) control +5 mg B/kg diet, 3) control + 15 mg B/kg diet. Boron was supplemented as sodium borate. In experiment 2, 48 crossbred weanling pigs were assigned to the same treatments described in experiment 1; however, the basal diet was a semi- purified basal diet (1.0 mg B/kg diet). Experimental diets were fed for 40 d, then blood samples were obtained for determination of plasma mineral and metabolite concentrations. Femurs were harvested from 8 pigs per treatment on d 40 for the determination of mechanical properties, ash, and lipid percentage. In experimental 1, B supplementation or concentration did not affect animal performance plasma mineral and metabolite concentrations, or bone properties. In experiment 2, B supplementation improved (P<.05) gain:feed, increased plasma cholesterol and triglyceride concentration, decreased bone lipid percentage, and improved maximum bending force of the femurs. The other dependent variables in experiment 2 were not affected by treatment. In conclusion, B supplementation to a diet low in B elicited biological responses of physiological importance to the pig; however, B supplementation to a natural ingredient diet did not elicit a response.