Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2001
Publication Date: N/A
Citation: Interpretive Summary: Betaine is an amino acid present in most living organisms and is concentrated in high levels in the sugar beet, from which it is extracted as a byproduct. Betaine is an obligatory intermediate in the catabolism of choline and serves as a methyl donor with potential lipotropic effects. It is also an osmotically-active organic solute that accumulates in tissues under water or salt stress. As a feed additive, betaine is associated wit decreased lipid deposition and altered protein utilization in finishing pigs. It has been suggested that the positive effects of betaine on growth and carcass composition may be greater in energy-restricted pigs. The purpose of this study was to examine the effects of dietary betaine over a range of concentrations on nutrient utilization and body composition in young feed-restricted pigs growing from 36 to 64 kg live weight. As the betaine content of the diet was elevated from 0 to 0.5%, carcass fat, fat depth and viscera weight were decreased, while total carcass protein, and the rate and efficiency of protein deposition were increased. The decrease in viscera weight may indicate an energy-sparing role of betaine. These data suggest that betaine alters nutrient partitioning in young feed- restricted pigs such that protein deposition is enhanced at the apparent expense of carcass fat and in part, visceral tissue. When added to the diets of growing pigs, betaine could help to provide leaner, healthier pork products.
Technical Abstract: The purpose of this study was to examine the effects of dietary betaine over a range of concentrations (0 to 5 g/kg) on growth and body composition in young feed-restricted pigs. Thirty-two barrows (36 kg, n = 8 pigs per group) were restrictively fed one of four corn-soybean meal-skim milk based diets (18.6% crude protein, 3.23 Mcal ME/kg) and supplemented with 0, 1.25, ,2.5 or 5g/kg betaine. Feed allotment was adjusted weekly according to body weight. At 64 kg, pigs were slaughtered and visceral tissue was removed and weighed. Carcasses were chilled for 24 h to obtain carcass measurements and were ground for chemical analysis. Linear regression analysis indicated that, as betaine content of the diet was elevated from 0 to 5 g/kg, carcass fat (P < 0.06), P3 fat depth (P < 0.15) and viscera weight (P < 0.13) were decreased, while total carcass protein (P < 0.13), protein deposition rate (P < 0.10) and lean gain efficiency (P < 0.12) were increased. Overall, greatest improvement over control pigs were observed in pigs consuming 5 g/kg betaine, where carcass fat and P3 fat depth were decreased by 10% (P < 0.06) and 26% (P < 0.09), respectively. Carcass protein:fat ratio was 19% greater (P < 0.14) in 0.5% betaine pigs, compared to controls. In addition, carcass protein deposition was 23% greater (P < 0.10) and lean gain efficiency was increased by 23% (P < 0.12) in 0.5% betaine pigs compared to controls. Dietary betaine had minimal effects on growth rate, visceral tissue chemical composition and visceral fat and protein deposition rates, and serum urea and ammonia concentrations. These data suggest that betaine alters nutrient partitioning such that carcass protein deposition is enhanced at the expense of carcass fat and in part, visceral tissue.