Journal of Animal Science, Vol 76, Issue 12 3072-3078, Copyright © 1998 by American Society of Animal Science

JOURNAL ARTICLE

Production of bovine alpha-lactalbumin in the milk of transgenic pigs

G. T. Bleck, B. R. White, D. J. Miller and M. B. Wheeler
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.

High production of milk and its components are necessary to allow maximal growth of developing pigs. In this study, transgenic pigs were produced containing the alpha-lactalbumin gene, whose product is a potential limiting component in the production of milk. Two lines of transgenic pigs were produced to analyze the effects that overproduction of the milk protein alpha-lactalbumin may have on milk production and piglet growth. Transgenic pigs were produced through microinjection of the bovine alpha-lactalbumin gene. The gene construct contained 2.0 kb of 5' flanking region, the 2.0 kb coding region, and 329 bp of 3' flanking region. Sows hemizygous for the transgene produced as much as .9 g of bovine alpha-lactalbumin per liter of pig milk. The production of the bovine protein caused approximately a 50% increase in the total alpha-lactalbumin concentration of pig milk throughout a lactation. The concentration of bovine alpha-lactalbumin was highest on d 0 and 5 of lactation and decreased as lactation progressed. The ratio of bovine to porcine alpha-lactalbumin changed during the sow's lactation. This ratio was 4.3 to 1 on d 0 of lactation, but by d 20 of lactation the ratio was .43 to 1. This suggested that the bovine transgene and the endogenous porcine gene are under slightly different control mechanisms. The higher level of total alpha-lactalbumin present on d 0 of lactation was correlated with higher lactose percentage on d 0 in transgenic sows (3.8%), compared with controls (2.6%) (P < .01). Although there was also a trend for higher lactose percentage in transgenic sows on d 5 and 10 of lactation, no significant differences were observed. These data suggest that alpha-lactalbumin is limiting early in lactation of swine. Furthermore, higher concentrations of alpha-lactalbumin early in lactation may boost milk output.

This article has been cited by other articles:

				J. Wang, P. Yang, B. Tang, X. Sun, R. Zhang, C. Guo, G. Gong, Y. Liu, R. Li, L. Zhang, et al. Expression and Characterization of Bioactive Recombinant Human {alpha}-Lactalbumin in the Milk of Transgenic Cloned Cows J Dairy Sci, December 1, 2008; 91(12): 4466 - 4476. [Abstract] [Full Text] [PDF]

				K. M. Marshall, W. L. Hurley, R. D. Shanks, and M. B. Wheeler Effects of suckling intensity on milk yield and piglet growth from lactation-enhanced gilts J Anim Sci, September 1, 2006; 84(9): 2346 - 2351. [Abstract] [Full Text] [PDF]

				S. M. Donovan, J. L. Hartke, M. H. Monaco, and M. B. Wheeler Insulin-like Growth Factor-I and Piglet Intestinal Development J Dairy Sci, July 1, 2004; 87(13_suppl): E47 - 54. [Abstract] [Full Text] [PDF]

				M. B. Wheeler Production of transgenic livestock: Promise fulfilled J Anim Sci, March 1, 2003; 81(suppl_3): 32 - 37. [Abstract] [Full Text] [PDF]