Li S, Hacker R R
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
J Anim Sci. 1995 Feb;73(2):534-40. doi: 10.2527/1995.732534x.
Pregnant Yorkshire gilts (n = 42) were fed caffeine (6 g/d) or served as controls from d 60 of pregnancy until d 4 postpartum to test the effect of caffeine on mammary gland development, milk yield, and feed consumption. Caffeine reduced voluntary feed intake (P = .001) and body weight gain (P = .001) of gilts from d 60 to 109 of gestation. Pig birth weight in the treated group was less than (P = .01) that in the control group. However, pig viability score at birth was not affected by maternal caffeine ingestion. For assessing mammary gland DNA, RNA, dry fat-free tissue (DFFT), fat, and protein content, four sows from the caffeine group and three controls were slaughtered on the 1st d of lactation. Immediately after slaughter, mammary systems were removed, separated by gland, and dissected free of skin, muscle, and fatty pad, which had not been invaded by glandular tissue. The DNA and RNA content were evaluated in DFFT. Caffeine increased mammary RNA content (P = .023) and milk yield (P = .001) on d 1 of lactation. However, DNA, DFFT, fat, and protein were not significantly increased, although values were somewhat greater in the treatment group (approximately 82%). On d 21 of lactation, milk yield of treated sows did not differ from that of controls. The increased milk yield on d 1 of lactation was due to increased mammary epithelial cell activity and cell numbers. These results indicate that caffeine feeding can have a positive effect on porcine mammary gland development as well as milk yield.
42头怀孕的约克夏母猪从妊娠第60天至产后第4天，分别饲喂咖啡因（6克/天）或作为对照组，以测试咖啡因对乳腺发育、产奶量和采食量的影响。从妊娠第60天至109天，咖啡因降低了母猪的自愿采食量（P = 0.001）和体重增加量（P = 0.001）。处理组仔猪出生体重低于对照组（P = 0.01）。然而，出生时仔猪的活力评分不受母体摄入咖啡因的影响。为了评估乳腺的DNA、RNA、无脂干组织（DFFT）、脂肪和蛋白质含量，在泌乳第1天屠宰了咖啡因组的4头母猪和3头对照组母猪。屠宰后立即取出乳腺系统，按腺体分离，剔除未被腺体组织侵入的皮肤、肌肉和脂肪垫。在DFFT中评估DNA和RNA含量。咖啡因增加了泌乳第1天的乳腺RNA含量（P = 0.023）和产奶量（P = 0.001）。然而，DNA、DFFT、脂肪和蛋白质含量虽未显著增加，尽管处理组的值略高（约82%）。在泌乳第21天，处理组母猪的产奶量与对照组无差异。泌乳第1天产奶量增加是由于乳腺上皮细胞活性和细胞数量增加。这些结果表明，饲喂咖啡因对猪乳腺发育和产奶量有积极影响。
