Effect of Caffeine on Nitrogen Retention, Carcass Composition, Fat Mobilization and the Oxidation of C -Labeled Body Fat in Pigs

Publisher Website
Google Scholar
Abstract
Four experiments employing nitrogen balance, technique, growth and carcass analysis trials, and respiration work with C14-palmitate, were used to study the effect of caffeine on the deposition of protein and the mobilization and oxidation of body fat in pigs. Caffeine, at a level of 1.5 gm./kg. of feed, increased(P<.01) nitrogen retention by 7.9% over a period of 4 wk. in 65-kg. pigs fed 2 kg. of feed per day. Weanling pigs fed the same level of caffeine until market weight deposited 6.6% less fat in their carcasses than pair-fed controls in one experiment and 13.1% less (P<.01) in another. Growth rate, feed efficiency and the protein content of the carcasses were unaffected by the caffeine in the former experiment but were increased by 5.2% (P<.01), 6.6% (P<.01), and 4.0% (P<.05),respectively, in the latter experiment. Caffeine, at a level of 1.5 gm./kg. of feed tended to restrict feed consumption and a level of 3.0 gm./kg. greatly restricted feed consumption and produced a severe skin rash. In the fourth experiment, 60-kg. pigs were fed C14-palmitate to label their body fat and then caffeine was compared with norepinephrine and colchicine in its ability to promote the mobilization and oxidation of the labeled fat. The injection of norepinephrine at a level of 2.0 mg./kg. of body weight resulted in the expiration of up to 10 times as much C14O2 as in control periods when no drug was given. Caffeine, fed at 50 mg./kg. of bodyweight resulted in up to six times as much C14O2 and colchicine, at 0.1 mg./kg. intramuscularly, had no effect. Norepinephrine produced a large increase in the plasma levels of free fatty acids, caffeine a moderate increase and colchicine a slight decrease.