Submitted to: Journal of Animal Science
Publication Type: Abstract only
Publication Acceptance Date: 2/28/2005
Publication Date: 7/24/2005
Citation: Lay Jr, D.C., Marchant Forde, J.N., Richert, B.T., Marchant Forde, R., Mcmunn, K.A. 2005. Effects of albuterol on the physiology of finishing pigs. Journal of Animal Science. 83(1)245. Interpretive Summary:
Technical Abstract: Several growth promoters for swine have been tried with variable success and there has been concern about compound efficacy and alterations of behavior or physiology. This experiment examined the physiological effects of a proposed growth promoter, albuterol - a beta-2 agonist. The study used 192 pigs (88.8±0.9 kg BW) housed in groups of six in 32 pens (1.4m x 4.1m) and assigned to one of four treatments: 1) Control - standard finishing ration, 2) ALB-R2 - diet with 2 ppm of the pure R-enantiomer of albuterol, 3) ALB-R4 - diet with 4 ppm of pure R-albuterol, or 4) ALB-RS8 - diet with 8 ppm of a racemic mix of R- and S-enantiomers. All diets supplied 18.3% CP, 1.1% lysine and 3534 kcal ME/kg and were offered ad libitum. One pig from each pen was chosen randomly and blood was collected four times: Week 0 - prior to treatment, Week 2 - at 10 days on treatment, Week 4 - at 24 days on treatment and, SAC - at exsanguination. All pigs were fed control diet for 24h (50% of pigs) or 48h (50 % of pigs) prior to exsanguination. Blood was analyzed for NEFA, CK, glucose, lactate, BUN, ammonia, insulin, cortisol, norepinephrine, and epinephrine. Data for Weeks 0 to 4 were analyzed together using a repeated analysis of variance with Week 0 as a covariate. SAC data were analyzed separately as these data represent the difference in the 24h or 48h clearance. There were no treatment differences in epinephrine or norepinephrine concentrations at any point. During Week 4, Control pigs had lower CK (P<0.02) and greater BUN (P<0.005) compared to pigs fed all the albuterol treatments. A gender effect was found for CK and BUN (P<0.05) indicating that males had greater concentrations of CK and BUN than females. The ALB-R4, male pigs had greater concentrations of insulin than male pigs in the other three treatments during Week 2 (P<0.001). Control female pigs had lower concentrations of cortisol compared to female pigs in the other three treatments during Week 2 (P<0.02). Taken together these data indicate that albuterol altered protein metabolism, without altering catecholamine levels, at the doses administered in this experiment. Gender-specific effects of albuterol should be explored further.