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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Animal Metabolism-Agricultural Chemicals Research » Research » Publications at this Location » Publication #296931
Title: Consumption of ground beef obtained from cattle that had received steroidal growth promotants does not trigger early onset of estrus in prepubertal pigs

Author
item MAGOLSKI, JAMES - North Dakota State University
item Shappell, Nancy
item VONNAHME, KIMBERLY - North Dakota State University
item ANDERSON, GIOVANA - North Dakota State University
item NEWMAN, DAVID - North Dakota State University
item BERG, ERIC - North Dakota State University

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2014
Publication Date: 11/1/2014
Publication URL: http://handle.nal.usda.gov/10113/60079
Citation: Magolski, J.D., Shappell, N.W., Vonnahme, K.A., Anderson, G.M., Newman, D.J., Berg, E.P. 2014. Consumption of ground beef obtained from cattle that had received steroidal growth promotants does not trigger early onset of estrus in prepubertal pigs. Journal of Nutrition. 144(11):1718-1724.

Interpretive Summary: Implants of estrogenic steroids are used by the beef industry to increase the rate of weight gain and to improve tenderness of meat. Consumer groups have expressed concern that this practice used in beef cattle is associated with the early onset of puberty in girls who eat beef. A study was conducted using young female hogs as a model for humans. The estrogenicity of each diet was measured using a very sensitive bioassay (E-Screen). Diets supplemented with beef from implanted or non-implanted cattle were nearly identical in relative estrogenicity, while tofu burgers contained more than 100-times the estrogenic activity of burgers from implanted cattle. Consumption of beef from implanted cattle did not alter the onset of puberty or body composition of gilts in this study. Nor did daily consumption of beef from non-implanted (i.e. natural) cattle or a common meat alternative food (tofu) result in early onset of puberty, in spite of the known high level of estrogenicity of the tofu supplement.

Technical Abstract: Onset of puberty was assessed when pre-pubertal gilts were fed a diet low in estrogenic activity versus a diet supplemented with ground beef obtained from steers implanted with growth enhancing compounds. The base diet was formulated using canola meal replacing soybean meal to reduce diet estrogenicity. Feed intake was limited by offering the base diet as a percentage of body weight (BW). Animals were assigned to treatments based on dam and initial BW (mean 24.5 +/- 3.2 kg) at 61 days of age. The negative control base diet (CON) was supplemented with daily feedings of a cooked patty from non-implanted steers (NAT), from steers that had been treated with growth promotants (100 mg trenbolone acetate and 14 mg estradiol benzoate) (IMP), or cooked tofu patty (TOFU). Estradiol (E2) equivalents (ng/kg, as fed as analyzed by E-Screen) of the TOFU (a soy-based product) supplement were ~ 570 fold times the NAT and ~ 170 fold the IMP supplement. There were no observed differences across treatments in live weight gain (P = 0.90), loin muscle area developed at the 10th and 11th rib interface (P = 0.46), and subcutaneous fat deposition (P = 0.41) at the same location over time on test, or in the number of days to reach estrus (P = 0.55). It appears that beef from growth implanted or natural steers does not impact growth or onset of estrus in gilts. Moreover, a diet higher in phytoestrogens does not contribute to the onset of puberty in gilts.