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ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #293832
Title: Comparison of methionine chelated versus sulfate trace minerals on rate and efficiency of gain and pregnancy rates in beef heifers

Author
item WHITEHURST, W - Montana State University
item PATERSON, J - Montana State University
item HARBAC, M - Montana State University
item Petersen, Mark
item DUFF, G - Montana State University
item Geary, Thomas

Submitted to: Western Section of Animal Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/1/2012
Publication Date: 7/15/2012
Citation: Whitehurst, W.A., Paterson, J.A., Harbac, M.M., Petersen, M.K., Duff, G.C., Geary, T.W. 2012. Comparison of methionine chelated versus sulfate trace minerals on rate and efficiency of gain and pregnancy rates in beef heifers. Western Section of Animal Science Proceedings 63:274-277.

Interpretive Summary: Objectives of this experiment were to compare rate and efficiency of gain, and conception rates of yearling heifers supplemented with Cu, Zn, and Mn as either metal methionine hydroxy analogue chelated trace minerals (CTM; provided as MINTREX) or the same trace minerals in SO4 form. The experimental design utilized 3 ranches, each having 2 replications per treatment with pen as the experimental unit for ADG, DMI, and G.F. Individual heifer was the experimental unit for pregnancy diagnois. Ranch A contained 498 Angus heifers, Ranch B, 240 Red Angus composite heifers, and Ranch C, 1,742 Angus composite heifers. All heifers were fed silage based diets that contained approximately 13.5% CP, 64% TDN (DM basis) and had no sigificant levels of SO4, Mo or Fe in feed or water. Diets contained an average of 24 ppm Cu, 70 ppm Zn and 64 ppm Mn. Diets were fed for 181 d (Ranch A), 149 d (Range B) and 151 d (Ranch C) prior to breeding. Heifers were weighed once at trial initiation (initital BW 270 kg +_ 2.8), end of drylot feeding, at breeding, and at pregnancy diagnosis. Ranch A heifers were bred by AI followed by natural service (45 d breeding), Ranch B heifers were bred by natural service (50 d breeding) while Ranch C heifers were bred by AI once. Pregnancy was determined via ultrasound using trained technicians. No ranch x treatment interactions were detected for any measurements (P >_ 0.47) and no difference (P < 0.001) for gain, ADG, G:F and overall pregnancy rate, but not for conception in the first 21 d of breeding. Conception rate increased (P=0.03) for CTM fed heifers from Ranch C with one AI breeding. Conception rates during the first 21 d of breeding did not differ (P=0.12) between treatments but overall pregnancy rate was greater (P-0.05) for heifers supplemented with CTM vs SO4 form. Under the conditions of this experiment, results suggest that supplementation wtih CTM contributed to increased pregnancy rates in heifers.

Technical Abstract: Objectives of this experiment were to compare rate and efficiency of gain, and conception rates of yearling heifers supplemented with Cu, Zn, and Mn as either metal methionine hydroxy analogue chelated trace minerals (CTM; provided as MINTREX) or the same trace minerals in SO4 form. The experimental design utilized 3 ranches, each having 2 replications per treatment with pen as the experimental unit for ADG, DMI, and G.F. Individual heifer was the experimental unit for pregnancy diagnois. Ranch A contained 498 Angus heifers, Ranch B, 240 Red Angus composite heifers, and Ranch C, 1,742 Angus composite heifers. All heifers were fed silage based diets that contained approximately 13.5% CP, 64% TDN (DM basis) and had no sigificant levels of SO4, Mo or Fe in feed or water. Diets contained an average of 24 ppm Cu, 70 ppm Zn and 64 ppm Mn. Diets were fed for 181 d (Ranch A), 149 d (Range B) and 151 d (Ranch C) prior to breeding. Heifers were weighed once at trial initiation (initital BW 270 kg +_ 2.8), end of drylot feeding, at breeding, and at pregnancy diagnosis. Ranch A heifers were bred by AI followed by natural service (45 d breeding), Ranch B heifers were bred by natural service (50 d breeding) while Ranch C heifers were bred by AI once. Pregnancy was determined via ultrasound using trained technicians. No ranch x treatment interactions were detected for any measurements (P >_ 0.47) and no difference (P < 0.001) for gain, ADG, G:F and overall pregnancy rate, but not for conception in the first 21 d of breeding. Conception rate increased (P=0.03) for CTM fed heifers from Ranch C with one AI breeding. Conception rates during the first 21 d of breeding did not differ (P=0.12) between treatments but overall pregnancy rate was greater (P-0.05) for heifers supplemented with CTM vs SO4 form. Under the conditions of this experiment, results suggest that supplementation wtih CTM contributed to increased pregnancy rates in heifers.