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United States Department of Agriculture

Agricultural Research Service

Research Project: Alleviating Rate Limiting Factors that Compromise Beef Production Efficiency

Location: Livestock and Range Research Laboratory (LARRL)

Title: Comparison of methionine hydroxy analogue chelated versus sulfate forms of copper, zinc, and manganese on growth performance and pregnancy rates in yearling beef replacement heifers

Authors
item Whitehurst, W -
item Paterson, J -
item Harbac, M -
item Petersen, Mark
item Duff, G -
item Geary, Thomas
item Zanton, G -
item Wistuba, T -

Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 1, 2014
Publication Date: May 1, 2014
Repository URL: http://handle.nal.usda.gov/10113/59344
Citation: Whitehurst, W.A., Paterson, J.A., Harbac, M.M., Petersen, M.K., Duff, G.C., Geary, T.W., Zanton, G.I., Wistuba, T.J. 2014. Comparison of methionine hydroxy analogue chelated versus sulfate forms of copper, zinc, and manganese on growth performance and pregnancy rates in yearling beef replacement heifers. Professional Animal Scientist. 30:62-67.

Interpretive Summary: Our objectives were to compare growth performance and pregnancy rates of heifers supplemented with Cu, Zn, and Mn as either methionine hydroxy analog chelate (provided as MINTREX) or in the S04 form. The experiment used 3 ranches, each having 2 replicate pens per treatment. Performance data were analyzed by AN OVA as a randomized complete block design using pen as the experimental unit. Pregnancy diagnosis data were analyzed using Chi-squared analysis. Heifers (n = 2,480) were fed diets for 181 d (ranch A), 149 d (ranch B), and 151 d (ranch C) before breeding. Heifers were weighed (shrunk) at trial initiation, end of feeding, 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), and ranch C heifers were bred by AI once at estrus detection only. No ranch x treatment interactions were detected for any measurements, and no differences were detected between treatments for gain, ADG, and G:F. Ranch effects were significant for gain, ADG, G:F, and overall pregnancy rate but not for conception in the first 21 d of breeding. Pregnancies conceived during the first 21 d of breeding did not differ between treatments. Overall pregnancy rate was increased by 2% for heifers supplemented with methionine hydroxy analog chelate versus SO form. Under the conditions of this experiment, methionine hydroxy analog chelate contributed to increased pregnancy rates compared with a available inorganic form of trace mineral.

Technical Abstract: Our objectives were to compare growth performance and pregnancy rates of heifers supplemented with Cu, Zn, and Mn as either methionine hydroxy analog chelate (provided as MINTREX) or in the S04 form. The experiment used 3 ranches, each having 2 replicate pens per treatment. Performance data were analyzed by AN OVA as a randomized complete block design using pen as the experimental unit. Pregnancy diagnosis data were analyzed using Chi-squared analysis. Heifers (n = 2,480) were fed diets for 181 d (ranch A), 149 d (ranch B), and 151 d (ranch C) before breeding. Heifers were weighed (shrunk) at trial initiation, end of feeding, 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), and ranch C heifers were bred by AI once at estrus detection only. No ranch x treatment interactions were detected for any measurements, and no differences were detected between treatments for gain, ADG, and G:F. Ranch effects were significant for gain, ADG, G:F, and overall pregnancy rate but not for conception in the first 21 d of breeding. Pregnancies conceived during the first 21 d of breeding did not differ between treatments. Overall pregnancy rate was increased by 2% for heifers supplemented with methionine hydroxy analog chelate versus SO form. Under the conditions of this experiment, methionine hydroxy analog chelate contributed to increased pregnancy rates compared with a available inorganic form of trace mineral.

Last Modified: 10/22/2014
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