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" Trace mineral interaction on reproductive performance of beef cattle under range conditions in Edwards and McCulloch Counties, Texas "
J. C. Doyle, II
J. E. Huston
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Latin Dissertation
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English
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| Record Number
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1112358
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TLpq303793926
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| Main Entry
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J. C. Doyle, II
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J. E. Huston
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| Title & Author
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Trace mineral interaction on reproductive performance of beef cattle under range conditions in Edwards and McCulloch Counties, Texas\ J. C. Doyle, IIJ. E. Huston
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| College
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Texas A&M University
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| Date
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1989
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| student score
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1989
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| Degree
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Ph.D.
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| Page No
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142
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| Abstract
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In Exp. I the effect of mineral supplementation on reproductive performance of cows grazing native range at two locations (McCulloch--supplemented prior breeding season and Edwards--supplemented throughout breeding season) was monitored by tissue (serum and liver) parameters, body condition score (BCS) and days to conception (DTC) in cows and adjusted weaning weight (AWW) in their calves. A randomized block design contained forty-five cows (4 cows usd\cdotusd treatment usd\cdotusd pasture usd\cdotusd location). Treatments consisted of the following: negative control (NC), feed control (FC), FC with additional phosphorus (P) and P + additional Zn, Cu and Mn (TM). At the McCulloch location, TM increased (P <.10) BCS and serum Cu (P <.05). At the Edwards location, average DTC were 42, 35, 29 and 22 d for NC, FC, P and TM, respectively (P usd Experiment II monitored the effects of supplemented nutrients on in situ dry matter disappearance (DMD) of three materials (sudan hay, alfalfa meal and cotton). The Latin square design consisted of restricted trials (each trial consisted of one animal per treatment with four treatments). The treatments were negative control (NC), feed control (FC), FC with additional P (FC + P) and FC + P + Cu, Mn and Zn (TM). Supplementation (FC + P + TM) depressed cotton DMD (P <.01), possibly as a result of toxicity from accumulated trace elements at the fiber surface. Experiment III investigated the influence of mineral supplementation on elemental concentration in tissues (serum, liver and endometrium) and reproductive efficiency. A randomized block design contained thirty-two, 22 to 24 mo old, heifers. These heifers were assigned to one of four treatment groups (NC, FC, FC + P and FC + P + TM). Neither estrous (d-1 vs d-12) nor treatment influenced serum or liver Cu and Zn concentrations. Endometrial tissue concentrations of Cu, Zn, Ca, Na, K, P and Mg were elevated (P <.05) for collection period (d-1 vs d-12). Progesterone's negative influence on endometrial elemental concentration indicated involvement of a hormonal interaction within the endometrium. The endometrium proved to be the most sensitive tissue to FC + P + TM.
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| Subject
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Biological sciences
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Cattle
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Edwards County
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Livestock
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McCulloch County
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