title: Magnesium-aspartate-hydrochloride reduces weight loss in heat-stressed laying hens.
abstract: Two separate experiments were conducted to determine the ability of magnesium aspartate hydrochloride (Mg-Asp-HCl) to antagonize the effects of thermal stress in laying hens. In both experiments, hens were exposed to either a cyclic ambient temperature of 27 C to 35 C (hyperthermic group) or 23 C (control group) for 7 days. In Experiment 1, hens were given a single injection of either saline, 40 mg, or 80 mg Mg-Asp-HCl. Experiment 2 hens received a single injection of saline, 40 mg Mg-Asp-HCl, or twice daily injection of 40 mg Mg-Asp-HCl. In both experiments, heat-stressed hens had elevated body temperature and reduced body weight, feed consumption, and circulating mean Mg concentrations. Hyperthermic hens also had reduced egg weights in Experiment 1. A single daily injection of 40 mg of Mg-Asp-HCl significantly reduced body weight loss in heat stressed hens by 41 and 51%, in Experiment 1 and 2, respectively, when compared with heat-stressed hens not receiving Mg-Asp-HCl (controls). The Mg-Asp-HCl treatment did not affect overall feed intake, egg production, or body temperature in either experiment. The highest dose of Mg-Asp-HCl (80 mg) elevated circulating magnesium concentrations. A single daily injection of 80 mg of Mg-Asp-HCl or twice daily injections of 40 mg Mg-Asp-HCl did not provide any additional benefit when compared with a single daily dose of 40 mg. The antistress effects of Mg-Asp-HCl are apparent in these experiments as evidenced by the increased body weight of heat-stressed hens. Use of this compound may prove to be beneficial in maintaining the performance characteristics of poultry exposed to elevated ambient temperature.
authors.affiliation: Department of Poultry Science, Texas A&M University, College Station 77843.
authors.forename: D J
authors.initials: DJ
authors.lastname: Donoghue
authors.forename: W F
authors.initials: WF
authors.lastname: Krueger
authors.forename: A M
authors.initials: AM
authors.lastname: Donoghue
authors.forename: J A
authors.initials: JA
authors.lastname: Byrd
authors.forename: D H
authors.initials: DH
authors.lastname: Ali
authors.forename: M E
authors.initials: ME
authors.lastname: el Halawani
mesh_terms: D000818:Animals; D001224:Aspartic Acid / Q000633:toxicity*; D001831:Body Temperature / Q000187:drug effects; D002645:Chickens; D004435:Eating / Q000187:drug effects; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects*; D008274:Magnesium / Q000627:therapeutic use*; D010058:Oviposition / Q000187:drug effects; D011201:Poultry Diseases / Q000188:drug therapy*; D013312:Stress, Physiological / Q000188:drug therapy / Q000662:veterinary*; D015431:Weight Loss / Q000187:drug effects
chemical_list: D001224:Aspartic Acid; D008274:Magnesium