Submitted to: Animal Science Progress Report
Publication Type: Other
Publication Acceptance Date: 10/12/1999
Publication Date: N/A
Technical Abstract: Early growth is an important determinant of gain and efficiency in young pigs, but a major limiting factor of piglet growth is feed intake. Orexins, newly discovered neuropeptides, may be important regulators of appetite. The porcine orexin gene was recently cloned by our lab. The objective of this study was to evaluate the effect of orexin on feed intake ein weanling pigs. Twenty-six crossbred piglets were utilized in three replicates (n=8-10/replicate). Piglets were weaned between 2-3 wk of age. One wk after weaning, equal numbers of animals in each replicate received intramuscular injections of synthetic porcine orexin-B (3 mg/kg body weight) or vehicle (sterile water). Feed intake was monitored from -24 to 24 h relative to injection (time 0). The orexin-injected pigs ingested an additional meal at 12 h when compared with the control animals (P=.02). Cumulative feed intake was increased by orexin-B administration from 12 to 24 h postinjection (P<.05). Total feed intake at 24 h was improved by 18% in orexin-treated pigs (P=.05). The ability to stimulate appetite during critical periods of early growth, particularly following weaning, could result in significant improvements in swine production efficiency.