Introduction
Bernabucci et al., 2009 described a reduction in feed intake by finishing lambs as a result of heat stress conditions. Dávila-Ramírez et al., 2014 hypothesized that the use of β-adrenergic agonists as a feeding management strategy to improve carcass characteristics in reduced feed intake lambs. Zilpaterol hydrochloride (ZH) use in steers resulted in the mobilization of tissue from visceral organs and directed these nutrients to carcass tissues during periods of ZH supplementation (Baxa et al., 2010). The mobilization of non-carcass tissue nutrients results in lower energy requirements for growth and subsequently lower feed intake (Reeds and Mershmann, 1991). However, Macías-Cruz et al., 2010; observed that ZH increases longissimus …show more content…
To test this hypothesis, objectives for the study include 1) inducing heat stress conditions in Hampshire wethers 2) feeding the β-adrenergic agonist, Zilpaterol hydrochloride in doses common to feedlot practices 3) analysis of feedlot performance (i.e. ADG, Feed to Gain ratio, and feed intake) 4) analysis of slaughter performance (Hot carcass weight, cold carcass weight, percent carcass yield, muscle pH, and tenderness) 5) analysis of wholesale muscle tissues for β2-receptors using real time PCR and …show more content…
This analysis of β2-receptors will answer more of the hypothesis of ZH’s effect on carcass performance in animals exposed to long term heat stress. Expected results of the treatments being, increased feedlot and carcass performance of group 2, with greater RNA and expression of β2-receptors, an expected decrease in feedlot and carcass performance of group 3, with decreased RNA and expression of β2-receptors. Comparatively, the pair-fed group 5 would have decreased performance and expression of β2-receptors to group 1, however would have increased performance and expression of β2-receptors to group 4. This comparison study would show that the decrease in feed intake as a result of heat stress is responsible for some of the effects in performance observed. The sheering, transportation, and acclimation of these sheep at the prior to the treatment phase would provide for a control in other stressors among all groups. There would be an expected higher level of catecholamines in all groups subjected to heat
Bernabucci et al., 2009 described a reduction in feed intake by finishing lambs as a result of heat stress conditions. Dávila-Ramírez et al., 2014 hypothesized that the use of β-adrenergic agonists as a feeding management strategy to improve carcass characteristics in reduced feed intake lambs. Zilpaterol hydrochloride (ZH) use in steers resulted in the mobilization of tissue from visceral organs and directed these nutrients to carcass tissues during periods of ZH supplementation (Baxa et al., 2010). The mobilization of non-carcass tissue nutrients results in lower energy requirements for growth and subsequently lower feed intake (Reeds and Mershmann, 1991). However, Macías-Cruz et al., 2010; observed that ZH increases longissimus …show more content…
To test this hypothesis, objectives for the study include 1) inducing heat stress conditions in Hampshire wethers 2) feeding the β-adrenergic agonist, Zilpaterol hydrochloride in doses common to feedlot practices 3) analysis of feedlot performance (i.e. ADG, Feed to Gain ratio, and feed intake) 4) analysis of slaughter performance (Hot carcass weight, cold carcass weight, percent carcass yield, muscle pH, and tenderness) 5) analysis of wholesale muscle tissues for β2-receptors using real time PCR and …show more content…
This analysis of β2-receptors will answer more of the hypothesis of ZH’s effect on carcass performance in animals exposed to long term heat stress. Expected results of the treatments being, increased feedlot and carcass performance of group 2, with greater RNA and expression of β2-receptors, an expected decrease in feedlot and carcass performance of group 3, with decreased RNA and expression of β2-receptors. Comparatively, the pair-fed group 5 would have decreased performance and expression of β2-receptors to group 1, however would have increased performance and expression of β2-receptors to group 4. This comparison study would show that the decrease in feed intake as a result of heat stress is responsible for some of the effects in performance observed. The sheering, transportation, and acclimation of these sheep at the prior to the treatment phase would provide for a control in other stressors among all groups. There would be an expected higher level of catecholamines in all groups subjected to heat