Combined Effects of VFA Composition of Rumen Fluid and Heat Exposure on General Clinical View and Insulin Secretion Response in Sheep

고온환경에 있어서 면양의 제일위내 VFA 조성비율이 일반임상소견 및 Insulin 분필반응에 미치는 영향 - VFA-TG 인공영양사육법의 응용 -

  • 홍경선 (축산기술연구소(National Livestock Research Institute, R.D.A.)) ;
  • 정태영 (건국대학교 축산대학(Department of Animal Science, College of Animal Husbandry, Kon-Kuk University)) ;
  • 좌야굉명 (일본, 암수대학) ;
  • 지하농랑 (일본, 암수대학) ;
  • 중와방야 (일본, 암수대학) ;
  • 안보계일 (일본, 암수대학)
  • Published : 1997.06.01

Abstract

This study was conducted to investigate the combined effects of VFA composition of rumen fluid and heat exposure (30${\pm}$2$^{\circ}C$) on the general clinical view and insulin secretory response to glucose in sheep. The total infusion of nutrients was examined in sheep via the technique of continuous alimentation. Four adult Suffolk sheep fitted with a permanent ruminal cannula and a simple T-shaped duodenal cannula were used. A peristaltic pump was used to infuse the solutions of volatile fatty acid triglycerides (VFA-TG) consisting of 70 triacetin : 20 tripropionin : 10 tributyrin (low propionin division: LP) and 50 triacetin : 40 tripropionin : 10 tributyrin (high propionin division: HP) on the basis of energy and minerals into the rumen, and casein solution into the duodenum. The effects of heat exposure and type of the levels of VFA-TG solutions on the insulin secretory response to glucose in sheep were investigated by using hyperglycemic clamp (HGC) technique. The results obtained are summarized as follows: 1. During the heat exposure (latter half of the infusion period), respiration rate, heart rate and rectal temperature increased (P<0.01, P<0.01, P<0.05), but the levels of VFA-TG solutions (LP and HP division) did not affect the general clinical view except for the heart rate. 2. In the HGC technique, glucose infusion rate (GIR) and mean plasma insulin increments (MPII) tended to be ower in the heat exposure than in the thermoneutral environment, but no significant difference was found among the treatments. GIR and MPII remained unchanged between the levels of VFA-TG solutions. 3. In the HGC technique, ratio of MPII to GIR (MPII/GIR) which represents pancreatic ${\beta}$-cell response to glucose stimulation remained unchanged among the treatments.

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