The influence of pregnancy and plane of nutrition during pregnancy on pancreatic digestive enzymes and insulin-containing cell cluster morphology in beef cows

Abstract

To determine effects of pregnancy (experiment 1) and plane of nutrition during pregnancy (experiment 2) on pancreatic digestive enzymes and morphology of insulin-containing cell clusters, beef cows were slaughtered, and the pancreas collected 4 wk before parturition (if pregnant or similar time on feed for nonpregnant cows). In experiment 1, mature, nonlactating cows [717 ± 70 kg; nine pregnant (PREG) and nine nonpregnant (OPEN)] were used. In experiment 2, nonlactating, pregnant cows (639 ± 68 kg) were fed at 85% (n = 11; LOW) or 140% (n = 11; HIGH) of net energy (NE) requirements. Concentration (U g−1) and content (U kg−1 BW) of α-amylase and trypsin activities were greater (P ≤ 0.05) in OPEN than PREG cows. Pregnant cows had greater (P ≤ 0.03) insulin-cell cluster size and proportion of large insulin-containing cell clusters than OPEN cows. Concentration and content of α-amylase activity were greater (P ≤ 0.04) in HIGH than LOWcows. These data indicate that pregnancy status (PREG vs. OPEN) impacts pancreatic exocrine and endocrine functions and that plane of nutrition (85% vs. 140% of NE requirements) of pregnant cows may not greatly impact pancreatic exocrine and endocrine functions.