Physiochemical properties of oviductal fluid from rabbits exposed to heat stress.

Oviductal fluids (OF) were collected at 24 hour intervals from 27 does. Fluids were collected from all does during estrus and subsequent pregnancy or pseudopregnancy. After collecting OF for 15 days from all does maintained at 21 degrees C and 45% relative humidity (RH), approximately one-half of the does were then subjected to heat stress (33.20+/-0.75 degrees C and 65.4+/-2.3% RH). Oviductal fluid was then collected for 5 days from heat stressed estrous does (HSER), after which all does (both control and HSER) were mated to fertile bucks. Human chorionic gonadotropin was administered to each doe to insure ovulation. Fluids were compared between HSER and heat stressed pregnant rabbits (HSPR) and control estrous (NHER) and pregnant rabbits (NHPR) for volume, pH, various protein concentrations, and total protein content. Fluid volume decreased due both to heat stress and pregnancy. Heat stress increased pH, whereas pregnancy resulted in a decrease. Protein concentration of OF from HSER declined due to heat stress. Protein concentration of OF from NHPR increased prior to breeding, peaking at day 3 of pregnancy, then declined to initial levels. While from HSPR there was also a tendency to have a similar increase, the peak in protein concentration was on day 4 and then decreased on day 5. Total protein content (concentration x volume) of OF from HSER decreased due to heat stress. Total protein content from HSPR and NHPR had similar changes with or without heat stress, although the total protein content from OF of HSPR was less (except for day 3) for the entire 5 day period studied. Relative percentages of albumin decreased and postalbumin increased during the first day of pregnancy (NHPR). These trends were reversed (a relative increase in albumin and a decrease in postalbumin) in OF from HSPR.