Organochlorine pesticides in swine tissues and the effect of dieldrin on the progesterone profile in gilts
This study was carried out to investigate the levels of organochlorine pesticide residues in swine tissues, and the effect of dieldrin on the progesterone profile of the estrous cycle of gilts. In the first part, the study intended to measure the level of organochlorine pesticide residues in swine fat, muscle, liver, follicular fluid and corpus luteum. The second part was designed to find the effect of feeding gilts with dieldrin spiked feed on the progesterone profile of the estrous cycle. Tissue samples for the survey were obtained from slaughter house material. Two groups of gilts were used; one group came from farms that used only commercial feed; the other originated from farms that used commercial feed and swill interchangeably. Fat tissue analysed in the survey was found to have ahigher occurrence of pesticide residues compared to the other tissues. No pesticide residues were detected in follicular fluid. The main contaminant in all the tissues was p,p'-OOT and its metabolite p.p'- DOE. There was a fair occurrence rate of other DOT metabolites, P.p'- ODD and o,p'-DDT in all the tissues and a poor occurrence of aldrin, dieldrin and heptachlor (detected only in fat). The liver had an exceptionally higher occurrence of p,p'-DDD compared to the other tissues. __ The mean sum DDT in mg/kg wet weight ranged from 0.350 in muscle tissue to 0.867 in the corpus luteum. The pigs which had been fed on commercial feed only had mean sum DDT levels of 0.423, 0.534, 0.322 and 0.069 mg/kg fat in fat, muscle, liver and corpus luteum respectively. Those which had been fed on both commercial feed and swill had mean sum DOT levels of 1.268, 1.233, 1.378 and 0.552 mg/kg fat in fat, muscle, liver and corpus luteum respectively. A significant difference (p < 0.05) in the sum DOT levels was observed in the liver and muscle analysed from the two groups. A similar difference was observed in the p,p'-DDE in the muscle and corpus luteum tissues. The mean p,p'-DDT to p,p'-DDE ratio in the pigs which had been fed on commercial feed only was found to be 1.358, 1.487, 2.991, and 1.212 in the fat, muscle, liver and corpus luteum respectively. The mean p,p'-DDT to p,p'-DDE ratio in the group of pigs which had been fed on both commercial feed and swill was found to be 2.102, 2.774, 2.978 and 1.442 in the fat, muscle, liver and corpus luteum respectively. There was a significant difference (p < 0.01) in the ratio between the fat and muscle from the two groups. Eight gilts comprising three controls; and five treatment animals that had been given feed spiked with 40 ppm of dieldrin for 60 days; were used to study the effect of dieldrin on the progesterone profile in the estrous cycle of gilts. The following mean levels in mg/kg fat weight were observed in the tissues: fat 16.19; liver 11.36; muscle 16.17; corpus 1uteum 11.18; kidney 12.50; serum 3.71; and brain 1.62. Serum progesterone levels were also analysed and no significant difference (p > 0.10) between the progesterone profile of the control and the treatment animals was observed.
CitationMaster of Science in Animal Physiology
University of NairobiDepartment of Animal Physiology, University of Nairobi,