Document 44br3Rwwk4R9e1z5DVwOV5zrj

-149- EFFKCT Of DIETARY POLYCHLORINATED BIPHENYLS ON GROWTH AHO REPRODUCTION OF MINK R. K. Klnger, R. J. Aulerich and M. Zsblk Departments of Poultry Science add Entomology Michigan State University Eaat Lansing, Michigan 48623 Tho Groat Lake* have played a protainont col* in the devatopmont of the mink Industry In nearby eietee aa rheae lakes furnished the rancher with an inexpensive and abundant supply of fish deemed desirable for mink feed. During the middle 1960s. reports from alnk ranchers stating that reduced reproduction wee a consequence of feeding Great Ldkaa fish wvre called to the at r ant Ion of university reaearchere (Hartaough. 1965). Coho salmon taken from the tributaries of Lake Michigan during the spawn ing run In 1967 were made avallchle to tmmMU1 ranehere food for mink and resultad in a precipitous Incraaae In newborn mink (kit) mor tality. The extent of mortality appearad aa a tine-deaage raaponae to coho a.ilmon In the diet. Adult breeders were rtported to be unsffected. Ran cidity, chlorinated hydrocarbon pesticide contamination and mercury poi soning war* each prominent suspects as the causative agant responsible for tits high kit mortality. Hecauaa of the disastrous effect of feeding coho aelmon, mink ranchers discontinued use of Great Lakes fish in mink Hl-t., In 1969 our laboratory confirmed the mink industry's observation tlmt Lake Michigan coho salmon, when fed to breeder mink, reeulted in either totul cessation of mink reproduction (embryo toxicity) or kit mortality, the degree of complication being dependent upon the percentage coho salmon fed and thu duration of feeding (Aulerich et al.. 1971), Coho salmon par aa were not Implicated eince west eoaet coho salmon yielded totally acceptable reproductIva parameter*. Subsequent reproduction studies yielded dace indicating that the causative agent(a) was not eonfined solely to the salmon from Lake Michigan, but was apparently present, al though to a leaser extent, in other fiah from the Great Lakes (Aulerich ct el.. 1971). Rancidity and mercury contamination data for the various fiah did not correlate with mink toxicity data and each was discounted ae a con tributor to the problem) however, hydrocarbon pesticide contaminstlon (total DDT and laomers or dieldrln) of tbs fish fed was inversely pro portional to number of mink offspring born par feswla. This relation ship appears spurious and may reflect, in pert, the fet content of the fish. Fending cither DDT end Isomers or dieldrln in levela far in ex cess nf that found analytically in the fiah failed to simulate the cflect on mink of feeding diets containing eoho salmon (Auierleh end Ringer, 1970; Aulerich cc al.. 1971). Title study wag undertaken to investigate the effects of polychlorinated biphenyls, known to contaminate Lake Michigan and its fish, on growth and reproduceiou of ranch mink- L i`:U te 17-: lit?? ft, I L'\p mons mjenram^ia^iw'p ' .W.'/ .'j . -:% ,*u- ir uaat.,i;f*wisi>-pwi.f |i me niaymujl.fSI , `a* V:--:'?',;:-; "ci. i .*Ju; j >\-.;xv,iJ-*,yr'<' ;C ' ' 'S ' ' . ikv*| .1. ,\t >31* w> ' *' ' 'T*'\ * ' oai?7i . l' * ,, v*; veda^m -150- materials AND METHODS This study consisted of throe feeding trlele encompassing polychlorlneCed biphenyls (PCB) supplementation to mink. PCB supple mentation was by Incorporating the Aroclor Into s coreel grain premix and then Into the diet. The same basal (control) diet, except ss specified, was fed in all experiments. The diet composition was cereal, 1ST; tripe, 201; beef liver, 5%; hottamest, 15%; chicken, 13%; and fish, 30%. Standard tench procedures of animal care and breeding were ueed throughout the course of the experiments. Experiment I RESULTS A total of 45 mink were divided into 3 groups (12 femslos and 3 melts per distsry treatment group). The treatments ware a basal diet containing ocean fish, substitution of coho salmon for the ocean Itah, and the baaal diet supplemented with 10 ppm each of Aroclora 1242, 1249, and 1254. No femtla mink receiving dietary coho salmon bore young (whelped) nor did thoee receiving 30 ppm PCB supplementation (Table 1). All adult mink fad supplemental PCB'a died by the end of the normal whelping period. Those females, on FCB'a, that survived sufficient time 0 produce offspring showed no signs of whelping. Six mink fed coho salmon died during die experimental period of Jonuary 1 to June 30. No aduLt control mink died. Table 1 Effect of Dietary PCB Supplementation^) on Reproduction of Ranch Mink (January 1 to June 30) Females mated Females wheloed Kits born Alive Dead Kits alive ( 4 wks.) Basal (control) 30% coho salmon Basal 4 30 ppm PCB'a 12 12 11(2) U 0 0 35 19 00 00 29 0 0 (1)10 ppm each of Aroclora 1242, 1248, and 1254. (2) One femele died prior to the mating season. Tissue analysis for PCB residues from several mink that diod while on experimentation are shown In Table 2. Control mink were sacrificed for tissue analysis. The similarity In the tissue residues of the PCB AroclorTM is the trade name of polychlorinated biphenyls by Monsanto Company, St. Louie, Mo. MOWS HjL'm >'.,'*>.w *.`.t-.^ V-y' /' -.ji-iw'J'.sV-iA* .l*-'- ..'ft" treatment and the coho treatment group la striking. Organ weights expressed ss a percentage of brain weight from those mink that died and from sacri ficed controls were not significantly different (p > 0.0S). Table 2 PC Tlsaue Residues (in ppm) of Mink Chat Oled While Receiving Dietary Coho Salmon or Supplasmntal PCS'ed) and from Sacrificed Controls (Hsn + S.S.) Basal (control) 30% coho salmon Basal 4 30 era PCB`a No. mink 4 3 12 Brain < 0.01 11.07 i 0.78 11.00 + 1.43 Liver < 0.01 5.21 1.68 4.18 0.58 Kidney < 0.01 4.37 4 0.25 4.47 + 0.42 Spleen Lung Muscle < 0.01 < 0.01 < 0.01 6.19 + 0.09 5.13 + 0.22 4.73 + 1.80 4.79 + 0.39 4.78 + 0.53 4.88 0.54 Heart < 0.01 2.84 1.21 3.26 0.49 (1) 10 ppm each of Aroelors 1242, 1248, and 1254. Experiment II Thirty-five mink were divided Into five groupe of eix females end one male per group. Dietary treatmente ware initiated on Auguet 23 to measure growth rate of young, growing mink and will continue until June 30 whan the reproductive phase la complete. Treatments consisted of a basal diet with ocean flail, baaal plus 5 ppm Aroclor 1254, basal plus 10 ppm Aroclor 1254, basal plus 10 ppm Aroclor 1234 and 10 ppm 0TTT, and basal plus 10 ppm Aroclor 1254 and 0.3 ppm disldrin. faults of body weight gains for the growth phase from August 25 to December 22 are shown in Table 3. Results for the reproduction phase are Included in Table 4. V''"' ' v.'.." . ' l'&3^ '.vJ-S V /^1.^*V^y^ V-jV-;'-;:'--'' '*.- i'-v ...:. . " . , ;- v nA. *Ti A*. !'m --l --.-..MM'. '.kijMi'lML , ;. v ;.', s.**; ; %vyy:';T 3^. *;'` */. -153- Date front tit 10 experiment demonstrate chat 10 ppm Aroelor 1254 de pressed growth gains, when fed continuously to growing mink. A dose-response curve for data on 0, 3, and 10 ppm Aroelor 1254 at 4 months treatment yielded a regression equation of T * 207.5 - 107.4X where X * In (^{2 + 1). This regression equation gives a significant dose-response (P < .05). All mink fed PCB supplemented diets felled to produce offspring. Those breeders that died during the gestation period exhibited various degress of embryo toxicity when the uterue wee opened for examlnetlon. (experiment til One hundred twenty-eight mink were divided into eight groups of twelve females and four males par group to evaluate the effect of Aroelor 1256 on reproduction. The dletery treatments were initiated on January 1 and will continue until June 30. Included in the treatments (Table 3) was a group given 5 ppm Aroelor 1254 plus 6 ppm DOT and 0.2 ppo dleldrln. These levels approximate the residua values found In diets where 30 percent raw Lake Michigan coho salmon constituted the fish portion of the diet. Cooked coho ealnan (120* C et 1.05 kg/sq cm for 30 min) wee Included to test for the heat eiabillty of the feccor(e) causing the reproductive problem. Table 5 Kffect of Aroelor 1254 Fed Singly and In Combination with Hydrocarbon on Reproductive Parameters (Jan. 1 to May 10) (12 females and 4 meles/group) Female* Females Kit* born Kits/female X mortality alive wheLpad Alive Dead alive Control (preen flah) Raw coho salmon Cooked cohe salmon 1 ppm PCB'*^ 5 ppm PCB IS ppm PCB 3 ppm PCI + 6 ppm DDT 5 ppm l*TB + 4 ppm DDT 4 0.2 ppm dicldrin 6 19 6 6* 0 31 0 19 11 ll 56 10 6.0 ll O 0 0 0 12 0 0 0 0 10 8 35 8 4.3 12 3 3 6 0.8 8 0 00 0 12 4 5 6 0.9 10 5 15 7 2.2 (1) Aroelor 1254. * One female escaped. Data tn Table 5 Indicate chat 5 ppm Aroelor 1254 markedly reduced reproduction when fed only 4 months, 1 ppm Aroelor 1254 caused only slight reduction and IS ppm PC8 totally inhibited reproduction. The factor(a) present In Lakii Michigan coho salmon was host stable and duplication, in HONS 081775 *Wii<h'<feta'Jli uiiitfri'^ii^liiwif<11^ rf>p1irfi ^ >i li'ttfif * 1 -Im part, of several factor* known to be present in the iiliwn did not totally reproduce the coho aalnon effect. The reeult* of these experiment* clearly point out the enairivlty of oink to polychlorinated biphenyl* and c**t auapiclon on KB'* a* a poaelblo factor involved in the poor reproduction following Lake Michigan coho aalnon feeding. LITERATURE CITED Aulerlch, R. J. end R. X. Rlnger> 1970. Some effect* of chlorinated hydro carbon peatieidoe on mink. Amer. Pur Breador 43: 10. Aularlch, R. J.. R. K. Ringer, H. L. Beagran an* W. C, Yemu, 1971. Effect of feeding coho anlmoo oad other Great Lakaa fieh on mink reproduc tion. Can. J. tool. 49: 611-614. fUrteowgh. G. R., 1965. Great UIm flah new euepeet ae mink food. Amer. Pur Breeder 38: 2$. MONS 081776 .V / ' w