EFFECT OF FURAZOLIDONE-TREATMENT ON REPRODUCTIVE FUNCTIONS, SERUM ESTRADIOL AND GONADOTRAPHIN IN FEMALE RHODE ISLAND RED LAYER BIRDS

Abstract

The current study was carr ied out to determine the effects of furazolidoneadministration on reproductive performance of female Rhode Is land Red birds. Birds were allocated to four groups and each group consisting of eight female and one male. Furazolidone was administered ora lly at the prelaying age at doses of control Omg/kg feed, group I 200mg/kg feed, group II 400mg/kg feed and group III 800mg/kg feed for period of 5 weeks (1S -20weeks of age) and birds kept for another four weeks on furazol idone free diet. At the age of 24 weeks birds were sacrificed. Furazolidone produced dose dependent effects on body weight of the birds. However, in 2nd week of furazolidone-administration the body weight of group III was significantly (P<O.OS) reduced. In the 3rd and 4th week, furazolidone-treatment resu lted in significant (P<O.OS ; P<O.02) decrease in body weight of group II and III respectively. Similar, highly significant (P<O . Ol~ trend in reduction in body weight of the group II and III was observed during 5t week of treatment. There was no difference in the body weight of group I compared to control birds at any stage of furazo lidone-adm inistration. This reduction in body weight was also observed during I SI and 2nd week of furazolidone cessation that sijn ificantly (P<O.O I;P <0.02) lower in group II and III compared to control. During 3r week of the mean body of group II became similar to control whereas in group III it remained significantly (P<O.02) lower compared to control. Body weights of all groups were comparable in 4th week. Feed conversion ratio (FeR) was comparable in group I and II to control birds during 1st, 2nd and 3rd week of furazo lidone treatment. FeR in group III was comparable to control birds at the end of first week but reduced significantly (P<O.05) during 2nd and 3rd week of furazolidone-treatment. There was significant (P<O.02) decrease in FeR of group II and III during 4th and Sth week of furazolidone-treatment Furazolidone-treatment decreased (P<O.OOO I) serum cholesterol level in all treated birds. Serum cholesterol reduced significantly (P<O.02; P<O.Ol) during 1st and 2nd week of furazolidone-treatment in group II and III. Serum cholesterol concentration was adversely affected (P<O.OO I )during 3rd_Sth week of experiment in group II and III. After withdrawal of furazolidone serum cholesterol level remained significantly (P<O.05 ; P<O.02; P<O.O I; P<O.OO I) lower in all the treated groups compared to control. In 4th week cholesterol level was comparable in all groups except group III. Serum estradiol concentration reduced (P<O.OOOl) in all groups by the furazolidoneadministration. Serum cholesterol level was similar in all groups at the end 1st week but significant (P<O.OS; P<O.02; P<O.OO I) reduction was observed in group II and III during 3rd and Sth week. Serum estradiol concentration remained significantly (P<O.O I; P<O .OO I) lower in group II and III at 2nd week of furazolidone cessation and approached to normal at 4 th week. Furazolidone-treatment decreased (P<O .0368) serum LH level in all groups. Lower dose of furazolidone caused no change in serum LH levels. However, a significant reduction was observed in serum LH level with higher concentration during 3rd and 5th week of furazolidone-administration. Even after fourth week of furazolidone withdrawal, serum LH remained significantly (P<O.OS; P<O.OOI) lower in all the treated groups. Furazolidone-administration resulted in delay in egg laying and reduced (P<0.0032) egg production in all treated groups. A significant increase (P<O.OOOI) in ' egg production was observed with increasing age of the birds. The weight and volume of the eggs increased (P<O.OOO I; P<O.OO I) with the advancement of age. Furazolidone did not effect the size of the egg. The total ovarian weight with large follicles was not affected by furazolidoneadministration but ovarian weight with on ly small follic les (P<O.OI) and ovarian vo lume with small fo llicles were red uced (P<0.02; P<O.OI) in group II and III. Ovarian size was comparable to control birds. The length of oviduct significantly decreased (P<0.05; P<O.OI) in g Oup II and III compared to control but did not effect the weight and volume of the oviduct. Furazolidone-administration did not significantly (P>0.05) effect the secondary sex organs (Wattles and Com b) and liver weight of the birds. Furazolidone also induced various changes in oocyte proliferation. Furazolidoneadministration caused significant (P<0.05; P<O.OI; P<O.OOI) decrease in mean number of oocyte diameter in the range of 10 1-400j.lm in all the treated birds. The mean number of oocyte diameter in the range of 401 -600j.lm decreased (P<O.02; P<O.O 1) in group II and III on ly. The oocytes with diameter in the range of 601- 700)lm and 70 1-800j.lm were not found in treated birds. The mean number of follic les with granulosa layer thickness 1-10)lm decreased in group II and III. While, follicles with granulosa layer thickness in the range of 11 - 50j.lm did not differ from control in all groups. The mean number of oocytes with nuclei diameter in the range of 21 - 60~Lm decreased in treated bird. The mean number of oocyte with nuc lei in the range of (60-80j.lm) were only found in control group Furazolidone-treatment caused significant reduction (P<0.05; P<O.OI) in mean number of yolky folli cles of diameter in the range of 1-1 Omm in treated groups II and III. The mean number of yolky follicles diameter in the range of 21 -25mm decreased in group II and III. Furazolidone-administration also altered the organization of ovarian structures. The ovary of treated birds showed di sru pted zona pellucida, loose stromal tissue, no cytoplasmic extension and small size lesser number of follicles on the cortical region.