TREATMENT OF CYSTIC OVARIAN DISEASE IN COWS WITH GONADOTRO 이 NS

Summary Eighteen multiparous and 8 nulliparous cows with cystic ovarian disease (19 having follicular cysts, 7 with luteal cysts) were administered either 3000 I. U. HCG or 300 gg LHRH. Ten animals responded satisfactorily leading to normal estrus within a period of 15 to 30 days and subsequent conception. In 8 animals cysts recurred and no effect of treatment was observed in 3 patients. Plasma progesterone concentration was significantly lower in animals liavjng follicular cysts compar ­ ed to those with luteal cysts.


Introduction
Cystic ovarian disease (COD) is one of the important causes of infertility in dairy cattle. Ovarian cysts are often classified as follicular or luteal or follicular-lutein cysts (Roberts, 1971: Grunert, 1982. The incidence of ovarian cysts in dairy cattle varies from 5.6 to 18.8 percent (Morrow et al., 1966: Whitmore et al., 1974: Britt et al., 1977. According to Morrow et al, (1966) several of the cows that develop ovarian cysts before the first post-partum ovulation re-establish ovarian cycles spontaneously and hence may not be detected al though the disease may prolong the post-partum interval of first estrus and conception in 10 to 30% of dairy cows.
The methods of treatment of COD have varied from manual rupture (Dawson, 1957) with as high as 63% of 829 cows later becoming pregnant (Schjerven, 1971) to the administration of LH, HCG or products high in LH activity (Roberts, 1971: Nakao et al., 1978: Bugalia and Kohli, 1981 with or without progesterone (Johnson andUlberg, 1967: Nakao andOno, 1977) with the recovery ranging from 61 to 77%.
In the present investigation, attempts were made to treat the COD in cattle with HCG or LHRH.

Materials and Methods
Twenty six corssbred dairy cattle (18 parous and 8 heifers) with cystic ovarian conditions from two different farms and animals visiting Veterinary Clinics at Pautnagar were included in this study. On the basis of twice weekly per rectal examina tion for over a period of four weeks, 19 animals (11 parous, 8 heifers) with the history of irregular estrus and possessing soft enlarged follicular struc tures with no palpable corpora lutea over the ovaries were diagnosed as cases of follicular cysts (FC) and seven anestrous cows having somewhat hard and thick walled structures on the ovaries were termed as cases with luteal cysts (LC). Eleven, animals (6 cows plus 5 heifers) had developed cysts following administration of estrogen-progesterone for induction of lactation.
One group of thirteen animals (12 cows + 1 heifer; 7 FC and 6 LC were injected i/v w辻h 3000 I.U. HCG (Chorulon-Intervet International, Holland) while the other group of 10 animals (3 cows + 7 heifers: all FC were administered i/v with 300 Mg LHRH (UCB-Bioproducts, Belgium) in saline. Three cows served as control and were injected with saline only. AU animals following treatment were examined daily per rectally.
Heparinized blood samples from 17 animals collected through the jugular venipuncture on alternate day upto day 10 were centrifuged and the separated plasma was stored at -20°C pend ing progresterone estimation by radioimmuno assay procedure (Kamonpatana et al. 1983).

Results
Following HCG/LHRH administration the cysts regressed within 6-8 days in most cases but reappeared in many animals. Of the 13 animals treated with HCG, 6 (2 FC + 4 LC) responded with manifestation of normal estrous signs within a period of 16 to 30 days. They were artificially inseminated and all of them conceived. Out of the 7 remaining cows there was no effect in 3 cases while in the rests cysts recurred following reduc tion after treatment and estrous cycle remained irregular (table 1).
Of the 10 animals, treated with LHRH, only 4 animals responded satisfactorily leading to appear ance of estrus within 15 to 28 days and subsequ ent conception (table 1). Two of the non-respond ing animals developed endometritis while in. the remaining four, the cysts firstly regressed but re developed. No significant change in respect of ovarian picture and estrous irregularity was noticed in the control group.
The data further indicated that HCG gave satisfactory response in 66.6% of cases with LC and 28.5% in cases with FC while LHRH gave satisfactory response in 80% of the cases having follicular cysts (table 2).
Data on plasma progesterone (P4) concentra tion (table 3) indicated that animals suffering from follicular cysts had significantly lower plasma P4 compared to those having luteal cysts. In two animals with FC, HCG treatment firstly decreased and the increased P4 levels. One of these animals was successfully treated. In animals having luteal cysts two types of responses were obtained: those animals (n=2) in which cysts recurred, the plasma  P4 progressively declined but in the animal (n=l) which later exhibited estrus signs and became pre gnant, the P4 level firstly decreased until day 8 and then increased on day 10. In all animals receiving LHRH treatment (FC cases), the plasma P4 were generally low previous to treatment. In successfully treated animals (n= 4) there was a small decrease in plasma P4 but it was elevated later particularly on days 8 and 10. In the animals in which cysts recurred (n=4) there was also elevation of P4 on day 8 and 10 the values almost equal to those seen in treated cases.

Discussion
The recovery rate (number of cows conceived/ number of cows treated following 3,000 I.U. of HCG administration in animals with COD was 6/ 13 or 46.1%, the conception taking place within 24.3 ± 1.9 days. This conforms well with the report of Nakao et al. (1978) who injected 1,000 MU(equivalent to 30,000 I.U.) of HCG in 12 cows i/m and only 4 cows responded with conception within 64 ± 51 days. Several other workers (Elmore et al., 1975;Laing, 1979;Koppinen et al., 1984) have used LI I, HCG or products high in LH in doses ranging from 1,000 to 10,000 LU, and reported establishment of estrous cycle within a period of 28 to 30 days after treatment and recovery rate of 65-80% although the 1st service conception rate varied from 38 to 58%.
Only 4 out of 10 animals recovered in the LHRH-treated group within a period of 19.7 ± 1.7 days after treatment. In 2 animals there was re currence of cyst and 4 animals began to exhibit regular estrous cycle with repeat breeder symp toms. In the studies by Bierschwal et al. (1975), Elmore et al. (1975), Seguin et al. (1976) and Kesler et al, (1979) GnRH caused around 80% of cows to re-establish ovarian cycles within 28 to 30 days of the treatment. The percentage of cows conceiving to first service was 37-55 percent. In the present study this percentage was 40%.
The occurrence of repeat breeder syndrome appear to be independent of the pre-existing cystic condition and could have been due to the uterin infection, as two animals suffered with endometritis. Low conception rate at first insemi nation after cyst regression in cattle with endome tritis was also observed by Zoldag (1984). Our results are in line with Richardson et al, (1982) who reported that an injection of 100-250 pg GnRH stimulates luteal tissue formation in bovine follicular cyst and about 75-85 percent of treated cows responded positively to GnRH with normal estrus in 67 percent within 10-30 days after treat ment.
High P4 concentration (above 1 ng/ml) was observed in the cows.having luteal cysts, while in case of follicular cysts the P4 concentration was below 1 ng/ml. Similar pattern of P4 was observed by Glenuoss and Munro (1974), Kesler et al. (1980), Zoldag (1984), Narayana and Honnappa (1985) in case of luteal cysts and follicular cysts, respectively.
Animals with follicular cysts after i/v injection of HCG or LHRH showed a substantial rise in P4 concentration by day 6 while P4 level of animals with luteal cysts decreased below 1 ng/ml within 6-8 days. Kesler and Garverick (1982) had reported increased level of P4 in the cases of follicular cysts and decreased level in the cases of Juteal cysts within 9 to 13 days after GnRH treatment.
Some of the animals with follicular cysts showed periodical high (more than 1 ng/ml) plasma P4 concentration and this is corroborative with the findings of Kesler et al. (1980) and Narayana and Honnappa (1985). Aberrant luteal tissues either in the form of luteinized cystic follicles or small accessory corpora lutea peculiar to cows with cystic ovaries (Tanabe and Brofee, 1982) or the possible diagnostic inaccuracies in per rectal examinations (Dawson, 1975) are pre sumably accountable for the wide variations in plasma P4 concentration noted in the present study.