Treatment and control of cystic ovarian disease in dairy cattle: A review

Abstract

Cystic ovarian disease, a common, clinically recognized cause of infertility in dairy cattle is characterized by one or more large anovulatory follicles(s) in one or both ovaries that persist for at least 10 days in the absence of a corpus luteum, and by abnormal oestrus behaviour. The incidence of cystic ovarian disease has been reported to be 6 to 19%. The incidence of this disease is probably even higher because 60% of the cows that develop ovarian cysts before the first postpartum ovulation re-establish ovarian cycles spontaneously, therefore, cystic ovarian disease is a serious cause of reproductive failure in dairy cattle. Repeated manual rupture of cysts at 6 to 10 days intervals, especially the follicular type during the early postpartum period, has produced 37 to 45% recovery rates. This frequent manual massage is injurious to the ovary and possible complications from manual rupture include haemorrhage and adhesions leading to infertility. Investigators have shown that 65 to 80% of the cows with ovarian cysts re-establish ovarian cycles within 28 to 30 days following treatment with therapeutic agents high in LH activity. This treatment has produced 38 to 58% first service conception rates. It has been concluded that 2500 to 5000 i.u. of LH or HCG i v are the most economical to use. Treatments with products like FSH or PMSG have produced only 48% recovery rates in cows with ovarian cysts and are no longer recommended. A first service conception rate of 32% and a pregnancy rate of 74 to 85% have been reported in cows with cystic ovaries treated with i m injections of corticosteroids. Corticosteroid treatment is more useful in cases of cystic ovarian disease, where injections of gonadotropins have failed. The use of progestational compounds as a single dose (750 to 1500 mg) or daily (200 to 500 mg) over a period of 10 to 17 days i m or s c has produced recovery rate; of 61 to 72% and overall conception rate of 50%. Combined preparations of chorionic gonadotropins and progesterone used i v have resulted in recovery rate of 60 to 80%. There is a marked delay in the resumption of oestrous cycles of cows with ovarian cysts after treatment with progesterone. Gonadotropin releasing hormone (GnRH), which stimulates the re-establishment of ovarian cycles within 28 to 30 days in 62 to 97% of treatment has recently been recommended for ovarian cysts. Most cows that re-establish ovarian cycles subsequent to GnRH treatment exhibit oestrus 18 to 23 days after treatment, and conception rate at this first oestrus after GnRH treatment is 37 to 57%. The interval from GnRH treatment to oestrus has been reduced by administering prostaglandin F 2 alpha (PGF 2 alpha) 9 days after GnRH. The PGF 2 alpha appears to regress the luteinized ovarian cysts and cows exhibit oestrus 2 to 3 days after PGF 2 alpha treatment (11 to 12 after GnRH). With PGF 2 alpha treatment of luteal cysts luteolysis of cysts occurs within 2 to 5 days in over 90% of the cases with normal oestrous behaviour and fertility. Gonadotropin releasing hormone has also been used to reduce the incidence of ovarian cysts in post partum cows. For better success in reducing the incidence of ovarian cysts, GnRH should be administered about 14 days postpartum. Because cystic ovarian disease in cows is frequently due to an inherited weak hormonal constitution and treatments are of only temporary value. Alternatively, it is better to select against ovarian cysts to reduce their incidence.