Post by Liz on Jun 28, 2009 13:51:53 GMT -5
Website link: Bovine Reproduction Research
Treatment of Ovarian Cysts Here
Article link from Purdue, 2001:
Ovarian Cysts in Dairy Cattle Here
Excerpt:
Genetic Influences
In a Swedish study, Al sires were culled if their daughters had ovarian cysts. Over a 20-year period (1954-1974) the national incidence of cysts in Sweden declined from 10 to 3 percent. This decline in the incidence of ovarian cysts implicates genetics as having a major role in the transmission of cystic ovarian disease from one generation to the next. Therefore, culling cows and heifers with ovarian cysts would appear to be one method of permanently decreasing the occurrence of ovarian cysts in dairy herds. Unfortunately, many cystic cows are also the high producers, making effective culling difficult to implement in many cases.
Nutrition Influences
To date, comprehensive studies have not demonstrated a link between nutrition and ovarian cysts in dairy cattle when experiments were conducted with properly balanced rations. In other words, if the ration meets all of the nutrient requirements of the cow, additional amounts of selected nutrients (i.e., Beta-carotene and selenium) will not revent ovarian cysts. However, it is of utmost importance that rations be properly balanced and provided in adequate amounts to meet the requirements of milking cows.
Production Influences
Although it is a common belief that high producers may be more prone to develop ovarian cysts, no experimental data supports this contention. Increased milk production may be a result of the altered hormone environment that occurs with ovarian cysts rather than a cause of ovarian cysts.
Treatments
In the early part of this century, manual rupture (via rectal palpation) was used as a treatment for ovarian cysts. Recovery rates were approximately 45 percent. However, because of possible hemorrhaging, formation of adhesions around the ovary and the advent of hormonal treatments, manual rupture is used less frequently than in the past. More recently, hormones having high LH - like activity have been successfully used as a treatment for ovarian cysts. Initially, pregnant mare's serum gonadotropin (PMSG) and human chronic gonadotropin (hCG) were utilized, but, due to their large molecular weight, some cows developed antibodies against these products and retreatments were not always successful. However, hCG is still a commonly used treatment for ovarian cysts.
Currently, gonadotropin releasing hormone (GnRH) is the most frequently recommended treatment for cows with ovarian cysts because it causes the pituitary to release LH and does not result in antibody formation. Table 1 lists the treatments for follicular and luteinized follicular cysts and describes the expected outcome after treatment. Because a high proportion of cysts spontaneously regress during the early postpar tum period, treatments are usually not administered until after 30 days postpartum. The GnRH treatment causes luteinization of the cyst, and the subsequent prostaglandin treatment of the luteinized cyst causes regression of that structure.
Summary
1. Ovarian cysts reduce reproductive efficiency in most dairy herds.
2. Rectal palpation is the only practical method to detect ovarian cysts.
3. The exact cause of ovarian cysts is unknown.
4. Culling cows and heifers that have had ovarian cysts can permanently decrease the incidence of ovarian cysts in most dairy herds.
5. An injection of GnRH is an effective treatment for ovarian cysts.
links verified: 10.07.10
Treatment of Ovarian Cysts Here
Article link from Purdue, 2001:
Ovarian Cysts in Dairy Cattle Here
Excerpt:
Genetic Influences
In a Swedish study, Al sires were culled if their daughters had ovarian cysts. Over a 20-year period (1954-1974) the national incidence of cysts in Sweden declined from 10 to 3 percent. This decline in the incidence of ovarian cysts implicates genetics as having a major role in the transmission of cystic ovarian disease from one generation to the next. Therefore, culling cows and heifers with ovarian cysts would appear to be one method of permanently decreasing the occurrence of ovarian cysts in dairy herds. Unfortunately, many cystic cows are also the high producers, making effective culling difficult to implement in many cases.
Nutrition Influences
To date, comprehensive studies have not demonstrated a link between nutrition and ovarian cysts in dairy cattle when experiments were conducted with properly balanced rations. In other words, if the ration meets all of the nutrient requirements of the cow, additional amounts of selected nutrients (i.e., Beta-carotene and selenium) will not revent ovarian cysts. However, it is of utmost importance that rations be properly balanced and provided in adequate amounts to meet the requirements of milking cows.
Production Influences
Although it is a common belief that high producers may be more prone to develop ovarian cysts, no experimental data supports this contention. Increased milk production may be a result of the altered hormone environment that occurs with ovarian cysts rather than a cause of ovarian cysts.
Treatments
In the early part of this century, manual rupture (via rectal palpation) was used as a treatment for ovarian cysts. Recovery rates were approximately 45 percent. However, because of possible hemorrhaging, formation of adhesions around the ovary and the advent of hormonal treatments, manual rupture is used less frequently than in the past. More recently, hormones having high LH - like activity have been successfully used as a treatment for ovarian cysts. Initially, pregnant mare's serum gonadotropin (PMSG) and human chronic gonadotropin (hCG) were utilized, but, due to their large molecular weight, some cows developed antibodies against these products and retreatments were not always successful. However, hCG is still a commonly used treatment for ovarian cysts.
Currently, gonadotropin releasing hormone (GnRH) is the most frequently recommended treatment for cows with ovarian cysts because it causes the pituitary to release LH and does not result in antibody formation. Table 1 lists the treatments for follicular and luteinized follicular cysts and describes the expected outcome after treatment. Because a high proportion of cysts spontaneously regress during the early postpar tum period, treatments are usually not administered until after 30 days postpartum. The GnRH treatment causes luteinization of the cyst, and the subsequent prostaglandin treatment of the luteinized cyst causes regression of that structure.
Summary
1. Ovarian cysts reduce reproductive efficiency in most dairy herds.
2. Rectal palpation is the only practical method to detect ovarian cysts.
3. The exact cause of ovarian cysts is unknown.
4. Culling cows and heifers that have had ovarian cysts can permanently decrease the incidence of ovarian cysts in most dairy herds.
5. An injection of GnRH is an effective treatment for ovarian cysts.
links verified: 10.07.10