Lec 6 Flashcards
(110 cards)
What constitutes functional forms of infertility in cows?
Abnormalities of the reproductive endocrine control systems constitute functional forms of infertility.
What is the most common result of functional infertility in cows?
Most forms of functional infertility result in anoestrus, which is the failure of the cow to display oestrus.
What are the inherited factors that can lead to anoestrus in cows?
Inherited factors are one of the causes of abnormalities that can lead to anoestrus in cows.
What management aspects can contribute to functional infertility in cows?
Management aspects that can contribute include stress of production, nutritional deficiencies, and excess social influence.
How does stress of production affect fertility in cows?
Stress of production can lead to abnormalities in the reproductive endocrine control systems, resulting in functional infertility.
What role do nutritional deficiencies play in anoestrus in cows?
Nutritional deficiencies can lead to abnormalities in the reproductive endocrine control systems, contributing to anoestrus.
What is the impact of social hierarchy on cow fertility?
Excess social influence, such as stable social hierarchy, can create stress that affects reproductive health and leads to anoestrus.
What are some causes of anoestrus in cows?
Causes of anoestrus include pregnancy, ovarian inactivity, failure to observe oestrus, silent heat, cystic ovarian disease, miscellaneous conditions such as spontaneous prolongation of the lifespan of the corpus luteum, infections, and early embryonic or fetal death.
What happens to oestrous cycles during pregnancy in cows?
Oestrous cycles cease during pregnancy and do not resume straight away after calving.
What hormonal condition during pregnancy affects the hypothalamo-pituitary axis?
High progesterone concentrations during pregnancy cause negative feedback suppression of the hypothalamo-pituitary axis.
What is the level of follicular activity during pregnancy?
Follicular activity is minimal during pregnancy.
What must occur after calving before oestrous cycles can resume?
A period of restoration of both gonadotrophin secretion and ovarian follicular activity has to occur after calving.
How can postpartum anovulatory anoestrus be regarded?
Postpartum anovulatory anoestrus could be regarded as a normal condition.
What is a clinical sign of anoestrus in cows related to their reproductive cycle since calving?
Animals have not been seen in oestrus since the time of calving.
What are the characteristics of the ovaries in cows affected by anoestrus when examined per rectum?
The ovaries are small, quiescent, and usually flat and smooth, especially in heifers.
What is observed in cows with very small, inactive ovaries in terms of ovarian structures?
They are devoid of any significant structures, with no palpable follicles and luteal.
What condition is indicated by the enlargement of the ovary?
Cystic ovarian disease
What can the presence of a large corpus luteum within an ovary indicate?
Pregnancy, endometritis, or pyometra
What is a sign of anoestrus in old cows?
Roughened, irregular ovaries
How can the presence of uterine tone help in identifying recently ovulated animals?
It may help to identify animals that have recently ovulated.
What examination can be used to assess the ovaries?
Ultrasonographic examination of the ovaries
What is the purpose of re-examination after 10 days in diagnosing anoestrous in cows?
To differentiate between the cyclic and anoestrous ovary
What are the methods used for progesterone determination in diagnosing anoestrous?
Milk or blood progesterone determinations can be done with two samples taken at 10-day intervals or a single sample taken 10 days before a rectal palpation.
What are the predisposing factors for anovulatory anoestrus?
Anovulatory anoestrus is influenced by management, nutritional deficiencies, energy levels, roughage, vitamins (like Selenium and Vitamin E, A), and minerals (such as Calcium, Manganese, and Iodine deficiencies).