Anoestrous is the period of complete absence of sexual cycles and estrus. Anoestrus is a period of reproductive insufficiency characterised by a reduction in hypothalamic secretion. Pituitary LH levels are also dramatically reduced in the anestrous. Lack of follicle growth is seen by the virtual decrease in ovarian steroids in peripheral circulation, progesterone, and estradiol secretion is also undetectable. The Anoestrus syndrome is observed in cattle during gestation, lactation period, and during off breeding season. 

Classification of Anoestrus in cattle as described by Roberts (1971) can be used also in the case of buffalo. He classified the anoestrus in two types:  type 1 – female with a normal functional corpus luteum and Type 2 – female with no functional corpus luteum. Type 1 anoestrus is mainly seen during pregnancy. Type 2 anoestrus is seen when the ovaries are inactive.

Anoestrus

Definition – Anoestrous is the period of sexual inactivity between two periods of sexual activity in cyclically breeding cattle 

Types of anoestrus 

1. True anoestrus – in this condition there is insufficient pituitary stimulation that causes the development of ovarian follicles.

              Causes of true anoestrus:

• Insufficient energy or bad nutrition. 
• Any chronic diseases such as parasites, chronic peritonitis.
• A deficiency of any Iron content such as Cu, Mg, Fe, P, and vitamin A.
• Most of the true anestrous cases are due to nutritional deficiencies. 

1. Anoestrous associated with persistence corpus luteum – In the regular estrus cycle, when pregnancy does not happen then the corpus luteum degenerates and initiates another cycle. In certain cases, the corpus luteum continues and leads to anoestrus. 

There are four types of anoestrus associated with the corpus luteum:

• Early embryonic death.
• Mummification of the fetus. 
• Fetal softening.
• Pyometra.

1. Anoestrus is associated with cystic ovaries.

In this case, one ovary is enlarged due to excessive development of luteal tissue.

Treatment of Anoestrus

Anoestrus can be treated by following the below-mentioned measures:  

• Increasing cattle comfort.
• Hormonal therapy.
• Improving nutritional, mineral, vitamin supplementation.
• Supplementing with FSH and GnRH.
• Intravaginal progesterone releasing devices and Cu mate can restart the estrus cycle in anoestrous animals.

Repeat Breeding

Definition – Repeat Breeding is defined as the cattle that have a normal oestrous cycle, have no abnormal vaginal discharge but have failed to get pregnant after three or more consecutive insemination but are unable to conceive a calf.

Causes of Repeat breeding

1. Oviduct obstruction – It is commonly observed that the individual cattle females may be infertile due to a cause that does not involve other animals in the herd. Congenital or acquired genetic abnormalities are an important cause of infertility. Cows having tubular abnormalities may show Repeat breeding.
2. Genetic reason – Genetic defects can also be the reason for repeating breeding. Genetic defects are passed on from one generation to the next.  Primarily, defects or deficiencies that occur during the differentiation process could be responsible for Repeat Breeding Syndrome.
3. Improper ovarian function – The development of ovarian cysts is one of the main reasons that the cattle don’t conceive and lead to reproduction failure. These ovarian cysts are also considered as one of the main causes of repeat breeding in herds.
4. The inborn structural defects of the genital tract – The reproductive canal offers a suitable atmosphere for oocyte development, sperm transport, fertilization, and implantation. Structural or functional defects of these organs will cause gestational failure and repeat breeding.
5. Age – Age effect is also one of the factors that cause infertility.  Higher occurrences of repeat breeding have been seen in old cows. So, the older the cow is the higher the occurrences of repeat breeding. 

Treatment of repeat breeding 

• Nutritional supplements should be used to restore the imbalances at the herd level.
• If herds are facing problems of repeated estrus then their diet should be supplemented with Cu and Mg to increase fertility.
• It is also essential to improve all measures related to heat detection.
• Provide the animals with clean water to drink. 
• Ingestion of oil-rich seeds by dairy animals should be avoided.

Repeat breeding is one of the major infertility problems of cattle. The major causes of repeat breeding mainly include pathological endometritis, nutritional deficiency (especially), insufficient mineral intake, vitamin A and endocrine dysfunction. The cattle fail to reproduce newborn calves due to the reduction of the efficiency of the reproductive system of the cattle. When the function of the reproductive system is reduced, cattle fail to produce calves regularly. Repeat breeding is defined as the cow’s failure to conceive from 3 or more regularly spaced services in the absence of any identified abnormalities. It is a costly problem for dairy producers. Anoestrus and repeat breeding are one of the major problems of reproduction faced by cattle.

Conclusion 

Anestrus is a state in which a female is not exhibiting normal estrus cycles. Anestrus can be normal or pathological. Seasonal anestrus contributes to a major adaptability and survival rate of conceived fetuses. It is the complete absence of the estrus cycle.

A repeat breeding cattle fails to conceive from 3 to 4 regular spaced services. It causes great economic loss for dairy farmers. The incidence of repeat breeding in dairy cows worldwide ranges from 3 – 10 %. The potential causes mainly include nutritional deficiencies, trace minerals, pathological endometritis, vitamin A, imbalance of hormonal level in the blood, delayed ovulation, anovulatory estrus cycle, etc. supplementation of exogenous progesterone on 5th day after AI and GnRH analogue on 12th day after AI. Thus, improving the conception rate in repeat breeding cows.