Introduction
Animal Reproduction is the main key element in the dairy herds. Good reproduction and production rate are the main important points to grow a dairy enterprise. The productive life of any animal starts with parturition. After that cow needs regular conception and calving to begin lactation which is important point of her production life. Therefore any reproduction related problems lead to economic loss. For this, the animal should be in proper reproductive state i.e. it is able to produce one calf crop per year. There are several factors which affect normal reproductive process in an animal which are repeat breeding syndrome, anestrus, polycystic ovarian disease etc. Out of these repeat breeding is the important issue nowadays as it will cause direct effect on the loss of the normal reproductive process along with economic loss of the individual. A repeat breeder animal is animal, which fails to conceive after at least two successive conceptions, which is having no clinical abnormalities and cycling process.
- Genetic causes of repeat breeding:
Chromosomal or genetic abnormalities of parents which can be transmitted to the offsprings that may lead to cause this syndrome. In breeding may provoke incidence of repeat breeding.
- Age of the animal:
Effect of age on fertility is commonly reported as negative. Higher incidences of repeat breeding have been seen in old cows.
- Uterine infections and estrus cycle:
Uterine environment is important for embryo implantation and growth. Thus any disease related with uterus may lead to cause early embryonic death and thus repeat breeding syndrome. Uterine infections negatively influence the uterine and cervical postpartum involution, follicular development, causes embryo mortality and repeat estrus rates.
- Anatomical defects of the genital tract:
Anatomically perfect reproductive tract can offer good environment for reproductive function. Thus any change in this anatomical structure may lead to cause this problems.
- Improper ovarian function:
Ovarian cyst like problem is the serious reason of reproduction failure. Delayed ovulation and anestrus conditions are also linked with this.
- Nutritional status of animal:
The importance of nutrition in all vital processes is indisputable, and the qualitative and quantitative differences in the ration in dairy cattle may cause reproductive dysfunctions . Weight of breeding indigenous and jersy heifer should be 240-275 kgs and for HF cross heifer 260-290 kgs. Underweight animals show poor repeoduction function i. e. poor conception rate. Balanced feeding is the effective solution for this. Some trace elements like copper, cobalt, iron etc are important for steriodogenesis. Supplementing trace minerals and Vitamins A, D3 and E, can assist in treating the problem of anoestrus/repeat breeding dairy animals.
- Artificial insemination:
Any disorder at any action like bull preparation, artificial vagina preparation, semen collection, semen processing, storage, thawing, post-thaw handling of semen, incorrect insemination in relation to stage of oestrus may result into repeat breeding. Insemination time is also important. We should inseminate the indigenous cows according to AM.-P.M. rule i.e. if a cow comes in heat in morning, she should be inseminated in the same day evening and if came to heat on evening she should be inseminated on next day morning.
Diagnosis of repeat breeding syndrome:
- External inspection and vaginal examination:
By external inspection we can know the congenital or acquired defects like pneumovagina, vulvar defects, tumours or injuries. The vaginal contents should
be inspected to detect urine (if urovagina), pus (if endometritis, vaginitis), blood (post-ovulation or some diseases) or clear and clean mucus (associated with heat).
- Rectal palpation:
It is widely used techniques as it is easy to palpate genital organs and less expensive than other techniques. Plastic gloves are lubricated and then feces are withdrawn. Air should not be present into the rectum to get a more relaxed mucosa and easily manipulate the structures beneath. The cervix is presented as a solid structure, tubular, fibrous, with 3-4 folds projected inside and localized on pelvis floor in normal non-pregnant cows. It is cylindrical, with a length of 5-10 cm and a diameter of 1,5-7,0 cm. Cranially the uterus can be palpated. At heat, uterus is turgid, erect and coiled. However, it is soft and flaccid during luteal phase and palpation is a bit more difficult; it is a consequence of the progesterone action, released from CL
- Hormonal level tests:
Sex hormones and other substances are important in sexual cycle of cows and buffaloes. Progesterone assay is an objective and accurate test to evaluate the ovarian function and to diagnose certain diseases that otherwise could not be correctly determined, such as delayed ovulation, persistent luteal activity, ovarian cysts or suprabasal progesterone levels. Radioimmunoassay and enzyme immunoassay can also be done.
- Oviductal potential
- Endometrial cytology
- Uterine infection/ uterine bacterial culture test:
It is important to know the microbiological and pathological condition of the uterus.if any infection is there then it should be cured otherwise it may lead to infertility or any other isssues regarding conception failure.
Management of repeat breeding:
- Maintain breeding record properly
- Avoid overcrowding of animals at the time of AI
- Mineral mixture supplement should be provided to the animals @ 2% of ration
- Provide clean water to drink
- Provide as much as cool climate during summer
- Animals with congenital effects with ovary, uterus or fallopian tube should not be inseminated.
- Underweight, malnourished, anaemic animals should never be inseminated.
- Do not feed mould infested grains and green fodder.
- Cows showing turbid or discoloured mucus discharge should not be inseminated and should be checked any uterine infection.
- Avoid putting the straw back into the liquid nitrogen cylinder once it has been taken out. Once the straw is taken out, it should be used immediately.
- To avoid contamination the AI gun should never be pulled out of the vagina and reinserted into it.
- Only efficient trained person should allow to do AI
- Never use bulls with known vaginal infections for AI.
- Avoid inbreeding.
- Use hormonal treatment if necessary.
Clinical approach to repeat breeding syndrome:
- Nutritional supplements therapy:
Diets containing higher concentration of inorganic iodine from 8-12 days before estrus improve the stimulation of the pituitary gland, reducing at the same time the RBC rate. Herds with problems of repeated estrus were supplemented with copper and magnesium, minimizing fertility problems
- Assisted reproductive techniques:
Abnormal implantation and transport of gametes are associated with endometrial defects, resulting in RBC syndrome. Certain assisted reproduction techniques, as in vitro production of embryos or intraperitoneal insemination, have been proposed to solve this syndrome. Intraperitoneal insemination could be an alternative procedure to the normal deposition of semen in the genital tract of the cow. In vitro fertilization and embryo transfer techniques are also important to reduce repeat breeding syndrome.
- Intrauterine therapy:
Prophylactic practices have been used, as the uterine administration of antiseptic solutions (lugol) 24 h. after mating/AI, although fertility results are poor.
- Other medicinal treatment:
Moxibustion has been used to reduce reproductive failure in RBCs. We also find references in the literature about the positive effect of aquapuncture therapy.
- Hormonal therapy:
Hormonal treatment should be given if any hormonal cause found. Progesterone is useful in implantation and maintainance pf pregnancy. GnRH hormones at the time of insemination is useful to accelerate ovulation in animals. If luteal deficiency is suspected as reproductive failure in cows, GnRH (100 μg) could be used on day 5 post-AI. A comprehensive study carried out in RBCs indicates that the administration of GnRH at the AI time may be beneficial for improving fertility in these cows.
Discussion:
Repeat breeding is the important problem in nowadays in farm animals as it directly affects farm profitability. it not only affects reproductive ability but also affects production abilty of the individual. Causes can be different of this condition according to that we have treat the animal. By proper management we can avoid this syndrome. As given above these managemental practices improve the health condition of the animal and help to avoid repeat breeding condition.
1Dr. Deepak Gahlot, 2Dr. Manisha Singodia and 3Dr. Lokesh Tak
1Department of Veterinary Physiology, Mumbai Veterinary College
2 Department of Veterinary and Animal Husbandry Extension Education, RAJUVAS, Bikaner
3Department of livestock products technology, RAJUVAS, Bikaner