A cow is called as repeat breeder when it has failed to conceive even after three or more number of services, has normal estrus cycle length, no abnormality in the vaginal discharge, no palpable abnormality in the reproductive tract, has calved at least once before and less than ten year of age. Repeat breeding is one the most import infertility problem faced by field veterinarians. The cows look apparently normal and it is difficult to diagnose the cause. One of the major loss making reproductive problems in dairy cattle prevalent at field level is existence of a large number of repeat breeder cows. A repeat breeder is a cow that has normal estrous cycle, is free from palpable clinical abnormalities, has no abnormal vaginal discharge, is less than 10 years old, has calved at least once but has failed to conceive after at least three or more consecutive inseminations. In a simpler term, in case of repeat breeding cows will come to heat regularly but not succeed to conceive after successful mating. Repeat breeding causes financial loss in terms of repeated inseminations, treatment, cost of feeding without production, production loss due to delayed conception.
Repeat breeders can be divided into two groups:
1. Early Repeats
Cows that come into heat within 17-24 days after AI.
In these animals the luteal function has been shorter than normal or typical for the physiological oestrus cycle in non bred cow. In these cows the most probable event is either failure of fertilisation (delayed ovulation, poor semen quality etc.) or early embryonic death (delayed ovulation, poor embryo quality, unfavourable uterine environment, precocious luteolysis)
2. Late Repeats
Cows that come into heat later than 25 days after AI.
In these animals the luteal function was maintained for longer than the physiological luteal phase in non bred cows. Fertilisation and initial recognition of pregnancy probably took place but for some reason (inadequate luteal function, inadequate embryo signalling, infectious diseases, induced luteolysis) luteolysis was induced and pregnancy lost.
Causes of Repeat Breeding (RB) Syndrome:
The aetiology of RB appears to be multi-factorial. The reason may be genetic, environmental, infections, altered ovarian activity. All these etiological factors ultimately results into either failure in fertilization or embryonic death that leads to repeat breeding.
The Major Reasons for Repeat Breeding are:
1. Genetics :
Chromosomal or genetic abnormalities of parent and those defects that occur during the differentiation process may negatively affect fertility. For example Repeat Breeding has been noticed in cows with chromosomal abnormalities as translocation 1/29 or trisomy X (Roberts, 1971; Lafi & Kaneene, 1988; Bruyas et al., 1993). Factors like inbreeding, aged gamete also may provoke genetic defects leading to repeat breeding. There also exists breed difference in occurrence of repeat breeding in cattle. The incidence of repeat breeding is mostly prevalent in Jersey and Holstein cross bred cattle in our country.
2. Age :
Effect of age on fertility is commonly reported as negative (Hodel et al., 1995). Higher incidences of repeat breeding have been seen in old cows (Hewett, 1968). It is observed that fertility in dairy cows get better after the 1st or 2nd parturition, and then declines from the 4th and 5th(Dominguez, 1989).
3. Uterine Infection and Repeat Oestrous Cycles:
The uterine environment encourages the normal embryonic development. Hence, any disorder or defects like uterine infections, endometritis, pyometra, metritis etc adversely affects the survival of the embryo causing embryonic death which is also one of the major reasons for repeat breeding. Francos (1979) noticed that from 3.5 to 5.7% of cows suffering from metritis had repeat estrus. Uterine infections negatively influence the uterine and cervical postpartum involution, follicular development, causes embryo mortality and repeat estrus rates (Lewis, 1997, Santana et al., 1998).
4. Anatomical Defects of the Genital Tract :
The reproductive tract of cow offers a appropriate atmosphere for oocyte growth, sperm transport, fertilization and implantation. Anatomical or functional alterations of these structures can compel gestational failure and repeat breeding.
5. Improper Ovarian Function :
The problem of ovarian cysts in dairy cows is a serious reason of reproduction failure. Cystic ovarian degeneration (COD) is a cause of repeat breeding in cattle. Delayed ovulation, anoestrus are also linked with this problem. Luteal inadequacy resulting into progesterone deficiency may provoke repeat breeding syndrome.
6. Nutritional Causes :
The conception of the cows is associated with body weight. Mandatory weight which cows should achieve before breeding is for indigenous and jersey cross heifer 240-275 kg and for HF cross heifer 260-290 kg. Underweight animals show poor rates of conception. Balanced feeding (energy, fat, protein, vitamins and minerals) is the solution for this. The trace minerals particularly copper, cobalt, iron etc. are requisite for steroidogensis. Supplementing trace minerals and Vitamins A, D3and E, can assist in treating the problem of anoestrus/repeat breeding dairy animals (Garg et al., 2008).
7. Artificial Insemination :
Any disorder at any action involving 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. If animals are not inseminated at accurate time, it may cause conception failure. 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. The exotic/crossbred should be inseminated in mid to late heat. It is better to give double insemination should always be done with the gap of 12-24 hours after first AI in crossbreds.
The other causes of repeat breeding are :
8. Early or latent embryonic mortalities
9. Deficiency of oxytocin
10. Deficiency of energy
11. Deficiency of progesterone
12. Excess estrogen
In general, diagnosis of repeat breeding is a challenging task. But the treatment and therapeutic response are positive on many incidences. Traditionally, there were antibiotics, antiseptics, hormones, micronutrient supplementations and herbal remedies were attempted. But the targeted therapy involves right diagnosis of the cause. In the recent decade, uterine lavage with normal saline and hypertonic dextrose (50%) solution gain popularity and advocacy. In repeat breeding cows with endometritis, infusion of 300-400 ml of isotonic saline into the uterus claimed to have advantage of good cellular response. Some studies describe the use of hypertonic dextrose also. Infusion of ozone into the uterus is a new treatment option in uterine infections. Antiseptics do not create the issue of milk residues; but many are irritants; previously, iodine preparations like polyvinyl pyrrolidone (Povidone®) were used for the treatment of uterine infections in cattle. But in recent reports, it was noted that the irritant nature of iodine preparations potentially damage the endometrium and reduced the conception rate in forthcoming estrum. Many studies support this view of replacing the antiseptics with intrauterine antibiotic preparations.
For clinical and subclinical endometritis, many commercial preparations are available. But ceftiofur sodium @ 2.2mg/kg is the only recommended. It has the added advantage of attaining Minimum Inhibitory Concentration in uterus rapidly and furthermore it is effective against common uterine pathogens like Escherichia coli, Trueperella pyogenes, Fusobacterium necrophorum and Prevotella melaninogenica are the very common isolates in uterine infections. In the post-partum uterine environment, these four organism work in synergy to brought about metritis.
Tetracyclines are irritants. Aminoglycosides and sulphonamides do not work in the presence of purulent material. Many antibiotics are not permitted to be used as IU owing to long milk withdrawal period. Parenteral administration of antibiotics is advocated in the recent years after the awareness of antibiotic residues in milk. In Indian commercial market, cephelosporins are available as intra-uterine medication.
For repeat breeding due to uterine infections, prostaglandins can be used at 13 days apart. But presence of functional CL is essential. Usage of PGF2 alpha as a prophylactic measure for metritis in post-partum situations is not advantageous. Combination of uterine lavage with PGF2 alpha is preferred for treating endometritis with overwhelming advantage of zero-antibiotic residue and zero-withdrawal period. Oxytocin is also used but in limited circumstances.
Dry matter intake is the single most influential factor for reproductive health. Especially in transition period, all out effort is to be made to maintain the energy balance positively. Negative energy balance could provoke a cascade of metabolic reaction lead to ketosis, abomasal displacement and fat deposition in liver. Ketosis and hypocalcemia are very important precipitating factors for post-partum uterine infections, ROP, dystocia etc. Recents trend of feeding anionic diet could prevent the occurrence of hypocalcemia but it should be accepted that anionic feed is not without risk. Anionic diets are not advisable for farm situations where Dietary Cation- Anion- difference (DCAD) is not practically calculated. Feeding monensin and rumen protected choline are proven prophylactic measures against ketosis, mastitis and later on indirectly on uterine health.
Microminerals are beneficial although some controversies cropped up wherein supplementation beyond the content in feed. But the indisputable roles of micronutrients like Se, Zn, Cu, and Mn and vitamins A and D have been proved again and again. For instance, supplementation of 3000 IU vitamin E/cow/day in late gestation prevented occurrence of uterine diseases. Similarly Se is allowed to be incorporated in feed at the level of 0.3 ppm (mg/kg DM) only to harvest the good effects on fertility. Considering the bioavailability, organic trace minerals (e.g: selenium yeast) are preferred over inorganic one (eg: sodium selenite).
Repeat breeders should be carefully evaluated in order to define the most probable reason for the failure to conceive (early repeats) or failure in pregnancy maintenance (early and late repeats).
Initially heat records should be evaluated to classify the cow as early or late repeat.
Cows that have had three services and are not pregnant should be checked before serving again by a veterinarian.
Specific treatments for conditions like endometritis, delayed ovulation may be carried out whenever suspected them as the cause. If specific cause was not identified the following guidelines may be followed. Bring the animal into positive nutritive balance Use good quality semen having more than 50 per cent progressive forward motility. Inseminate the cow at right time of the estrum. Do AI twice at 12 to 24 hour interval. Follow proper AI technique. After AI, Clitoral massage or 100 micro grams of GnRH or 1500 IU of luteinizing hormone may be administered to stimulate ovulation. Skip the AI; administer 1 million units of penicillin in saline twice at 12 hours intervel during estrum. Flushing the uterus with normal saline with moderate pressure to remove cellular debris/ mild blocks in oviducts. Sexual rest for two consecutive cycles and breeding.
1. Adopt good management and good hygiene at the time of A-I using good
A-I technics with good quality of semen, at right time of oestrus.
2. Feed 1 Kg of geminated, grind and boiled horse gram for 20 to 30 days.
3. To over come endometritis, infections causing retention of fetal membranes,
abortion, salphingitis, ovaritis, cervicitis and to induce and regulate anovularory heat, the following formula, is adopted.
Alteris farinose 30
Aurum muriaticm Natronatum 30
Calcarea phos 30
Phosphorus 30 aa 3 ml
Made upto 120 ml with vimeral liquid.
Dose : 2-5 ml BID for 25 days
Ethno Veterinary Medicine for Repeat Breeder Cows
For animals suffering repeat breeding, infertility or suboestrus or not coming to heat the following method has to be followed. Administer orally Gheekumari (Aloe vera) 1‐2 petals for 3 days in the empty stomach. Administer orally sprouted chana dal (bengal gram) or sprouted bajra or sprouted wheat 200 gm daily for 15 days. When signs of oestrus cycle is noticed administer orally neem oil 100‐150ml before taking the animal for insemination or natural crossing (insemination shall be within 24 hours of noticing the symptom). After insemination feed the animals with curry leaves about 2 handfull daily for a week.
Precautions to Check Repeat Breeding Problem:
Repeat breeding is a very widespread problem of dairy cattle which causes economic loss to the farmers. Always prevention is better than cure. The following precautions may be taken to minimize the incidences of repeat breeding in cows.
1. Maintain breeding record properly
2. Avoid overcrowding especially at the time of AI.
3. Mineral mixture supplementation should be an integral part of diet @ 2% of ration.
4. Provide the animals clean water to drink.
5. Provide as much as cool climate to the animals during summer especially to crossbred animals. Heavy plantation around the farm, sprinkling water, bathing and roof painting will help to keep the animals cool and healthy in summer.
6. Animals with congenital defects of ovary, fallopian tubes or uterus should not be inseminated. These diseases are transmitted to next generations. Therefore, such animals should be culled immediately.
7. Underweight (less than 250 kg), malnourished, anaemic animals should never be inseminated.
8. Overfeeding of oil seed cakes to dairy cows should be avoided since it can enhance embryonic mortality.
9. Do not feed mould infested grains and green fodder and soiled wheat straw to dairy cows.
10. Cows showing turbid or discoloured mucus discharge should not be inseminated and should be checked for any uterine infections and treated accordingly.
11. Avoid putting the straw back into the liquid nitrogen cylinder once after it has been taken out. Once straw has been taken out, it should be used immediately or throw away.
12. To avoid contamination, the AI gun should never be pulled out of the vagina and reinserted into it.
13. Only efficient trained personnel should do artificial insemination.
14. Never use bulls with known genital infections for AI.
15. Do not use same bull again and again for breeding in same cow.
16. Do not use a bull for AI with his own daughter to check inbreeding. Maintain the record properly and rotate the breeding bull among the dairy farmers minimum after every 3rd year to check inbreeding.
17. Met oestrus/Post oestrus bleeding indicates the culmination of the heat and animals should never be inseminated at that time.
18. Use hormonal treatments judiciously only when required.