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Buffalo are said to be seasonal breeders. However, this is not entirely true as buffalo are polyestral animals and may breed all year round. The buffalo’s reputation as a difficult breeder is because of its inherent susceptibility to environmental stress, which causes anoestrus and sub-oestrus. These conditions are responsible for prolonged inter-calving periods, resulting in great economic losses for the buffalo dairy industry. Susceptibility to heat stress also affects feed intake and in turn the nutritional balance, and this also inhibits reproductive efficiency.
Bulls reach sexual maturity at two to three years of age. Semen is produced all year round but it is highly affected by heat stress and low quality feed. The buffalo bull seems to be most fertile in spring, when the volume of ejaculate and sperm concentration is highest. Sperm vitality is also much higher in spring than at other times of the year. Corresponding values are lowest in summer time. Heat stress may have a negative effect on libido.
Wild or feral female buffalo reach sexual maturity at two to three years of age. Domesticated buffalo that are cared for and fed properly may reach puberty earlier. Puberty is highly affected by management factors. Size is more important than age, and a Murrah heifer should weigh around 325 kg at insemination or mating and 450 to 500 kg at her first calving. The age of puberty in buffalo is 36 to 42 months in India. It is comparatively late compared to other countries like Italy, where the age at first calving is between 28 to 32 months on average (Borghese and Mazzi, 2005).
Delayed puberty in both male and female buffalo is common in India. This is due to neglect of calves during their growing period. Buffalo have the potential to gain 400 to 800 gm daily after about four to six months of age, and can attain the 300 to 450 kg body weight suitable for breeding at about 24 months of age. However in a majority of dairy buffalo calving occurs at four to six years of age. This is mainly due to an inadequate supply of feed and nutrients during the growing phase (Ranjan and Pathak, 1992).
The oestrus cycle varies between 21 and 29 days depending on breed. The total duration of oestrus is usually 24 hours but varies from 12 to 72 hours. The most reliable sign of oestrus is frequent urination. The signs of oestrus are much less pronounced in buffalo than in cattle. Many buffalo show oestrus only at night time, and then it is difficult to detect. A lactating animal may have a slight decrease in milk yield when in heat, although it is seldom as pronounced as in cattle. The buffalo may be more restless and be difficult to milk (Bhikane and Kawitkar, 2000).
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• Age at puberty: 36 to 42 months
• Length of oestrus cycle: 21 days
• Duration of heat: 12 to 24 hrs
• Time of ovulation: 10 to 14 hrs after end of oestrus
• Period of maximum fertility: last 8 hrs of oestrus
• Gestation period: 310 days
• Period of involution of uterus: 25 to 35 days |
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The reproductive efficiency of a species is determined by many different processes, which result from interaction among genetic and environmental factors. The processes involved, individually or together, include age of puberty or maturity, pattern of oestrus cycle and oestrus behaviour, length of breeding, ovulation rate, lactational anoestrus period, post-partum anoestrus, inter-calving period and reproductive life span. A combination of these traits is used to measure breeding efficiency or breeding performance in farm animals (Agrawal, 2003). Reproductive efficiency in buffalo is reported to be alarmingly low, causing severe economic losses to milk producers (Ranjan and Pathak, 1992).
1. The first post-partum heat varies greatly with season, breed and individual. It has been reported to appear within less than 60 days in some cases and over 230 in others. Average post-partum oestrus in the Murrah breed of India has been reported to be 100 days. The first post-partum oestrus is not always fertile, especially if it comes very near partus.
2. At birth buffalo have fewer primordial cells in the ovary than cattle have.
3. Compared to cows, buffalo suffer from higher atresia of follicles – 20000 versus 100000 (Bhosrekar, 2005).
4. Buffalo have a high proportion of silent oestrus and short duration oestrus. This is one of the most important problems in buffalo reproductive efficiency. It is even more problematic during the hot and humid months when it is compounded by thermal stress. Short and silent oestrus is the main reason why heat is often undetected in buffalo.
5. A large number of buffalo suffer from post-partum anoestrus, a complete absence of oestrus cycle and no signs of heat. This is one of the most common causes of buffalo infertility.
1. Climate affects both production and reproduction in all farm animals. However as buffalo are very susceptible to extreme conditions of heat and cold they show a tendency towards better performance during the cool months. In India 70 to 80% of buffalo conceive between July and February. In Italy the usual calving season is from September to December. In India it is reported that a lower number of services are needed during the July to February breeding season than in the March to June season (Agrawal, 2003). Buffalo are sexually activated by decreased daylight.
2. As mentioned earlier buffalo have poor thermal tolerance on account of an under developed thermo regulatory system and are unable to get rid of excess body temperature. If their housing is not designed to take care of this special species-specific requirement for adequate shade and ventilation, it will affect production and reproduction (Ramesh et al., 2002).
3. Nutrition plays a major role in the reproductive performance of buffalo, as with other farm animals. However there is a strong possibility that the consequences of poor nutrition are often interpreted as seasonality of breeding in buffalo. Under feeding, over feeding or unbalanced feeding, as well as deficiencies in minerals, vitamins or trace elements will cause reduced fertility in buffalo just as in other farm animals. A poor body condition score at calving affects fertility, characterised by prolonged post-partum intervals, reduced conception rates, and more services per conception. A very low protein diet can cause cessation of oestrus (Agrawal, 2003).
4. One of the reasons buffalo suffer from long post-partum anoestrus is because their natural behaviour of rolling in dirty water pools, and unhygienic shed conditions, cause buffalo to suffer from a high incidence of endometritis. The loose broad uterine ligaments and rolling in water cause torsion of uterus cases in buffalo. Buffalo also suffer from uterine prolapse and retention of the afterbirth. All these lead to uterine infections, delayed involution of the uterus and endometritis in buffalo resulting in the need for repeat breeding.
Hygiene during calving is very important for preventing endometritis in buffalo
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1. Providing the right kind of housing for buffalo to suit their natural behavioural requirements
is important for their optimum performance. Free stall as well as tied systems work well for buffalo. However it is important that the housing provides sufficient shelter from both heat and extreme cold. During summer they have to be protected from extreme heat while in winter they have to be protected from extreme cold as well (Ramesh et al., 2002).
2. Showers or foggers with fans or wallowing tanks should be made available to buffalo during
the hottest part of the day. Thermal ameliorative measures such as sprinkling and cooling
are known to increase comfort levels and feed intake in buffalo (Sastry and Tripathi, 1988; Thomas et al., 2005).
3. Balanced feeding with mineral supplements, plenty of green fodder, and concentrate as per each animal’s specific need, is necessary to bring buffalo into normal reproductive cycles.
4. Regular testing of all buffalo and bulls for infectious reproductive diseases like brucellosis
and regular culling of infected animals are crucial for good reproductive health in the herd. Attending cases of difficult birth and retained placenta in time and maintaining good hygiene during parturition are also crucial to prevent reproductive disorders such as endometritis.
5. Wall charts, breeding wheels, herd monitors and individual buffalo records are important oestrus detection aids. See Appendix 1. The key to successful use of these inexpensive management aids is to accurately record every heat, beginning with the first heat after
calving, and to make daily use of the information to identify those buffalo that are due to return to oestrus (Ramesh et al., 2002).
(Ståhl Högberg and Lind, 2003)
(Ståhl Högberg and Lind, 2003)
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Regularity in conception and a short calving interval are most important to achieve a high lifetime milk production. Calving interval in buffalo is highly dependant on management, climate and nutrition. It is therefore shorter in some regions and longer in others (see Table 2). In order to shorten the calving interval the female should be serviced again as soon as possible after calving, after providing a sufficient period of rest (see Figure 3). Weaning of calves at birth has been shown to decrease the service period in comparison to unweaned buffalo. A shorter service period will lead to a shorter calving interval – a calving interval of less than 410 days is recommended.
Except for a very small percentage of the world’s buffalo, most are bred through natural mating. In most cases at the village level and in the home tracts of buffalo there is no information on the buffalo bull or on the dam’s milk yield, and this information is seldom considered while breeding. This has been one of the major reasons for the diversity in both the productive and reproductive traits of buffalo. Even in Italy where buffalo production is more advanced, 95% of buffalo are bred naturally.
In Italy as well as in Egypt and India, one bull is maintained for 30 females. However as this method persists on the farms it is crucial to avoid the spread of venereal diseases which cause infertility and sterility in both sexes. In recent years these problems have shown an increasing pattern in buffalo herds in India (Ingawale and Dhoble, 2004).
Having a breeding bull with the dams all the time enhances the chances of fertile mating. This bull seldom misses a female in heat. However, to be able to calculate the time of calving it is advisable to keep some sort of record of expected heat. The observant farmer will soon learn how his buffalo behave when in heat and when to expect conception and calving. The females can be teased with a bull twice a day around expected oestrus. A breeding bull can be put into service from three years of age.
In Italy, it is recommended that a breeding bull on a large farm should be exchanged after a maximum of five years. One bull, if managed correctly, can serve 20 to 25 females. On a smaller farm, the bull should be exchanged more often to avoid interbreeding. If the bull shows signs of loss of interest in the females or is otherwise ill, he should be taken out of service immediately. In order to perform best, bulls must be fed high quality feed and be protected from heat and cold stress in the same way as the rest of the herd. Bulls should not be used for service more than twice a week.
Genetic improvement of dairy animals to improve productivity has been the centre of focus of many advanced dairy countries. Using genetically superior animals can improve the reproductive efficiency of dairy species. With the help of AI improved genes are transmitted to a large number of offspring, and the interval between generations is reduced.
Buffalo generally have more difficulty conceiving by artificial insemination than cattle do. Reports from the National Dairy Research Institute, Karnal, India, show that the conception rate for first insemination is around 40% and the conception rate for third insemination is around 77%. Even in Italy only about 2500 buffalo are inseminated per year specifically for progeny testing.
Although intensive research is going on at various universities and institutions around the world, breeding programmes for buffalo are not readily available for the common farmer. In the state of Gujarat in India, the National Dairy Development Board has a breed improvement programme called Dairy Herd Improvement Programme Actions (DIPA). The genetic gain of buffalo is being improved through selective mating of both sire and dam, to breed sires with the desired genetic traits. A progeny testing programme is being followed, producing 100 completed first lactation records of progeny per bull. Twenty bulls are put to test every year, with 2000 doses of frozen semen from each bull being distributed to the selected villages, and 5000 doses being stored until the test results are available.
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In order to solve these breeding and infertility problems and to enhance buffalo fertility, oestrus/ovulation synchronization can be adopted as an integral part of breeding. Ovulation synchronization trials have been successfully carried out in coastal Andhra Pradesh, in the districts of Guntur, Vijaiwada and Vishakapattanam in India. More than 400 buffalo from 24 villages were synchronized with the following protocol.
(Bhosrekar, 2005)
It was reported by Bhosrekar (2005), that more than 700 buffalo were screened. Those having reproductive problems like endometritis, cystic degeneration of ovaries, adhesions etc. and poor body score were excluded from the synchronization programme. The buffalo included in the programme were vaccinated against foot and mouth disease (FMD), Haemorrhagic Septicaemia (HS) and Black Quarter (BQ) and were dewormed before the start of the ovulation synchronization programme. The above-mentioned protocol was followed and buffalo were inseminated on the predetermined dates.
Most of the buffalo were of graded Murrah type (crossbred with local breeds) and suffering from post-partum anoestrus ranging from 110 to 300 days. One hundred percent of the buffalo came in heat and were inseminated as scheduled 16 and 24 hours after the last GnRH injection. On the first AI after synchronisation, the conception rate ranged from 19 to 29%. However on the second and third AI the conception rate improved to give an overall 77.3% conception rate from three inseminations.
Bhosrekar (2005) also reported another trial, of subcutaneous norgestomet implants in buffalo and cow heifers aged between four to six years, with well developed genital organs but not showing oestrus. The trial population of 75 buffalo and cattle heifers were in the areas of the Vishakapattanam dairy of Andhra Pradesh and the Kolar milk union of Karnataka in India. All the heifers came in heat and were inseminated. A twelve day protocol was followed.
(Bhosrekar, 2005)
On first AI after synchronization the conception rate obtained was 48%. These trials have shown farmers a way forward for breeding management. Oestrus synchronization in heifers has helped to reduce the age at first calving. Feed supplementation is important too: two kilograms of mineral mixture were distributed to the farmers to feed the participating buffalo and heifers during the trial period.
Replacing good milking buffalo with their own daughters instead of purchasing new buffalo from the market has some advantages. First, the spread of diseases is limited compared to selling and purchasing on the market. Next, the farmer has full control over his herd. He knows the history of each buffalo and can make more accurate decisions concerning the future. He will know whether the buffalo has had any diseases or problems with fertility. The buffalo will already know the farmer and will therefore be easier to handle, which is most important when it comes to machine milking. High milk yield, ease to milk, short let down time, high conception rate, and temperament, are some of the selection criteria which are desirable in a good breeding buffalo.
When creating a breeding programme it is important to keep records of the buffalo (see Appendix 2, Breeding records). History, milk yield of mother, peak yield, lactation length, and services per conception, are all parameters that it is important to track. When breeding for a higher milk yield it is especially important to register milk production correctly at regular intervals. The International Committee for Animal Recording (ICAR) has put up some basic rules for milk recording which are similar in all countries:
• All buffalo in the herd must be recorded.
• Milk yield should be recorded once a month.
• Lactation yield is calculated by summing the average yield of two consecutive tests multiplied by the number of days between tests.
• Lactation duration should be 270 to 310 days.
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