The water buffalo has a reputation for being a sluggish breeder, but the average animal is so poorly fed that it's reproductive performance is unrepresentative of it's capabilities. Without reasonable nutrition the animals cannot reach puberty as early in life or reproduce as regularly as their physiology or genetic capabilities would normally allow.
With good management, adequately nourished buffaloes can reach puberty at about the same age as cattle, as early as 18 months of age in buffalo bulls. In northern Australia, Swamp females have conceived at 16 months of age43. In the herd at Punjab Agricultural University in Ludiana, India, 11 River buffalo heifers showed estrus at ages less than 18.5 months and a few came into heat when less than 15 months old44.
The water buffalo also can calve at an age comparable to that of cattle. At the Ain Shams University in Egypt a well fed Egyptian buffalo herd of several hundred animals has an average age at first calving of 27 months, 22 days45. Because of uncertainties, El Ashry and his colleagues believe that the body weight is a better indicator of sexual preparedness than age. These researchers at Ain Shamus University recommended mating heifers when they weigh 365 kg no matter what their age. Research at Punjub Agricultural University shows that heifers can be bred when they weigh over 270 kg and manifest estrus. Most animals in the Punjab Agricultural University River buffalo herd calved before 35 months, one at 28.3 months46. In one Venezuelan herd almost all heifers 20-24 months old were pregnant; virtually all calved before age 38 months, most by 30 months, and one at age 23 months47. In trials in Queensland, Australia and in Papua New Guinea it was noticed that female buffaloes (Swamp breed) came into estrus even while they were losing weight because of adequate nutrition, whereas cattle did not. Under these stressful conditions the buffalo calves also reached sexual maturity earlier and the buffaloes had a higher calving percentage and a shorter calving interval because they came back into estrus more quickly than cattle48. The age at first calving of more than 60 nutritionally poor buffaloes was 38 months in one herd and 45 months for Brahman cross cattle. Similar observations have been made in Florida. Trinidad, the Brazilian Amazon, Venezuela, and elsewhere. Although these are exceptions to the normal observations in Asia, where buffaloes seem to breed more slowly than cattle, they do demonstrate the buffalo's potential for improved breeding.
Unclean surroundings, poor nutrition, and poor management, causes a great number of early embryonic deaths and a high death rate among the calves; this also contributes to the buffalo's often low reproductive rate.
Female Reproduction
ESTRUS
Oestrus, estrus or heat is a specific period of reproductive
function when the female becomes receptive. Estrus in buffaloes
is manifested by changes in the reproductive system and in
behavior. It usually lasts about 24 hours, but duration varies and may range from 11 to 72 hours. It occurs on an average of 21 day cycles. Determination of when a buffalo cow is in estrus is difficult because often the animal shows few external signs of "heat". This increases the chances of missing a cycle, especially for artificial insemination.
The intensity of estrus behavior in Egyptian and Indian buffaloes
has been found to be much less than cows 48a. The usual weak symptoms of estrus in the normal breeding season (October to
February in Asia and India) become still weaker during the hot
months of summer. Unlike most of the buffalo breeds of tropical
and temperate regions, the symptoms of estrus in Philippine
buffaloes have been reported to be even more pronounced than
cattle 48b. The problems of estrus detection in Swamp buffalo of Thailand has been described as one of the main constraints of the breeding program 48c.
Diurnal patterns of estrus behavior have been observed in most
buffaloes. The Swamp usually breed at night 48d. In about 855 of Egyptian and Indian buffaloes signs of estrus have been recorded between 6 pm and 6 am 48e. However during monsoon, estrus often
commences in the afternoon hours. In the Phillipines the management concept of night corrals has been used to increase reproductive performance.
Due to the high incidence of silent heat large numbers of buffaloes are left unbred. In Egyptian buffaloes 86% silent heat 48f has been reported. In Indian buffaloes, one study showed only 15% silent heat .
Work on estrus synchronisation using CIRD implants has been done in New Zealand.
ESTRUS DETECTION
Frequent urination is the most reliable symptom of estrus. The
animals urinate small quantities every 4-6 minutes in some cases.
Mucus vaginal discharge in quietly sitting animals can also be
observed. Many buffaloes show clear or transparent cervical mucus
at the onset of estrus which becomes cloudy and turbid to dirty
translucent with the advancement of the estrus.
For the detection of estrus in buffaloes the application of a
combination of aids has been suggested 48g.
- A vasectomized or teaser buffalo bull should be paraded in
the morning and in the evening in the area where open buffaloes
are kept. Interest by the bull or the female buffalo mounting upon the bull or showing affinity for the bull should be indicate heat. This
procedure can be increased to three time a day during the peak
breeding seasons. In many areas, vasectomized bulls are not
available and an intact animal that has been suitably trained and
accustomed to control can be used. This method is most suitable
in operations where the cows are confined in station alleys. The
ability, observation skills, and training of the bull handler
are extremely important in this method.
- Breedable open buffaloes should be regularity checked at 3-4
hour intervals for vaginal discharge. Mucus discharge from the
vagina flows as a string from the vulva of animals in heat. The
thick stringy appearance is characteristic. The inner side of the
tail should be examined for vaginal discharge.
- Cervical mucus should be collected and spread over a clean
microscopic slide and left for drying at room temperature.
Typical fern pattern crystallization indicates estrus.
- Suspect animals should be examined through rectal palpation
for uterus tone and the presence of mature follicles on the
ovary.
- Under freestall or pasture conditions a vasectomized bull
with a marker apparatus may be left loose with the cows. Tailhead
chalk, paint or other marking devices can also be useful to
detect "riding"...even if a vasectomized bull is not available.
- In hot weather both female and males should be protected from
direct solar radiation and heat stress. Some studies have shown
the value of water spray cooling and sprinkling in intensifying
the signs and extending the duration of estrus.
ESTRUS DURATION
In young Murrah buffaloes in India average estrus period has been
observed to be 29 (24-72) hours 48h. Other studies have shown variations according to location, breed and season ...24 hrs 48iin the Philippines ...12-36 hrs in Egypt ...24-36 hrs in Bulgaria and 19.5 (with a range of 3 to 69 hrs. in Pakistan. The duration of estrus is usually slightly longer...and more regular in aged than in young buffaloes. An estrus duration of about 24 hours is usually used for practical purposes.
ESTRUS CYCLE
Similar to other bovines, the estrus cycle in buffaloes can be
approximately divided into phases...
- Proestrus
... the ovary is more active. FSH hormone stimulates
the growth of follicles. This proestrus period of the cycle is
also called the follicular phase or ..due to the rising levels of
estrogen it is called the estrogenic phase. The increased
secretion of estrogen from growing follicles increases blood
supply and growth of tubular genitalia. Various degrees of
swelling of the vulva due to congestion may be seen and mucus
secretion may start. The duration of proestrus may be 2-3 days.
- Estrus
...characterized by the typical breeding behavior of
females. The animal becomes restless and urinates frequently.
there is stringy clear mucus discharge from the vagina with
marked edema of internal and external genitalia. During this
period females are ready for mating and ovulation usually takes
place about 5-24 hours after the cessation of estrus signs. In
the latter part of estrus secretion of LH increases and that of
FSH decreases. This changed pattern of hormone secretion causes
ovulation and then formation of corpus luteum (CL) in the ovary.
- Metaestrus
...this phase is 3-4 days. During this period there is a sharp
decline in the levels of estrogen and early development takes
place. The vulva shrinks to the original form, tubular genitalia
return to normal size and the flow of mucus becomes cloudy,
thinner and gradually stops.
- Dioestrus
...during this period the CL remains functional with high levels of
progesterone. In cases of conception the CL remains throughout
the gestation period for the normal maintenance of pregnancy.
When there is no successful fertilization of ovum the dioestrus
phase lasts from 10 to 20 days or sometimes longer.
GESTATIONAL ESTRUS
The condition of gestational estrus or heat signs after a
successful breeding has been observed in 6-18% of buffaloes (R).
Animals which return to heat after service should always be
examined for ovarian structure before rebreeding and if
follicular status is vague, AI service should be placed outside
the cervix rather than thru it into the uterine horn.
One important limiting factor influencing the productivity of
buffaloes is the seasonality of breeding. This may be due to
anoestrus or silent estrus during the non breeding season.
Temperature, humidity, light periods and nutrition have all been
mentioned as causes of this seasonality.
POSTPARTUM ESTRUS
The appearance of estrus signs following parturition is known as
post partum estrus. The literature shows ranges of from 10 to 400
days. Again environment, nutrition and heat detection has
significant influence on the length of this period. 30-60 days is
considered an average return time. In Punjab, India, River buffaloes have been observed to come into estrus as early as 40 days after calving52.
ARTIFICIAL BREEDING
Based on work done at the University of Florida in the early 1980s some embryo transfer is also being done.
At the Philippine Carabao Center work on in-vitro maturation (IVM) and in-vitro fertilization (IVF) is in progress.
MALE REPRODUCTION
In general the buffalo bull is very similar to other bovines. The
volume of buffalo semen ranges from 1.5 to 5.0 ml per ejaculate
and semen quality is influenced by many factors. Most bulls are
put into service between 18 and 24 months although environment,
management and nutrition significantly influence their sexual
activity. Young bulls less than 24 months, average volume (1.91 ml), initial mortality (22.8%), count of live spermatozoa (46.4%) and density of spermatozoa (107.14x10(6) per ml) indicate the poor quality of semen. This improved significantly in bulls of 2-8 years. Training of buffalo bulls
for semen collection usually starts at 20-24 months.
Loss of potency has been observed by 6-7 years but many bulls
remain fertile beyond 9 years however the largest period of
usefulness is between 3 and 7 years 52a.A good bull can serve about 100 buffalo cows per year in natural service. In many parts of the world artificial insemination is practiced, however much
of the population depends upon natural service by free living
buffalo bulls of improved breed (mostly Murrah), stray
nondescript bulls or entire working buffalo males. Distance of
AI centers, frequent closure, and awkward times of estrus are
the usual problems. Usually one buffalo bull operates in 2-4
villages having 200-300 breedable females in most parts of Nepal
and India. These bulls serve a good number of animals during
their active life. Some bulls are seen covering cows even after 10 years although with more enthuasism than effect.
OPTIMUM USE
In theory, the quantity and quality of semen collected
successfully up to an average 8.75 ejaculates daily is almost
identical. The calculated daily spermatozoa production capacity
of bulls has been found to be 2.3-2.5 billion 52b. However, in practice this is not possible due to decreased libido and natural endurance problems. Thus the use of buffalo bulls for natural breeding or semen collection should be organized in a systematic manner for optimum utilization. Buffalo bulls should probably be used not more than 75 times a year....however in most areas about 75% of the services are required during 4 months of the peak
breeding season. Breeding bulls should be used 3 times per week during the peak breedng season. Each mating should comprise two services with about a 15 minute interval.
ARTIFICIAL INSEMINATION
This technique for breeding buffaloes can be used for progeny
improvement programs, optimum usage of good breeding bulls and
ease of transportation to remote locations. AI was started in the
early forties at Allahabad Agricultural Institute in India, and
the first buffalo calf was born on 21 August, 1943 52c.Since the semen of each ejaculate is multiplied through the use of suitable extenders for the breeding of larger numbers of females it is essential to use semen of high quality. This increases the probability of high conception and the introduction of desired traits in the progeny.
SEMEN CHARACTERISTICS
In practice maximum rate of collection is on alternate days
during the peak breeding season and twice weekly during the rest
of the year.
INITIAL MOTILITY
For semen evaluation the determination of initial or mass
motility of undiluted semen is an important quick test. The
initial motility is either judged by the movements and waves
(swirls) in a drop of semen under the microscope on a 0 to 5
scale (sometimes 0 to 10) or by counting the total and non-motile
spermatozoa with the help of a hemocytometer. The former gives a
rough estimate and the later provides actual percentages of
motile sperm in the semen. The average mass motility of Murrah
semen has been reported to be 3 to 4. Good cooling arrangements
significantly improve the motility 52d.
MORPHOLOGY
A normal sperm of the buffalo is constituted of 3 distinct parts
...head, mid piece and tail. It resembles a balloon with an
attached string or a tadpole. The head of the buffalo spermatozoan is more rectangular than that of cattle. Head length, breadth, and shape can be affected by extenders season, number of ejaculates and handling of the ejaculate.
MOTALITY
This is determined by counting the percentage of motile sperm in
semen diluted to contain about 20 million sperm per ml. The
percentage of motility in fresh diluted semen of nondescript
buffalo bulls was 67, which gradually decreased after storage at
4-6C. The motility was 40 after 5 days and 30 after 8 days of
storage in egg yolk glucose bicarbonate extender 52e. A wide variation in motility, from 45% to 85% has been reported for the buffalo bull In the same sample ...65% in fresh whole semen, 75% in fresh diluted semen and 62% in diluted semen frozen in ministraws and then thawed was observed.
LIVE/DEAD COUNT
The percentage of live and dead sperm is determined by counting
of slides prepared by a differential staining technique. The
nigrosine eosin stain is widely used for differential staining of
buffalo spermatozoa. A wide variation in the ratio of live and
dead sperm of buffalo semen has been found. Again age, breed,
frequency of collection, season, extender, temperature and
handling all influence the percentage. Averages of 75% to 85%
live in fresh collections are expected but 40% is commonly seen.
ABNORMAL SPERM
A large variety of abnormalities in the structure of sperms have
been reported. The ratio of normal and abnormal is used as a
parameter for the determination of semen quality. 2% to 20 % is
seen with about 6% being average.
EXTENDERS
The development of efficient extenders for the preservation of
live spermatozoa and their fertility for extended time requires
knowledge of detailed chemical composition of spermatozoa and
seminal plasma. A significantly lower initial content of fructose in the semen of the buffalo was observed 52f. However, later work has indicated that this is probably a handling defect. Chloride content is higher 52g and citric
acid lower. Several specialized extenders for buffalo semen have
been developed.
FREEZING
The life span of unprocessed spermatozoa in whole warm semen is
limited to a few hours The high temperature has been found
unsuitable and the rate of deterioration is rapid due to
increased metabolic processes. Cooling can extend this life for
several days... however if the temperature becomes too low
crystallization of water occurs within the cells and they can be
damaged. Therefore for freezing semen needs to be extended in a
suitable medium which is little affected by the freezing process.
Glycerol has been found to protect the sperm considerably from
the freezing process. Deep freezing of buffalo semen was started in India in 1955. Limited research has been done on freezing
buffalo semen and even after 50 years of research it is not in
wide use nor of equal quality as cattle semen. About 80% recovery of motile spermatozoa on thawing of deep frozen buffalo semen in egg yolk glycine extender has been reported 52h. Pregnancy percentages from the insemination of thawed semen preserved deep frozen for several months have been reported at 40% to 70%.
Reasonable quality deep frozen semen is now commercially available in some areas and it's use is spreading. Overall conception rates of 70-80 percent are reported. It is estimated that some 100,000 buffaloes are now being artificially inseminated50.
Reproductive Indexes
PREGNANCY
The pregnancy is an important reproductive function ... and
should be the objective of every reproductive program .
Unfortunately focus is sometimes lost and the breeding or
insemination numbers are stressed and used to evaluate livestock
development programs. In buffaloes, development of the fetus
occurs in the uterine cornua and involvement of the right cornua
is much more common than the left 50a. Corpora lutea are almost always present in the ovary of the same side. Recto-vaginal palpation of the gravid uterus is the most common method for
diagnosis of pregnancy in both buffaloes and cows. Diagnosis of
pregnancy in the buffalo before 2-3 months of gestation is
difficult, especially for those with little experience and practice. At many AI centers the non return of inseminated animals is considered as a measure of pregnancy .... which may be true due to large numbers of available entire males. Recently progesterone levels in blood, plasma or serum, and milk has been used for diagnosis at early stages of gestation. Hopefully, the use of these techniques will provide improved evaluation of
buffalo reproductive programs.
In many areas, calving is seasonal. This seems to be largely due to changes in nutrition. It may also be caused by heat stress, in either males or females, which results in a low breeding rate during the hot seasons. However, when buffalo cows are well fed and cooled, they come into estrus and will breed in any season.
CONCEPTION RATES
A wide variation in the conception rate of buffaloes has been
reported by different observers. Most values are based on non
return rates of the inseminated buffaloes for reinsemination.
Rates of 50-60% are average for natural service and half that for most
evaluated AI field services. The color and consistency of cervical mucus
has a significant influence on the conception rates. When mucus
changes from transparent to turbid and the crystallization
pattern is normal fern like, the conception rate is highest.
Many natural matings take place at night and are therefore unobserved. In one set of pregnancy diagnoses in northern Australia, the buffalo's conception rate (81%) was higher than that of the Brahman crossbreeds (70%) they were with49. Similar figures have been recorded in Venezuela49a.
GESTATION
The length of time required to carry the result of conception to
it's full term under normal physiological environment is known as
gestation period.The water buffalo's gestation period is about one month longer and is more variable than that of cattle. Whereas cattle give birth after about 280 days(Angus, 279,Holstein, 279-280, Brown Swiss,286), buffaloes take 300-334 days (average 310) or roughly 10 months and 10 days. In Egypt, the average period according to a study of 424 gestations, is 316+/- 8 days. The development of the fetus in buffaloes is affected by many factors such as breed, type, parity, season, nutritional status, sex of calf and geographical location )51. Wide variation in the gestation period of River(300-315 days) and Swamp (320-340 days) buffalo has been observed )51a.
PARTURATION
Dilation of the cervix, expulsion of the fetus, and detachment of
the placenta are all similar to other bovines. Involution of the
uterus averages about 30-50 days.
PREGNANCY RATE
The definition of pregnancy rate is: detection of estrus (%) times conception rate (%). The detection of estrus can be defined as the number of cows in estrus per 21 days divided by number of cows in the breeding group. Pregnancy rate includes all cows in the breeding group whether or not insemination has occurred. It is the best reproductive managment tool available for buffalo but not widely used.
CALVING INTERVAL
The interval between the subsequent calvings is known as calving
interval or intercalving period. It is a significant reproductive
trait for the assessment of the life time production potential of
buffaloes. Similar to other reproductive traits the calving
interval is also widely variable. Range of 334-580 days with mean
of about 465 days in River buffaloes and 350-800 days with a 553
mean in the Swamp. Only under uncommon circumstances can a buffalo cow produce a calf each year. In one herd of 800 cows in Venezuela the average female buffalo over 4 produces 2 calves every 3 years53. In response to a recent questionnaire, the majority of Indonesian farmers estimated that the calving rate was between 3 and 5 calves in 5 years54. A few claimed a calf a year, some only 1 or 2 calves in 5 years. In Florida it has been noted that some buffalo cows having just calved became pregnant more quickly than cattle, so that a calf may indeed be produced each year55. Calving intervals of 14-15 months have been reported in Egypt and Venezuela55a. Regular yearly breeding has been noted also in northern Australia56.
Preliminary results in northern Australia indicate that weaning can be carried out as late as 12 months of age without any effect on conception times of the buffalo dam.57
SERVICE PERIOD
The interval between calving and conception is known service
period. The shorter the service period the longer would be
productive life. 100 to 150 days is reported.
DRY PERIOD
The interval between the end of lactation and subsequent calving
is called dry period. A minimum dry period of 60 days has been
suggested as resting period which helps in rebuilding of body
reserves and mammary tissue. Dry periods of 0 to 250 days have
been reported with about 150 days average.
REPRODUCTIVE FAILURES
Anestrus...Anatomical, hereditary, functional and nutritional
conditions either singly or in combination produce anestrus in
buffaloes. It is highest during the hot months and has
characterized the buffalo as a seasonal breeder. Small, hard
inactive ovaries are the rule rather than the exception in most
buffalo of the world. Perhaps as newer management methods are
developed we will see more information and research on this
important constraint to buffalo reproduction. The major cause of
infertility in Asian buffaloes is subactive ovaries. Poor
feeding, nutritional deficiencies and parasites are the main
cause of ovarian inactivity and excessive follicular atresia with
the failure of maturation and ovulation.
OVARY PATHOLOGY
Hypojunctions, cysts, persistent CL and
encapsulation of ovaries are common observations in buffalo. One
should consider that many of these reports are from the
observation of collected genitalia in slaughter facilities....
from old animals at the end of their useful life.
Tubular Genitalia ....Salpingitis has been reported as much
higher in buffalo than cattle(R). Cervicitis, metritis, pyometra
and vaginitis have all been observed but again many of these
reports are from slaughter animals. A high number of iatrogenic
tubular genital problems occur in AI programs because of rough
handling and poor technique.
The incidence of abortions, dystocia, retained placenta, and other parturition problems in buffaloes is similar to that in cattle. Twinning is very rare; probably no more than 0.01% of buffalo pregnancies produce twins.
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david j. ligda
djligda@netnitco.net
Last Updated:Monday, February 16, 1998 8:24:37 PM