D. Age at first calving

The age at first calving on buffaloes is generally higher than that reported By proper feeding and management, the age at first calving can be reduced and at the same time the expenses in rearing heifers from birth to calving would also be reduced. Under average village conditions in India, the feeding of buffalo calves is very much neglected and as a result, their maturity is delayed and their age at first calving is 4-5 years which is higher than that of farm bred animals under proper feeding and management.

Late maturity and delay in conception increase the age of the heifers at first calving and thereby raise their cost of feeding and management considerably and also affect their life time production adversely. The breeding of heifers at an earlier age will definitely reduce the age at first calving and increase the efficiency of life-time milk production.

In the Indian sub-continent, the average age of buffalo heifers at first calving is 40 months with a range of 30-50 months. In mullah breed of river of type buffalo, the age at first calving is found to be 44 months (on an average). In Indian buffalo in Military Dairy Farms it is 42 months while at IARI Delhi it is found to be 45 months. The Bhadhawari type of buffalo takes 50 months. According to a study on the optimum age at first calving it was. found that the buffalo heifers calving between 42:48 months and producing more than 1800 kg milk in first lactation are most economical; Table 2 gives observation recorded at various places in India.

III. Breeding and Calving Seasons of Buffalo

Records indicate that India, the inter-regional difference in the reproductive trait of Indian water buffalo is very little. The breeding and corresponding calving seasons are almost same throughout India, the breeding season from September to February and the calving season from July to November. During this breeding period, the bulls have been found to be very active sexually and the quality and quantity of semen is very high particularly during winter (November to February).


The buffalo cow show the maximum of ovarian activity and largest percentage of them conceive during this period. This holds the same for river as well as swamp buffaloes.

There is a big gap in our knowledge concerning the biology of seasonal sexual periodicity in the domestic buffaloes. The existence of a biological mechanism which makes them sensitive to the breeding stimulus during a particular season of the year is well established, but the exact nature of the internal mechanism that controls seasonal responses is not known. The endocrine mechanism of any animal may be responsible for its seasonal sex periodicity. During the late autumn and early winter seasons average day length and daily temperature is associated with the sexual vigour of the animal.

High environmental temperature above 23.6 oC upsets the normal physiological functions of the buffaloes. High environmental temperature adversely affects spermatogenesis in the buffalo bulls and ovarian activities in the buffalo cows. It has been established that species evolved in the tropics and sub tropics do not respond to seasonal light stimuli and they appear to be sexually activated by decreasing day length and or developing temperature.

Although the seasons are not so markedly differentiated in the tropics and the sub tropics like the temperate zone, there are some perceptible variations between seasons which become very much pronounced in the tropical and monsoon belts within these regions. And with this these narrow seasonal variations the buffalo responds sexually to seasonal influences which induce high or low intensity of sexual behaviour during a particular season of the year.

In a study conducted on murrah buffaloes it was found that the conception rate was highly correlated with day length and rainfall. The rainfall may be indirectly correlated with the conception rate through its effects on the growth of vegetation. The level of nutrition has been identified as an important factor on controlling reproduction of all animals. Among the climatic factor only. the effects of temperature and humidity are known from a limited number of experiments in India.

There is a need of research and investigation on the factors responsible for the seasonal sex periodicity on the domestic water buffaloes and to find out suitable husbandry practices for extending its breeding period and thereby to maintain the supply of milk for a greater part of the year than at present. The breeding and calving seasons of water buffalo is seen in table 3


Table 3: Breeding and calving seasons of water buffalo

SNo	Type Breed	Country, Place	Breeding and calving season and other features of seasonal sex periodicity in buffalo
01.	River type		Buffaloes show a distinct seasonal sex periodicity
02.	Indian buffalo	Govt. farms, India	Breeding period with the maximum number of buffalo cows coming into heat: Oct to Feb. the peak month being October. Approx. 61.7% of the calvings take place between July to November
03.	Indian village buffalo	Insemination figs. Of 13,620 villages in Coimbatore District, India	Peak period of heat Oct to Feb
04.	Indian (murrah)	Animal genetics section, Livestock Res. Station, Mathura, North India	Buffalo cows were observed to indicate seasonal sex-periodicity in respect of oestrus and conception; the period with highest oestrus frequency (62.8%) was Oct to Feb with peak in Dec. and this period coincided with higher conception rate, during the period April to Sept. with comparatively longer days and higher intensity of the sun, ovarian activity appears to be adversely affected. Bulls were least active sexually during humid season in respect of semen ejaculation and output
05.	Indian (murrah)	Hissar, Haryana, N.India	Definite seasonal periodicity in calving was observed: 79.5% of the buffalo cows calved during July to Nov., the minimum (1.8%) during April
06.	Indian buffalo	India	Most calving occurred during the period June to December
07.	Indian buffalo	Indian Vet. Res. Inst. Izatnagar, N.India	Marked seasonal variation in the quality of the buffalo semen was observed: the quality was best during the period Sept to Oct. which corresponds with the maximum ovarian activity in the she-buffaloes

Next : Gestation period of different types of buffaloes