SIGNS OF ESTRUS IN CATTLE AND BUFFALO

Pashu Sandesh, 02 July 2018

Dr. Sriti Pandey, Dr Abhishek Rajput, Dr. Mohit Gautam, Dr.Irfan Ahmad Bhat

• Estrus refers to the phase when the female is sexually receptive ("in heat"). Under regulation by gonadotropic hormones, ovarian follicles mature and estrogen secretions exert their biggest influence. The female then exhibits sexually receptive behavior, a situation that may be signaled by visible physiologic changes.
• Estrus is a regularly recurrent state of sexual excitability during which the female of most mammals will accept the male and is capable of conceiving.  
• Estrus is the periodic state of sexual excitement in the female of most mammals, excluding humans, that immediately precedes ovulation and during which the female is most receptive to mating.  

ESTROUS BEHAVIOR IN CATTLE

Three distinct patterns are observed during estrus includes male like mounting, rise in spontaneous activity and mating responses. Receptive animal may perhaps be identified in herd by sexual attractiveness and receptivity. The female stands immobile for mounting on her, indicates that she is definitely in heat. Pug mark on back and dirt on flank is also a clear cut indication of animal in heat. Hair on tail head is ruffled or missing due to frequent mounting by herd mates. Standing to be mounted is yet the best sign of heat, although it is displayed only in limited cases. Therefore mounting on herd mate is better option. Secondary behavioral sign observed before real “standing heat” includes frequent urination, separation from herd, chin resting, back rubbing, nervousness, restlessness, walking along fences, bawling, aggression, arching of back, loss of appetite and sudden drop in milk production. Other supportive sign include licking, sniffing, head lift up, lip curling and flehman's reaction (up curling of lips by female or male after touching the genitalia of raged animal). Physical sign of estrus include the tumefaction of vulva, reddening of vulva (bright cherry pink color), excess mucus discharge and tone in uterus. Closeness in animals coming into heat usually congregates and form small groups of three to five animals called sexually active group (SAG). It is easy to detect heat if sexually active group exist in herd. The period of receptivity lasts for 18-24 hrs. A bloody discharge at cessation of behavioral estrus usually indicates a missed heat. A careful monitoring required for such animal with bloody discharge for returning to heat. The sign of heat is clear cut and prominent when activities like milking and feeding are minimal, i.e heat detection should be avoided at milking and feeding time. Failure to watch critically for long time is most common cause of poor heat detection. During copulation the female may display postural alteration to facilitate mating, called sexual presentation. The cow may exhibit an orgasm like reaction, since some females maintains a typical posture for several seconds after copulation. At the time of ejaculation the electrical resistance of skin dropped suddenly.

ESTROUS BEHAVIOR IN BUFFALO

Buffaloes are shy or poor breeder. They are seasonally poly estrous; the estrous behaviors are shown during September to January, with a peak during October to November. The onset of the breeding season is associated with a higher intake of energy and a lower intake of protein. Low blood glucose level with high serum urea concentration in summer, associated with sub fertility. Behavioral sign in buffaloes are less obvious than those in cattle; therefore less than one third of buffaloes in heat might be detected by homosexual behavior. Unlike cattle obvious and raged sign in buffaloes are not pronounced. Hetero sexual behavior, particularly standing to be mounted by a bull, is most reliable sign of estrus in buffaloes, where as homosexual behavior observed only occasionally. Sign such as swelling of vulva, clear transparent mucus discharge, spontaneous milk letdown, bellowing, restlessness, frequent urination and raised tail vary in intensity from animal to animal, and in relation to standing estrus. Generally in buffaloes, estrus commences towards late evening and the peak sexual activity occurs during hours of darkness. The cases of silent estrus higher in herd using A.I. rather adopting natural service and this may often indicate that the problem may lie with the heat detection rather than animal itself. Copulation in buffaloes lasts for 20-30 seconds. Bio-stimulation favors behavior sign of estrus clearly.