Methods for Estrus detection in Farm animals
Mohsin Ahmad Parray1, Aamir ahmad raina2, Rangasai Chandra3, Deepak chopra2, Kashif Dawood khan3 Nishant Kumar4, Mir muneeb5 T.K. mohanty6
1 Phd. scholar (Animal Reproduction, Gynaecology and Obstetrics),2 Phd. Scholar (Livestock Production Management), 3 Phd. (Animal Genetics and Breeding),4Senior Scientist (Animal Reproduction, Gynaecology and Obstetrics), ICAR- National Dairy Research Institute, Karnal-132001 (Haryana) 2 MVSc. Scholar (Livestock Production Management), 6Principal Scientist (Animal Reproduction, Gynaecology and Obstetrics), ICAR- National Dairy Research Institute, Karnal-132001 (Haryana)
mohsinparray584@gmail.com
Efficient Estrus detection will predict the time of ovulation and thereby appropriate time of insemination. Failure to detect standing estrus will lead to improper timing of insemination resulting in extended calving intervals and additional semen expense. Before discussing the methods of heat detection, it is essential to understand the primary and secondary signs of heat in order to achieve accurate and efficient heat detection.
Primary sign- A cow to be mounted is the most accurate and primary sign of estrus. Standing heat is the most sexually intensive period of the estrous cycle and is related to time of ovulation. The average duration of standing heat is 15 to 18 hours, in cows ovulation occurs 10-14 hours after the end of standing heat. Accurate detection of animals in standing estrus is the goal of good estrus detection and plays a vital role in the success of any AI program.
Secondary signs – Secondary signs vary in duration and intensity. These signs may occur before, during, or after standing heat and are not related to time of ovulation. To determine whether cows exhibiting secondary signs will stand to be mounted, they may be isolated with a sexually active cows or teaser animals.
- a) Mounting other cows: cattle that exhibit this behavior may be in heat or approaching heat. Mounting activity is performed much less frequently by cows in midcycle. Cows exhibiting such behavior should be watched closely for standing behavior. Homosexual behavior is prominent in cattle, but not in buffaloes.
- b) Bellowing, restlessness and drop in milk yield: cows in heat are more restless and alert to their surroundings.it has been observed that cows in heat spend less time in resting than non- estrous herdmates. Cattle may bellow more frequently during estrus. There is also a drop in milk yield during estrus period in cows.
- c) Mucus discharge: Due to increased estrogen level mucus is produced in the cervix and accumulates with other fluids in the vagina before, during and shortly after estrus. During estrus, long viscous, clear elastic strands of mucus generally hang from the vulva
- d) Swelling and reddening of the vulva: vulva swells and becomes moist and red. These symptoms appear before heat and remains for a short period after heat.
- e) Rubbed tailhead hair and dirty flanks: As a consequence of being ridden, the hair on the tailhead and rump is fluffed up, rubbed or matted, the legs and flanks may be smeared with mud or manure.
Methods of Estrus Detection:
- Fern pattern of cervical mucus discharge: cervical mucus at estrus shows a typical fern pattern. If fern pattern shows more branching, it shows appropriate time for insemination. The air dried smear can also be observed in an instrument called as crystoscope.
- Uterine tone: During estrus the uterine horns become erect, coiled and turgid. It is one of the most reliable indication of estrus. The external os of the cervix opens and remains relaxed.
- Heat expectancy charts: this simple management aid allows heat to be recorded and the time of next heat to be predicted so that cows can be viewed more closely at the time of next expected heat.
- Use of teaser bulls in female heard: these are vasectomized bulls, Androgenized steers/ cows and surgically modified bulls/ Gomer bulls: these are the animals that take an interest in an estrous cow and thus making the stockperson aware of it. they are more effective if equipped with chin ball marker.
- Milk progesterone detection: The progesterone level in milk is four to five times higher in plasma. Blood progesterone level is the best way to accurately determine the optimum fertile period of bitch. The milk progesterone is detected by ELISA or RIA. But it involves a high cost.
- Vaginal cytology: Due to increasing levels of estrogen in estrus, vaginal epithelium becomes cornified. The surface cells become large and flattened, with small or absent nuclei. The characteristics cytological feature during estrus is the predominance of superficial cells. This technique is used widely in managing canine breeding programs.
- Vaginal pH: pH is good indicator of animals in estrus. the pH falls from 7.0 to 6.72 one day before estrus which further fall to a level of 6.45 immediately before ovulation.
- Measurement of vaginal conductivity using probe: During estrus there is an increase in the volume and ionic content of vaginal mucus, so that it is better able to conduct conductivity. The vaginal electrical resistance increases after ovulation
- Temperature measurement: The temperature of skin, deep body, and vagina is measured as means of detecting estrus in cattle. Infrared thermography based vaginal temperature measurement has also been used with a reliable result.
- Tail painting: Tail painting is an easy method of heat detection’s result is not good in buffaloes due to wallowing activity and false positive reading can occur if smearing occurs from false contact with low tree branches or from lying in free stalls. It is applied from the base of the tail forwards of about 20 cm long and 5 cm wide. Which will be rubbed by mounting cows, should last for at least 4 weeks unless rubbed
- Bio- stimulation: Presence of male in the vicinity of the females, will improve expression of estrus to be detected.it is commonly used for silent heat problems especially in buffalo.
- Pressure sensitive KaMaR or Beacon heat detector: It is fitted on sacrum of cows. Proper fixation is important to avoid loss of device. The efficiency is 80-90 percent. When a cow wearing a heat mount is mounted by a herdmate, constant pressure from the brisket of the mounting animal turns the detector red- bright enough to be seen from distance.
- Pedometer and activity meters: The cows in heat are more reliable and walk two to four times more as compared to non-estrous animals. Some pedometer emits signal in the form of light when cows show increased activity. Efficiency of heat detection is 90 to 96 percent.
- Use of Ultrasonography for monitoring of ovarian status: Monitoring the ovarian function with the help of ultrasound in bovine has improved the knowledge and understanding of follicular dynamics and number of developing follicles. Ultrasonography accurately guides the estrus detection and ovulation time. The efficiency of ultrasonography is around 85 to 95 percent.
- Synchronization of estrus: it is easy method for detection of estrus and timed A.I. Synchronization of heat is a process by which group of animals are managed in such a way that they will come into heat on the same day, as estrus is controlled and harmonized on a particular day.
- Use of Nanotechnology for motion sensing: It Assists in the detection of raised physical activity in cow. The activity data is collected every hour for the cows. The data is analyzed using nanotechnology-based intelligence, the soft wares then filters the data against usual activity of herd mates to recognize the cows in estrus and ready to breed.
- Video camera recording using CCTV: this system of data recording is unique for round the clock observation of herd. Using time lapse and fast play back, the estrus activity during the night can be viewed in half an hour. It is applicable in intensive system of housing however the range of camera may miss cows.
- Electronic odour detector: The principle of the device is based on detection of pheromones related to heat. Dogs can detect estrus by smelling urine and milk, after being trained with vaginal fluid samples. The BOVINOSE is a pheromone-based sensor system for estrus detection. It is based on the principle of detection of sex pheromones that are secreted by the cows exclusively during estrus.
- Doka: it is a physiological phenomenon used for heat detection in buffaloes. In this phenomenon without any external stimuli teat engorgement occurs one to two days before the day of estrus. The efficiency of Doka is around 95 %.
- Infra-red spectroscopy and magnetic resonance spectra: these are used to see the inflammatory reaction in vagina, vulva and vestibule that occurs during the estrus.
Conclusion
Reproductive performance is a major factor affecting the production and economic efficiency of dairy and beef herds. For herds using artificial insemination, heat detection rate and calving rate are two major determinants of the compactness of the calving season and ultimately of the calving to calving interval. Insufficient or inaccurate estrus detection leads to delayed insemination, reduced conception rates and thus extended calving interval.
https://www.thebeefsite.com/articles/2362/estrus-detection-in-cattle/
https://www.pashudhanpraharee.com/heat-detection-in-dairy-animals/
