In the last two blog posts I have provided details on handling semen tanks and later handling frozen semen for best results. I hope the information was of value. In the new blog post I will try to provide the information on heat detection. The article below is has been contributed by Mr.Lindell Whitelock, Consultant to World Wide Sires, USA and also information has been taken from Estrus Detection Guide, South Dakota University.
Success in conception is dependent on insemination timing, which is dependent upon a good heat detection program. A continued education program for the workforce is important. A successful heat detection program and subsequent proper timing of insemination will pay dividends in increasing reproductive efficiency. If a cow shows estrus in the morning, it must be inseminated the same day, next day would be too late. If estrus is detected in the afternoon, must plan to inseminate morning of next day at the latest. Plan inseminations in the morning – evening (AM-PM) rule and inseminate the animals within the 5-12 hr period of estrus cycle.
Estrus detection is the key to improving reproduction performance in the dairy herd. It is important not only to determine which cows are in “heat” but also to determine when the cow actually came into standing heat so the cow can be inseminated at a time when the cow is most likely to conceive.
The standing estrus (the sexually receptive period) is a result of a series of hormonal changes that occur at the end of each estrous cycle. Standing estrus is when a cow/heifer stands to be mounted by a bull or a female. In a normally cycling animal, standing estrus will occur approximately every 21 days, but this can range from 17 to 24 days.
Cows enter standing estrus gradually; secondary signs that an animal is getting close to standing estrus will progress until the animal stands to be mounted. None of the secondary signs alone is a positive determination of standing estrus. Standing to be mounted by a bull or another cow/heifer is the only conclusive sign that an animal is in standing estrus and ready to be inseminated.
The period of standing estrus usually lasts about 15 hours but can range from less than 6 hours to close to 24 hours. To maximize detection of standing estrus, it is extremely important to monitor cows/heifers as closely as possible—early in the morning and late at night as well as during the middle of the day.
A report suggests that continuous observation of over 500 animals in three separate studies indicated that 55.9% of cows initiated standing estrus from 6 p.m. to 6 a.m. When cows were checked for standing estrus every 6 hours (6 a.m., noon, 6 p.m., and midnight), the estrous detection rate increased by 19% compared to checking at 6 a.m. and 6 p.m. alone. Checking for standing estrus at 6 a.m., noon, and 6 p.m. increased the estrous detection rate by 10% compared to detecting estrus at 6 a.m. and 6 p.m. alone.
Unfortunately on many farms the estrus detection rate is very low, many times at less than 40%. A good estrus detection program should result in an estrus detection rate of 70% to 80%. Developing a good estrus detection program should be a priority if a farm is experiencing a low pregnancy rates.
Detecting standing estrus (“heat detection” or “detecting standing heat”) is simply looking for the changes in animal behavior that are associated with a cow/heifer standing to be mounted by a bull or another female. Detecting animals in standing estrus is critical to the success of any artificial insemination program. Animals not in estrus around the time of insemination have little chance of becoming pregnant.
The development of a successful estrus detection program involves the following steps.
Development of a Standard Operating Procedure (SOP): The SOP should address many issues. The SOP should identify the person or persons who are responsible for the task. It should set forth the times when and where the cows are to be observed. It should also specify where the information will be recorded and who gets the information. It should also specify who gets that information and when.
Trained Personnel: Ensure the persons who are assigned the task of estrus detection are trained and confident in identifying the cows. To assist the people who are responsible for identifying the cows, prepare alert lists, consider using estrus detection aids, and even though a cow has been bred, keep watching until a pregnancy is confirmed. Ensure observed heats are recorded and the information is used to make breeding decisions.
Group all the open cows together: By locating all of the cows in one group, the cows are more likely to show behavioral signs of estrus and the observation of the cows can be conducted in a more efficient manner. Ensure the area where the cows are kept is comfortable and the floor surface provides for good footing for the cows. Do not overstock the pens; cows need room to move around if they are to exhibit signs of estrus.
Sore feet: Cows with sore feet do not mount other cows, and they do not allow othe cows to mount them. A cow with sore feet can be identified by an arch in her back. Cows with healthy feet walk with a straight back, so if several cows have even a slight arch in their back, the likelyhood of them showing physical signs of estrus are very low. Minimize sore feet to improve estrus detection.
Observe cows every 6 to 8 hours: The observation, unless using a “Chalk & Breed” program should not be done at milking time or when cows have been fed. Multiple times observation will not only find more cows in estrus, but will also assist in being able to determine when the first standing heat occurred. This will also result in higher conception rates. ensure the data is recorded and reported so the cow is inseminated.
Estrus Detection Aids: Estrus detection aids such as pedometers may be used to assist in the identification of cows that are in estrus. If aids are used, then it is important to observe the cow as well. Look for secondary signs of estrus that would indicate the cow is actually in heat. Estrus detection aids can only help, but they do not replace actual observation of the cow.In every herd there will be problem cows. Cows that are not observed in estrus may require other actions. A program of using an estrus synchronization or hormonal program should be considered for the herd. A protocol should be developed to determine what the voluntary waiting period will be and when synchronization programs would be implemented. There are several synchronization protocols that can be used.
Problem Cows: In every herd there will be problem cows. Cows that are not observed in estrus may require other actions. A program of using an estrus synchronization or hormonal program should be considered for the herd. A protocol should be developed to determine what the voluntary waiting period will be and when synchronization programs would be implemented. There are several synchronization protocols that can be used. Amit Sachdev
India Consultant
World Wide Sires, USA
Email: indiawws@gmail.com
No comments:
Post a Comment