3 Follicular Wave Pattern, Synchronization using Prostaglandin

Transcript

Dear Field Practitioners!

Actually, I used to enjoy taking a Follicular wave pattern in cattle because this is fundamental to achieve success and manipulating the Estrous cycle in Bovines. We will continue with the Follicular wave pattern today. You know Follicular development is a continuous process. It occurs even during Anestrous that too is true Anestrous even during pregnancy. The only thing is that a Corpus Luteum formation is prevented. So, there are various types of Follicular wave patterns. The animal may have two-wave or three-wave or four-wave Follicular wave patterns. Sometimes four waves also. Depending upon the number of waves the Estrous cycle length also varies. Those animals which are having two-wave will have a lesser Estrous cycle length and those animals which have three-wave Follicular waves will have more Estrous cycle length than the two wave animals.

So, what is a Follicular wave? The follicular wave consists of, Recruitment, Selection, Dominance, and Atresia or Ovulation. These are the words.

What is Recruitment? Suppose! Today the animal is coming to heat, tomorrow it is going to Ovulate. So, at the time of Ovulation, on too many animals, many numbers Follicles start to grow. So, this is called Recruitment.

Among these many numbers of follicles, few follicles will be selected, they will be growing. This process is called a Selection.

Among the selected follicles, one follicle will reach a large diameter, which is called Dominance. This follicle will dominate, and it will suppress the growth of subordinate follicles. So, in Recruitment more follicles will be recruited, and the few follicles will be selected in Selection, among the few follicles, one follicle will be reaching the highest diameter. It is called the Dominant follicle. This Dominant follicle will suppress the growth of subordinate follicles. Then it will be growing and reaching the maximum size. But since Progesterone is secreted, no LH surge occurs. So, this will not Ovulate, and it will undergo Atresia. If it is a second wave, the progesterone level goes down GnRH will be released, then. FSH, LH will come, then LH will cause Ovulation, ovulating follicle. So, what I want to stress is Dominant follicle of the last wave is the ovulating follicle. Suppose if two waves are there, the first wave dominant follicle undergoes Atresia, so the Dominant follicle of the second wave undergoes Ovulation. If there are three waves in a cycle, the dominant follicle of the first wave and dominant follicle of the second wave undergoes Atresia. The dominant follicle of the third wave is the Ovulating Follicle. This is how it is happening.

So, for understanding the Estrous Synchronisation program, you must know the Follicular wave pattern also. I already told you this is the two-wave Follicle. You look at the dominant follicle of the first wave undergoes Atresia, the dominant follicle of the second wave is going for Ovulation, because, in a cyclical animal, the progesterone level goes down, then animals start to secrete GnRH and LH that results in Ovulation. This is the second wave. When you do induction of ovulation, if we give PGF2 Alpha on day 7, then this dominant follicle of the first wave will be the ovulating follicle. When you give this on day 6, PGF2 Alpha, the dominant follicle of the first wave will be the Ovulating follicle. You are not allowing the animal to undergo a second follicular wave pattern. Again, this is the induction of Ovulation with the first wave. So, with the first wave, instead of undergoing Atresia, you can make this follicle Ovulate with the Estrous induction program.

So, now we will go into detail about how with the PGF2 Alpha we are doing the Estrous Synchronisation program. I already told you there are two types of Prostaglandins available. One is Natural Prostaglandin, the other is Synthetic Prostaglandin. Both Synthetic Prostaglandin and Natural prostaglandin can be used for Estrus Synchronization. The Natural Prostaglandin is available as Lutalyse. It is available in 5 ml and 10 ml vials, each ml contains 5 milligrams per ml. Whereas Synthetic Prostaglandin is available in the form of Pragma, Clostenol, Repregna, Pragma, Clostenol, Repregna, Entremets etc. So, these are available as 2 ml vials.

There are 3 programs available with PGF2 Alpha.

Programme A -If there are groups of animals or a single animal, whatever it is in the field condition. You palpate the ovary. If there is a presence of Corpus Luteum in any of the ovaries, inject PGF2 Alpha and do AI at 72 and 96 hours. I told when you are doing this, the animal must have matured CL. The matured CL is very important to respond. This is a program A. (Repetition)Animal is brought to you for examination, you are examining the ovary. Matured corpus luteum is present in the ovary and you are injecting the PGF2 Alpha and do AI without Estrous deduction, you can do AI 72 and 96 hours.

Program B- There is no palpation of the ovary. And inject PGF2 Alpha into all the animals. Suppose 20 animals are there is a camp, inject all the animals PGF2 Alpha. Either Natural prostaglandin or Synthetic prostaglandin, whatever you have, you inject the dose I told synthetic prostaglandin as 500 micrograms Intramuscularly, Natural prostaglandin 25 milligrams Intramuscularly. Then deduct heat and breed, that is 72 and 96 hours you can breed. Animals that have not expressed. Estrous sign, so after 11 days give PGF2 Alpha. Those animals which have come to heat, you breed or give PGF2 Alpha. Those animals which have not come to heat, give PGF2 Alpha, then breed animals 72 and 96 hours. (Repetition) Program B in which, there is no palpation of the Ovary, you need not palpate the ovary, suppose 20 animals are coming for you in the camp or you identified 20 animals as infertile, then to all the 20 animals give PGF2 Alpha, either Natural prostaglandin or Synthetic prostaglandin. If it is Natural prostaglandin give 25 milligrams, Synthetic prostaglandin 500 micrograms Intramuscularly. Deduct heat, suppose out of 20 animals, 12 animals have come to eat, breed those animals, or do AI at 72 and 96 hours. Those animals which have not come to heat, give injection PGF2 Alpha 11 days, 11 days after the first injection, then breed the animal at 72 or 96 hours.

Programme C- There was no palpation of the ovary. Give PGF2 Alpha to all the animals, repeat PGF2 Alpha after 11days. This is a typical double injection schedule. Then after giving PGF2 Alpha, do AI at 72 or 96 hours. Second PGF2 Alpha – After the first PGF2 Alpha, you need not inseminate, after the entire second PGF2 Alpha you can inseminate all the animals. This is the PGF2 Alpha program.

Dear friends!

So far, we have discussed two-wave follicular wave patterns, three-wave follicular wave patterns in cows and buffaloes, followed by the prostaglandin use in the Estrous Synchronisation program. I think you would have understood the Estrous Synchronisation technique with PGF2 Alpha thoroughly. We will move to the next class, that is with Estrous Synchronisation by using Progestogens.

Thank you!