1 Introduction, Definition, Prevalence, Economic Importance and Classification

Transcript

Hi! Friends,

I am glad to introduce myself as Dr. S.Raja, Assistant Professor in the Department of Veterinary gynecology and obstetrics. Veterinary College and Research Institute, Namakkal, which is a constituent college under Tamil Nadu Veterinary and Animal Sciences University, Tamil Nadu, India.

I am sure you all are enjoying the online courses from MOOCs in collaboration with IIT Kanpur and Commonwealth of learning Canada. I am happy to say, I am the content creator for the course “Anestrum” with a special reference to Anestrum in dairy animals. Let’s move on to the Objectives and this Anestrum course has 5 series of lectures and the course outline which includes the 1st lecture, which is on an Introduction to Anestrum. For any condition or any disease condition, understanding the introduction is very important followed by prevalence. Understanding the prevalence gives an idea about the pattern of the reproductive disorder, prevalence not only in the State among the entire Nation and followed by economic importance. So why do we need to study Anestrum and what way it is contributing to the economy and what way farmers are getting affected or benefited? So, we will be discussing the economic importance followed by etiology and classification concludes lecture 1. so, lecture 2 will be focusing on the main classification, we will be discussing False Anestrum. So, what is meant by False Anestrum followed by the types? What are all the subtypes under False Anestrum and its etiology? What are all the etiological factors which are being contributed under False Anestrum? Followed by in lecture 3, we will be continuing the false Anestrum but the focus is more on the Diagnostic methods, what are all the Diagnostic methods under the False Anestrum can be identified because it needs to be differentiated from the true Anestrum, so diagnosis plays an important role in approaching therapeutic interventions for false Anestrum, followed by the therapeutic methods or any intervention protocols that concludes lecture 3. Followed by in lecture 4, under the main classification will be discussing on true Anestrum, so what is mean by true Anestrum, what are all the subtypes and what are all the etiological factors which are being contributed under true Anestrum and in the final lecture, we will be continuing the true Anestrum with focusing on various diagnostic methods as well as a various therapeutic intervention and finally, we will be concluding with the summary of entire Anestrum. So, with this objective’s background, we will move on to the Introduction.

So, in general, from in farmer’s point of view Infertility is being expressed in two ways, one[1]whether the animal is not showing any signs of estrum, so that is Anestrum which we will be discussing in the session in a very detailed way, that is one. And the second problem is the animal is cyclic but not getting conceived, so which means that the animal is repeatedly cyclical inactivity, repeatedly approaching for the breeding but even then, the animal is not getting conceived. So that is a topic under repeat breeding, which will be covered separately.

So, we will be discussing Anestrum, so Anestrus is characterized by failure of estrus, failure in the sense, absence of estrus. So, the term Anestrus meaning without cyclicity. So means the word ‘An’ means absence. so, the absence of estrus that is- Anestrus. So, the absence of estrus is Anestrum, which means the absence of cyclicity, literally the word means. So, Anestrus is observed more commonly either in postpartum condition, so that is after parturition or sometimes in a pre-service condition also, because to understand this Anestrum can happen in normal physiological conditions also like before puberty or during pregnancy, but these conditions are often physiological in nature, which means that we need not worry about it. So only thing is we should know when the absence of cyclicity that is there has to be considered under Anestrum. So, this means that after puberty the animal has to show cyclical signs at the period of the interval of 18 to 21 days, if that is getting delayed then probably, we can put it under Anestrum. Similarly, after parturition, we need to wait for the period of around 2 months to 3 months, the average period is 60 days, if it is going beyond 90 days even though the animal is not showing any signs of estrum, then probably we can be put under the category of Anestrum. So, with this introduction, we will move on to what is Anestrus? what Anestrus is being defined? So, Anestrus is a functional disorder of the reproductive cycle which is characterized by either the absence of overt signs of estrum manifested either due to lack of expression of estrum or failure of its detection, so what it means here 3 points I would like to insist one is the absence of overt signs, overt signs mean it is not being exhibited, the other one is lack of expression of estrum or failure of detection. Here are the 3 points which include 1) is the animal itself not showing any signs of estrum, which means that ovaries are also not functional, functional in the sense, in terms of cyclicity, the ovary is not functional, the animal is not showing any signs of estrum. 2)The second thing is the animal is showing signs of estrum, but we are a failure in detecting, for example in large farm conditions, labors have been not properly educated and they may be skipping the estrus signs, that is an absolutely managemental error which is also coming under Anestrum. 3)The other condition is, the ovary is functional, but the animal is not showing signs of estrum, so which means that physiologically the ovary is developing a follicle, the follicle is getting ovulated and there is a formation of corpus luteum, but the only thing is there are no behavioral signs of estrum, so which is also coming under Anestrum. So Anestrum means the absence of signs of estrum, which means that exhibition is not there, either it can be due to lack of expression or failure in detection, so this is what Anestrum means.

Next is Prevalence- for any reproductive disorder or any disease condition we should understand the prevalence, by understanding the prevalence, we could able to get an idea of how effectively or how far this disease is causing a loss or how effectively the population is being affected, which means the prevalence of Anestrum, for example in Tamil Nādu is around 16.6% in case of cattle almost throughout the entire Nation the percentage is more than 15%, so you could able to predict around 15% of the cattle population is being affected with Anestrum so rough estimate. So next thing is by understanding the prevalence we will be able to get an idea about the economic importance of why Anestrum is linked with economic importance or what way it is being linked. So, Anestrus has a great economic impact. so, what kind of an impact? For example, if the animal is having an Anestrum, which leads to economic losses through increased inter-calving interval, so which means that the time period or the gap between the two successive calving’s is getting delayed. The optimal period is a calf a year, which means that within a period of 12 months or a maximum of 15 minutes I can say the animal has to go for the next subsequent calving if suppose if the animal is entering into the period of Anestrum, this inter-calving period is getting extended. So, what happens overall is affecting the annual calf production of the cow, for example, in a lifetime of the cow the overall calf production is getting reduced, this in turn affecting the production loss, How? Often the farmers are thinking, the increased or greater lactation length is a permanent profit, but strictly speaking, the greater or the longer lactation period is only a temporary profit. so, what comes the permanent profit, so in a shorter duration of time the maximum number of pregnancies or maximum calving has to happen, then only it is a permanent profitable way. So increased or greater lactation length even though the animal is having an Anestrum, it is only in temporary profit, so the farmer should understand within a short period of time the maximum pregnancies and maximum calving has to happen which in turn increases the production. If suppose it doesn’t happen, the calving inter[1]calving period gets increased, overall, it is affecting the production so that the farmer is forced to involve in treatment expenses. In turn the cost of replacing mature animals with the first calving heifer. Overall, the farmer is sacrificing some portion of his profit for the treatment. The other one is an estimated loss roughly from Anestrus is around rupees 200 per day in case of purebred and rupees 250 in case of the crossbred, so you can able to imagine if the animal or if the expression of heat signs is getting delayed by one day it is almost giving a loss of rupees 200. A per animal. rupees loss of 200 is affecting the farmer, the farmers are directly contributing to the state economy, the state economy is directly proportionate to the Nation’s economy. So, each and every cow, for example, I can say each and every day if Anestrum is happening our estrus signs is getting delayed it is directly affecting the nature’s economy. So overall I can say each and every day, if it is due to Anestrum it is affecting the GDP of our country. So, each and every cow is being contributed.

So, with this importance of the economy, we will move on to the Classification, In general, in the clinical aspect, the Anestrum is categorized into two types: one is Class I Anestrum and the other one is Class II Anestrum. So, Class I Anestrum is also referred to as False Anestrum so Class II is also referred to as True Anestrum.

What is the major difference between a Class I Anestrum and Class II Anestrum or between False and True Anestrum? In the case of False Anestrum, the animal is having a functional CL, in the case of True Anestrum, the animal is having No functional CL, so what it means for example if False Anestrum, the ovary is having a corpus luteum, this secreting progesterone and because of that, the animal is not showing any signs of estrus but in the case of the True Anestrum the ovary is smooth, smooth doesn’t mean that no structures, it can have varying degrees of structure which include multiple small follicles or sometimes you can find medium[1]sized follicles or sometimes you could able to find a dominant follicle also but there will not be any CL. The only thing is the ovary will be having a variety or kind of sizes of the follicle but there will not be any estrus signs. Often, we will be under the impression, in the case of true Anestrum there will not be any development of follicles, but strictly speaking, when you go perform ultrasound examination regularly, you could able to find in case of True Anestrum also you will be finding a different size of the follicles even more than 8 to 10 mm in diameter. Even though the animal will not show any clinical signs of estrus, so that is True Anestrum. In general, False Anestrum means with CL, True Anestrum means No functional CL. So, with this understanding of Classification, we will try to conclude today’s Session. So we had seen the introduction about Anestrum and its importance followed by the Prevalence in Tamil Nadu as well as in overall India’s nation and the importance in terms of economy and what way it is affecting the economy followed by a broad classification of Anestrum which includes True Anestrum and False Anestrum, with this, we will conclude today’s session and we will continue in the next session.

Thank you!