cidr protocol

Anestrus Management in Cattle – CIDR Protocol

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Anestrus and its Causes in Dairy Animals

Anestrus is a functional disorder of the reproductive cycle characterized by cyclicity failure-absence of heat signs. In simple meaning when cows and buffalo do not show signs of heat (Estrus). They are termed as anestrus. It is one of the most commonly occurring reproductive problems of cattle in India affecting livestock productivity and economics to a great extent to avoid that CIDR protocol is used. Anestrus is mostly observed in Heifers and lactating dairy animals. Anestrus is a multifactorial problem and its occurrence signals inadequate nutrition, hormonal imbalance, persistent CL, deficiency of trace mineral, phosphorus and fat-soluble vitamins. Cows in negative energy balance are at a very high risk of anestrus and delayed onset of cyclicity. A body condition score (BCS Body condition score (BCS) are an indirect estimate of energy balance. A score of 1 denotes a very thin cow, while 5 denotes an excessively fat cow, and 3 is an average body condition on a 1–5 scale. Regular monitoring of body condition score is essential for identifying these changes in energy balance and is thus a crucial part of fertility management.) of less than 3.0 on a 1–5 scale is commonly an indicator of negative energy balance.

Cows with low BCS are more likely to be anestrous and it has been reported that the influence of body condition on the duration of the postpartum anestrous period is mediated through differences in LH pulse frequency. Cyclic cows with low BCS tend to have poor conception rates and higher embryonic losses.

The Economic Impact of Anestrus on Dairy Producers

Infertility due to anestrus has a great economic impact on dairy farmers. Anestrus leads to economic losses through increased inter calving intervals, loss of calf, production loss and treatment expenses. There are reports in India pertaining to economic impact analysis due to anestrus. In 2011 reported estimated loss of anestrus is around Rs 193 per day in cows. As the incidence of Anestrus in India has been reported high, the above figures show a high economic impact on dairy farming business at the country level.

Difference between Anestrus and Repeat breeders

A Repeat breeder is generally defined as any cow or buffalo that show the normal signs of estrus but does not conceive even after three or more services (AI). The etiology of repeat breeding appears to be multifactorial and include uterine infections and reproductive tract abnormalities, hormonal dysfunction and nutritional inadequacies, and poor breeding and health management. The causes of repeat breeding have been classified in cows in a number of ways, yet Fertilization failure and early embryonic mortality are two major causes for repeat breeding problems and external factors such as environmental stress and poor breeding management.
Anestrus Whereas Anestrus is a functional disorder of the reproductive cycle characterized by cyclicity failure-absence of heat signs. In simple meaning when cows and buffalo do not show signs of heat (Estrus). They are termed as anestrus.

Anestrus due to Persistent corpus luteum

In this type of anestrus, the follicular growth proceeds through all developmental stages and undergo ovulation and CL formation which subsequently turn into anestrus due to the failure of luteal regression. This is probably due to the absence of failure of the estrogenic dominant follicle at the time of luteal regression. Persistent CL is mostly associated with uterine pathology such as endometritis, pyometra, fetal resorption, maceration, mummification.

Sub-Estrus / Silent estrus

Sub-estrus or silent estrus is the condition in which animals will not show behavioral signs of estrus although physiological symptoms of heat present. Silent heat is usually manifested as unobserved heat by the dairy owners. Under these conditions, follicular development and ovulation occur normally in animals without the manifestation of overt signs of estrus. Sub estrus is common during the post-pubertal period in heifers and early postpartum (30 to 120 days) in high yielding dairy cows. Progesterone secreted from regressing CL of the previous cycle potentiates the action of estrogen and seems to favors the manifestation of estrus in the next cycle. Thus, lack of Progesterone It is hormone secreted by the corpus luteum, suppresses the further development of follicles and the secretion of estrogen. High levels of progesterone and low levels of estrogen prevent a cow from coming into heat. Progesterone is necessary for preparing the uterus to receive the fertilized egg and maintains the proper uterine environment for the continuation of pregnancy. priming results in sub–estrus.

Common trends in Anestrus treatment and management in dairy animals

Anestrus is a multifactorial problem. Hence Veterinarians have to keep a rational approach based on the causes involved in the development of anestrus. The case of the anestrus needs to be ruled out based on factors involved like inadequate nutrition, improper body condition score (BCS), hormonal imbalance, persistent CL, deficiency of trace mineral, phosphorus and fat-soluble vitamins. If the dairy animal is non-cyclic due to hormonal causes. The hormonal treatment needs to be done.

Exogenous use of Progesterone in Anestrus Management in Dairy animals

Exogenous progestins (Progesterone devices) are considered appropriate for noncyclic (anestrus) postpartum cows. CIDR inserts are approved for the induction of estrus cycles in anestrus dairy animals. When exogenous progesterone is used in the synchronization protocol, a desirable follicle is produced and been shown to elicit an increase in LH pulse frequency in postpartum anestrus cows. The progesterone from the controlled internal drug release (CIDR) was sufficient to increase and maintain a progesterone concentration in blood >2 ng/ml in the absence of CL on the ovary. Blood progesterone level rises rapidly after the insertion of CIDR and declined rapidly within 24 h after its removal causing ovulatory estrus.

The application of CIDR Protocol devices to be followed with suitable protocols. The inclusion of CIDR to the Ovsynch protocol considerably increased conception and pregnancy rates compared to the Ovsynch protocol alone in dairy cattle. CIDR inserts to be implanted in dairy cattle cautiously using hygienic precautions.

The information on CIDR devices and their usage in the management of Anestrus and sub estrus in dairy animals are discussed in detail below.

Controlled Internal Drug Release Device

What is CIDR

Controlled internal drug release (CIDR Protocol) devices are used for the treatment of Anestrus and for the synchronization of estrus in dairy animals. They are T-shaped devices -nylon spine molded with silicone rubber skin. The silicone coating is impregnated with progesterone.

CIDR protocol for cattleCIDRs are inserted intra-vaginally using a specialized applicator. The wings of the CIDR insert have the ability to be folded together in order to insert intravaginally. Once inserted, the flexible wings return to their original T-shape position and apply pressure to the vaginal walls to hold the insert in place. The expansion of the wings retains its position; CIDRs have very high retention rates that may exceed 97%. A thin nylon tail remains exteriorized and is used for removal.

How does CIDR works in Anestrus management in dairy animals

Each CIDR insert contains the exogenous hormone progesterone. The CIDR intravaginal release insert delivers progesterone at a controlled rate into the vagina of the treated animal. This progesterone is released by diffusion from a silicone rubber matrix encapsulated over a nylon spine which is shaped to retain the insert in the vagina. The progesterone from the CIDR insert is absorbed through vaginal mucosa resulting in plasma progesterone levels of sufficient magnitude to suppress the release of LH and FSH from the hypothalamus for the duration of the recommended treatment period. This negative feedback effect on the pituitary prevents oestrus and ovulation. CIDR induces cyclicity in anestrus animals on removal after the 7th day. It triggers the pituitary gland to release GnRH Gonadotropin-releasing hormone is a releasing hormone responsible for the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary. leading to the production of FSH and LH that helps the animal to get back on estrus. The mechanism by which non-cyclic dairy animals get back to cyclic is as below. After placement or insertion of CIDR in dairy animals, the progesterone hormone once inserted, CIDRs provide slow-release administration of progesterone, which artificially extends the luteal phase. Plasma progesterone levels rapidly increase upon insertion and remain relatively consistent while in place. Following CIDR removal, progesterone levels decrease rapidly. Occasionally, vaginal irritation may occur and triggers the pituitary gland to release GnRH. This is normal and does not impact the effectiveness of the device or the animal’s performance. Removal of CIDR insert allows LH pulse frequency to increase resulting in oestrus and ovulation of the emerging dominant follicle.

What is Ovsynch-CIDR Protocol

There is various CIDR protocol reported by several authors during field studies. Ovsynch-CIDR is the well-documented hormone treatment protocol used by veterinarians to treat anestrus cases in heifers and dairy animals. As per literature and publications available, it is documented that after application of the scientific protocol, non-cyclic heifers and dairy animals can bring back to estrus successfully. The probable conception and pregnancy rates are also significantly higher than other protocols.
 Ovsynch-CIDR Protocol

The Ovsynch-CIDR protocol is as follows:

Day 00: 1 shot of GnRH and CIDR vaginal insert with applicator

Day 07: Removal of CIDR and 1 shot of Prostaglandin PGF2 alpha The prostaglandin primarily affecting the cow’s estrous cycle is prostaglandin F2α (PGFα), which is produced by uterus. PGF2α causes the natural regression of the luteal cells of the corpus luteum at the end of the estrous cycle or pregnancy. (PGF2α)

Day 09: 1 shot of GnRH 48 hours after PGF2α

Day 10: Inseminate 16 hours after day 9 GnRH shot

This CIDR protocol is well-practiced for estrus synchronization in larger dairy farms to make profitable dairy production. The advantage of CIDR protocol is a fixed time of artificial insemination (TAI Timed AI or fixed timed AI have become a popular reproductive strategy in estrus-synchronization protocols to improve pregnancy rate (PR) in modern dairy cattle operations. The advantage of these protocols is that detection of estrus is not necessary. Therefore, TAI has become crucial in herds in which detection of estrus is difficult, especially in large dairy herds.) hence there is no need for heat detection on the 10th day. In the case of heifers, CIDR has to be removed on 5th day. The other protocol remains the same.

What are the benefits of Ovsynch-CIDR protocol in the treatment of anestrus heifers and dairy cows?
  1. To induce estrus cycle in dairy animal
  2. Easier and more accurate heat detection
  3. Fixed time of artificial insemination Higher conception and pregnancy rates
  4. Reduced inter calving period
  5. How to administer CIDR in dairy animals

For best results, follow these steps:

  1. Wear protective gloves whenever handling the Eazi-Breed CIDR.
  2. Prepare a container of clean water with a disinfectant solution to wash the applicator between uses.
  3. Fit the body of the insert into the applicator with the tail along with the slot. The two wings will be pushed together, protruding about 1 inch above the top of the applicator.
  4. Apply a generous amount of lubricant to the tip of the insert.
  5. Shift the animal’s tail to one side, and clean the vulva.
  6. Make sure the tail of the EAZI-BREED CIDR Cattle Insert is facing upwards.
  7. Open the lips of the vulva and insert the applicator at a slight upward angle, moving forward over the pelvic bone until it meets resistance, then rotate the applicator so the tail is curling down to hide from curious pen mates.
  8. Dispense the insert from the applicator by depressing the plunger, then slowly withdraw the applicator body.
  9. To prevent removal by curious pen mates, you may want to clip the tail of the insert so that 2.5 inches protrude from the vulva.
  10. To withdraw the insert, simply give the tail a gentle but firm pull to release the insert.
  11. Dispose of used inserts in a sealed, plastic container in accordance with applicable local, state and federal regulations.

Ovsynch-CIDR Protocol usage Checklist for Veterinarians:

1 EAZI-BREED CIDR Insert in a bag (1x 10 insert) 1 Insert for intravaginal use on Day 0
2 CIDR Applicator The instrument for inserting CIDR insert through intravaginal route
3 Hand gloves-Disposable/Surgical To maintain hygienic precaution at all steps of CIDR administration
4 Antiseptic- diluted Povidone-iodine or Potassium permanganate crystals to be diluted in clean water For Disinfection of CIDR Applicator prior to use. It is carried out by putting Potassium permanganate 2-3 crystals in a bucket of clean water until it takes purple color
5 Lubricants-Glycerin solution To be applied on CIDR applicator for ensuring smooth insertion of insert through intravaginal route and to reduce pain at the time of administration
6 Two plastic/steel buckets a) One bucket for antiseptic solution preparation in which CIDR applicator to be disinfected. B)Other clean water Bucket for Rinsing of CIDR applicator
7 Disposable Paper/Disposable cotton To dry the applicator after taking out of clean water bucket
8 Clean washed cloth For cleaning of the vulva to remove organic material-dung, urine stains prior to the administration on Day 0
9 GnRH injection 2.5 ml + 2.5 ml For intramuscular use on Day 0 and Day 9
10 Dinoprost-prostaglandin Injection 5 ml For intramuscular use on Day 7 after CIDR removal
11 Vet Apron PVC full size For wearing Vet while CIDR application procedure
12 Scissor To cut the excess length of Tail part of CIDR insert
Dr. Vijay Muley 
LEAD-Technical,
Ruminants Zoetis India Limited