It is defined as absence of periodic manifestation of estrus, with the absence of palpable follicular or luteal structures (smooth ovaries) or absence of normal physiological signs of estrus associated with  a corpus  luteum (subestrus, physiological anestrus). Inactive or non-functional ovary is one of the most important causes of anestrus in buffaloes. Anestrus is one of the most commonly occurring reproductive disorders in buffaloes. Ovarian inactivity is more frequent (30%) in buffaloes on low level of feeding than in those given high level feeding and also in summer (41–46%) than in other seasons (7–33%) calvers. Ovarian inactivity constituted 28% of all the functional causes of infertility in postpartum buffaloes and 67% of all cases of inactive ovaries in these buffaloes. Incidence of anestrus is buffalo 20-67%.

Summer anestrus is the major problem occurring in buffaloes caused by many factors. Ameliorating or eliminating those factors has proved useful in reducing anestrus in buffaloes with varied degree of success. They are through management, nutritional, breeding and hormonal approaches.

Management strategy

1. Reducing heat stress : Proper extensive housing system and sprinkling of water to the body surface or providing wallowing facilities during hotter part of the day in summer can reduce the heat stress considerably, reducing the adverse effects on buffalo fertility. Various show that conception rate was increased in buffaloes by giving showers in addition to wallowing facilities, which considerably reduced the incidence of early embryonic mortality.
2. Improving estrus detection methods:  One of the factors that increase the calving-conception interval of buffalo during the hot season of the year is poor detection of estrus. The use of teaser bulls, tail head paint, the heat watch system, radio-telemetric pressure transducers and pedometers can improve estrus detection and thus fertility.

Feeding strategy

Feeding strategy for buffaloes during hot climate is imperative in reducing infertility problems. Roughage feeding during night to buffaloes will reduce the heat stress in buffaloes. Moreover feeding green fodders, ad- libitum water and mineral mixture supplementation improve the efficiency of reproduction during summer. There are several key areas of nutritional management which should be considered during hot weather. These include formulation to account for reduced dry matter intake, greater nutrient requirements during hot weather, dietary heat increment, and avoiding nutrient excesses. It is important to predict dry matter intake, in order to formulate an adequate diet for buffaloes in a hot environment. The energy requirements of lactating buffaloes also increased under high temperature conditions, but this increase seemed to be caused mainly by the increase in metabolic energy. Low fiber, high fermentable carbohydrate diets lower dietary heat increment compared with higher fiber diets. Although the metabolic energy of dairy buffaloes increases in a hot environment, heat stress depresses feed intake.

Breeding Strategy

There are many aspects of genetics that influence the response to heat stress, and as the variation among breeds is large. The maintenance of body temperature is heritable through characteristics including sweating competence, low tissue resistance, coat structure and color. So selections of animals through specific markers for heat tolerance will address the problem of heat stress in buffaloes.

Hormonal treatment

Various hormonal treatment regimens are followed to alleviate anestrus to stimulate ovarian activity, estrus behavior in turn leading to ovulation. Different hormones were used either alone or in different combinations producing varied degrees of success.

Progesterone based treatment regimens (PRID, CIDR, Crestar, Progesterone injections) either alone or in combination with gonadotrophins proved to be very effective in inducing ovarian activity in summer anoestrus buffaloes. The mechanism derived out of the treatments seemed to be the induction of follicle turnover by increased serum progesterone after PRID removal. It is further confirmed that the increased progesterone level in blood sensitizes the hypothalamus and pituitary to the gonadal feedback. Furthermore, PRID in association with PMSG yielded better results than PRID alone, both in terms of oestrus induction and conception/pregnancy rate. Moreover, ovsynch protocol alone or with other hormones is also useful in estrus induction and improved conception rate in buffaloes. Induction of follicular wave is also done using ECG in ovsynch protocol.  A double insemination is thus recommended to approach the time of ovulation for achieving better conception rates. Use of estrogen is also followed in treating anestrus in buffaloes. Approaches using other drugs such as melatonin, bromocriptine and antioxidants have been used with varied success rates.

Progesterone based treatment either alone or in combination with PMSG resulted in estrus induction (2.7-100%) and the conception rate varied from 50-100%. The success rate of PGF2α based treatment regimens in estrus induction varied from 58.3-89.5% with a conception rate of 13.8-75%. GnRH based treatment alone or in combination with insulin, progesterone, PMSG success rates in estrus induction and conception rate varied between 10.4-100 and 0-75%. Induction of estrus using ovsynch plus protocol with PMSG yielded estrus induction and conception rate of 80 and 30%, respectively. Induction of estrus Using miscellaneous drugs showed varied results: melatonin (55.5-100%), bromocriptine (56.2%) and antioxidants (22.2%).

Contributed by Indrajeet Singh ,Jerome A and A.K Balhara

Incidence of subestrus in buffaloes has a wide variation in the frequency (15 – 73%). The intensity of heat signs in buffaloes is generally lower and also homosexual activity is not pronounced as in cows. The intensity of expression of estrus is generally affected by housing, floor surface, yield, lameness and number of herd mates in estrus simultaneously. Summer anestrous is an important condition is buffaloes contributing to infertility in buffaloes. Heat stress has a pronounced effect on the estrus behavior of the female animals as heat stress reduces the length and intensity of estrus. Changes caused by heat stress reduce the likelihood of estrus detection. Heat stress causes increased cortisol secretion and this hormone blocks estradiol-induced sexual behavior. Effect of heat stress on estrous behavior also includes actions independent of the pituitary-adrenal axis reducing the ovarian activity and follicular development. Heat stress causes a reduction in peripheral concentrations of estradiol at estrus.  Moreover reduced physical activity is also probably an adaptive response that limits heat production and reduced estrous behavior.

Heat stress during the follicular growth period potentially compromises the oocyte, either because of direct actions of elevated temperature on the oocyte or because of alterations in follicular function that will compromise oocyte. Heat stress at the beginning on the day of ovulation reduces the diameter and volume of the dominant follicle of the estrous cycle. Secretion of the hormones regulating reproductive tract function is also altered by heat stress. These changes lead to variable changes in steroid hormone concentrations in peripheral blood. This reduced action of steroid hormones on reproductive tract tissue during heat stress eventually impairs uterine and oviductal functions. Effect of heat stress on embryonic survival and development during early stages of pregnancy is more pronounced as there is decrease in embryo survival in early stages of development due to heat stress. Disruption of early embryonic development results from actions on the embryo itself or on the oviductal or uterine environment in which the embryo resides.

Factors responsible for anestrus are environmental stress, endocrine (endogenous opioid peptide, lower insulin concentration, imbalance in hormones such as LH, FSH, prolactin, melatonin and thyroid), nutritional (negative energy balance, micro and macronutrient deficiency), managemental factors such as lactational stress, suckling etc.  A lower level of body weight, total serum protein, blood hemoglobin, blood glucose, blood insulin, inorganic phosphorus, calcium, manganese, iodine, cobalt, copper, iron, cholesterol and vitamin A deficiency also causes anestrus. Anestrus may be diagnosed by per-rectal palpation of reproductive organs and frequent activity of reproductive cycles of buffaloes using ultrasonography.

Incidence of anestrus in buffaloes has been documented in various states as given below:

(Khan et al. 2009)

A repeat breeder is generally defined as any buffalo that has not conceived after three or more services associated with true estrus. A repeat breeding animal has normal or nearly normal estrus; estrus cycles as well as reproductive tract and though has been bred three or more times by fertile bull semen but had failed to conceive.

The cause of repeat breeding are

• Fertilization failure
• Anovulation and delayed ovulation
• Tubal obstruction
• Early or latent embryonic mortalities
• Deficiency of oxytocin
• Deficiency of energy
• Deficiency of progesterone
• Excess estrogen
• Poor breeding and management techniques
• genetic, nutritional and infections.

Incidence of repeat breeding buffaloes is 0.61-29.8%. The incidence varies with breed, farm, agro-climatic and managemental conditions.  Incidence of repeat breeding  has been found higher in older and higher milk producing dairy animals . Stress of milk production interfere in the synthesis and release of gonadotrophins leading to repeat breeding. Different species of bacteria are responsible for repeat breeding are Streptococcus, Staphylococcus, Bacilli, Cornyebacterium, E. coli, Proteus.

Incidence of Repeat Breeding in buffaloes reported in different states

(Khan et al. 2009)

Therapeutic strategies for Repeat Breeding

Anovulatory heat and delayed ovulation

In anovulation, ovulation will not be evident and hence no CL will be felt on days of examination. Hormonal therapy includes hCG or LH preparations 1500 to 3000 IU I/V on the day of AI or GnRH i.e. Receptal or Fertagyl 500 mcg I/M on the day of AI. Proluton depot 250 mg I/M at AI and 25% Dextrose 400 ml I/V + Inj. Vitamin C 200 mg on 5th and 17^th can also be tried. Other treatment include Copper glycinate 10 ml. I/M on the day of AI as well as feeding carotene daily 400-600 mg/day per animal. Feeding of homeopathy drugs such as Aurun Iodum, Thyroidinum, Aguns castus 10 pills of each, 3 times a day  for 10 days may be beneficial. Feeding of chelated mineral supplement daily especially containing Iodine, phosphorus, and manganese is recommended.

Tubal Blockage

It is possible to diagnose the tubal blockage on careful per-rectal palpation. Blockage can be diagnosed by injecting 10 ml of   0.1% Phenol red sol. intra-uterine in one horn preferably at the tip of the horn.

contributed by Indrajeet Singh and Jerome A

This is a very common reason of RB. Under our managemental conditions, the main causes are  endometritis, too early or too late AI, High environmental temperature, Nutritional status of animal i.e. low energy diet, low protein diet, Mineral & vitamin deficiencies and Hormonal imbalance. It is advised to use antibiotic by systemic route on day 3rd of AI and on day 10th after AI in case of endometritis

In case of LH hormonal deficiency it is also advised to inject 1500 –3000 IU,  hCG / LH on the day of AI to produce large size CL. Insemination should be done at the end of heat and not too early or late i.e. follow AM / PM thumb rule. In oxytocin deficiency, animal passes large quantity of urine when examined P/R. Give 50 IU of oxytocin I/M, after AI. Atonicity may also be due to high progesterone content, since the CL may not have regressed totally. This condition cannot be diagnosed in field condition except examination of CL size on 8th to 10th day of cycle for hypoluteal condition, but not at the time of AI. In this condition 2000 mg of Vitamin. C, I/V along with 400 ml of 25% Dextrose, after AI. 1500 IU HCG /LH on the day of AI, I/V and on 14th to 16th day post estrous will be beneficial. Recently COX-2 inhibitors have been on 15^th to 17^th day post AI t o reduce the incidence of embryonic mortality due to luteal regression with 80% success rate.

Feeding and shelter management

Animal should be fed crushed maize ½ kg well soaked daily for 60 days or germinated grains during period post insemination. Chelated mineral supplements should be provided for better conception rate. Positive protein energy balance should be maintained for better conception rate. Excess energy or protein disrupts the uterine environment and causes embryonic mortality and repeat breeding. Negative effect of feed deficiency of B-carotene and vitamin E causes silent heat, delayed ovulation, follicular and luteal cysts and early embryonic mortality. Well ventilated byres or keeping animals in tree shadows in hot times, sprinkling of water on body of animals , wallowing buffaloes to wallow and availability of ample & fresh drinking water at all the times will take care of the problem. During transporting of the estrous animal for AI leads to stress due to buffaloes around the onset of LH surge causing subnormal LH and leads to anovulatory infertility. It is better to make the animal take rest for 30 minutes before AI. As far as possible, avoid transporting animal, instead call vet at home.

Abortion is the expulsion, before full term, of a conceptus incapable of independent life. The cause of abortion other than infection includes genetic, nutritional, thermal, toxic and traumatic factors. Stillbirth is the delivery of a dead calf at full term. These pregnancy losses are approximately 5-10 % in normal herds.  Incidence of abortion in buffaloes is 7.5-10.5%.

Causes:

Infectious causes:

• General infections with high fever
• Specific infections such as brucellosis, leptospirosis, listerisis, TB, vibriosis, trichomoniasis, IBR-IPV, FMD, bluetongue, BVD, aspergillosis, toxoplasmosis, babesias.
• The incidence of infectious causes are brucellosis 4-10 %, vibriosis <0.5%, trichomonisis 11-28 %, IBR 14-27%, and Mycosis 5% of reported aborted cases.

Non-infectious causes:

• Genetic
• Environmental: temperature
•  Nutritional : phytotoxins including mycotoxins
•  Iatrogenic: administration of abortifacient drugs.

Nutritional deficiency of iodine, vitamin A also causes abortion.

Preventive measures:

• Proper hygienic and biosecurity measures in the animal’s environment and feed storage
• Isolation of aborting cows and immediate removal of aborted materials
• Systematic evaluation of the feed for mycotoxins and other phytotoxins
• Adequate immunization against infectious diseases causing abortion
• Maintenance of adequate breeding and treatment records to avoid insemination of pregnant animals and administration of drugs that may cause abortion to pregnant animal

Contributed by Indrajeet Singh, Jerome A and A.K Balhara

It is the inflammation of the endometrium. It is the most frequent cause of infertility in buffalo especially under field conditions. Incidence of endometritis is high in buffaloes 9.07-67.11%. The most important cause of endometrits is non specific opportunist pathogens that contaminate the uterus during the peri-parturient period. Other conditions are retention of placenta, abortion, dystocia, induction of parturition, genital prolapse, uterine inertia and traumatic lesions in the genital tract. Uterine function is often compromised in buffalo by bacterial contamination of the uterine lumen after parturition; pathogenic bacteria frequently persist, causing uterine disease, a key cause of infertility. It is called nonspecific infection because the initial colonizing bacterium is not known and the specific bacteria causing the signs of infection are not known, even though numerous bacteria in a variety of combinations have been isolated from infected uterus.

Incidence of Metritis/ Endometritis in buffaloes in different states

(Khan et al. 2009)

Diagnosis of Endometritis/ Metritis on the basis of clinical manifestations and rectal examination is not reliable and hence we always treat with various drugs to cure infection and avoid repeat breeding. In general, the current therapies of Endometritis / Metritis and uterine infections, can be of following types:

Antibiotics

These have been widely used as treatment of uterine infections, but success of these treatments varies from beneficial to no benefit. When Penicillin is used, it may be inactivated through bacterial production of the enzyme Penicillinase. In case of Tetracyclines, the need of large systemic dose to get effective tissue concentration against A. pyogenes could be toxic to the animal.  The anaerobic environment of the uterus makes Aminoglycoside group (Gentamicin, Kanamicin, Streptomycin & Neomycin) ineffective because of the regular need of the oxygen for their activity. These antibiotics also inhibit phagocytosis. This suppression of leukocytic activity is further increased, if the bacteria are resistant to the antibiotic applied. In endometritis, the absorption of many drugs is diminished, due to which therapeutic levels in the deeper layers of the uterus and other parts of genital tract are not likely to be achieved.

Penicillins are rapidly absorbed following intra uterine infusion, reaching peak plasma concentration in 1 h and decline below MIC after 4 h. Crystalline Penicillin G (1 million IU) & Procaine Penicillin (1 million IU) maintained detectable levels24 & 48 h, post-infusion respectively. Benzyl Penicillin following I/M route at 22000IU / kg body wt. peak levels in blood & endometrial tissue were attained 15 & 60 minutes post-administration, respectively and remained for longer periods of time.

Ampicillin: I/M @ 4-6 mg/kg bodyweight (b.w) need to be repeated at 24 h

Cephalexin: I/V 15 mg/kg b.w. needs to be repeated at 9 h.

Aminoglycosides: Dihydrostreptomycins attain peak 1-2 h following I/Ut. Intra-uterine dose is 1 gm. Detectable concentration remains for 24 h in uterine lumen.

Gentamicin: I/M administration @ 5mg/kg.

Tetracyclines: I/V twice daily@ 9-11 mg/kg b.w.

Chloramphenicol : Gives better results in uterine infection. I/M @ 20 mg/kg b.w. attains serum peak in 30 min. Needs to be repeated at 10 h in normal cycling & 12 h in dystocia  suffering animals.

Sulfonamides: Sulfonamides @ 80 mg/kg b.w. as loading dose and 65 mg/kg as maintenance dose provides antimicrobial cover to uterus up to 14 h.

Antiseptics

Weak or dilute Lugol’s Iodine solution has been an effective treatment of endometritis

Hormonal Therapy

• Estrogens: They increase the uterine defense mechanism of reproductive tract by increasing the blood circulation, leukocyte infiltration to the uterus, uterine contractions, mucus flow and phagocytosis. Dose of Estradiol benzoate given I/M is small i.e. 5–6 mg. However, long acting estrogens and Stilbestrol have been associated with more severe infections of oviducts & myometrium and development of cystic ovaries.
•  Oxytocin: It increases phagocytosis. The effect can be seen upto 8 days post partum, ifinvolution has been delayed.
•  Prostaglandin F analogues: It brings about luteolysis & decreases.
• Progesteroninduced inhibition of UDM and increases estrogen induced UDM. It has been observed that systemic use of antibiotics gives better results. Only a double dose of an antibiotic is required to achieve the optimum level of drug in the uterine lumen.

Other products

They are mainly based on substances which cause activation of uterine defense mechanism. These substances are E. coli endotoxins, Serum plasma & hyperimmune serum, Polymononuclear cells extracts and Component Granululocyte – Macrophage colony stimulating factor and 1-10 % Oyster glycogen.