Incidences of various etiological factors responsible for repeat breeding syndrome in cattle and buffaloes
J Singh, D Dadarwal, M Honparkhe, A Kumar
buffalo, cattle, progesterone, repeat breeding
J Singh, D Dadarwal, M Honparkhe, A Kumar. Incidences of various etiological factors responsible for repeat breeding syndrome in cattle and buffaloes. The Internet Journal of Veterinary Medicine. 2008 Volume 6 Number 1.
A total of 214 repeat breeding (Cattle-183; Buffalo- 31) and 30 normal (Cattle-20; Buffaloes- 10) animals from different dairy farms were selected. All the animals were subjected to repeated (3-5 days interval) clinico-gynaecological examinations along with blood sampling atleast for 21 days. The diagnosis was made on the basis of history, clinical signs, rectal findings, body condition scores (BCS) and blood plasma progesterone (P4) profiles. Out of 183 repeat breeding cattle, 13 (7.10 %) had acquired anatomical abnormalities, 52 (28.42 %) had hormonal aberrations, 33 (18.03 %) had genital tract infections, 27 (14.75 %) were affected with poor management and 58 (31.70%) were having a combination of more than one aforesaid factors. The number of repeat breeding buffaloes in the respective categories were 2 (6.46 %), 8 (25.80 %), 8 (25.80 %), 5 (16.14 %) and 8 (25.80 %). Out of the animals repeating as a result of acquried anatomical abnormalities, 8 (61.54 %) cattle and 2 (100 %) buffaloes were repeater due to hard and kinked cervix. Out of the animals affected with hormonal aberrations, 33 (63.5 %) cattle and 8 (100%) buffaloes were exhibiting prolonged estrus period. Poor semen quality or faulty AI techniques were found to be major managemental factors in cattle (25/27) and buffaloes (2/2). In the category more than one etiological factor, the combination of genital infections and hormonal aberrations was the major contributing factor to repeat breeding (Cattle- 23/58; Buffaloes- 3/8), followed by combination of anatomical defects and hormonal aberrations (Cattle-19/58; buffaloes- 1/58); genital infection and anatomical defects (Cattle- 19/58; Buffaloes- 1/58). Hence, it was concluded that hormonal aberrations and its combination with other factors constitute the major cause of repeat breeding syndrome in dairy animals.
Repeat breeding syndrome is responsible for long service period and inter-calving interval thereby causing low milk and calf production resulting in to greater economic loss to dairy industries. To curtail these losses exact and early diagnosis of the underlying etiology followed by timely interventions is a prerequisite. The factors responsible for this malady are multiple viz. anatomical, hormonal, managemental and infectious, and vary from herd to herd, animal to animal and estrus to estrus. The incidence of repeat breeding in India has been reported from 5.5 to 33.33 % in cattle and from 6 to 30 % in buffaloes (Saxena, 2004). In view of the fact that the incidence of repeat breeding syndrome has increased over decades; surveys elaborating the major underlying factors are necessary. Therefore, a field oriented study was planned to identify the major factors causing repeat breeding, so that timely intervention could be done to avoid further loss to dairy industries.
Materials And Methods
The study was carried out in 18 randomly selected villages of Malwa region of Punjab, India. A total of 214 animals (cattle- 183; buffaloes- 31) with the history of repeat breeding and 30 normal animals (cattle-20; buffaloes-10) were selected. All the animals were subjected to repeated clinicogynaecological examinations, culture sensitivity test of oestrual mucus and blood collection at 3-5 days interval for 1-2 estrous cycle. The diagnosis was made on the basis of history, rectal findings, body condition score (Edmondson et al.,1986) and blood plasma progesterone profiles. On the basis of diagnosis, all repeater animals were grouped as follows:
Anatomical abnormalities (Gp-1) – This group consisted of animals with kinked and hard cervix, ovaro-bursal adhesions (OBA), combination of OBA and kinked cervix and uterine tumor. Animals belonging to this group had clear cervico vaginal mucus, regular cycling, good BCS (3.5-4.0) and plasma P4 profiles comparable with normal animals.
Genital infections (Gp-II): This group included animals with endometritis, salpingitis, combination of endometritis and salpingitis. Animals belonging to this group had turbid cervico vaginal mucus, regular cyclicity, good BCS (3.5-4.0) and plasma P4 profiles comparable with normal animals.
Hormonal (Gp-III): This group was made up of animals with cystic ovarian degeneration, delayed ovulatory conditions and luteal insufficiency. These animals had abnormal progesterone profiles over the estrous cycle and clear cervico-vaginal mucus discharge.
Managemental (Gp-IV): The animals of this group had clear cervico vaginal mucus, poor BCS (1.5-2.0), normal genitalia and plasma P4 profiles comparable with normal animals. These animals were inseminated with poor quality semen or at wrong time.
Multiple factors (Gp-V): This group included combinations of factors of Gp I & II, I & IV, II & IV and II & III.
The blood plasma progesterone concentrations were estimated by radioimmunoassay precoated tube method with the help of RIA kits supplied by FAO/IAEA Agricultural and Biotechnology, Seibersdorf, Austria. The mean intra- and inter-assay coefficients of variation were 6.71 and 10.08 % respectively. The sensitivity of the assay was 0.032 ng/ml.
Overall incidences of various etiological factors
The various abnormalities identified and their incidences in repeat breeder cattle and buffaloes have been depicted in Table 1. Out of 183 repeat breeding cattle, more number of cattle (31.70%) were suffered due to a combination of more than one factors i.e. multiple factor (Gp V), followed by hormonal aberrations (Gp III; 28.42 %), genital tract infections (Gp II; 18.03 %), poor management (Gp IV; 14.75 %) and acquired anatomical abnormalities (Gp I; 7.10 %). The number of repeat breeding buffaloes in respective categories were 8 (25.80 %), 8 (25.80 %), 8 (25.80 %), 5 (16.14 %) and 2 (6.46 %).
Out of the animals belonging to Gp I, 8/13 (61.54 %) cattle and 2/2 (100 %) buffaloes were repeater due to hard and kinked cervix. In the present study the incidence of OBA was found 2.2 % (4/183) in cattle whereas, no buffalo had OBA which might be due to less number (n=31) of buffaloes presented at field during the study. Among Gp I animals one cow and no buffalo were found with uterine tumor. The plasma P4 profiles of Gp I animals were comparable with that of normal animals (Table 2).
Out of Gp II animals most of the cattle (26/33) and all the buffaloes were suffering from endometritis. The incidence of salpingitis in the present study was 2.7 % (5/183) in cattle whereas, the condition was not encountered in buffaloes. However, two cattle had combination of endometritis and salpingitis. The plasma P4 profiles of Gp II animals were comparable with that of normal animals (Table 2).
The plasma P4 profiles of Gp III animals have been depicted in Table 3. Among this group, maximum numbers of cattle were having cystic ovarian degeneration (19/52), followed by delayed ovulation (17/52) and luteal insufficiency (16/52), whereas, buffaloes in this group had delayed ovulation (50%) and early luteal deficiency (50 %). Among the delayed ovulators, 10 cows and 4 buffaloes had suprabasal P4 (0.87±0.21ng/ml & 0.50±0.07 ng/ml respectively) on the day of estrus. All these animals had prolonged estrus period (3-5 days). However, 7 cattle showed prolonged estrus even with basal progesterone level (0.14 ± 0.02ng/ml) comparable to that of normal animals on the day of estrus.
Out of the cattle suffering from luteal insufficiency, maximum number of cows were early luteal deficient (day 5 post-ovulation 68.7 %), followed by mid (days 5-10 post-ovulation; 12.5%), late (days 10-15 post-ovulation; 12.5 %) and during both early and mid (up to day 10 post-ovulation; 6.25 %) luteal deficient.
Despite having clear cervicovaginal mucus, anatomically normal genitalia and normal plasma P4 profiles (Table2), 14.7 % (27/183) cattle and 16.1% (5/31) buffaloes of Gp IV were repeater due to managemental and nutritional factors (Table 1). Either they had poor BCS (1.5-2.0) or inseminated with poor quality semen. Poor semen quality or faulty AI techniques were found to be major managemental factors in cattle (25/27) and buffaloes (2/2).
In the category of Gp V animals (Table 4), the combination of genital infections and hormonal aberrations was the major contributing factor to repeat breeding (Cattle- 23/58; Buffaloes- 3/8), followed by combination of anatomical defects and hormonal aberrations (Cattle-19/58; buffaloes- 1/58); genital infection and anatomical defects (Cattle- 19/58; Buffaloes- 1/58).
Overall incidences of various etiological factors
Higher incidence of repeat breeding due to combination of multiple etiologies than other single causes was observed in the present study. This is the fact that lack of expertise and inappropriate interventions at farmer’s doorsteps exaggerate the condition of repeat breeding syndrome and hence involve multiple factors to complicate the situation. Rao (1981) also observed relatively higher incidence of functional abnormalities (73.14 %) followed by infections (20.85 %) and anatomical abnormalities (6.0%) in crossbred cows.
Many of known inherited causes of infertility involve anatomical abnormality like kinked cervix. The hardness of cervix may appear due to trauma or lacerations during calving and AI followed by infection and fibrosis. The incidence of cervicitis varied from 0.9 – 5.52% in cattle (Mylrea, 1962; Rao, 1981) and 0.5 – 2 % in Indian buffalo (Kumar et al., 1988). The another important anatomical anomaly i.e. ovarobursal adhesions (OBA) develop between ovary and ovarian bursa as a result of faulty handling of ovary, intrauterine infusion of irritating drugs in large volume under pressure and due to infections. The incidence of OBA has been reported earlier as 0.29 - 1.8 % in cattle (Rao, 1981; Dobson and Kamonpatana, 1986) and 0.8-2.0 % in buffaloes (Rao and Sremannarayana, 1982). However, in the present study the incidence of OBA was found 2.2 % (4/183) in cattle whereas, no buffalo had OBA which might be due to less number (n=31) of buffaloes presented at field during the study. Tumors of bovine reproductive organs are quite rare (Salisburry, 1985) while the incidence of uterine tumor in buffaloes has been reported very low i.e. 0.3 – 0.72 % (Agarwal and Tomer, 1998).
The endometritis and pyometra are the most commonly encountered anomalies causing infertility in cattle and buffaloes under field or farm conditions. The incidence of endometritis has been reported to be 3.0 – 13.97 % in cattle (Zemjanis et al.,1961; Rao, 1981) and 2.4 – 20.0 % in buffaloes (Rao and Sreemanarayana, 1982) during clinical investigations. Slaughterhouse studies and clinical investigations revealed higher incidence of endometritis in buffaloes than in cattle (Dobson and Kamonpatana, 1986). The reason being habit of wallowing, not closely opposed vulval lips and improper postpartum care renders buffaloes more prone to endometritis (Agarwal and Tomer, 1998).
Salpingitis is one of the major disorders of fallopian tube. The incidence varied from 2.2 –3.6 % in cattle (Mylrea, 1962; Rao, 1981) and 0.8 – 4.5 % in buffaloes (Agarwal and Tomer, 1998).
The cystic ovarian degeneration was not encountered in buffaloes in the present study. The incidence of cystic ovarian degeneration observed in earlier studies varied from 8.8 – 27.4 in cattle (Tanabe and Brofee, 1982; Zemjanis, 1987) and 0.9 – 2.0 % in buffaloes
(Rao and Sreemanrayana, 1982; Kumar and Agarwal, 1986). The lower incidence of cystic ovarian degeneration in buffaloes may be due to lower stress of milk production than dairy cows (Agarwal and Tomer, 1998). The plasma P4 concentration more than 0.35 ng/ml at the time of standing estrus is considered as suprabasal progesterone, which may be a cause of prolonged estrus (Bage et al
Besides, genetic, infectious and endocrine factors, managemental and nutritional factors also play an important role in causation of repeat breeding syndrome. The BCS is a useful field tool for estimating changes in body weight, tissue reserve and for assessing dairy managemental practices and ration. The recommended BCS for a dairy cow is 3.25-4.0 (Edmondson et al., 1989). Large negative energy balance during post partum period is associated with reduced BCS and subfertility (Royal et al., 2000).
In the present study, there was a slack in any one of the steps involving storage, thawing, post-thaw handling of semen, incorrect and inappropriate insemination with respect to stage of estrus. Correctness and precision of these steps are mandatory in achieving high success rate with AI (Salisburry et al., 1985).
Involvement of more than one factor for causing repeat breeding was observed in maximum number of cattle and buffaloes in the present study. Kutty and Ramchandran (2001) also observed high incidence of repeat breeding because of combination of ovulatory disturbances and reproductive tract infection. The results of other combination factors could not be compared due to scarcity of similar type of work.
Hence, the present study indicated that hormonal aberrations and its combination with other factors constitute the major cause of repeat breeding syndrome in dairy animals.
The authors are thankful to IAEA (International Atomic Energy Agency), Austria for providing progesterone kits for this research work.