Thirty healthy, parous, cyclic crossbred cows aged under 8 years were selected and randomly divided into two groups as group I (n=10) and group II (n=20). Group I served as control and group II cows were synchronized with CIDR + PGF2α protocol in the presence of matured CL. Breeding was carried during the observed estrus in group I and at 48 and 72 h after removal of CIDR in group II cows with good quality frozen thawed Jersey crossbred semen. The group II cows showed 100 per cent estrus induction with a mean time of onset of induced estrus of 46.20 ± 0.50 h in group II cows. The duration of estrus was 25.40 ± 0.45 and 26.30 ± 0.47h in group I and group II, respectively. The incidence of intense and intermediate estrus was significantly higher in group II when compared with group I cows. The length of estrus in non-conceived cows was 22. 13 ± 0.52 and 21. 37 ± 0.62 days in group I and II, respectively with a conception rate of 20 and 60 per cent in group I and II. It was concluded that application of CIDR and PGF2α with FTAI was effective in improving conception rate in cross bred cows.

The study was conducted on repeat breeding cows at Large Animal Gynaecology Ward, Department of Clinics, Madras Veterinary College, Chennai and some private cattle farms in and around Koduvalli region, Tiruvallur district, Tamil Nadu. In experiment I, Jersey crossbred cows (n=31) synchronized by PGF2a and inseminated on exhibited estrum. The cows were randomly divided into five groups viz. Group I (control, n=6), group II (n=7,100mg), group III (n=6, 150mg), group IV (n=6, 200mg) and group V (n=6, 250mg) and supplemented with fish meal on day 13, 14 and 15 of post insemination in addition to their routine feed. Pregnancy diagnosis was carried out by rectal palpation on day 60 of post insemination. In experiment II, twelve repeat breeding Jersey crossbred cows were selected and synchronized using PGF2a followed by timed insemination. On day 10 of post estrus, rectal examination was performed to identify the corpus luteum and randomly divided into two group viz. Group I and Group II (control). Group I cows were injected with Meloxicam @ 0.5 mg/ kg body weight through intramuscularly on day 13 to 15 post-insemination. The conception rate in experiment I as in Group I, group II, group III, group IV and group V are 16.67%, 71.43%, 66.67%, 66.67% and 50.0%, respectively. The conception rate in meloxicam treated animal was 66.7% and in control animal was 33.3%. The fish meal treatment and Cox-2 inhibitor in repeat breeding crossbred cows had improved the conception rate. Further, the supplementation of 100mg offish meal in repeat breeding cows has shown higher conception rate as compared to other groups in experiment II. Hence, it may be used in field condition for enhancement of conception rate, however, further studies in larger population is warranted.

The present study was designed to assess the therapeutic efficacy of Randia dumetorum, Tinospora cordifolia and commercial herbal medicine (Prajana HS, Indian Herbs Overseas) for induction of cyclicity in anoestrus buffalo heifers.Fourty eight anoestrus buffalo heifers were examined and redistributed into six groups(G0, G1, G2, G3, G4 and G5) and each comprising of eight (n=8) animals. Untreated anoestrus animals (G0) andcyclic animals (G6) were kept as an anoestrus control and cyclic control, respectively. Group G1 wassupplemented with the mineral mixture, while G2, G3, G4, and G5 groups were treated with Prajana HS, Randiadumetorum,Tinospora cordifolia,and the combination of Randia dumetorum andTinospora cordifolia,respectively along with supplementation of mineral mixture. Overall estrus induction and conception rate were recorded as 50 % and 75 % in mineral mixture (G1),75 and 83.33 % in Prajana HS (G2), 87.50 % and 85.71 % in Randia dumetorum (G3), 62.5% and 80% inTinospora cordifolia (G4), and 87.5% and 85.71% in Randia dumetorum and Tinospora cordifolia combination(G5) whereas none of heifers were exhibited estrus symptom in untreated anoestrus control group.

Albendazole, administered orally at a dose rate of 25 mg/kg of body weight to presumed pregnant cows or heifers on days 21, 31, 41, 51, and 61 of gestation, did not induce toxicosis in embryos or fetuses, and all calves born were structurally normal. Albendazole administration at a rate of 25 mg/kg to cows at 7 and/or 14 days of gestation decreased the apparent conception rate (ie, embryolethality), but did not have a teratogenic effect. Apparent embryolethality was greater in cows administered 25 mg/ kg only on day 14, compared with those administered the drug only on day 7. Single dosage of 25 mg/kg given in the final 3 months of gestation did not induce abortion. There were no adverse effects of albendazole at a dosage of 10 or 15 mg/kg on developing embryos or fetuses when administered to presumed pregnant cows at various times in early gestation.

To test the efficacy of a polyvalent Tritrichomonas foetus vaccine, 130 nulliparous heifers were randomly assigned to either receive the test T. foetus vaccine or to serve as nonvaccinated controls. The polyvalent test vaccine consisted of a Campylobacter fetus/Leptospira canicola-grippotyphosa-hardjo-icterohaemorrhagiae-pamona bacterine containing 5 X 10(7) killed T. foetus/dose. The polyvalent control vaccine consisted of the aforementioned formulation without T. foetus. Heifers were administered 2 doses of control or experimental vaccine at 3-week intervals. Heifers were bred to T. foetus-infected bulls and their conception and pregnancy rates were determined throughout gestation. In addition, serum samples were analyzed to determine induced concentrations of antitrichomonal antibodies and vaginal secretions were sampled to determine T. foetus infection rates in control and vaccinated animals. One week after each of the 15-day breeding periods, 60% (6 of 10) of tested vaccinates and 80% (8 of 10) of tested control animals were T. foetus culture-positive. The mean duration of infection of vaccinates was 3.8 weeks (+/- 7.5 days), compared with 5.4 weeks (+/- 7.5 days) of infection for control heifers. All vaccinates developed increased immunofluorescence and serum neutralizing antibody titers following the first immunization, and had additional increases of at least fourfold in response to the second injection. In contrast, no consistent increase in immunofluorescence or serum neutralizing antibodies was observed in control animals. Conception rates were 89.2% for vaccinates and 85.9% for control animals 30 days after breeding and 80 to 90% of these remained pregnant 60 days after breeding. However, within the next 4 months, the pregnancy rate of control heifers decreased to 30% for those that had conceived. During the same 4-month period, more than 60% of vaccinated heifers remained pregnant. Significantly, 62.5% of heifers vaccinated against T. foetus produced calves, whereas only 31.5% of control heifers produced calves. These findings indicate that the polyvalent test vaccine induced an immune response that was effective in lowering the rate of T. foetus infection, decreasing the duration of infection, and reducing losses in calf production attributable to early fetal death and abortion caused by T. foetus infection.

The objective of this study was to determine rates of estrus and conception in lactating multiparous Holstein cows given 500 μg of cloprostenol intramuscularly after detection of the following ≥ 60 d after parturition: a solid corpus luteum (CL), a CL with a nonechodense cavity ≤ 20 mm in diameter (CLcav), a luteal cyst (cavity > 20 mm in diameter and a luteinized wall > 3 mm in diameter), or a follicular cyst (cavity > 20 mm and a luteinized wall ≤ 3 mm in diameter). The estrus rates were 335/419 (80.0%), 183/223 (82.1%), 170/182 (93.4%), and 44/87 (50.6%), respectively (P < 0.0001), and the conception rates 30 to 36 d after insemination among the estrous cows with an apparently normal mucus discharge were 130/285 (45.6%), 44/141 (31.2%), 39/79 (49.4%), and 19/30 (63.3%), respectively (P < 0.002). Compared with a solid CL, a CLcav did not affect the estrus rate but significantly reduced the conception rate (P < 0.05), and the estrus rates were significantly higher and lower in cows with a luteal or follicular cyst, respectively (P < 0.05).

An experiment was conducted to determine whether balancing dietary crude protein for optimal rumen degradability would improve fertilization rate and quality of ova in lactating dairy cows. Thirty-eight Holstein cows in early lactation were fed 1 of 2 diets formulated to be isocaloric and isonitrogenous, containing 16% crude protein. Diet 1 contained 73% rumen degradable intake protein, whereas diet 2 contained 64% rumen degradable intake protein. The cows were induced to superovulate and were inseminated, and ova were recovered nonsurgically on postbreeding day 7. Ova were counted and classified as fertilized or unfertilized. Fertilized ova were scored as excellent, good, fair, poor, or degenerate. Unfertilized ova and poor and degenerate embryos were considered to be nontransferable ova and excellent, good, and fair embryos were considered to be transferable ova. There were no differences for mean number of fertilized, unfertilized, transferable, or nontransferable ova recovered from cows fed the 2 diets (P > 0.10). Mean percentage of fertilized ova recovered from cows was greater (P < 0.05) in those fed diet 2, compared with diet 1. Mean percentage of transferable ova recovered from cows tended to be greater (P = 0.06) in those fed diet 2, compared with diet 1. More cows failed to yield transferable ova (P < 0.05) when fed diet 1, compared with diet 2. Fertilization failure or early degeneration of embryos may occur in cows fed excess rumen degradable protein.

Cattle heterozygous for deficiency of uridine monophosphate synthase required more breeding services per calving when mated to other heterozygotes than did matings of normal cattle. Gestation length, number of breeding services per calving, and days from breeding to pregnancy examination were monitored on 759 complete gestations, 76 false-positive pregnancy diagnoses, 14 false-negative pregnancy diagnoses, and 413 negative pregnancy diagnoses in a dairy herd between 1983 and 1987. For complete gestations, 15 heterozygote X heterozygote matings required 3.13 +/- 0.37 breeding services per calving, which was significantly more than the 2.05 +/- 0.05 breeding services required for normal X normal matings; gestation length and days from breeding to pregnancy examination were similar between mating types. For false-positive pregnancy diagnoses, females diagnosed pregnant, but subsequently found not to be pregnant, 5 heterozygote X heterozygote matings averaged 51 +/- 23 days of gestation, which was less than the 93 +/- 6 days required for 71 normal matings; services and days from breeding to pregnancy examination were similar between mating types. All false-negative pregnancy diagnoses, females diagnosed not pregnant but later found to be pregnant, were made on cattle with normal matings. For negative pregnancy diagnoses, heterozygous matings averaged 0.3 more breeding services per examination than normal matings.