• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.131-136
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• 1994

In an effort to confirm true oestrus and to detect early pregnancy in Zebu cows (Bos indicus), sequential blood and milk samples were collected at the day of imsemination (Day 0) and days 14, 20 and 24 after insemination. Progesterone was determined in skimmed milk and plasma by solid phase radioimmunoassay (RIA). Of the cows thought to be in oestrus plasma, (n = 46) and milk (n = 58) samples demonstrated low progesterone concentrations ($0.99{\pm}0.11$ and $2.02{\pm}0.14nmol/l$) in 42 (91%) and 52 (90%) cases respectively. Thirty two (76%) and 30 (71%) cows were thought to be pregnant by plasma progesterone RIA ($20.23{\pm}1.03$ and $20.48{\pm}1.01nmol/l$) at days 20 and 24 respectively. At the same period, 40 (77%) and 37 (71%) cows were thought to be pregnant by milk progesterone RIA ($27.82{\pm}1.28$and $28.02{\pm}1.27nmol/l$). Assuming 100% accuracy for rectal examination of pregnancy diagnosis between days 60-65 postservice, the RIA was found to be 84% and 90% accurate for plasma and 84% and 92% accurate for milk at day 20 and 24, respectively. All cows thought to be non pregnant by progesterone measurement were correctly diagnosed. Progesterone assay at 24 days after oestrus may therefore be accurate for early diagnosis of pregnancy in Zebu cows.

• Korean Journal of Animal Reproduction
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• v.14 no.3
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• pp.165-173
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• 1990

A simple and sensitive microplate enzyme immunoassay(ELISA) was developed for progesterone, based on progesterone monoclonal antibody as anti-progesterone, horseradish peroxise(HRP) as enzyme-label and tetramethylbenzidine(TMB) as substrate. The assay has a sensitivity of 5pg-120pg/well and intra- and inter assay coefficients of variation for progesterone standard curve(0.1ng-3.2ng/ml) were ranged 4.4-10.6% and 5.-12.6%, respectively. They assay is performed in less than two hours and provide reliable values to differentiate among samples from day 0(A.I.), day 14 and day 19. The discriminatory levels for early pregnancy diagnosis are [>10ng(day 19) & decreasing rate <1.5 : pregnancy] and [ 7ng & decreasing rate 1.5 : non-pregnancy]. The accuracy of the pregnancy diagnosis for cows classified as positive(pregnancy) and negative(non-pregnancy) were 96% and 100%, respectively.

• Biomedical Science Letters
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• v.8 no.4
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• pp.235-244
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• 2002

This study was carried out to determine the blood and milk progesterone by enzyme-linked immunosorbent assay (ELISA), and milk urea nitrogen (MUN) in cows. MUN and protein concentration were determined using automated infared procedures. The optimum conditions of ELISA system was investigated including the first and second antibody titres, bound percent, and enzyme conjugate and also the factors on MUN and protein concentration by sampling procedures and addition of preservatives. Progesterone antibodies did not react to pregnenlone, testosterone, estrone, estradiol-l7$\beta$, aldosterone, cortisol, corticosterone and 11$\alpha$-dehydroxycortisone (DOC), but reacted with only progesterone. The intra and inter-assay coefficient of variation 4.5%, 6.1~9.4% when used of bovine serum. The morning, MUN concentration (17.6$\pm$2.8 mg/100 ml) in the 13 herds was similar to that of evening MUN concentration of the lactating cows from the same herd. A significant relationship between morning and evening milk samples of upper parameters was found r=0.93. Difference in MUN concentration with sampling procedures and using of preservatives were investigated.

• Journal of Embryo Transfer
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• v.26 no.2
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• pp.105-109
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• 2011

Ovulation synchronization (ovsynch) has proved to increase the number of insemination in cattle by overcoming the problems of heat detection. The aim of this study was to do ovsynch in water buffaloes where heat detection is a major reproductive problem and to determine the conception rates after timed artificial insemination (TAI). Twenty cyclic buffaloes at ${\geq}$ 60 days postpartum were selected by examining 24 unobserved estrus buffaloes based on milk progesterone assay (progesterone concentration ${\geq}$ 1.0 ng/ml) from the Mymensingh district of Bangladesh. Ovsynch treatment regimen was started irrespective of the stage of estrous cycle. Gonadorelin (500 ${\mu}g$) was injected intramuscularly at Day 0 followed by Alfaprostol (8 mg) at Day 7. A second injection of Gonadorelin was given at Day 9 and TAI was done with frozen semen from Mediterranean buffalo bulls at 16~20 hours of the second Gonadorelin injection. Milk progesterone ELISA at Day 10~12 post AI confirmed ovulation in 16 out of 20 (80%) buffaloes (progesterone concentration ${\geq}$ 1.0 ng/ml). High progesterone concentration (${\geq}$ 1.0 ng/ml) at Day 10~12 and Day 22~24 of AI showed pregnancy in six out of 20 (30%) buffaloes. Pregnancy was further confirmed by ultrasonography at Day 40 in these six buffaloes. In conclusion, ovsynch followed by TAI could be applied in cyclic buffaloes for overcoming the estrus detection problems; however, more studies are needed to increase the conception rate.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.833-841
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• 1995

Ultrasonography was used to measure the corpus luteum area for determining the relationships between corpus luteum size and milk progesterone concentration during the estrous cycle in 16 dairy cows. Cows were classified retrospectively into cows that had corpus luteum with(n=P) and without(n=7) cavity. Ultrasound examination and collection of milk samples for progesterone assay were performed with 2 day intervals from Days 0 to 12, and then daily from Day 14 to the day of the next ovulation. The means for corpus luteum area and for milk progesterone concentration during the estrous cycle were not significantly different between cows that had corpus luteum with and without cavity. The correlation coefficients between corpus luteum area and milk progesterone concentration during luteal development (Days 2 to 8) were 0.71(p<0.0001) and 0.74(p<0.0001) for corpus luteum with and without cavity, respectively, during luteal regression(Days -6 to 0 relative to the next ovulation) 0.73(p<0.0001) and 0.76(p<0.0001), respectively. The correlation coefficients combined fur both stages of estrous cycle and both luteal statuses were 0.70(p<0.0001). These results indicate that corpus luteum area is significantly correlated to milk progesterone concentration, and ultrasonographic assessment of the corpus luteum is a reliable method fur estimating peripheral progesterone concentrations during the estrous cycle in cows.

• Biomedical Science Letters
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• v.9 no.1
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• pp.29-36
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• 2003

Progesterone levels in the blood plasma or skim milk of cows are considered to be very useful indicator fur the detection of estrus cycle and early pregnancy diagnosis. During 13 to 14 days after estrus the level of progesterone in plasma or skim milk were not different between the inseminated arid non-inseminated cows. In the pregnant cows the peak level of progesterone reached on 14th day after artificial insemination (AI), but in the absence of conceptus the level declines after the 14th day slowly, and then very rapidly towards the basal level after the 17th day. This low level persists about 4 days, including those of estrus and ovulation a highly characteristic pattern which differs so markedly from that in the pregnant cows. Progesterone levels in blood plasma or skim milk can provided a reliable diagnosis of early pregnancy and monitoring ovarian activity in cows. The mean $\pm$ standard deviation of milk urea nitrogen(MUN) and protein concentration in the cows at 9 herds were 17.7$\pm$2.35 mg/dL and 3.2$\pm$0.17%, respectively. The days of nonpregnant after parturition was shorter in the cows in which the lower level of MUN than higher level of MUN concentration.

• Journal of Embryo Transfer
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• v.1 no.1
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• pp.35-49
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• 1986

Recipients are an integral part of embryo transfer and they are expensive to maintain as a good recipient. Recipient management is one of the most important components in a successful embryo transfer program. Management includes selection and subsequent care of the animals. A good recipient is basically on "open" cows or heffers whose reproductive tract is capable of receiving one or two embryos and incubating it to term. Potential recipients should be always be healthy and cycling normally ranging from 18 to 23 days. A thorough veterinary examination is recommended for candidate of recipients and cattle for questionable health should be eliminated from the recipient herd. Age and size of recipients are particularly important considerations when heifers are used, because of most embryos available for transfer are from large dams and sires. Body condition can influence a recipient's production, reproduction and health. Obese and underconditioned cattle should be avoided for use. Transfer of fresh embryos especially requires precise synchronization of donors and recipients. For estrus synchronization, PGF$_2$$\alpha$ is injected twice 10 to 12 days apart and short4erm progestagen treatment is applied to potential recipient cattle by coil into vagina (PRID) or ear implant (Synchro-Mate-B). The highest pregnancy results are achieved in recipients at exact synchrony with donors or 12 to 24 hr earlier than donors. Estrus detection is a major factor in breeding efficiency. High accuracy can be achieved by use of heat mount detection alds or by obserbing cattle for 30-minute peroids 3 times daily. Assay progesterone in milk can be used to discrIminate between pregnant and nonprenant recipients. Rectal palpation on day 35 to 70 after is an accurate and safe method of pregnancy diagnosis. Embryonic mortality in recipients may be associated with factors such as high environmental temperature and nutritional or lactational stress in early lactation period. Achievement of short calving interval requires concentrated management activity during the first 90 days following calving. Acceptable candidate for a recipient should be routinely vaccinated for infectious diseases. Proper nutritional programs according to NRC requirements and body condition scoring system for recipient cattles are vital to the ultimate success of an embryo transfer program.r program.