1. Introduction Materials and Methods Aim Results Conclusion References
EVALUATION OF NORGESTOMET CRESTAR® IN THE REPRODUCTION PERFORMANCE OF DAIRY CATTLE: CASE OF THE AREA OF THE BASS KABYLIE, ALGERIA
A. AYAD1,*, H. BENBAREK2, Y. BELLIK1, M. IGUER-OUADA1
1Faculty of Life and Nature Sciences, University A. Mira, Bejaia, 06000, Algeria
2Faculty of Life and Nature Sciences, University M. Istambouli, Mascara, 29000, Algeria *
Introduction
Hormone interventions have been used to increase the probability of estrus detection and insemination, and to increase pregnancy rates of dairy under a variety of management systems.
Poor rates of estrus detection combined with low conception rates make management of reproduction in lactating dairy cows a challenge in most dairy herds.
Problems with estrus detection can lead to major financial implications for farmers and increase the numbers of cows culled for infertility (Walker et al. 1996). Synchronization of estrus has been developed to help framers manage reproduction more efficiently.
The hormones used pharmacologically control the estrus cycle are identical to the reproductive hormones in cattle.
Materials and Methods
After a waiting period (~ 90 days postpartum), Holstein-Frisian females (2-10 years old, 0-8 parity) on different dairy farm were inseminated after detecting estrus (n=135).
Females were allocated randomly to treated (n=69) or control (n=64) groups.
The treated animals received a CRESTAR® during 9-10 days, and artificial insemination (IA) at implant removal (56-60 hours).
Blood samples were collected from the coccegeal vein into a tube containing EDTA on Days 0, 21 and 30 after service. The plasma was immediately separated (1,500 x g for 15 min) and stored at -20°C until assayed (Delahaut et al., 1979).
The day of AI was considered as Day 0. Plasma progesterone (P4) and pregnancy-associated glycoprotein (PAG) levels were determinate by RIA technique (Ayad et al., 2007; Lopez-Gatius et al., 2007).
Females were classified as anestrus if samples of P4 were < 1 ng/ml and as cyclic if samples of P4 were ≥ 1 ng/ml. A cut-off value of 0.8 ng/ml PAG was used to confirm pregnancy in the cow.
Aim
The objective of our study was to evaluate the effectiveness of norgestomet Crestar® for synchronisation of estrus and the effect on pregnancy rate in cows.
Results
This experiment showed a higher rate of heat synchronisation in treated group (94%) in comparison with control group (86%).
Thirteen cows from treated and control group were inseminated when progesterone concentrations were higher than 1.0 ng/ml (4 and 9, respectively).
The plasma PAG levels at Day 30 after IA were significantly lower in the treated group (7.13 ± 2.29) compared to the control group (8.75 ± 2.16), and pregnancy rates were 26% (15/57) and 41% (18/43), respectively.
Conclusion
This hormonal treatment cannot be recommended as a general method for improving reproduction performance of dairy cattle. However, these data suggest that this hormonal protocol can be used to obtain satisfactory cyclic cow rates and less incidence of incorrect timing of insemination.
References
Ayad et al., 2007, Reprod. Dom. Anim. 42,
Lopez-Gatius et al., 2007,Theriogenology, 67,
Delahaut et al., 1979, Ann. Méd.Vét. 23:
Walker et al., 1996, J. Dairy Sci . 79:

3. AYAD1,*, M. IGUER-OUADA1, H. BENBAREK2 * E-mail: hanine06@gmail.com
Electrochemiluminescence immunoassay of the testosterone by using a heterologous system in plasma ovine: Preliminary study
AYAD1,*, M. IGUER-OUADA1, H. BENBAREK2
1Faculty of Life and Nature Sciences, University A. Mira, Bejaia, 06000, Algeria
2Faculty of Life and Nature Sciences, University M. Istambouli, Mascara, 29000, Algeria *
Introduction
Testosterone in males is a prerequisite for normal spermatogenesis (Goeritz et al., 2003), normal function of the reproductive tract and sexual behaviour (Luke and Coffey, 1994).
Many alternatives have been advocated and developed to replace the radioactive label in immunoassays because of concerns for radiation safety, short shelf-lives of radioactive reagents and radioactive waste disposal.
Some of the kits developed for humans could be used for cattle because progesterone is not species specific
Materials and Methods
The animals were divided into two groups namely: Group male-1 (n=4, aged 2-3 months) and Group male-2 (n=4, aged 9-36 months).
The experiment was conducted during the period of April 2012 in Bass Kabylie, Algeria (36°43’N, 5°04’W).
Blood samples from the jugular vein were collected between 09:30 and 11:00 a.m. Blood samples were collected in tubes EDTA-containing and centrifuged at 1500 rpm for 20 min.
Plasma was rapidly separated and stored at -20 °C until assayed.
Parameters of validation were taken into consideration in this study namely minimal limit of detection, reproducibility (coefficient of variation inter- and intra-assay), precision and parallelism.
Aim
The aim of the present study is the use of electrochemiluminescence immunoassay (ECL) method with the specific kit human testosterone (Elecsys 2010, Roche diagnostics) for measuring plasma testosterone in ovine.
Results
The estimated dose of testosterone measurement extends from to 15 ng/ml and the minimal detection limit was ng/ml.
The test of reproducibility inter- and intra-assay of the system electrochemiluminescence assay is satisfactory (5 and 7.3%, respectively). The accuracy (96-102%) and the test of parallelism were largely acceptable.
As for specificity test, no cross-reaction was observed with different hormones (PMSG, hCG, progesterone, oxytocin and PGF2α) following concentrations 10 UI/ml and 10-3 UI/ml.
Peripheral testosterone concentrations determined by ECL system in all male extends from to 4.5 ng/ml.
Conclusion
The preliminary results show clearly that human testosterone electrochemiluminescence kit can be used to measure testosterone in plasma ovine for the characterization of reproduction seasons, the evaluation of reproduction performance and possibly the diagnosis of some pathology in testicle.
References
Goeritz et al., Seasonal timing of sperm production in roe deer: interrelationship among changes in ejaculate parameters, morphology and function of testis and accessory glands. Theriogenology 59, 1487–1502.
Luke, M.C., Coffey, D.S., The male sex accessory tissues. Structure, androgen action and physiology. In: Knobil, E., Neill, D.S. (Eds.), The Physiology of Reproduction. Raven Press, New York, pp. 1435–1487.