Determination of the proper time for mating after oestrous synchronisation during anoestrous or oestrous by measuring electrical resistance of cervical mucus in ewes

The purpose of the present study was to investigate whether the electrical resistance values of the cervical mucus and/or blood estradiol-17 beta and progesterone concentrations at mating, after oestrous synchronisation during the anoestrous or oestrous period in ewes, are related to fertility. Oestrus was induced by medroxyprogesterone acetate-impregnated intravaginal sponges (Veramix, Upjohn, USA), either for 12 days (12-day group; 24 Kymi and 28 Chios) or for 14 days (14-day group; 24 Kymi and 28 Chios), plus 400 IU equine chorionic gonadotropin (Intergonan, Intervet, the Netherlands) i.m., at the time of sponge removal. In each case, one blood sample was collected from all ewes at sponge insertion, at sponge removal and at oestrus, for the determination of serum estradiol-17 beta and progesterone concentrations, using a radioimmunoassay. The electrical resistance of the cervical mucus was measured once, just after oestrus detection by teaser rams, using a digital heat detector. All ewes found to be in oestrus were mated to fertile rams. Pregnancy was determined by transabdominal ultrasonography 35-40 days after mating. Kymi ewes were in anoestrous, while those of Chios were in the oestrous period. The 14-day treatment resulted in better outcome as concerns oestrus detection and pregnancy rate than the 12-day treatment, in either oestrous or anoestrous period ewes. Oestradiol-17 beta concentrations at sponge removal and at oestrus were lower (P < 0.05) in the 14-day group than in the 12-day group, in both oestrous or anoestrous period ewes. Progesterone concentrations at sponge insertion and removal were higher (P < 0.05), while progesterone concentrations and electrical resistance values of the cervical mucus at oestrus were lower (P < 0.05) in ewes of both groups who conceived compared to those that did not, either in oestrous or in the anoestrous period. Linear regression analysis revealed a positive relation between the electrical resistance values of the cervical mucus and blood serum progesterone concentrations in both oestrous or anoestrous period ewes. The electrical resistance of cervical mucus could be useful for the detection of the proper time for mating after oestrous synchronisation in ewes

Milk composition disturbance and animal organism dysfunction caused by aflatoxins: A review

Aflatoxins constitute toxic metabolites of the fungi Aspergillus flavus and Aspergillus parasiticus and are considered to be the mycotoxins, first detected and researched by the scientists. Aflatoxin consumption by animals or humans could lead to their organism function disorders, mainly depending on the duration of consumption and the quantity of the toxin. Such disorders, caused by aflatoxins and/or by other mycotoxins as well, could seriously affect animal production, the quality of the foods of animal origin and also the farmers' income. After aflatoxin B1 is consumed by lactating animals, it is metabolised to aflatoxin M1, which is excreted into the milk. As a consequence of aflatoxin influence on the general condition of animals, together with the excretion into the milk, the effects on milk quality, including changes in some milk components concentrations could be considered as possible. Unfortunately, the presentliterature regarding this suggestion is inadequate. The reports regarding aflatoxin effects on the general condition of animals are mainly related with basic parameters, whose changes could influence animal production. Such parameters are the body weight and the biochemical parameters of liver and kidneys. Reduction of body weight, decreased food consumption, increased concentrations of aspartate aminotransferase and probably of alanine aminotransferase, and extensive liver damage are reported by most authors. As for the milk fat content some researchers did not reveal any aflatoxin effects on fat values, while others report a significant reduction of milk fatty acids. These results were attributed to the inhibition or the decreased production of some enzymes, appropriate for fatty acids synthesis, such as synthetase. Regarding the milk protein content, no aflatoxin effects on it are reported. Most researchers make reason for a slight increase of total protein blood levels after aflatoxin consumption, as well as, for RNA polymerase suspended action, resulting in the inhibition of a lot of metabolic reactions, such as protein synthesis. Moreover, no significant changes were recorded concerning either the milk lactose content or the glucose blood concentration, after aflatoxin consumption. The likelihood of the possible aflatoxin effects on udder health, resulting in mastitis, or on somatic cell count and total microbial count changes cannot be supported by the up-today existing data. Additionally, these parameters could be affected by a variety of factors, requiring, for this reason, extensive research. © 2013 Nova Science Publishers, Inc. All rights reserved

Association of soybean-based extenders with field fertility of stored ram (Ovis aries) semen: A randomized double-blind parallel group design

Two consecutive randomized double-blind field fertility experiments were conducted over a 4-month period and aimed at evaluating the association of two commercial soybean lecithin-based extenders (AndroMed [Minitub, Tiefenbach, Germany] and BioXcell [IMV Technologies, L'Aigle, France]) with pregnancy rates of chilled-stored (CS) and frozen-thawed (FT) ram semen. Semen samples with more than 2 x 10(9) sperm per mL and 70% progressive motile spermatozoa were collected via an artificial vagina from twelve proven fertile Chios rams, split-diluted with the above mentioned extenders, packaged in 0.25 mL straws and either stored at 5 +/- 1 degrees C for 30 to 36 hours or frozen and thawed. Non-lactating multiparous ewes were inseminated in progestagen-synchronized estrus either with CS (AndroMed: N = 212 and BioXcell: N = 206; intracervical AI) or with FT (AndroMed: N = 114 and BioXcell: N = 92; laparoscopic intrauterine AI) semen. Ovulation was confirmed in all ewes based on determination of blood plasma progesterone (>1 ng/mL) 8 days post AI. Ewes were screened for pregnancy diagnosis by transabdominal ultrasonography 65 days post AI. BioXcell was superior to AndroMed in preserving the fertilizing potential of CS (P 0.05). Ram-by-extender interactions were significant for pregnancy rates of CS and FT semen. Irrespective of extenders, overall pregnancy rates after intracervical and intrauterine AI were 75.1% and 62.2%, respectively (P < 0.001). In conclusion, BioXcell is a suitable extender for short- and long-term storage of ram semen. Selection of the ewes, farms, and extenders for intracervical AI programs can contribute to satisfactory fertility rates with semen preserved more than 24 hours at 5 degrees C. (c) 2013 Elsevier Inc. All rights reserved

The application of in vitro fertilization techniques for the evaluation of ram fertility

The prediction of field fertility of a given ram by using in vitro tests would be of great importance for the reproductive management in sheep flocks. There are many in vitro procedures available for evaluating semen quality and fertilizing ability, and the method chosen depends on the objective of evaluating the sperm and the available resources. The in vitro evaluation of semen fertilizing ability was firstly developed for the artificial insemination (AI) purposes and secondly for the application of in vitro fertilization (IVF) technique. The IVF techniques allow the assessment of fertility in terms of ability to penetrate and fertilize in vitro mature oocytes and ultimately to yield component embryos following IVF and culture. In this review are briefly presented in vitro studies performed in an attempt to establish an accurate laboratory test for the evaluation and, even more, the prediction of field fertility in sheep

Influence of the injection site on the pharmacokinetics of amoxicillin after intramuscular administration of a conventional and a long-acting formulation in sheep

The pharmacokinetics of amoxicillin (AMX) were investigated in sheep following intravenous (i.v.) and intramuscular (i.m) injection, comparing two different drug formulations, a conventional and a long-acting AMX-trihydrate suspension. For the i.m. application two different injections sites, the neck area and the hind limb were used to identify possible differences in the kinetic parameters related to the site of injection. A three-compartment open model could best describe AMX disposition after i.v. administration. Data analysis after i.m. administration of the conventional suspension at both injection sites revealed the occurrence of a flip-flop phenomenon, clearly indicating that absorption of AMX is the rate-limiting step of its overall disposition. A moderate effect of the injection site was observed with a tendency for the neck area to be advantageous, mainly in terms of rate rather than extent of absorption. Injection of the long-acting formulation led to a focal depot formation, thus yielding lower but remarkably prolonged serum AMX levels reflected in the respective terminal half-lives. The concentration-time profile of AMX after administration of the long-acting formulation was less affected by the injection site, but the low serum levels justify its use only in cases in which a high susceptibility of the involved bacterial population is confirmed