PREGNANCY-ASSOCIATED GLYCOPROTEIN CONCENTRATIONS IN NON-PREGNANT COWS: A CASE STUDY

The aim of the present work was undertaken to describe three cases of the bPAG concentration measure by three RIA systems during the post-partum period in non-pregnantcow. Three Holstein-Friesian cows of mixed age and parity were diagnosed as non-pregnant. Blood samples were removed from the coccygeal vessel into EDTA-coated tubes. Samples were collected every 2 days during a stabling period of two months in the absence of males. Plasma was obtained by centrifugation immediately after collection and was stored at -20 C until assay. Plasmatic PAG concentration was measured by radioim-munoassay technique with some modifications. In RIA-780 and RIA-809, there were high peak of PAG concentration that reached 2.56 ng/ml and 0.89 ng/ml, respectively. These peaks lasted longer than 3 days (two successive samples were positive). The other RIA systems gave the values of PAG concentrations below cut-off of pregnancy diagnosis (> 0.8 ng/ml) and remains always non-pregnant. Our data shows clearly that there is another source of glycoproteins expression (e.g. ovarian) apart from the placenta in cow. The present study could be a field for future larger studies on the same subject by exploring deeply other extra structures placental

EFFECT OF MOBILIZATION OF BODY RESERVES ON OVARIAN REACTION OF COWS SUBJECT TO SUPEROVULATION TREATMENT

The aim of this work is to highlight the influence of variations of some energy balance indicators on the ovarian reaction to superovulation treatment. A three day superovulation protocol was implemented in five cows. Glycemia, BHB (β-hydroxybutyrate), NEFA (non-esterified fatty acids) and body condition score (BCS) were monitored before and during treatment. The ovarian reaction was assessed by estimating the number of corpora lutea. All biochemical parameters underwent variations at one time or another during the protocol. Maximum concentrations of 2.2 mmol/l, 1.01 g/l, 1.36 mmol/l were recorded respectively for BHB, glycemia and NEFA. Despite the lack of correlation between these parameters and the number of corpora lutea, the assays demonstrated a mobilization of body reserves in all the cows which caused a negative energy balance. Our results show that the parameters studied can support clinical data in the selection of embryo donor cows and serve as a discriminatory factor for those with a negative energy balance

Effect of exogenous circulating anti-bPL antibodies on bovine placental lactogen measurements in foetal samples

BACKGROUND: The involvement of placental lactogen (PL) in the regulation of foetal growth has been investigated in different species by in vivo immunomodulation techniques. However, when circulating antibodies are present together with the hormone, the procedure for hormonal measurement becomes considerably complex. The aim of this study was the immunoneutralization of bovine placental lactogen (bPL) concentrations in bovine foetal circulation by direct infusion of rabbit anti-bPL purified immunoglobulins (IgG) via a foetal catheter (in vivo study). The ability of a RIA based on guinea pig anti-bPL antiserum, for the measurement of bPL concentrations in samples containing exogenous rabbit anti-bPL immunoglobulins, was also analyzed in in vitro and in vivo conditions. METHODS: Six bovine foetuses were chronic cannulated on the aorta via the medial tarsal artery. Infusion of rabbit anti-bPL IgG was performed during late gestation. Pooled rabbit anti-bPL antisera had a maximal neutralization capacity of 25 microg bPL/mL of immunoglobulin. Interference of rabbit anti-bPL immunoglobulin with radioimmunoassay measurement using guinea pig anti-bPL as primary antibody was first evaluated in vitro. Polyclonal anti-bPL antibodies raised in rabbit were added in foetal sera to produce 100 samples with known antibodies titers (dilutions ranging from 1:2,500 till 1:1,280,000). RESULT(S): Assessment of the interference of rabbit anti-bPL antibody showed that bPL concentrations were significantly lower (P < 0.05) in samples added with dilutions of rabbit antiserum lower than 1:80,000 (one foetus) or 1:10,000 (four foetuses). It was also shown that the recovery of added bPL (12 ng/mL) was markedly reduced in those samples in which exogenous rabbit anti-bPL were added at dilutions lower than 1:20,000. Concentrations of foetal bPL were determined in samples from cannulated foetuses. In foetuses 1 and 6, bPL concentrations remained almost unchanged (<5 ng/mL) during the whole experimental period. In Foetus 3, bPL concentrations decreased immediately after IgG infusion and thereafter, they increased until parturition. CONCLUSION(S): The use of a bPL RIA using a guinea pig anti-bPL as primary antiserum allowed for the measurement of bPL concentrations in foetal plasma in presence of rabbit anti-bPL IgG into the foetal circulation. Long-term foetal catheterization allowed for the study of the influence of direct infusion of anti-bPL IgG on peripheral bPL concentrations in bovine foetuses

Septic arthritis in calves

Septic arthritis is the most frequently diagnosed orthopedic pathology in calves; it is difficult to treat and causes irreversible lesions. With a correct diagnosis it is possible to provide farmers with the right therapy, medical or more often surgical, according to the single case needs