Diagnosis and therapy of retained fetal membranes, puerperal metritis and clinical endometritis in cattle: Results of the Online-survey among Swiss practitioners. II. Puerperal metritis and clinical endometritis

The aim of the study was to obtain the diagnostic and therapeutic approach among Swiss practitioners in cows with puerperal metritis and clinical endometritis (part 2). All members of the Association for ruminant health were contacted per email via the newsletter. The survey was completed by 128 veterinarians, partially responded by 140 veterinarians. The following main symptoms of puerperal metritis were stated by the practitioners: purulent vaginal discharge, fever and reduced appetite. A vaginal and rectal examination was performed to diagnose the disease. Usually, an intrauterine treatment with tetracycline or cefapirin was done. Parenteral administration of tetracycline or penicillin was often combined with PGF(2α), NSAIDS or cortisone. Clinical endometritis was also diagnosed by vaginal and rectal examination and the main symptom indicated was purulent vaginal discharge. The therapy consisted of the administration of PGF(2α), uterine infusions predominantly with cefapirin, and rarely with parenteral administration of antibiotics. Further diagnostic tools were not used and normally cows were not rechecked. The success of the therapy of puerperal metritis and clinical endometritis was judged to be satisfactory to excellent.

Diagnosis and therapy of retained fetal membranes, puerperal metritis and clinical endometritis in cattle: Results of the Online-survey among Swiss practitioners. I Retained fetal membranes

The aim of this study was to obtain the diagnostic and therapeutic approach among Swiss practitioners in cows with retained fetal membranes (RFM) (part 1). All members of the Association for ruminant health were contacted per email via the newsletter. The survey was completed by 128 veterinarians, partially responded by 140 veterinarians. The manual removal of the fetal membranes is practiced by 129 of the responding veterinarians. Cows with/without fever are treated usually with intrauterine antibiotics. Cows with RFM with/without fever are most commonly treated parenterally with tetracycline or penicillin. The use of cephalosporins and quinolones in cows with fever is more common than in cows without fever. With the present results of the survey veterinarians should critically question the supposed benefits of the manual removal of the placenta and the use of antibiotics in cows with RFM.

Delivery of the p67 sporozoite antigen of Theileria parva by using recombinant Salmonella dublin: secretion of the product enhances specific antibody responses in cattle

The p67 sporozoite antigen of Theileria parva has been fused to the C-terminal secretion signal of Escherichia coli hemolysin and expressed in secreted form by attenuated Salmonella dublin aroA strain SL5631. The recombinant p67 antigen was detected in the supernatant of transformed bacterial cultures. Immunization trials in cattle revealed that SL5631 secreting the antigen provoked a 10-fold-higher antibody response to p67 than recombinant SL5631 expressing but not secreting p67. Immunized calves were challenged with a 80% lethal dose of T. parva sporozoites and monitored for the development of infection. Two of three calves immunized intramuscularly with the p67-secreting SL5631 strain were found to be protected, whereas only one of three animals immunized with the nonsecreting p67-expressing SL5631 strain was protected. This is the first demonstration that complete eukaryotic antigens fused to the C-terminal portion of E. coli hemolysin can be exported from attenuated Salmonella strains and that such exported antigens can protect cattle against subsequent parasite challenge.

The Cell Agglutination Agent, Phytohemagglutinin-L, Improves the Efficiency of Somatic Nuclear Transfer Cloning in Cattle (Bos taurus)

One of the several factors that contribute to the low efficiency of mammalian somatic cloning is poor fusion between the small somatic donor cell and the large recipient oocyte. This study was designed to test phytohemagglutinin (PHA) agglutination activity on fusion rate, and subsequent developmental potential of cloned bovine embryos. The toxicity of PHA was established by examining its effects on the development of parthenogenetic bovine oocytes treated with different doses (Experiment 1), and for different durations (Experiment 2). The effective dose and duration of PHA treatment (150 microg/mL, 20 min incubation) was selected and used to compare membrane fusion efficiency and embryo development following somatic cell nuclear transfer (Experiment 3). Cloning with somatic donor fibroblasts versus cumulus cells was also compared, both with and without PHA treatment (150 microg/mL, 20 min). Fusion rate of nuclear donor fibroblasts, after phytohemagglutinin treatment, was increased from 33 to 61% (P < 0.05), and from 59 to 88% (P < 0.05) with cumulus cell nuclear donors. The nuclear transfer (NT) efficiency per oocyte used was improved following PHA treatment, for both fibroblast (13% versus 22%) as well as cumulus cells (17% versus 34%; P < 0.05). The cloned embryos, both with and without PHA treatment, were subjected to vitrification and embryo transfer testing, and resulted in similar survival (approximately 90% hatching) and pregnancy rates (17-25%). Three calves were born following vitrification and embryo transfer of these embryos; two from the PHA-treated group, and one from non-PHA control group. We concluded that PHA treatment significantly improved the fusion efficiency of somatic NT in cattle, and therefore, increased the development of cloned blastocysts. Furthermore, within a determined range of dose and duration, PHA had no detrimental effect on embryo survival post-vitrification, nor on pregnancy or calving rates following embryo transfer.

Differential Cytoplast Requirement for Embryonic and Somatic Cell Nuclear Transfer in Cattle

Effective activation of a recipient oocyte and its compatibility with the nuclear donor are critical to the successful nuclear reprogramming during nuclear transfer. We designed a series of experiments using various activation methods to determine the optimum activation efficiency of bovine oocytes. We then performed nuclear transfer (NT) of embryonic and somatic cells into cytoplasts presumably at G1/S phase (with prior activation) or at metaphase II (MII, without prior activation). Oocytes at 24 hr of maturation in vitro were activated with various combinations of calcium ionophore A23187 (A187) (5 microM, 5 min), electric pulse (EP), ethanol (7%, 7 min), cycloheximide (CHX) (10 micro g/ml, 6 hr), and then cultured in cytochalasin D (CD) for a total of 18 hr. Through a series of experiments (Exp. 1-4), an improved activation protocol (A187/EP/CHX/CD) was identified and used for comparison of NT efficiency of embryonic versus somatic donor cells (Exp. 5). When embryonic cells from morula and blastocysts (BL) were used as nuclear donors, a significantly higher rate of blastocyst development from cloned embryos was obtained with G1/S phase cytoplasts than with MII-phase cytoplasts (36 vs. 11%, P < 0.05). In contrast, when skin fibroblasts were used as donor cells, the use of an MII cytoplast (vs. G1/S phase) was imperative for blastocyst development (30 vs. 6%, P < 0.05). Differential staining showed that parthenogenetic, embryonic, and somatic cloned BL contained 26, 29, and 33% presumptive inner cell mass (ICM) cells, respectively, which is similar to that of frozen-thawed in vivo embryos at a comparable developmental stage (23%). These data indicate that embryonic and somatic nuclei require different recipient cytoplast environment for remodeling/ reprogramming, and this is likely due to the different cell cycle stage and profiles of molecular differentiation of the transferred donor nuclei.

Octamer-based genome scanning distinguishes a unique subpopulation of Escherichia coli O157:H7 strains in cattle

Multilocus-genotyping methods have shown that Escherichia coli O157:H7 is a geographically disseminated clone. However, high-resolution methods such as pulse-field gel electrophoresis demonstrate significant genomic diversity among different isolates. To assess the genetic relationship of human and bovine isolates of E. coli O157:H7 in detail, we have developed an octamer-based genome-scanning methodology, which compares the distance between over-represented, strand-biased octamers that occur in the genome. Comparison of octamer-based genome-scanning products derived from >1 megabase of the genome demonstrated the existence of two distinct lineages of E. coli O157:H7 that are disseminated within the United States. Human and bovine isolates are nonrandomly distributed among the lineages, suggesting that one of these lineages may be less virulent for humans or may not be efficiently transmitted to humans from bovine sources. Restriction fragment length polymorphism analysis with lambdoid phage genomes indicates that phage-mediated events are associated with divergence of the lineages, thereby providing one explanation for the degree of diversity that is observed among E. coli O157:H7 by other molecular-fingerprinting methods.

Double muscling in cattle due to mutations in the myostatin gene

Myostatin (GDF-8) is a member of the transforming growth factor β superfamily of secreted growth and differentiation factors that is essential for proper regulation of skeletal muscle mass in mice. Here we report the myostatin sequences of nine other vertebrate species and the identification of mutations in the coding sequence of bovine myostatin in two breeds of double-muscled cattle, Belgian Blue and Piedmontese, which are known to have an increase in muscle mass relative to conventional cattle. The Belgian Blue myostatin sequence contains an 11-nucleotide deletion in the third exon which causes a frameshift that eliminates virtually all of the mature, active region of the molecule. The Piedmontese myostatin sequence contains a missense mutation in exon 3, resulting in a substitution of tyrosine for an invariant cysteine in the mature region of the protein. The similarity in phenotypes of double-muscled cattle and myostatin null mice suggests that myostatin performs the same biological function in these two species and is a potentially useful target for genetic manipulation in other farm animals.

Livestock health encyclopedia; the control of diseases and parasites in cattle, sheep and goats, swine, horses and mules. /

Bibliography: p. 605-613.

Economic factors in cattle feeding.

Cover title.

Serological diagnosis of brucella in cattle,

Translated from Revista de Zootehnie si Medicina Veterinara, Rumanian, no. 10, 1967 pp. 36-51.