Anales de la Facultad de Veterinaria de León

List of doctoral theses read during the 1994-1995 and 1995-1996 academic years

Anales de la Facultad de Veterinaria — 1996-01-01

Milk sialoglycoconjugates

S. Martín-Sosa — 1996-01-02

Changes in the sialoglycoconjugate content of cow, goat and ewe milks during the different stages of lactation were studied. Total and ganglioside sialic acid contents were high in the colostrum and decreased thereafter until the end of the period analysed in the three ruminants considered. Goat milk shows a total sialic acid content higher than cow and ewe milks, whereas cow milk contained approximately 10 times more ganglioside sialic acids than goat and ewe milks. Regarding N-glycolylneuraminic acid content, ewe and goat milks have percentages (in the total sialic acid content) of 60-80% and 30-60% respectively, whereas cow milk has 6-30%. The distribution of the different sialoglycoconjugates has also been determined in cow milk pointing out a content of oligosaccharide-bound sialic acid higher in colostrum than in mature milk.

Study about the in-vitro disinfectant activity of N-Duopropenide on Actinobacillus pleuropneumoniae

Elías Fernando Rodríguez Ferri — 1996-01-02

The efficacy of N-duopropenide, a new generation disinfectant composed of a mixture of quaternary ammonium iodides, against Actinobacillus pleuropneumoniae serotype 1 was studied. The organisms were suspended in both saline and bovine serum and tested in vitro in suspension and carrier tests. A total of six concentrations (0.05%, 0.1%, 0.5%, 1%, 2.5% and 5%) and six contact times for each (15", 30", l', 3', 5' and 10') were studied. The disinfectant was more effective in the suspension test than in the carrier test, and when organisms were suspended in saline than in organic matter. Even in the most disadvantage conditions (carrier test with bovine serum) such a short contact time as 15 seconds was already highly effective for inactivating A. pleuropneumoniae.

Effect of pregnancy on ovine haematlogy

Juan Rejas López — 1996-01-02

Haematological variations on ovine gestation and the beginning of lactation has been studied. During the first two months of pregnancy, there was an increase in red blood count (RBC), packed cell volume (PCV) and haemoglobin concentration. Later, these values fell until parturition. RBC and PCV rose few hours after parturition and at the beginning of lactation.

Increasing meat production potential of beef cattle through manipulation of hormonal status regulating growth

Pedro José Álvarez Nogal — 1996-01-02

Several methods of growth promotion in beef cattle are reviewed. They are a way of increasing meat production potential based on both rising of daily weight gain and a better carcass performance; at the same time they induce a metabolic shift towards more muscle and less fat deposition. Different techniques have been applied in order to get these goals, the most relevant ones being the administration of anabolic agents, the immunomodulation procedures and the gene transfer technique, whose mechanisms of action are exposed as well as their legal position at the European Union.

Effectiveness of sodium chloride as inhibitory agent for Bacillus stearothermophilus

Ana Bernardo Álvarez — 1996-01-02

The effects of different salt concentrations in the recovery medium on the unheated and heated Bacillus stearothermophilus spores (ATCC 12980, 7953, 15951 and 15952) were investigated. Uninjured spores of strain 7953 did not form colonies after addition of salt at concentration of 3%, whereas the other strains were able to growth up to a level of 6%. Sodium chloride had a marked effect on the recovery of injured spores. Concentrations as low as 0.5% caused a reduction in the recovery efficiency. In all cases, increasing the salt levels resulted in a progressive reduction of recovery rates, although the minimum inhibitory concentration varied among the strains, from 2% for 7953 and 15952 strains, 3% for 15951 strain and 4% for 12980 strain. D-values gradually decreased as the salt content in the medium increased resulting in a reduction of 50% when survivors were recovered in the presence of 2% of salt. No statistical significance (p>0.05) differences were detected among calculated z-values for all strains in all assayed conditions. z-Values ranged from 7.35 to 8.08, with a mean value of 7.81+_0.23.

Animal production and DNA technology

José María Castro González — 1996-01-02

Current limits for the possible role of biotechnology in animal production seem to be advancing further than what is ethically acceptable. In all areas of animal production, modern molecular genetics techniques find application. This review is an overview of the potential of modern biotechnology in animal production with special focus in sheep and goat production traits and animal health.

Ovine as1 and k-casein haplotypes in the churra and manchega breeds

P. Masina — 1996-01-02

By using the RFLP (restriction fragment length polymorphisms) technique and five endonucleases, the ovine asi and k-casein haplotypes in forty-nine Spanish dairy sheep, 26 Churra and 23 Manchega, were analyzed. Four and five haplotypes were detected in the asi and k-caseins, respectively. The A+and D+ haplotypes were only found in Manchega. PIC (polymorphic information content) values were situated about 0.5 and 0.6 in Churra and Manchega, respectively.

Research related to aquaculture at the University of León

Andrés Sierra — 1996-01-02

A general overview of European aquaculture, which includes a list of animal species, culture purposes, state of culture methods and geographic location, is reported. Afterwards, the world and European output production is given followed by data from Spain, Castille-León and the province of León, where the research activities developed at the University and compiled in this paper are established. This compilation is organized by zoological groups, species and subject matter. Also, the list of papers arranged by alphabetic senior surname and publication date is provided.