Eleonora Munari

Boar spermatozoa encapsulated in barium alginate membranes: a microdensitometric evaluation of some enzymatic activities during storage at 18 °C

The customary dilution of boar semen for subsequent artificial insemination (AI) procedures damages the cell membrane of spermatozoa, resulting in a loss of enzymes and other cytoplasmic contents and acrosomal reactions. We encapsulated non-diluted boar semen in barium alginate membranes to optimize AI procedures and to improve the functional integrity of spermatozoal membranes during storage. The percentage of non-reacted acrosomes (NRA) and measurements of enzyme leakage (cytochrome c oxidase (COX), lactate dehydrogenase (LDH), and glucose-6-phosphate dehydrogenase (G6PDH)) were used as indices of the functional status of diluted, unencapsulated and encapsulated spermatozoa, stored for 72 h at 18 degrees C. Enzymatic activity was assessed in situ by microdensitometry, and non-reacted acrosomes were microscopically determined by staining. The percentage of acrosome integrity and the intracellular enzymatic activities during storage were different for unencapsulated and encapsulated semen. Semen dilution caused a rapid decline in enzymatic activities and concomitant acrosomal reactions. Encapsulated spermatozoa had significantly higher acrosome integrity (77% versus 55%; P < 0.01 after 72 h) and an overall higher in situ enzymatic activity. For cytochrome c oxidase and lactate dehydrogenase the greatest differences between encapsulated and unencapsulated spermatozoa were present after 72 h whereas for glucose-6-phosphate dehydrogenase significant differences were found within 24h of storage. The encapsulation process maintains a better preservation environment for boar spermatozoa and could be a promising, innovative technique to improve storage of these cells.

Alginate/Polymethacrylate Copolymer Microparticles for the Intestinal Delivery of Enzymes

Proteins administered orally must pass through the gastric environment in order to reach their site of absorption in the intestine. How to protect these exogenously administered proteins from the damaging effects of gastric acid and pepsin proteolytic activity, which often induce irreversible structural and functional alterations to the molecules, is an intriguing challenge. Another problem is the physical and chemical instability of proteins during some technological processes, which often involve the use of organic solvents or high temperatures. In this study we investigated the use of alginate microparticles containing one of two enzymes, an enteric polymer and a lyoprotectant for the intestinal delivery of proteins. The two enzymes tested in this protein delivery system were lactate dehydrogenase and alpha-amylase: the former was chosen because of its sensitivity to denaturation, the latter for its relevance in nutrition and medicine. A sodium alginate aqueous solution containing the enteric polymer, a lyoprotectant and the enzyme was either extruded or sprayed into a calcium chloride solution, with the resultant formation of beads and microspheres which were freeze-dried. About 90% of the enzyme activity was maintained during the process of loading the proteins into the microparticles and the subsequent freeze-drying process. The stability of the encapsulated enzyme in an acid medium and the enzymatic activity in an intestinal environment were then investigated by a dissolution test. This consisted of exposing the microparticles to simulated gastric fluid (pH 1.2) for 2 hours and to simulated intestinal fluid (pH 7.5+/-0.1) for 1 hour. The morphology of the microparticles did not change in the acid environment, whereas they completely dissolved within 3 min in the simulated intestinal fluid. Residual enzymatic activity after the test remained satisfactory for both enzymes. In conclusion, these microparticle systems offer promise for applications in human and veterinary medicine as well as in human and animal nutrition.

Competence of Swine Oocytes Matured by Three-dimensional Gonadotropin-free Co-culture

Munari, E., Asti, A., Colombani, C., Benzoni, E., Faustini, M., Torre, M.L., Riccardi, A., Villani, S., Sesso, L., Conte, U. and Vigo, D., 2007. Competence of swine oocytes matured by three-dimensional gonadotropin-free co-culture. Veterinary Research Communications, 31(Suppl. 1), 181–184

Body measures and milk production, milk fat globules granulometry and milk fatty acid content in Cabannina cattle breed

Aim of the study was to achieve scientific information about body measures and milk production of Cabannina cattle, a local breed reared in northern Italy. Fourteen body measures and five morphologic indexes were recorded from 86 heads enrolled in the herd book. Low differences between males and females of the same age-class were shown. Body measures were generally greater than those reported in previous studies, probably due to recent crosses. With reference to milk production, 991 test-day records from 128 lactations of 59 cows were analysed. Average milk daily production was 8 kg/d in 1st lactation to 10.61 in 3rd (P<0.05); the parameters of the Wood equation draw atypical curves with the exception of curves from spring calving cows. Only 74.5% of lactations with an adjusted R2>0.75 showed a standard curve, with low persistence (7.7%), high value of d at peak (103 d) and peak production of 20.18 kg of milk. Moreover, 100 milk samples (40 to 220 d of lactation) were submitted to a granulometric survey by laser scatter technique in order to evaluate the dimensions of fat globules; then milk fat was analyzed by gas chromatography, and desaturase indexes were determined. Cabannina cows showed small fat globules with high specific surface. Furthermore mean diameter of milk fat globules decreased during lactation then rose. Milk fat contained high levels of cis-MUFA, and high desaturase indexes. In conclusion, the low size of Cabannina cattle orients for a limited meat production. Instead milk production has a higher economic potential, aimed at cheese production and human nutrition.

Pig reactivity to backtest and growth during the first three months of life.

M. Faustini*, E. Munari, V. Russo, G. Pastorelli, G.L. Restelli, S. Scocca and D. Vigo Dipartimento di Scienze e T ecnologie Veterinarie per la Sicurezza Alimentare, Facoltà di Medicina Veterinaria. Università degli Studi di Milano *Correspondence: Dipartimento di Scienze e T ecnologie Veterinarie per la Sicurezza Alimentare, Facoltà di Medicina Veterinaria, Università degli Studi di Milano, V ia Celoria,10, 20133 Milano, Italy E-mail: massimo.faustini@unimi.it

Cabannina Cattle Breeding: An Agro-Ecological Challenge for Sustainable Rural Development in Northern Italy

Intensive farming is an agricultural production system characterized by widely adopting ex‐ ternal inputs such as capital, mechanization, infrastructures, pesticides and chemical fertil‐ izers intensively used which affects the natural environment and rural societies. Since it allows to produce more food on a given land extension, such agricultural choice has been the predominant response to population growth so far. While permitting to raise many ani‐ mals in limited areas, intensive animal farming practices require a large amount of food, wa‐ ter, medical treatments, capital intensive technology, energy, and fuel. Is being the selection of animals with rapid food conversion into milk and meat the aim of every industrial farm, a decline in, for example, the animal reproductive performances and in the product quality follows. Thus, nowadays problems in the dairy cattle scenario are easily highlighted. Just to name Friesian breed, its reproductive performances decreased worldwide with negative consequences on both cow robustness and longevity due to increased stress, udder health disturbances and locomotion disorders, which meant damages to the physiological parame‐ ters typical of healthy cows.