Abstract - Thermal treatments are used to improve milk microbial safety, shelf life, and biological activity of some its components. However, thermal treatments can reduce the nutritional quality of milk, affecting the molecular structure of milk proteins, such as lysozyme, which is a very important milk component due to its antimicrobial effect against gram-positive bacteria. Jenny milk is characterized by high lysozyme content. For this reason, in the last few years, it has been used as an antimicrobial additive in dairy products in alternative to hen egg white lysozyme which can cause allergic reactions. This study aims to investigate the effect of pasteurization and condensation on the concentration and antimicrobial activity of lysozyme in jenny milk. Furthermore, lysozyme quantity and activity were tested in raw and pasteurized milk after condensation at 40 and 20% of the initial volume. Reversed-phase HPLC was performed under fluorescence detection to monitor lysozyme in milk samples. The antimicrobial activity of the tested milk was evaluated against Bacillus megaterium, Bacillus mojavensis, Clavibacter michiganensis, Clostridium tyrobutyricum, Xanthomonas campestris, and Escherichia coli. Condensation and pasteurization did not affect the concentration or antimicrobial activity of lysozyme in jenny milk, except for B. mojaventis, which showed resistance to lysozyme in milk samples subjected to heat treatments. Moreover, lysozyme in jenny milk showed antimicrobial activity similar to synthetic antibiotics versus some gram-positive strains and also versus the gram-negative strain X. campestris.

Key words: condensation, pasteurization, lysozyme, antimicrobial activity, jenny milk.

Cosentino C., Labella C., Elshafie H. S., Camele I., Musto M., Paolino R., D'Adamo C., Freschi P. 2016.  Effects of different heat treatments on lysozyme quantity and antimicrobial activity of jenny milk. Journal of Dairy Science, 99:5173-5179.http://www.journalofdairyscience.org/article/S0022-0302(16)30223-5/abstract

Valentini V., Cosentino C., Galgano F., Freschi P., Condelli N., Musto M., Paolino R., Pecora G., D'Adamo C. (2015). Primi risultati sullo sviluppo di prodotti caseari innovativi: accettabilita' del consumatore. Scienza e Tecnica Lattiero-casearia. 66(1-2):59-64.

P. Freschi, S. Fascetti, M. Musto, C. Cosentino, R. Paolino, V. Valentini. (2016). Seasonal variation in food habits of the Italian hare in a south Apennine semi-natural landscape. Ethology Ecology & Evolution (UK-Taylor&Francis). 28(2):148–162, http://dx.doi.org/10.1080/03949370.2015.1022906.

Use of technical and economical parameters for evaluating dairy cow ration efficiency

INNOVAZIONE DI PRODOTTO E DI PROCESSO NELLA FILIERA LATTE

Progetto MIBAF - MISURA 124 PIF - Resp. sc. Carlo COSENTINO

The aim of this study was the development of a model for evaluating dairy cow ration efficiency. This model took into account technical, metabolic, and economic parameters, which were divided into two main categories: input and output. Feeding (food administered and its nutritional characteristics) was considered as the input parameter. The output indicators were directly or indirectly correlated with feeding, and included: Quality and Quantity of milk, Body Condition Score, Live Weight, Reproductive Parameters, Incidence of animal diseases (laminitis), Undigested Fraction, Fecal Consistency, Feed Efficiency (FE), and Income Over Feed Cost (IOFC). The model was validated using ten dairy farms located in the northwest of Basilicata. The farms were divided into two groups (A and B) as a function of the urea level in bulk milk. In Group A, the urea level was between 25 and 31 mg/100 ml milk, whereas, in Group B, the range was 21-22.5 mg/100 ml milk. The model showed that the values of reproductive parameters were worse in Group A than in Group B. However, the Group A showed better milk qualitative and quantitative characteristics, such as a high average production per head (28.15 vs 26.93 kg), and a high fat (3.92 vs 3.71%) and protein (3.53 vs 3.37%) content of bulk milk. Moreover, the highest values of FE (1.45 vs 1.35 kg milk/kg DM) and IOFC (6.07 vs 5.32 €) were found in Group A. The model clearly showed that the administration of unbalanced rations, based on the physiological stage of the animals, negatively affected both the qualitative and quantitative characteristics of milk, as well as the reproductive performances. The administration of unbalanced rations for the energy/protein content caused dysmetabolic syndromes, which led to a reduction of both FE and IOFC. This, ultimately, caused a fall in the overall farm profitability.

Key words: fecal consistency, feed efficiency, milk margin, undigested fraction, urea.

F. Adduci, C. Labella, M. Musto, C. D'Adamo, P. Freschi and C. Cosentino (2015). Use of technical and economical parameters for evaluating dairy cow ration efficiency. Italian Journal of Agronomy, 10:682; pp 201-207. DOI: 10.4081/ija.2015.682