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ABSTRACT:The effect of the stage of lactation on blood redox homeostasis of bovine and buffalo cows was evaluated. The investigation was carried out on early lactating and mid-late lactating cows, reared in a farm located in Campania (southern Italy). Plasma concentration of α-tocopherol and ascorbate, the total antioxidant capacity (TAC), glutathione peroxidase (GPx), and superoxide dismutase activities were higher (P < 0.01) in mid-late lactating cows, thus suggesting a higher consumption of antioxidants during early lactation. Plasma concentration of protein-bound carbonyls (PC) and nitrotyrosine (N-Tyr), and the level of lipid hydroperoxides (LPO) were higher (P < 0.01) in early lactating cows, thus suggesting that lipid peroxidation and peroxynitrite production are crucial in determining oxidative modifications in plasma. TAC was positively correlated with ascorbate concentration (P < 0.03), and negatively correlated with PC concentration (P < 0.002), and ascorbate was negatively correlated with PC (P < 0.03) in mid-late lactating group. These findings demonstrate that circulating ascorbate plays a major role in preventing protein modifications induced by carbonyls, and that ascorbate scavenging effect is impaired during early lactation. We calculated a protein oxidative stress index as the ratio (PC + N-Tyr)/TAC multiplied by 100, and we found that this parameter was higher (P < 0.0001) in early lactating cows. Therefore, it could be useful for assessing the extent of protein oxidative damage in relation to the whole antioxidant status. Further, we suggest that the LPO/GPx ratio multiplied by 100 might be used as lipid oxidative stress index in lactating cows. This index was higher (P < 0.0001) in early lactating cows, and might represent a standard parameter for evaluating the lipid damage depending on a deficiency of the enzymatic antioxidant defence. These parameters are proposed for a possible effective description of physiological changes associated with lactation.

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The present study was conducted on milk samples from 30 Italian Mediterranean buffaloes, and as many goats, sheep and cattle. Milk samples were subjected to chemical-nutritional analysis and compared with commercially available milk samples. In the experiments, the management conditions could have influenced this parameter, determining the observed values. The higher fat content in sheep's milk differed significantly from that in the milk of the other animals analyzed. A higher lactose content was found in the milk of buffaloes and sheep, than in cows and goats. The highest cholesterol content was observed in cow and buffalo milk. These differences were statistically significant. To avoid excessive cholesterol intake, it is necessary to pay attention to both the quantity and quality of fats contained in food, bearing in mind that the introduction of large quantities of dairy products in the diet can cause a significant intake in cholesterol levels. Furthermore, when selecting the type of milk to be consumed, it is necessary to consider that the amount of total cholesterol is dependent on both the animal of origin and on the integrity of the lipid fraction. To complete the study, a chemical-nutritional analysis of milk samples normally marketed, both of vegetable and animal origin, was also included. Observing the results, some differences appear evident in the chemical-nutritional composition of goat and cow milk compared to the raw milk analyzed. In particular, goat's milk has a higher percentage of lipids. However, the differences observed herein were not significant and could be explained by the manufacturing process the samples were subjected to from the stable to the packaging industry. From the results obtained in the present study in the compositional analyses performed, and as also obtained from previous studies, it was found that sheep and goat milk, in particular, may be a valid substitute for cow's milk.

A total of 5852 records concerning daily milk yield, content of protein and fat, and somatic cell count was recorded in two farms (organic and conventional). Somatic cell count was log10- transformed before analysis because was not normally distributed. The mixed model methodology was used according to a repeated-measures scheme, as the restricted maximum likelihood method to estimate lactation curves at different season of calving and at different calving order. Calving order affected milk yield only in the first three calving order with the lowest production levels in the first six months of the year for both farm; no effect could be observed on fat and protein contents. The organic farm shows the minor milk production (7.77 vs8.10 kg/day/head organic and traditional respectively), but good qualitative characteristics of milk, and minor content of Somatic Cell Count. The milk production is major, in traditional farm, in summer respect the winter (10.4 vs6.34 kgof milk/day/ head). In biological farm no difference between seasons were observed. Peak milk yield occurs, for both farms, at around the 6^th - 7^th wk of lactation.  

The aim of this study was to verify the effects of environmental impact caused by dioxin on milk production and metabolic profile in the buffalo cows. The authors analyzed some representative blood parameters related to their different metabolisms, the amount of zinc in blood samples, and milk production parameters, on 160 buffalo cows raised in four farms located in areas with a different environmental impact. Urea, glucose, creatinine, AST (aspartate aminotransferase), ALT (alanine aminotransferase) and zinc contents were determined on serum samples. Milk samples from each buffalo were collected. Daily milk yield and milk composition were significantly different among farms. No difference in milk protein content was found.Urea content, was higher. Glucose concentrations were significantly lower than in farms located in an area contaminated by dioxin. Creatinine values were normal. AST and ALT values were slightly higher than normal. So far, there are not studies on the effect of dioxin on production and metabolic profile in buffalo cows. This study indicates that buffalo breeding herds exposed to dioxins would induce damage in the hepatic parenchyma cells as a result of animal welfare. Accordingly, the effects of environmental pollutants may expose the animals to several infections and diseases, which could affect not only the production traits, but also the qualitative features of their products devoted to human consumption.