1,720,966 research outputs found
Utilizzazione digestiva di Dactylis glomerata L. allo stato verde e dopo conservazione mediante insilamento e fienagione.
No full textQuantitative and compositional variations of Massese sheep milk by parity and stage of lactation.
No full textAttività antiossidante e stato ossidativo delle diverse frazioni del latte ovino
No full textThe aim of the study was to define a protocol to evaluate sheep milk oxidation aspects, with special reference to its protein and hydrosolubile fraction, in order to assess such parameters in a simple and inexpensive way. Twenty milk samples from 10 Comisana ewes were fractioned and aliquoted in whole milk, skim milk, whey and deproinated whey and the antioxidant activity were evaluated. Results showed that proteins clearly acoount for most part of the antioxidant capacity and the TAC method displayed higher correlation between protein content and antioxidant capacity (r=0.89 and 0.68, respectively in skim milk and whey). Moreover, caseins had a major role in milk antioxidant barrier and such activity could not be attributed to their negligible content of available sulfhydryls. Lastly, a relevant antioxidant effect of vitamin C in the deproteinated fraction was observed.
Ricerca eseguita con finanziamento PRIN, anno 2005, protocollo n. 200507588
Effect of Udder Health Status and Lactation Phase on the Characteristics of Sardinian Ewe Milk
No full textMammary involution and inflammation are known to negatively affect milk quality. A trial was carried out to elucidate the mechanism by which udder health status and lactational phase determine compositional modifications in ovine milk. A total of 60 individual milk samples was collected from a group of 20 pluriparous Sardinian ewes from mid to late lactation. Each sample was assessed for its chemical characteristics, quantitative distribution of casein fractions, lactodynamographic characteristics, and enzymatic activity. Udders were classed as healthy, doubtful, or infected on the basis of repeated somatic cell counts, and samples were grouped in 3 classes of days in milk. Results indicated that both udder inflammation and mammary involution can increase plasmin (PL) activity (15.6 vs. 18.4 U/mL in healthy vs. infected udders; 14.0 vs. 20.2 U/mL in phase 1 vs. 3), which is responsible for an evident protein breakdown in milk. Significant differences between groups were observed for several characteristics. With regard to udder heath status, casein index was lower in the infected vs. healthy udders (74.8 vs. 76.6%), and βtot-casein showed a similar trend (43.9 vs. 46.6%). As a consequence of protein degradation, γ-casein (5.78 vs. 2.82%) and proteolysis index (7.60 vs. 3.82) increased in the infected group with respect to the healthy group. Udder health status also affected milk technological traits. Udder inflammation resulted in longer clotting time (20.7 vs. 16.5min for infected vs. healthy, respectively) and in poorer curd firmness (35.6 vs. 47.6mm for infected vs. healthy, respectively). Frequency of samples reactive to rennet was 100, 93, and 67%, respectively, for healthy, doubtful, and infected groups. With regard to lactational phase, a decrease in αs1-casein (39.13 vs. 29.36%) and β1-casein (23.41 vs. 19.36%) occurred during phase 1 vs. 3, whereas κ+αs2-casein increased (12.30 vs. 21.56%, phase 1 vs. 3). Correlation coefficients confirmed the role of PL in protein degradation. It was concluded that PL activity was strongly affected by both lactational phase and udder health status and, in turn, could be an important agent enhancing milk quality detriment
Effect of two non-structural carbohydrate sources on the metabolism and productive performance of lactating Comisana ewes
No full textIn the hilly areas of Central Italy, where the different farms are located, the use of hay and silage of forage crop, such as lucerne, is frequent. Although they represent an interesting nitrogen source for the high rumen degradability, they nevertheless require the addition of highly fermentable carbohydrate concentrates. For this purpose barley and maize, mostly produced on the farm, are the best source of energy. To verify the effect of these carbohydrate sources on the metabolic state and the productive performance of lactating Comisana ewes, an investigation was carried out on 10 secondiparous animals of single birth (2 groups of 5 each). They were fed two isoenergetic diets including both (on the DM) 61% 2nd cut lucerne hay, 3% lucerne silage, 4% f laked soybean and differing for the remaining 32%, represented respectively by flaked barley (FB diet) and ground ear maize (GEC diet). The apparent digestibility of the several nutritional parameters was determined, using the indirect method of the acid insoluble ash, according to a Latin square 2x2 experimental design, with 25-day periods including adaptation (15 d) and the experimental phase (10 d). On each animal the following parameters were determined: daily intake of dry matter and milk yield; metabolic profile; physico-chemical, technological and cellular characteristics of the milk at the 1st, 4th and 10th day of the trial. The animals fed the FB diet had a better digestive utilisation of all the nutritional parameters and, consequently, a better intake of DM (101.18 vs 93.17 g/ kg0.75). Regarding the metabolic-nutritional aspect, the two rations had no digestive repercussions, in fact the haematic levels of several of the parameters were in the range for normal metabolism, except those higher in urea in the animals fed the FB diet. The ewes of group FB produced more milk than those of the GEC group; this was annulled by normalizing this parameter to 6.5 % fat. The different concentrations of NDF and NSC of the two diets could have caused the differences in the milk fat content of the two experimental diets (6.55 vs 7.26 %)
Effect of the chromogenic substrate on the colorimetric determination of plasmin and plasminogen in milk
No full textPresentata come poster al 16th Congress ASPA - Torino, 28-30 giugno 200
An evaluation of some environmental factors, feeding requirements and parasitological examination of intensively farmed fallow deer (Dama dama)
No full text
Evaluating the antioxidant capacity in different fraction of sheep milk.
No full textThe aim of the study was to design a protocol to evaluate sheep milk oxidation traits, both in the water soluble and the lipid soluble fractions, in order to assess such parameters in a simple and inexpensive way. Milk was fractioned as whole milk (WM), skim milk (SM), whey (W)) and deproteinated whey (DW). The antioxidant activity (TAC and AOP), available sulphydryls (SH), ascorbic acid (AA) and cholesterol content were determined, and the degree of antioxidant protection (DAP) of cholesterol was calculated. It was shown that current analytical methods should not be directly applied to milk, due to turbidity and peculiar pH behaviour of caseins. Therefore, samples may need some preparative steps before analysis. Proteins were found to account for most part of milk antioxidant capacity, with caseins playing the major role in milk antioxidant barrier. Such activity could not be attributed to available sulfhydryls (i.e. cysteine residues), suggesting a relevant contribution of other amino acids. The TAC method could be successfully applied for an overall estimation of both water and lipid soluble antioxidant activity of milk. However, peculiar classes of antioxidants, that are present at low concentrations, such as SH groups and AA may need more specific analytical techniques.
Sheep milk (antioxidant capacity
- …
