Relationships Between Somatic Cell Count and Intramammary Infection in Buffaloes

The objectives of this study were to evaluate the presence of intramammary infections (IMI) in dairy buffaloes and to examine the relationships among IMI, somatic cell counts (SCC), and milk production traits. Two farms in northern Italy were visited monthly for a complete milking season. Quarter-based milk samples were collected at each visit from 46 buffaloes. A total of 1,912 samples were assessed in this experiment. Samples were cultured for bacterial presence and were tested for SCC and percentages of milk protein and fat. In addition, daily milk yield was recorded from each buffalo. Prevalence of IMI was large; 63% of quarters were infected. No buffalo remained free from IMI throughout the course of the study. Coagulase-negative staphylococci were the most common pathogen (66% of positive samples). The SCC was distinctly greater in infected quarters; 100% of quarters with SCC >200,000 cell/mL had IMI, whereas 98% of quarters with SCC below this threshold were uninfected. The somatic cell scores (SCS) in these buffaloes were much lower than those commonly observed in dairy cattle. The mean SCS from quarters with IMI was only 2.93. The highest SCS was observed in quarters infected by streptococci. No drastic decrease in milk yield was observed among infected buffaloes relative to healthy contemporaries. The relatively low SCS and lack of a strong effect on milk yield provide evidence to discourage antibiotic treatment of buffaloes for subclinical IMI during lactation.

Distribution of plasminogen activator forms in different fractions of buffalo milk

In Italy buffalo milk is an important animal product utilized solely for the manufacture of Mozzarella cheese. Of an estimated population of 200000 buffalo there are ∼25000 controlled animals. The average milk production, expressed over 270 d lactation, is 2000 kg/head with average fat and protein contents of 82·6 and 46·4 g/l respectively (Associazione Italiana Allevatori, 1996). In recent years there has been a steady increase in the number of dairy buffalo replacing dairy cows as a consequence of the European Union quota system.

The cheesemaking qualities of milk depend on many factors, the most important of which are the concentrations of intact casein and fat. Milk in which casein has been broken down by proteolytic enzymes is of less value to cheese manufacturers (Lucey & Kelly, 1994). Plasmin (EC 3.4.21.7), the most important endogenous milk proteinase, occurs in milk together with its inactive proenzyme, plasminogen (Schaar & Funke, 1986). Plasmin hydrolyses αs-casein and β-casein, although κ-casein has been reported to be resistant (Fox, 1981). However, Andrews & Alichanidis (1983) found κ-casein to be hydrolysed quite rapidly by plasmin. Plasmin activity is higher in mastitic than normal milk (Bastian & Brown, 1996). Stage of lactation affects plasmin activity: late lactation is associated with higher concentrations of plasmin (Gilmore et al. 1995; Baldi et al. 1996). Thus, plasmin could be a major problem in herds with seasonal breeding such as buffalo, which progress through lactation in synchrony and are therefore at a similar stage of lactation at a given time.

The cascade of reactions leading to plasminogen activation is regulated by a complex network of molecular interactions between plasminogen activators (PA; EC 3.4.21.31) and at least three types of specific PA inhibitors (PAI-1; PAI-2; PAI-3; Saksela, 1985; Politis, 1996). There are two types of highly specific PA: tissue-PA (t-PA) and urokinase-PA (u-PA) (Saksela & Rifkin, 1988). PA activity is higher in mastitic than normal milk (Heegaard et al. 1994a). However, previous studies on PA in milk were carried out on bovine and caprine milk. No information is available on the presence and type of PA in buffalo milk. Thus the objective of the present study was to determine the level and type of PA in different fractions of buffalo milk: casein, serum, and somatic cells.

Relative bioavailability of vitamin E in dairy cows following intraruminal administration of three different preparations of DL-alpha-tocopheryl acetate

DL-alpha-tocopheryl acetate, a synthetic form of vitamin E, is routinely given as a dietary supplement to cattle. In this study we assessed the relative bioavailability of three formulations of DL-alpha-tocopheryl acetate in a kinetic study of plasma alpha-tocopherol in four Italian Friesian dairy cows, following intraruminal administration of a gelatin capsule containing 5,000 IU of DL-alpha-tocopheryl acetate. A Latin square design was used so that each animal received all formulations: (A) adsorbed on silica, (M) microencapsulated and (O) in oil form; 5,000 IU of DL-alpha-tocopheryl acetate was also administered intraperitoneally. The treatments were given following a 2-week period on a diet having no vitamin E supplementation with an interval of 8 days between each administration. Blood samples were collected at 0, 1, 10, 11, 21, 30, 48, 72, 96 and 168 h after each administration. The mean initial plasma alpha-tocopherol concentration (CO) was 2.38 +/- 0.57 micrograms/mL. Maximum plasma concentrations (Cmax) of alpha-tocopherol, adjusted for pretreatment values, were 3.90 +/- 0.13, 3.29 +/- 0.13 and 4.07 +/- 0.19 micrograms/mL, following administration of the A, M and O forms, respectively. The length of time required to obtain the maximum concentration (Tmax) in plasma was 57.5 +/- 7.8, 76.8 +/- 8.9 and 73.1 +/- 14.1 h, and the area under the curve (AUC) was 503.3 +/- 63, 620.25 +/- 108.5 and 465.4 +/- 38.7 micrograms.h/mL for A, M and O forms, respectively. Administration significantly increased the plasma alpha-tocopherol levels in all cases; however the A and M formulations had a lower elimination rate than the O form.

Effect of carnitine on serum HDL-cholesterol: report of two cases

In two otherwise normal male subjects selected for normal serum cholesterol and triglycerides but low serum high-density lipoprotein (HDL) levels, oral administration of 1 g per day of L-carnitine over a period of 10-15 weeks caused a substantial increase in high-density lipoprotein levels, as well as a decrease in serum triglycerides. The ratio of HDL-cholesterol to total cholesterol increased, but this change was not due to an obligatory lowering of total cholesterol. Possible mechanisms of the carnitine effect are discussed. Since elevated high-density lipoprotein levels significantly reduce the risk of arteriosclerotic cardiovascular disease, this action of carnitine deserves further study.