The production of milk rich in protein and low in fat, the fat having a high polyunsaturated fatty acid content

In two experiments, dairy heifers were offered a basal diet of ground dried grass cubes and flaked maize. In Experiment 1, the diet contained equal amounts of these components whereas, in Experiment 2, the proportions were varied from all-grass to equal amounts of grass and flaked maize. Before and after the main part of each experiment, the animals were offered a diet containing hay, molassed sugar beet pulp and barleybased concentrates. Compared to this diet, the grass cubes-flaked maize diet reduced the fat content of the milk and increased the crude protein content. The proportions of all the milk fatty acids up to 18:0 were reduced and those of 18:1, 18:2 and 18:3 were increased. In Experiment 1, the basal diet of grass cubes and flaked maize was supplemented with 180 and 360 g day^?1 soya bean oil given as crushed, unextracted soya beans or with 180 g day^?1 soya bean oil given as a formaldehyde-treated caseinoil preparation but none of these supplements had any effect on the composition of the milk. In Experiment 2, the crude protein content of the milk increased as the proportion of flaked maize in the diet was increased. Otherwise, there were no differences between the different diets.     

The yield,fatty acid composition and physical properties of milk fat obtained by feeding soya oil to dairy cows

The presence in the bovine mammary gland of a desaturase specific for the conversion of stearic to oleic acid allows the manipulation of the physical properties of milk fat by varying the dietary intake of C₁₆ and C₁₈ fatty acids. In particular, feeding the dairy cow an oil with a high C₁₈: C₁₆ ratio should allow the proportion of milk fat that is liquid at 5°C to be increased, with a consequent improvement in the low-temperature spreadability of butter. In this paper, the effect of feeding concentrate rations containing (a) soya oil as the free oil and as cracked soya beans; (b) various levels of soya oil, the ration being offered twice or 24-times daily, on the thermal properties of the milk fat and on the yield of milk constituents is examined in detail. Feeding ratios containing free soya oil greatly increased the proportion of milk fat liquid at 5°C, whereas cracked soya oil gave only slight increases. Proportion and yield of milk fat were decreased by feeding soya oil twice daily but were increased by continuous feeding.     

Whey protein aggregate formation during heating in the presence of κ-carrageenan

The effect of a negatively charged polymer, κ-carrageenan, on the aggregation behaviour of whey proteins during heating was studied. Aqueous solutions of whey protein isolate (WPI) at 0.5% were heated in the presence of κ-carrageenan (0.1%) at pH 7.0. This concentration was chosen as optimal in the detection of the intermediate aggregates during chromatographic analysis. The residual unaggregated protein, the intermediate aggregates and the soluble aggregates were all examined as a function of heating time and temperature, using size-exclusion chromatography coupled with light scattering detection. The presence of κ-carrageenan did not affect the aggregation of whey proteins heated at 75 °C; however, a change in the mechanism of aggregation seemed to occur at higher temperatures, and intermediates with higher molecular mass formed at 85 °C. At 90 °C, in the presence of κ-carrageenan, the extent of WPI aggregation was much larger, as soluble aggregates were no longer present and less residual protein was recovered in the unaggregated peak.     

Levels of prostaglandins in the small intestine of rats during primary and secondary infection with Nippostrongylus brasiliensis

The level of PGE is increased 10-fold in intestinal tissues during primary infection of the rat with Nippostrongylus brasiliensis. Peak levels (ca. 7,000 pg/cm) were assayed in the jejunal site of infection on day 7 of infection and similar levels were recorded in 'post-infection' (ileal) segments at this time. The level of PGE in 'post-infection' segments showed further increase to 12,000 pg/cm on day 10. The level of PGE also increased in 'pre-infection' (duodenal) but this was delayed by 4-5 days. The level of PGF also increased during primary infection (from about 100 to 950 pg/cm) but this occurred after expulsion. Increase in the level of PGE occurred earlier (at 3-4 days) during secondary challenge given 19 days after primary infection, but the PGE levels followed the primary response when challenge was given 10 weeks after primary infection. It is suggested that PGE plays a dual role in parasite immunity. (1) PGE may directly affect metabolism of the parasite. In this event it is also suggested that protective antibodies cause the release of PG. (2) Elevated levels of PGE act indirectly by affecting gastrointestinal function which alters the microenvironment at the site of infection. The duodenal migration of parasites may be due to this effect of PGE.     

Comparison of a self-control approach and an emotional coping approach to the treatment of obesity.

Compared the relative effectiveness of a self-control program that emphasized modification of external environmental-eliciting cues for eating behavior with an induced affect program aimed at decreasing eating behavior as a response to emotional states. Data from 40 female Ss indicate that although the self-control group lost significantly more of their proportion overweight than any of the other groups and significantly more pounds than the control groups at posttreatment assessment, they did not demonstrate continued treatment superiority during the follow-up period. It appears that some continued treatment contact may be critical for continued weight loss by self-control Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Creatine kinase. Modification of the working enzyme

The action of amiodarone (1.5 X 10(-5) M) on sinus node activity of spontaneously beating isolated right atria of rabbit at 30 degrees C was investigated using a microelectrode technique. The drug significantly increased the action potential duration and decreased the slope of diastolic depolarization, both effects leading to a reduction of the sinus rate. In contrast to beta-blocking agents, amiodarone reduced but did not completely abolish the adrenergic effects on the sinus node activity. It is concluded that the amiodarone-induced bradycarida observed in clinical trials might be due to a direct effect of the drug on the sinus node.     

Effects of high-pressure treatment on the microflora of oysters (Crassostrea gigas) during chilled storage

The microbiological quality of oysters high-pressure (HP)-treated in-shell at 260 MPa for 3 min, or 500 or 800 MPa for 5 min and then stored at 2 °C, were investigated. Microbial counts after HP treatment showed that the bacterial load was reduced after treatment at all pressures to levels below the detection limit. Randomly-selected isolates from the total aerobic viable counts of untreated and HP-treated oysters after 14 days of storage were identified by the API identification system. Bacteria isolated from oysters HP-treated at 260 MPa were Shewanella putrifaciens and Pseudomonas fluorescens. For oysters HP-treated at 500 or 800 MPa, the main bacteria isolated were Pseudomonas spp. Vibrio spp. comprised 44% of the microflora in untreated oysters after storage for 14 days at 2 °C, but no Vibrio were detected in HP-treated oysters. This study confirmed that HP processing can inactivate microorganisms and delay microbial growth in chilled stored oysters.

Industrial relevance

High-pressure (HP) treatment is being increasingly employed for commercial processing of oysters but no studies of the microflora of HP-treated in-shell oysters have been reported. HP treatment significantly changed the microflora of oysters and apparently has good potential for inactivation of Vibrio spp as HP treatment, in combination with adequate chilled storage, can improve the microbiological shelf-life and safety of oysters.