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Biomedical subjects

C Grainger

Publications and source records attributed to C Grainger.

16 recordsLinked to original sources

Dietary cation-anion difference and the health and production of pasture-fed dairy cows. 1. Dairy cows in early lactation.

Diets offered to lactating dairy cows in the pasture-based dairy systems in southeastern Australia can vary in their dietary cation-anion difference (DCAD) from 0 to +76 mEq/100 g. The effects of such a range of DCAD on the health and production of cows, on a predominantly pasture-based diet, were examined in an indoor feeding experiment. Four groups of five cows were offered a diet of 5 kg of barley and ad libitum pasture, which is a diet representative of what is offered to cows in early lactation in the region. The cows were supplemented twice daily, with varying levels of salt combinations to alter the DCAD, which ranged from +21 to +127 mEq/100 g. Although a reduction in DCAD to +21 mEq/100 g caused a nonrespiratory systemic acidosis, there was a threshold value, above which blood and urine pH did not appear affected, although the strong ion difference of blood and urine and the blood bicarbonate concentration increased linearly (P < 0.05, 0.001, and 0.01, respectively). A DCAD above +21 mEq/100 g linearly reduced dry matter intake (P < 0.1), average daily bodyweight gain (P < 0.05), and milk protein yield (P < 0.05) but did not have a significant effect on the concentration of fat, protein, or lactose in milk. Although data were consistent with a tendency for milk yield to decrease as dietary cation-anion differences increased, this trend was not statistically significant. Urine hydroxyproline to creatinine ratio increased (P < 0.001) as dietary cation-anion difference increased, possibly suggesting an increased rate of uterine involution. It is concluded that a range in the dietary cation-anion difference, above +52 mEq/100 g, may have deleterious effects on dry matter intake and milk production.

Animal Nutritional Physiological Phenomena↗

Dietary cation-anion difference and the health and production of pasture-fed dairy cows 2. Nonlactating periparturient cows.

Anecdotal observations of reduced hypocalcemia due to small reductions in the precalving dietary cation-anion difference (DCAD) are widely reported in Australia and New Zealand. Diets offered to nonlactating, periparturient dairy cows in pasture-based dairy systems in southeastern Australia can vary in their cation-anion difference from 0 to +76 mEq/100 g. The effects of such a range in the DCAD on the health and production of cows, on a pasture-based diet, were examined in an indoor feeding experiment. Four groups of four cows were offered pasture-hay and freshly cut pasture, a periparturient diet typical of that associated with the grazing system in Australia and New Zealand. Varying levels of salt supplementation were used to alter the dietary cation-anion difference, which ranged from -12 to +69 mEq/100 g. Blood and urine pH and mineral concentrations and urine hydroxyproline were measured. The addition of anions to the diet, to produce a negative DCAD, resulted in a nonrespiratory systemic acidosis. With decreasing DCAD, the pH of blood and urine and the strong ion difference of urine decreased curvilinearly, blood bicarbonate decreased linearly and the urinary ratio of Ca to creatinine increased curvilinearly. Although systemic pH was not reduced at a DCAD of +16 mEq/100 g, urine Ca-to-creatinine ratio had begun to rise, probably indicating increased calcium absorption. The absorption and renal excretion of Mg increased with decreasing DCAD. No differences were observed in urine hydroxyproline concentrations and no significant differences in milk production were measured.

Animal Feed↗

A low dietary cation-anion difference precalving and calcium supplementation postcalving increase plasma calcium but not milk production in a pasture-based system.

It was hypothesized that a reduction in the dietary cation-anion difference (DCAD) before calving, combined with an increase in Ca intake after calving, would reduce the incidence of periparturient hypocalcaemia and increase milk production in pasture-based dairy cows. Cows (n = 40) were assigned to one of two DCAD levels before calving (i.e., +7 and +50 mEq/100 g). Each group was then assigned to one of two dietary Ca concentrations after calving (i.e., 1.0 and 0.7%) in a 2 x 2 factorial design. The lower DCAD resulted in a nonrespiratory reduction in systemic pH as indicated by a lower urine pH. This acidosis resulted in an increased concentration of Ca in urine before calving. The lower precalving DCAD helped prevent the decline in blood Ca caused by the onset of lactation, even though blood Ca concentration was lower before calving compared with cows receiving a high DCAD. Supplementation of cows with Ca after calving increased plasma Ca concentration on the day of calving and during the subsequent 14 d. Milk production was not affected by pre- or postcalving treatments.

Animal Feed↗

Managing diet quality for Cheddar cheese manufacturing milk. 1. The influence of protein and energy supplements.

The effects of supplementing cows' diets with protein and energy on milk composition and the composition and yield of Cheddar cheese were investigated. This research addresses the problems of seasonal reduction in the capacity of cheese curds to expel moisture as observed in parts of south-eastern Australia. Milk was collected from cows offered a basal diet of silage and hay supplemented with different sources and levels of dietary protein and energy. The protein supplements were sunflower, canola, cottonseed meal and lupin, and the energy supplements were maize grain, oats, wheat and barely. This milk was used to manufacture Cheddar cheese on a pilot scale. Cheese moisture content was dependent on the source and level of dietary protein and energy. Milk from cows offered the lupin protein supplements and wheat energy supplements consistently produced cheese with a lower moisture content and moisture in fat-free matter. Milk from these supplemented diets had increased casein concentrations and higher proportions of alpha S2-casein than milk from the poor quality control diet. Cheese yield was directly related to the total casein concentration of milk, but was not influenced by differences in casein composition. Supplementing the cows' diets increased the inorganic P, Mg and Ca concentrations in milk. A low inorganic P concentration in milk from cows offered the control diet was caused by a low intake of dietary P. These findings showed that changes in the mineral and casein composition of milk, associated with diet, could influence the composition of Cheddar cheese.

Animals↗

Managing diet quality for cheddar cheese manufacturing milk. 2. Pasture v. grain supplements.

The effects of supplementing a basal diet of silage and hay with increasing amounts of harvested spring pasture, or with lupin and wheat, on the composition of milk and the consequent effects on cheese composition and yield were investigated in an indoor feeding study. Milk was collected from five groups of eight cows in mid lactation offered different diets and manufactured into Cheddar cheese on a pilot scale. Milk from cows given the lupin-wheat (LW) and the high pasture level (HP) diets produced low moisture cheese. Cheese produced with milk from cows given the control diet was high in moisture content compared with that made with milk from cows offered the LW diet. Cheese yields from the milk of cows offered the HP and LW diets were greater than from the milk of cows on the control diet, and were associated with the higher casein concentrations of these milks. Casein number was higher in milk from diets supplemented with pasture but was not an indicator of the functional properties of milk that affected cheese moisture. The proportion of beta-casein in milk from cows offered the HP diet was higher and that of gamma-casein lower than in milk from cows given the LW supplement, although cheese moisture content was similar with both diets. Milk from cows offered the HP diet had a greater inorganic P concentration than that from cows given the LW diet, although the dietary intake of P was higher for the LW diet. The significance of the effect of dietary P intake on the concentration of inorganic P in milk and hence its suitability for cheesemaking was apparent when dietary P intake was low, as shown in milk produced by cows offered the control diet.

Animals↗

Seasonal influences on Cheddar cheese manufacture: influence of diet quality and stage of lactation.

The influence of diet quality and stage of lactation on Cheddar cheese moisture and yield were segregated and the effects of other potential variables (cow breed, milk protein genotype, age and level of mastitis) were minimized. An experiment was conducted using milk of cows in mid lactation or late lactation fed on high or low quality diets. Increased moisture in cheese was largely due to the influence of cow diet. Milk from cows given high quality diets produced lower moisture cheese. Cheese yield was influenced by diet and stage of lactation. Cows in late lactation fed on high quality diets always gave milks yielding the most cheese. Fat and protein recovery in cheese was not influenced by diet or stage of lactation. The results suggest that low quality diets may induce changes in the complex interactions of milk proteins and other components that affect cheesemaking.

Animal Feed↗

Job satisfaction and health of house officers in the West Midlands.

A postal questionnaire survey was conducted in 1993 to determine the job satisfaction and current state of health of British-trained pre-registration house officers (PRHOs) working in the West Midlands Regional Health Authority. The questionnaire included parts of the Occupational Stress Indicator looking at job satisfaction, and mental and physical ill-health (as manifestations of stress). Out of 234 eligible PRHOs 182 (78%) returned questionnaires: female PRHOs had significantly higher scores for physical and mental ill-health than male PRHOs; 14.2% of PRHOs had scores for mental ill-health, and 17.6% scores for physical ill-health that were higher than the average reported for patients with psycho-neurotic disorders. The PRHOs had significantly lower scores for all individual aspects of job satisfaction and total job satisfaction, and significantly higher scores for mental and physical ill-health than a comparative group of junior hospital doctors (all grades), and a large group of non-health-care white-collar workers. These results indicate that there is a need to raise awareness of stress and stress-related problems faced by junior doctors, and to provide adequate support.

Adult↗

Day surgery--how much is possible? A Delphi consensus among surgeons.

Although day surgery (DS) has been performed for many years, it has only relatively recently become a popular and acceptable method of treating many common surgical conditions. With considerable pressure to maximise resource usage DS has been seized upon as a way of stretching scarce resources further. A review of the amount of DS undertaken within the West Midlands region revealed that the current workload showed considerable variation both between districts and between consultants. In an effort to gain clinical commitment to increasing generally the amount of DS undertaken, and obtaining more uniform coverage of DS across the region, a consensus conference was held. The two aims of the conference were to set targets as to the amount of DS considered feasible at a procedural level, and to seek clinicians' views as to the obstacles to developing the service. Targets for 43 procedures at one and/or five years were obtained by the use of a modified Delphi consensus. The groups showed a high level of consensus in the targets reached. A variety of obstacles were discussed. We have shown that it is possible to involve a large number of doctors in the decision-making/target-setting process by using a modified Delphi technique. It remains to be seen whether those targets are met in clinical practice. Surprisingly, obstacles to development were mainly concerned with management and personnel issues rather than capital investment.

Ambulatory Surgical Procedures↗

Over the obstacles.

Although recognised as a good thing, day surgery still has barriers to overcome if it is to become a first-rate service, argue Caron Grainger and Rod Griffiths.

Ambulatory Surgical Procedures↗

Assault on staff in psychiatric hospitals: a safety issue.

All reported injuries between 1985 and 1987 in a large Queensland psychiatric hospital were studied. There were 650 incidents investigated; travelling injuries and injuries sustained by staff members not involved with patient care were excluded. Forty-eight per cent (n = 323) were assault based injury. Student nurses were most frequently assaulted. It was concluded that training in aggression management should include both counselling and self defence techniques, and that patient and staff rights should be balanced. Student nurses should have experience in wards with a low injury rate, prior to being rostered to the high risk wards.

Accidents, Occupational↗