PubMed Health⌕ Search

Biomedical subjects

D Balnave

Publications and source records attributed to D Balnave.

At least 55 records · Page 3Linked to original sources
PubMed1978

The effect of ovariectomy on liver metabolism and maintenance energy requirement of hens.

Six pullets from each of an egg-producing and meat-producing strain were ovariectomised at 12 weeks of age. Ovarian regrowth occurred in two of the egg-producing and four of the meat-producing strain. 2. Measurements of heat production and energy balance were made after peak lay with ovariectomised and sham-operated laying pullets of both strains. Measurements on the ovariectomised pullets were made before and after implantation with oestrogen pellets. 3. Within each strain the ME requirements for maintenance (per kg W0.75), determined by linear regression analysis, were similar whether or not the starvation heat production data were included. 4. The ME requirements for maintenance decreased substantially after ovariectomy but subsequent implantation with oestrogen pellets did not increase these requirements. 5. Studies of hepatic enzyme activities indicated that the major influence of the mature ovary was on hepatic lipid metabolism. This was exerted through a specific stimulation of lipogenesis rather than a general increase in metabolism.

Animals↗
PubMed1977

A biochemical explanation for the fatty liver and kidney syndrome of broilers: its alleviation by the short-term use of dietary fat.

1. Fatty livers and kidney syndrome (FLKS) was induced in young broiler chickens by giving them a diet composed principally of wheat and meat meal. 2. FLKS resulted in reduced growth and increased liver weight; fasting for 18 h increased mortality, liver lipid and the specific activity of hepatic ATP-citrate lyase compared with birds fed on a commercial diet. The specific activities of hepatic fructose-1,6-diphosphate-1-phosphohydrolase and pyruvate carboxylase were reduced in birds suffering from FLKS and fasted for 18 h. 3. Feeding of the FLKS-inducing diet supplemented with 150 g animal tallow/kg for 54 h considerably reduced mortality while restoring liver composition and enzyme activities towards those observed in birds fed a commercial diet. Investigations indicated that the glycerol component of the fat was not responsible for the observed responses. 4. The present results suggest that in FLKS insufficiencies of biotin are induced in specific enzyme systems, but the syndrome may be alleviated without the use of supplementary biotin. 5. The evidence indicates that, when stressed, birds affected by FLKS diet from the hypoglycaemia occurring as a result of a reduced capacity for gluconeogenesis.

ATP Citrate (pro-S)-Lyase↗
PubMed1977

Studies of fatty liver and kidney syndrome in chickens: dynamics of glucose metabolism.

1. Fatty liver and kidney syndrome (FLKS) was induced in a proportion of a group of 4-week-old chickens by giving a diet of meat meal and wheat; inclusion in the diet of animal tallow for 54 h substantially reduced the occurrence of FLKS. 2. Measurements of dynamic aspects of glucose metabolism were made with single injections of [2-3H]glucose which indicated that birds given the 'FLKS-inducing' diet and showing physical symptoms of FLKS had significantly lower rates of synthesis of glucose than birds given either the same diet supplemented with tallow or a commercial diet. 3. In a second series of experiments glucose metabolism was studied in birds (1) with or without physical symptoms that were given the 'FLKS-inducing' diet and (2) birds given the same diet supplemented with tallow or biotin. Affected birds fed the 'FLKS-inducing' diet had significantly lower plasma glucose concentrations, pool sizes and synthesis rates than birds fed the same diet and not showing symptoms, or birds fed the supplemented diets. 4. It is suggested that the cause of death in birds with FLKS is a low rate of gluconeogenesis during periods without feed which results in a lack of glucose to meet essential functions.

Animals↗
PubMed1977

The in vivo estimation of body fat content in laying hens.

A comparison was made between the determined water space of 16 laying hens weighing between 1-1 and 3-5 kg and that predicted from tritiated water space, with the object of estimating body fat content. 2. The predicted water space over-estimated the determined water space by 15%, but body fat content in living hens with fat levels representing 8-6 and 39% of carcass weight could be predicted with a coefficient of variation of 14%.

Adipose Tissue↗
PubMed1976

The effects of estradiol administration of the hepatic activities of some enzymes of carbohydrate, amino acid and lipid metabolism in the immature pullet.

Two experiments were performed to examine the effects of intramuscular estradiol administration on the hepatic specific activities of some enzymes of lipid, carbohydrate and amino acid metabolism in the immature fowl. Estradiol increased the specific activities of the hepatic lipogenic enzymes, ATP citrate lyase and malate dehydrogenase (decarboxylating) (NADP), but had no effects on the activities of the glycolytic, gluconeogenic and amino acid metabolising enzymes except for pyruvate kinase and glutamate dehydrogenase which were reduced in activity in both experiments. The results indicate that the estrogen-induced increase in hepatic lipid biosynthesis is due to a specific effect on lipid metabolism and not to a general increase in liver metabolism.

ATP Citrate (pro-S)-Lyase↗
PubMed1976

Aspects of lipid and carbohydrate metabolism, dietary biotin and fatty liver and kidney syndrome in broilers.

Two experiments were performed to investigate the biochemical changes associated with FLKS. A diet reported to induce FLKS was fed with or without supplementary biotin to broilers. In experiment 1 various stresses were applied to the birds. 2. In experiment 1 mortality from FLKS was 6% and in experiment 2 nil. Stress had little effect on the induction of the syndrome. 3. There were no significant differences due to diet in any of the variables examined in apparently normal birds. 4. Birds affected by FLKS showed the typical changes of increased liver and kidney weights and lipid contents but hepatic enzyme activities did not differ significantly from those of normal birds except that malate dehydrogenase (decarboxylating) (NADP) activity was significantly decreased. 5. Despite the low content of biotin in the unsupplemented diet (57 mug/kg) liver biotin content was not low in birds fed on this diet. 6. The results suggest that the incidence of FLKS is not related solely to dietary biotin content.

ATP Citrate (pro-S)-Lyase↗
PubMed1975

The development of a biotin deficiency in domestic fowl given wheat-based diets.

1. Studies were done of the possible development of a biotin deficiency in domestic fowl of various ages as a result of feeding with diets composed mainly of wheat, and meat-and-bone meal. The degree of deficiency was estimated from physical symptoms, liver and kidney composition and hepatic enzyme activities. 2. Only a mild biotin deficiency developed in 3-week-old chickens and no adverse metabolic effect were found for chickens reared to 7 or 15 weeks of age or maintained for 9 months in lay on these diets, which were suspected of producing fatty liver and kidney disease in young chickens. At 3 weeks of age the deficiency was more severe the heavier the strain of chicken and the greater the rate of body-weight gain. 3. The present results question the supposition that biotin deficiency is the sole factor responsible for the development of fatty liver and kidney syndrome in young chickens.

Age Factors↗
PubMed1975

The influence of essential fatty acids and food restriction on the specific activities of hepatic lipogenic and glutamate-metabolizing enzymes in the laying hen.

1. Extended feeding of an essential fatty acid (EFA)-deficient diet to laying hens increased liver size and liver lipid concentration. 2. The specific activities of hepatic lipogenic and glutamate-metabolizing enzymes were increased by feeding the EFA-deficient diet. 3. Restriction of daily food intake to 75% of ad lib. intake did not affect the response to dietary fat concentration. 4. Hepatic enzyme activities in hens fed on restricted amounts of food and killed just before, or after, the normal daily feeding time indicated no reduced capacity for lipogenesis at the earlier time.

ATP Citrate (pro-S)-Lyase↗