Measurement of transit time of digesta through sections of gastrointestinal tract of pigs fed with diets containing various sources of dietary fibre (non-starch polysaccharides).

The effects of various sources of dietary fibre (defined as non-starch polysaccharides (NSP] on the transit time (TT) of digesta through sections of digestive tract were measured in pigs of 30-85 kg. The pigs were fitted with simple cannulas in the terminal ileum, caecum and mid-colon. Diets in experiments 1-3 were based on barley, wheat, soya bean meal and fish meal with NSP added in the form of wood cellulose (experiment 1), guar gum (experiment 2), wheat bran, pectin (experiment 3). Lactulose was also included in experiment 3 because of its NSP-like effects. Diets in experiments 4 and 5 were based on starch and casein and contained Phaseoluos vulgaris or Pisum sativum (experiment 4) and sugar beet pulp or wheat bran (experiment 5). Transit time (TT) was measured using 103Ruthenium phenanthroline to label solids and 51Chromium complexed to EDTA for liquids. Samples were taken every 3 h after marker administration for 51 h from all cannulas and the faecal output was collected every 3 h. The values obtained were very variable. The range of TT (h) defined as first arrival of markers and peak marker level was 3-12.2 and 3-12.2 to the ileum, 3-22.3 and 4.5-22.3 to the caecum, 4.5-50.3 and 16.5-48.8 to the colon and 24- less than 51 and 30- less than 51 to the rectum respectively.

The availability to the chick of pantothenic acid in foods.

1. The content of total pantothenic acid (PaA) in two foodstuffs of microbial origin was measured by standard microbiological and chick biological assays. 2. Substantially and consistently higher values were found by the chick assay than by the microbiological determination, indicating that PaA-containing compounds were present that were not utilized by the test micro-organisms but were available for chicks. Attempts to identify these compounds did not explain the source of excess PaA activity for the chick. 3. It is suggested that forms for PaA that are undetected by standard methods of microbiological assay differ from one food to another and require different treatments to make the vitamin available to the assay organism.

The influence of microorganisms and of stress on the chick's requirement for pantothenic acid.

1. The responses of germ-free (GF) and conventional (CV) chicks to suboptimal amounts of dietary calcium pantothenate (CaPa) were compared. At the lower levels of supplementation the signs of deficiency were more severe in the CV chicks. 2. Calculations based on mean body-weights of chicks given graded dietary supplements of calcium pantothenate (CaPa) in both environments showed that, to achieve the same body-weight and freedom from signs of deficiency, the GF birds required only approximately two-thirds the amount of CaPa as was needed by corresponding CV birds. 3. Increasing the dietary supplement of CaPa resulted in increased contents of PaA in the livers. GF birds had more PaA per liver than their CV counterparts. In both instances the effect was due to the larger liver size. Concentration of PaA in the liver was not affected by dietary supplement nor by the environment. 4. CV birds were deemed to be under greater stress than GF birds because their adrenal glands were heavier and contained less cholesterol. 5. CV chicks deliberately stressed by injections of adrenocorticotrophic hormone had heavier adrenals with lower cholesterol contents than unstressed controls, but the condition was not altered by increasing the dietary supply of CaPa.

The effects of high dietary supplements of copper sulphate on pantothenic acid metabolism in the chick.

1. The effects of incorporation of copper sulphate supplying 250 mg copper/kg semi-purified diet with graded amounts of calcium pantothenate (CaPa) were studied in chicks. 2. When the doses of CaPa were marginally adequate or less the Cu supplementation induced severe signs of pantothenic acid (PaA) deficiency. 3. Livers of the Cu-treated birds given low doses of PaA had lower concentrations of total and bound PaA than those of the corresponding control birds. The bound:total PaA value was also reduced. 4. The amount and concentration of coenzyme A (CoA) were significantly less in the livers of Cu-treated chicks. Fatty acid synthetase activity was not reduced. 5. It is suggested that high dietary supplements of CuSO4 induce PaA deficiency through interference in the biosynthesis of CoA.