Protein in potato flakes: Evaluation by the meadow vole (Microtus pennsylvanicus)

Th protein content of six potato cultivars, Russet Burbank and the numerically designated 58, 709, 711–3, 321–65 and 322–6, ranged from 5.5 to 8.7 g per 100 g. Similar results were obtained by both Kjeldahl and Biuret procedures. Amino acid analyses with a Beckman model 120C showed methionine to be the low level amino acid. Glutamic and aspartic acids were in higher amounts than the essential amino acids. The Chemical Score was similar to data of bio-assays by the meadow vole,Microtus pennsylvanicus. Cultivar 58 produced the greatest weight gain, but was only significantly higher than cultivars 709 and 711–3. Both weight gains and digestibility were increased by the inclusion of methionine in the diet.     

The influence of xylanase on the fermentability,digestibility, and physicochemical properties of insoluble corn-based fiber along the gastrointestinal tract of growing pigs

In theory, supplementing xylanase in corn-based swine diets should improve nutrient and energy digestibility and fiber fermentability, but its efficacy is inconsistent. The experimental objective was to investigate the impact of xylanase on energy and nutrient digestibility, digesta viscosity, and fermentation when pigs are fed a diet high in insoluble fiber (>20% neutral detergent fiber; NDF) and given a 46-d dietary adaptation period. A total of 3 replicates of 20 growing gilts were blocked by initial body weight, individually housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF) with 7.5% NDF, a 30% corn bran high-fiber control (HF; 21.9% NDF), HF + 100 mg xylanase/kg (HF + XY [Econase XT 25P; AB Vista, Marlborough, UK]) providing 16,000 birch xylan units/kg; and HF + 50 mg arabinoxylan-oligosaccharide (AXOS) product/kg (HF + AX [XOS 35A; Shandong Longlive Biotechnology, Shandong, China]) providing AXOS with 3–7 degrees of polymerization. Gilts were allowed ad libitum access to fed for 36-d. On d 36, pigs were housed in metabolism crates for a 10-d period, limit fed, and feces were collected. On d 46, pigs were euthanized and ileal, cecal, and colonic digesta were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment as a fixed effect. Compared with LF, HF reduced the apparent ileal digestibility (AID), apparent cecal digestibility (ACED), apparent colonic digestibility (ACOD), and apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), crude protein (CP), acid detergent fiber (ADF), NDF, and hemicellulose (P < 0.01). Relative to HF, HF + XY improved the AID of GE, CP, and NDF (P < 0.05), and improved the ACED, ACOD, and ATTD of DM, GE, CP, NDF, ADF, and hemicellulose (P < 0.05). Among treatments, pigs fed HF had increased hindgut DM disappearance (P = 0.031). Relative to HF, HF + XY improved cecal disappearance of DM (162 vs. 98 g; P = 0.008) and NDF (44 vs. 13 g; P < 0.01). Pigs fed xylanase had a greater proportion of acetate in cecal digesta and butyrate in colonic digesta among treatments (P < 0.05). Compared with LF, HF increased ileal, cecal, and colonic viscosity, but HF + XY decreased ileal viscosity compared with HF (P < 0.001). In conclusion, increased insoluble corn-based fiber decreases digestibility, reduces cecal fermentation, and increases digesta viscosity, but supplementing xylanase partially mitigated that effect.     

Biomicroscopy of the tear film: aqueous and lipid tear substitutes in the normal and abnormal eye

Polarised light biomicroscopy was used to assess the behaviour and interactions of two polymer-containing preparations of artificial tears, and two lipid-containing ointments, with the normal and abnormal pre-corneal tear film. The preparations were used topically in six normal dogs, and three dogs with keratoconjunctivitis sicca. A transient morphological alteration of the surface lipid layer of the tear film was commonly observed after the use of polymer solutions. The ointments spread as a continuous or semi-continuous layer over the normal, or polymer-supplemented, aqueous tears. Further applications of artificial tears produced only a temporary disruption of this layer. In dogs with keratoconjunctivitis sicca, thickening of the lipid layer of the tear film was observed for over 20 hours after the administration of ointment. These observations are discussed in relation to the prospects for the improved medical treatment of keratoconjunctivitis sicca by the use of polymer-containing solutions and ointments in combination.     

Control of inherited retinal degeneration in dogs and cats in the United Kingdom

The term progressive retinal atrophy (PRA) is synonymous with inherited blindness in both dogs and cats as the result of retinal degeneration. In fact several types of degeneration occur within this complex, but the ophthalmoscopic features are well recognised and practical disease control is possible through routine examination. However, effective measures demand the whole-hearted support of the breeds involved, and only extensively applied examination schemes in which there is a central pooling and use of results are likely to produce the degree of disease control necessary, Test-mating and electrorelinograph (ERG) examination also have a part to play in the identification of normal genotypes, but the application of routine ophthalmoscopic examination, perhaps associates with Kennel Club registration, currently offers the most effective way forward.     

Increased small intestinal fermentation is partly responsible for the anti‐nutritive activity of non‐starch polysaccharides in chickens

1. The mechanism of the anti‐nutritive activities of soluble non‐starch polysaccharides (NSPs) in broiler diets was investigated with emphasis on the inter‐relationship between viscosity and fermentation along the gut. Isolated soluble NSP were added to a control diet to effect high gut viscosity, and in vivo depolymerisation of the NSP was achieved using a commercial glycanase.

2. Addition of soluble NSPs significantly (P<0.01) increased gut viscosity, reduced the AME of the diet and depressed the growth and FCE of the birds. Enzyme supplementation of the NSP‐enriched diet reversed the adverse effects, increasing (P< 0.01) weight gain, FCE and AME. Comparisons of the viscosities (mPa) in birds fed on the NSP‐enriched diet and the same diet supplemented with enzyme were respectively: 11–9 v. 2–3 in the duodenum; 78–3 v. 4–4 in the jejunum and 409–3 v. 10–8 in the ileum.

3. Caecal volatile fatty acid concentration was markedly (P<0.01) elevated by enzyme supplementation, whereas ileal fermentation was inhibited.

4. Microscopic examination revealed that, among birds fed on the NSP‐enriched diet, there had been extensive small intestinal fermentation, which was eliminated by the enzyme supplementation.

5. Addition of a synthetic antibiotic (Amoxil) had no beneficial effects.

6. The current study demonstrated that increased fermentation occurs in the small intestine when a large amount of viscous NSPs is present in the diet and this is detrimental to the performance and well‐being of poultry.     

The effect of supplementary bacterial phytase on dietary metabolisable energy, nutrient retention and endogenous losses in precision fed broiler chickens

Thirty-two Ross 308 male broiler chickens were used in a precision feeding assay to investigate the effect of exogenous phytase (EC 3.1.3.26) on dietary apparent metabolisable energy (AME), dry matter digestibility (DMD) coefficient, nitrogen (NR), amino acid and mineral retentions. The excretion of endogenous losses measured as sialic acid (SA) was also determined. Four dietary treatments (control (C), C + 250 FTU (phytase units per kg feed), C + 500 FTU, and C + 2500 FTU) were studied with each treatment replicated eight times in randomised complete block design. Diets were formulated to be nutritionally adequate with the exception of available P content (2.3 g/kg non-phytate P). Over the 48-h collection period, the phytase fed birds retained 29.3 mg more Na and 2.3 mg more Zn (p < 0.05) than the control fed birds, with the relationship between phytase dose and Na and Zn retention being best described by a linear function (p < 0.05 and p < 0.001, for Na and Zn, respectively). Phytase supplementation did not have an effect on dietary AME, DMD and NR. However, increasing the dose of phytase led to a linear increase in dietary amino acid retention (p < 0.05). Dietary phytase decreased total sialic acid excretion in a linear fashion (p < 0.05). It can be concluded that supplementary phytase increases the retention (reduces the excretion) of dietary Zn and Na in broiler chickens. The beneficial effects of the addition of exogenous phytases to poultry diets seems to be mediated through improved dietary nutrients absorption and reduced endogenous losses.     

The effects of phytase and phytic acid on the loss of endogenous amino acids and minerals from broiler chickens

1. The effects of myo-inositol hexaphosphate (IP6) and phytase (EC 3.1.3.26) on the excretion of endogenous compounds were investigated using growing broiler chickens. 2. A total of 32 female Ross broilers were used in a precision feeding assay involving a 2 x 2 factorial arrangement of treatments. The materials administered were glucose, glucose + 1000 units of phytase activity (FTU), glucose + 1 g of IP6 and glucose + 1 g of IP6 + 1000 FTU. Excreta were collected quantitatively over a 48-h period following intubation of the test materials. The excretion of nitrogen, amino acids, minerals, sialic acid and phytate phosphorus was determined. 3. The ingestion of 1 g of IP6 by broilers increased the excretion of endogenous nitrogen, amino acids, iron, sodium, sulphur and sialic acid compared with birds fed on glucose. Supplementation of IP6 with exogenous phytase reduced the excretion of endogenous amino acids, calcium, sodium, phytate phosphorus and sialic acid compared with birds fed IP6. 4. It can be concluded that IP6 increases the excretion of endogenous minerals and amino acids in broiler chickens. Part of the beneficial effects of the addition of exogenous phytases to the diets of poultry appears to be mediated through a reduction in endogenous losses of these nutrients.