H. Jeroch

An investigation into the variability of extract viscosity of wheat-relationship with the content of non-starch-polysaccharide fractions and metabolisable energy for broiler chickens.

The in vitro extract-viscosity and the content of non-starch-polysaccharides were investigated in 34 defined wheat varieties grown at 5 locations each. Both, wheat genotype as well as growing location clearly influenced the viscosity of soluble extract from wheat. Furthermore, the content of non-starch-polysaccharides (soluble/total) and pentosans (soluble/total) were determined in 13 wheat varieties each grown at two locations. Soluble pentosan contents were highly positively correlated with extract viscosity of wheat at the locations Hayn (r = 0.86) and Biendorf (r = 0.90). The classical apparent metabolisable energy of 5 wheat samples having different extract viscosities was assessed. The AMEN values ranged from 14.0 to 14.6 MJ/kg DM and were significant negatively correlated to content of soluble arabinoxylans (r = 0.67) and to the extract viscosity (r = 0.83). Furthermore, the viscosity of jejunal (4.0 to 22.8 mPas) and ileal (13.1 to 78.0 mPas) digesta exhibited a clear relationship with soluble pentosan contents and extract viscosity. Under the conditions applied in this study the technique of extract viscosity measurement can predict the AME.

Interactions between dietary fat type and xylanase supplementation when rye‐based diets are fed to broiler chickens 2. Performance, nutrient digestibility and the fat‐soluble vitamin status of livers

1. The interactions between dietary fat type and xylanase supplementation of rye-based diets were investigated using a 2 x 2 factorial design in which a rye-based diet (610 g rye/kg) was combined with 100 g/kg of soya oil or beef tallow, with or without xylanase supplementation at 3000 IU/kg, and fed to 1-d-old male broilers for 35 d. Growth, nutrient digestibility and AMEN values were determined and the vitamin status of livers assessed at various ages. 2. There were significant interactions between crude fat and xylanase supplementation on the faecal digestibility of crude fat and crude protein. Fat digestibility was improved by xylanase in both fat type groups but to a greater extent for the tallow diets. However, the effects were found to be significant only for oleic, linoleic and linolenic acids. Similarly, protein digestibility and AMEN values were significantly improved by xylanase, but only for the tallow diet. 3. Ileal digestibility of nitrogen and amino acids also were affected by enzyme for both fat type diets, the effect generally being more pronounced for the tallow diet. 4. The deposition of the fat soluble vitamins A and E in livers was significantly increased by xylanase supplementation and was also better for soya oil than for tallow. 5. Xylanase supplementation increased the digestibility of insoluble pentosans whereas for the soluble pentosans the opposite effect was noted. 6. Without xylanase supplementation the tallow-based diet caused high mortality. Liveweight gain and the efficiency of food utilisation were greatest in the soya oil-based, xylanase-supplemented diet, followed by the unsupplemented soya oil-, supplemented tallow- and unsupplemented tallow-based diets.

Interactions between dietary fat type and xylanase supplementation when rye‐based diets are fed to broiler chickens. 1. physicochemical chyme features

1. The interactions between fat type and xylanase supplementation of rye-based diets were investigated using a 2 x 2 factorial design in which a rye-based diet (610 g rye/kg) was combined with 100 g/kg of soya oil or beef tallow, with and without xylanase supplementation at 3000 IU/kg, and fed to 1-d-old male broilers. Food passage time, viscosity of digesta supernatant, xylanase activity and pH in different segments of the digestive tract were examined. 2. Food passage throughout the digestive tract was accelerated by enzyme addition regardless of fat type. The time taken for 50% of the marker to be excreted was reduced from 8.4 to 6.7 h in animals receiving the rye-soya oil diets and from 8.0 to 6.9 h with the rye-tallow diets. 3. Viscosity in the supernatant of the jejunal and ileal digesta was markedly decreased after enzyme addition. Viscosities were generally higher in the ileal than in the jejunal supernatant, and fell as the birds aged from 14 to 28 d. The effect of enzyme was also reduced in older chicks. There was not a clear effect of the fat source on viscosity. 4. Xylanase activity was still found at the end of the ileum in digesta of birds fed on the enzyme-supplemented diets but not in control animals. Xylanase activity was also detected in the caeca of all groups. 5. Significantly lower pH values were found in tallow-fed birds in some segments of the digestive tract. A significant increase in pH after enzyme addition was detected in the proximal ileum; this was independent of fat source.

Barley in poultry feeding: a review *

In most European countries barley ( Hordeum vulgare L.) is an important feedstuff for poultry, and its use could increase with changes in economic circumstances. Compared with wheat, barley contains more fibre and less energy. The nutritive value and suitability of this grain as a feedstuff for growing poultry are more or less affected by varying β-glucan concentrations. The anti-nutritive effects of β-glucan in the gastrointestinal tract of young chicks can be avoided by adding β-glucanase of microbial origin to barley-containing or barley-based diets, thus making this grain crop acceptable for broiler fattening diets. Feed mixtures for layers may contain a higher proportion of barley without negative effects on egg production. When formulating diets, the low content of linoleic acid has to be considered.

Effect of different technical treatments of rapeseed on the feed value for broilers and laying hens

The effect of different technical treatments of rapeseed on its feed value for broilers and laying hens was the object of the study. The technical treatments comprised different grinding procedures (whole seed, roller mill--coarse and fine adjustment, flake mill) resulting in different average particle sizes of the ground seed and thermal treatments of flaked seed (hydrothermal treatment, micronizer, jet sploder). Each thermal treatment was carried out at two temperatures. A marked increase in the digestibility of organic matter and of the AMEN content was observed as the average particle size of the seed was decreased to < or = 0.56 mm and was much more pronounced for the broilers. AMEN contents of 21.1 to 22 and 22.6 to 23 MJ/kg DM were observed at this particle sizes for broilers and hens, respectively. Thermal treatment of rapeseed improved the apparent crude fat digestibility slightly whereas the apparent crude protein digestibility tended to decrease especially at the higher temperatures. This resulted in inconsistent changes in the apparent digestibility of the organic matter and the AMEN content. Only the treatment with hot air (jet sploder) seemed to have preferential effects on the feed value for both broilers and hens. For the thermal treatments AMEN contents ranged from 18.8 to 21.9 and 19.0 to 24.3 MJ/Kg DM for broilers and hens, respectively.

Effects of dietary fat type, pentosan level and xylanase supplementation on digestibility of nutrients and metabolizability of energy in male broilers.

A complete two by two by four factorial design was used to examine the main effects of dietary fat type (10% soya oil or 10% beef tallow), xylanase supplementation (with or without Avizyme 1300 at 1 g/kg diet) and pentosan level (7.7 g/kg, 11.0 g/kg, 14.3 g/kg and 17.6 g/kg soluble pentosans, respectively, by varying wheat/rye proportions) as well as their interactions on intestinal chyme conditions, nutrient digestibility and nutrient utilization in male broilers. Nutrient digestibilities for the total digestive tract and at various sites of small intestine were measured during the period from day 18 to 20 of age and at day 21 of age, respectively, using a marker technique. Jejunal and ileal supernatant viscosity increased in an exponential manner as dietary pentosan concentration was increased. This increase was more pronounced in tallow fed birds but was also found in enzyme treated groups albeit at a much lower level. Xylanase activity was still detectable in the ileum of birds fed enzyme supplemented diets but its activity was found to decrease as dietary pentosan content increased. Digestibility of crude protein and that of some amino acids at the terminal ileum was decreased as dietary pentosan content was increased and significantly improved by xylanase addition. No fat effect and no interactions were detected at this site. In contrast, measurements made over the whole gastrointestinal tract showed significantly lower protein and amino acid digestibility values for tallow fed birds, and significant higher enzyme effects especially in diets with higher pentosan concentrations. Nitrogen-corrected apparent metabolizable energy (AMEN) content and net protein utilization decreased with increasing dietary pentosan content and were significantly improved by xylanase addition and were lower in tallow fed birds. Again, xylanase effects were found to be more pronounced for tallow fed birds and at higher pentosan concentrations.

Effects of dietary fat type, pentosan level, and xylanases on digestibility of fatty acids, liver lipids, and vitamin E in broilers

A complete two by two by four factorial design was used to examine the main effects of dietary fat type (10% soy oil or 10% beef tallow), xylanase supplementation (with or without Avizyme 1300 at 1 g/kg diet), and pentosan level (calculated values: 7.7 g/kg, 11.0 g/kg, 14.3 g/kg, and 17.6 g/kg soluble pentosans, respectively, by varying wheat/rye proportions) as well as their interactions on intestinal chyme conditions, fat and fatty acid digestibility, fatty acid profile, and vitamin E content of livers in broilers. Jejunal and ileal supernatant viscosity increased in an exponential manner as dietary pentosan concentration was increased. This increase was most pronounced in enzyme unsupplemented, tallow-fed birds but was also found in enzyme-treated groups albeit at a much lower level. Lipase activity in jejunal samples was significantly enhanced in broilers fed tallow-containing and unsupplemented rye-based diet (17.6 g/kg soluble pentosans). Digestibility of fat at the terminal ileum was significantly decreased as dietary pentosan concentration was increased and significantly improved by xylanase addition, this effect being most apparent in tallow-fed birds. In addition, enzyme effects became greater at higher pentosan concentrations. Generally, fatty acid digestibilities responded in a similar manner. Saturated fatty acids (palmitic and stearic acid) responded mostly to dietary treatments compared with unsaturated fatty acids (oleic, linoleic, and linolenic acid), and fatty acids derived from tallow were more affected than those from soy oil. Xylanase supplementation shifted absorption of both into the more proximal regions. Vitamin E content of livers was significantly improved by xylanase addition but not influenced by the other dietary treatments. The fatty acid profile of liver lipids was markedly affected by dietary fat type but the effects of pentosan concentration and of xylanase supplementation were not always consistent. Der Einflus von Futterfettart, Pentosan- und Xylanasegehalt auf die Verdaulichkeit von Fettsauren, Leberlipiden und Vitamin E in Broilern. Es kam eine vollstandige 2 × 2 × 4-faktorielle Versuchsanlage zur Anwendung, um die Haupteffekte von Futterfett (10 % Sojaol bzw. 10 % Rindertalg), Xylanasezulage (ohne bzw. mit 1 g Avizyme 1300 je kg Futter) und Pentosanniveau (kalkulierte Werte: 7,7 g/kg, 11,0 g/kg, 14,3 g/kg bzw. 17,6 g/kg losliche Pentosane, durch Verschnitt von Weizen mit Roggen bei variierenden Anteilen) sowie deren Wechselwirkungen auf das intestinale Milieu, die Fett- und Fettsaurenverdaulichkeit sowie das Fettsaurenmuster und den Vitamin E-Gehalt der Leber beim Broiler zu untersuchen. Die jejunale und ileale Viskositat stieg mit zunehmender Pentosankonzentration exponentiell an. Dieser Anstieg war am deutlichsten ausgepragt bei den Broilern, die mit unsupplementierten und Talg-enthaltenden Mischungen gefuttert wurden, war aber auch bei den supplementierten Varianten festzustellen, wenngleich auf einem niedrigeren Niveau. Die Lipaseaktivitat war signifikant erhoht bei den Broilern der unsupplementierten, Roggen-und Talg-enthaltenden Variante (17,6 g/kg losliche Pentosane). Die Fettverdaulichkeit am terminalen Ileum sank signifikant mit steigendem Pentosangehalt und wurde durch die Xylanasezulage deutlich verbessert, wobei diese Effekte bei den mit Talg gefutterten Tieren am deutlichsten ausgepragt waren. Daruber hinaus stieg der Enzymeffekt mit zunehmendem Pentosangehalt. Die Fettsaurenverdaulichkeit reagierte generell in gleicher Weise. Die gesattigten Fettsauren (Palmitin-und Stearinsaure) reagierten starker auf die Behandlungen als die ungesattigten Fettsauren (ol-, Linol- und Linolensaure), wobei die vom Talg stammenden Fettsauren starker betroffen waren als die vom Sojaol. Die Xylanasezulage verschob die Absorption der Fettsauren in die proximalen Dunndarmregionen. Der Vitamin E-Gehalt der Lebern wurde signifikant durch die Xylanasezulage erhoht, durch die anderen Faktoren jedoch nicht beeinflust. Das Fettsaurenmuster der Lebern wurde stark durch die Futterfettart gepragt. Die Effekte von Pentosanniveau und Xylanasezulage waren dabei jedoch nicht immer konsistent.

Effects of dietary sulfur amino acids and crude protein on the performance of finishing broilers.

The effects of different combinations of dietary methionine + cystine (Met + Cys) and dietary crude protein (CP) in finishing broilers were investigated in two growth studies. In Exp. 1, male broilers 29 to 42 days of age were fed 18 diets containing 16.9%, 18.7%, or 20.4% CP with six levels of Met + Cys within each protein level. Similarly, in Exp. 2 another 12 diets containing either 18.0 or 21.5% CP were fed to male broilers 29 to 48 days of age. In general, the Met + Cys requirement for optimum feed conversion was higher than for maximum growth. In both experiments, between 0.80% and 0.85% methionine + cystine optimized feed conversion. These dietary levels were valid for a 13.05 MJ ME/kg diet fed to broilers growing from 1.2 kg to 2.2 kg (Exp. 1), or for a 13.60 MJ ME/kg diet fed to broilers growing from 1.3 kg to 3.0 kg (Exp. 2). The Met + Cys requirement was not consistently affected by the dietary CP content in Exp. 1. In Exp. 2, increasing dietary CP from 18.0% to 21.5% tended to increase the Met + Cys requirement for optimum feed conversion. A dietary CP level of 18.0% to 18.7% supported performance and carcass fat deposition equal to diets containing 20.4% or 21.5% CP, respectively, when the sulfur amino acid content was adequate.

Effect of soy oil supplementation and protein level in laying hen diets on praecaecal nutrient digestibility, performance, reproductive performance, fatty acid composition of yolk fat, and on other egg quality parameters

An experiment was carried out with laying hens in the age of 22—45 weeks to examine the effects of added soy oil (0%, 3.5%, 7%, 10.5%, and 14%) and dietary protein level (13.2% and 16.3%) on laying and reproductive performance, fatty acid composition of yolk fat, and other egg quality parameters. Moreover, digestibility of nutrients and of energy was determined by using a marker technique. Laying intensity and feed intake were not influenced by dietary treatments whereas egg weight and daily egg mass production were significantly improved by soy oil addition in a non-linear related manner. The feed conversion ratio reached a minimum at soy oil proportions between 3.5% and 10.5%. Reproductive performance in terms of fertilized eggs, hatchability, and mortality of chicks was not affected by dietary treatments. The increase of egg weights due to soy oil addition was accompanied by a simultaneous increase in the proportion of albumen and a decrease of yolk and shell percentage. Palmitic acid (C16:0) and oleic acid (C18:1) proportions in yolk fat decreased as soy oil addition was increased whereas the proportions of linoleic acid (C18:2 n-6), linolenic acid (C18:3 n-3), and docosahexaenoic acid (C22:6 n-3) were increased at the same time. Praecaecal digestibility of crude fat and fatty acids of the diets were non-linearly improved by soy oil addition. Digestibility of crude protein and amino acids were not affected by either protein content of the diet or by soy oil supplementation. In conclusion, a decrease in dietary protein content from 16.3% to 13.2% did not negatively influence performance of hens and egg quality under the experimental conditions applied. Soy oil addition improved egg quality.

The effect of sealing and of additives on the fermentation characteristics and mould and yeast counts in stretch film wrapped big‐bale lucerne silage

The effect of number of film layers was investigated in silages produced in wrapped big bales. The herbage used was difficult to ensile lucerne wilted to DM levels of 320-490 g/kg. Fermentation changed to a more homofermentative process as the number of film layers increased. An increasing number of film layers (4, 6, 8 or 10) also resulted in a notable decrease in moulds and yeasts. Four layers could not guarantee successful preservation in lucerne, and higher numbers of undesirable micro-organisms were detected. Hard stalks damaged the first two film layers during wrapping in the bales. Effect of number of film layers was more important than effect of additives for inhibition of mould and yeast counts.