Effect of xylanase and beta-glucanase supplementation of wheat- or wheat- and barley-based diets on the performance of male turkeys.

The efficiency of a mixture of xylanase and beta-glucanase enzymes was evaluated in two separate experiments on growing turkeys offered diets based on wheat or wheat and barley. 2. In the first experiment, the addition of 560 and 2800 IU of xylanase and beta-glucanase, respectively, per kg of diet significantly improved feed efficiency in turkeys fed on wheat- and barley-based diet throughout the entire experiment (42 d). 3. In the second experiment, the enzyme mixture significantly increased N-corrected apparent metabolisable energy (AMEN) by approximately 5%. 4. Furthermore, the combination of xylanase and beta-glucanase significantly improved body weight gain and feed efficiency. Feed efficiency was increased by 2.94, 2.47 and 5.91% in diets based on 500 then 540 g of wheat/kg of diet, 394 then 384 g of wheat and 100 then 150 g of barley/kg of diet and 180 g of wheat and 300 then 350 g of barley/kg of diet, respectively. 5. This enzyme mixture decreased in vitro viscosity of wheat, barley and soybean meal, the effect being larger for wheat and barley than for soybean meal. 6. In conclusion, the supplementation of diets based on wheat and barley with xylanase and beta-glucanase significantly improved body weight gain and feed efficiency. Therefore, wheat and barley could be used more efficiently by turkeys in the presence of an appropriate enzyme preparation.

Effect of enzyme preparation containing xylanase and beta-glucanase on performance of laying hens fed wheat/barley- or maize/soybean meal-based diets.

1. A commercial enzyme preparation (Quatrazyme HP) containing xylanase and beta-glucanase was examined in two laying hen experiments with wheat/barley- or maize-based diets. The activities of other enzymes were measured also. Starch, cell wall contents and effects of Quatrazyme HP on in vitro viscosity of wheat, barley, maize and soybean meal were determined. 2. In the first experiment, 90 ISA Brown laying hens at 28 weeks of age were given a wheat/barley basal diet with or without 20mg of Quatrazyme HP, which provided 560 and 2,800 IU of xylanase and beta-glucanase/kg diet. In the second experiment, 66 ISA Brown laying hens at 45 weeks of age were given a maize/soybean meal basal diet with or without 20 mg of Quatrazyme HP/kg diet for 9 weeks. Egg production, egg weight, egg mass, feed conversion ratio and change in body weight were recorded as response criteria. 3. There was a significant improvement in feed conversion ratio with enzyme supplementation. Birds given an enzyme-supplemented diet gained 86 g while those fed on the unsupplemented diet lost 103 g of their body weight by the end of the experiment. 4. The enzyme preparation did not affect either egg production, egg weight or egg mass of birds fed on the maize/soybean meal diet. However, a significant improvement in feed conversion ratio was detected. Birds on either the supplemented or unsupplemented diet exhibited an increase in their body weight at the end of the experiment. 5. Addition of xylanase and beta-glucanase decreased in vitro viscosity of wheat, barley, maize and soybean meal. This effect was greater for wheat and barley than for maize and soybean meal. 6. It was concluded that the beneficial effect of using an enzyme preparation containing xylanase and beta-glucanase is not limited to wheat/barley-based diets but also occurs with maize/soybean meal-based diets.

Xylanase and beta-glucanase supplementation improve conjugated bile acid fraction in intestinal contents and increase villus size of small intestine wall in broiler chickens fed a rye-based diet.

This study was performed with growing chickens (4 to 22 d of age) to evaluate the effects of feeding a rye-based diet supplemented with commercial enzyme preparation containing xylanase and beta-glucanase (Quatrazyme HP, Nutri-Tomen, France) on small intestine wall morphology, bile acid composition, nutrient digestibility, and bird performance compared with unsupplemented rye- or corn-based diets. The rye-based diet decreased (P < or = 0.05) weight gain, feed intake, and feed efficiency and increased water intake compared with the corn-based diet. Moreover, rye consumption reduced crude fat and protein digestibility as well as apparent metabolizable energy (P < or = 0.05). The small intestine wall showed that villus length, width, and surface were decreased in broiler chickens fed the rye-based diet compared with those fed the corn-based diet. However, crypt morphometry parameters were not affected by diet type. The concentration of conjugated bile acids in the small intestine contents of broiler chickens fed the rye-based diet was decreased (P < or = 0.05) compared with those fed the corn-based diet. These findings suggest that feeding a rye-based diet reduces villus capacity for nutrient absorption and bile acid capacity for fat solubilization and emulsification, resulting in decreased bird performance. The addition of xylanase and beta-glucanase to the rye-based diet improved (P < or = 0.05) weight gain, feed intake, and feed efficiency, and decreased water intake. The digestibility of nutrients and apparent metabolizable energy were also increased (P < or = 0.05). Addition of xylanase and beta-glucanase increased (P < or = 0.05) villus size and the villus height-to-crypt depth ratio, as well as the concentration of conjugated bile acids (P < or = 0.05) in the small intestine contents. Exogenous enzymes improved nutrient digestibility and broiler chicken performance, probably by improving the absorption capacity ofthe small intestine through increased villus surface and intestinal concentration of conjugated bile acids.

Effect of age and exogenous amylase and protease on development of the digestive tract, pancreatic enzyme activities and digestibility of nutrients in young meat-type chicks.

Day-old male meat-type chicks were fed a commercial starter diet supplemented with 2 levels of enzyme preparations containing amylase and proteases up to 14 d of age. Enzyme supplementation had no significant effect on feed intake or growth rate, and was accompanied by a significant decrease in gizzard content and small intestine weight. The intestine contents increased and this increase was accompanied by a significant decrease in its pH. Enzyme supplementation depressed the activity of chymotrypsin in the pancreas and the activity of amylase, trypsin and chymotrypsin in the intestinal contents. Some carry-over effects were observed on d 42, 4 weeks after the cessation of the enzyme supplements. These were mainly a significant depression in the activity of trypsin in the intestinal contents. In a balance study, diets supplemented with 0,250 and 1,000 micrograms/kg enzyme preparations were supplied. Exogenous enzyme supplements had no significant effect on the digestibility of all the nutrients studied except for the highest level of enzyme supplementation, which improved slightly but consistently the digestibility of amino acids. Some age effects were observed, mainly a decrease in the digestibility of fat and starch, and in the ME of the diet from weeks 1 to 2 followed by an increase during week 3. Protein digestibility and retention of nitrogen decreased with age.

Influence of amino-acid concentration in the culture medium on the rate of amino-acid incorporation into protein and amino-acid oxidation of cultured chicken hepatocytes.

Hepatocytes from a 70-d-old male broiler were dissociated using a modified technique of double perfusion with an isotonic solution through the jejunum mesenteric and pancreatic veins followed by collagenase perfusion. A basal medium was made up with the same amino-acid composition of the whole chicken egg, diluted 25 times. Dilutions of 1:1, 1:2, 1:4, 1:20, 1:40 and 1:80 of the basal medium constituted the experimental treatments. Amino-acid incorporation into protein and amino-acid oxidation were determined by counting the radioactivity of [3H]-leucine present in cellular proteins and the 14CO2 released by the cells for 6 periods of time. The rate of amino-acid incorporation into cellular proteins was proportional to the concentration of amino acids in the culture medium, indicating their effect on the regulation of protein synthesis. At least 6 h incubation is needed to reach the maximal values of incorporation. Media containing large amounts of amino acids also showed higher values for oxidation, but the ratio oxidation/incorporation was higher when the amino-acid concentration in the medium was low.

Comparative utilisation of sulphur-containing amino acids by genetically lean or fat chickens.

1. Genetically lean (LL) or fat (FL) male chickens were fed from 28 to 47 days of age on 5 experimental diets differing by their methionine+cystine content (5.4, 5.8, 6.2, 6.6 and 7.0 g/kg, respectively). 2. Growth rate of LL chickens was reduced by the lower sulphur-containing amino acid (SAA) concentrations whereas that of FL was not modified. 3. LL chickens exhibited a larger feather protein gain than FL, which was stimulated by SAA intake. 4. SAA retention, when plotted against SAA consumption, was always greater in LL than in FL. 5. Large differences were observed between genotypes for plasma-free amino acids. Lysine, glutamic acid, histidine and serine were found at significantly higher concentrations in LL birds. Branched amino acids, aromatic amino acids, SAA and arginine were found at higher concentrations in FL. No differences were observed for aspartic acid, glycine, alanine and total amino acids. Methionine supplementation decreased free amino acid concentrations, with the exceptions of arginine and leucine. 6. It is concluded that lean chickens require a higher dietary concentration of SAA than FL. This is mainly caused by their lower food consumption and their greater feather synthesis. However, LL use SAA more efficiently than FL.

Effect of age and sex on true digestibility of amino acids of rapeseed and soybean meals in growing broilers.

Studies were conducted to evaluate the influence of age and sex of birds on true digestibilities of protein (TDP) and amino acids (TDAA) of two rapeseed meals and a soybean meal. Sixty-four broilers (50% of each sex) were used both in the first (at 3 wk of age) and the second trials (on the same animals at 6 wk of age). At the end of 3 and 6 wk of age, the birds were fasted for 24 h and then force-fed with moistened diets (diet:water: 50:50) approximately 40 and 90 g, respectively. Excreta were collected during the two 24-h periods after force-feeding. The TDP and TDAA of rapeseed and soybean meals decreased significantly as the age of broilers increased from 3 to 6 wk. At 3 wk of age, the TDP and TDAA were not influenced by the sex of the animals. At 6 wk of age, the TDAA of the two rapeseed meals was higher in males than in females. The TDAA of soybean meal did not vary with sex. Sex had no effect on the TDP values of the three raw materials tested.

Effect of dietary lysine on muscle protein turnover in growing chickens.

Day-old male chickens were fed ad libitum isoenergetic diets containing 20% crude protein but differing in their lysine content (from 6.5 up to 11.3 g/kg). At 3 weeks of age, protein fractional synthesis rates in the pectoralis major muscle were determined using a large dose injection of 120 mumol per kg body weight of L-[4-3H] phenylalanine. Protein gain in the pectoralis major was measured between 19 and 23 days of age. Protein breakdown was obtained by calculating the difference between protein synthesis and deposition. Weight gain varied curvilinearly with dietary lysine intake and was maximum for 11.3 g lysine/kg of diet. In birds fed an adequate lysine intake (10.1-11.3 g/kg) protein fractional synthesis and breakdown rates were 23.6-25.9 and 17.8-19.8%/d respectively. Increasing lysine supplementation in the diet resulted in an impairment of protein fractional breakdown rates. By contrast, protein fractional synthesis rates remained unchanged owing mainly to an improvement in the synthesis efficiency (kRNA), until birds were fed an adequate lysine intake. These data suggest that the growth rate reduction of chickens fed lysine deficient diets was due to alterations in both rates of protein synthesis and breakdown in skeletal muscle. A maximum protein deposition is achieved when kRNA was optimal, ie for a dietary lysine content of about 9 g/kg, a value close to the requirement.

Effect of dietary lysine level on lipogenesis in broilers.

From 3-7 weeks of age, male and female broilers were fed ad libitum on 1 of the 8 experimental diets. These diets were isoenergetic (13.6 kJ/kg) and isoproteic (186 g/kg) and provided 7 to 14 g/kg lysine. The growth performances, the abdominal fat proportion and hepatic malic enzyme activity (malate dehydrogenase with decarboxylating EC 1.1.1.40) were measured. All parameters varied when dietary lysine concentration was increased from 7 to 9 or to 11 g/kg. The lysine requirement in the finishing period for minimum abdominal fat proportion was higher than for minimum feed conversion ratio, itseful higher than for maximal growth rate. Malic enzyme activity varied with abdominal fat proportion, and this variation could explain the reduction in fatness. However, an excess of lysine did not amplify the reduction of fat deposit.

Nitrogen metabolism in genetically fat and lean chickens.

Two experiments were conducted to investigate the effect of dietary protein content (170 to 230 g/kg in Experiment 1 and 131 to 251 g/kg in Experiment 2) and initial growth rate, estimated from live body weight at 4 wk of age, on growth rate from 4 to 7 wk of age, nitrogen retention, energy metabolism, and amino acid catabolism in genetically fat (FL) and lean (LL) lines of chickens. There was no difference between lines in energy utilization either in metabolizability or in expenditure (basal metabolic rate, maintenance, or diet-induced thermogenesis). The only divergence between lines was in the partition of a similar amount of retained energy between lipid and protein deposition. In both experiments, LL chickens showed greater protein retention efficiency than FL birds; moreover, the LL line did not appear more sensitive to low dietary protein contents than the FL line. Selecting birds on their growth rate or live body weight at 4 wk of age resulted in the selection of different rates of fattening. Indeed, the slow-growing FL and LL chickens differed less in their nitrogen metabolism than did fast-growing birds, which were also fatter. The lower protein retention efficiency observed in FL chickens was related to an increase of dietary amino acid degradation as revealed by a greater rate of uric acid excretion in the fed state.

Effects of dietary glucogenic amino acid supplementation on growth performance, body composition and plasma free amino acid levels in genetically lean and fat chickens.

Two experiments were conducted to investigate the effects of pair-feeding, nutritional status (fasting vs feeding ad libitum) and supplementing diets with alanine (2 g/kg), threonine (2 g/kg), glutamic acid (5 g/kg) and arginine (5 g/kg) on growth performance, body composition and free plasma amino acid levels in genetically lean (LL) or fat (FL) chickens of 4 to 7 weeks of age. When fed ad libitum, FL chickens ate more than LL birds and showed higher lipid and protein gains. However, when pair-fed, FL birds exhibited increased lipid retention but lower protein gain. Growth performance and body composition were not significantly affected by the addition of glucogenic amino acids to the diets. However, amino acid supplementation slightly improved food to gain ratios but depressed gross energy and protein efficiencies in both lines. FL chickens had lower plasma levels of most glucogenic amino acids and higher levels of branched-chain and sulphur amino acids than LL birds, irrespective of diet and nutritional status. These results are discussed in relation to hormonal characteristics of FL and LL birds.

[Diurnal variations in thee pancreatic proteases in th chicken fed with a meal]. / Variations nycthémérales des protéases pancréatiques chez le poulet nourri par repas.

Pancreatic protease contents (trypsinogen and chymotrypsinogen) were analyzed in 4- and 8-week-old chickens fed a single 2-hour meal daily. Enzyme activities showed a 24-hour cyclic degression and repletion rhythm. According to the age of the animal, pancreatic depletion preceded (4 weeks) or coincided (8 weeks) with the beginning of the meal. No rhythm was observed in the ad libitum fed chicken. Pancreatic secretion was also studied in the small intestine contents (duodenum, jejunum and ileum, successively) in the 8-week-old chickens.

Individual variation in the content of free amino acids observed in the blood and muscle of chicks fed a single meal daily.

1. Fifty broiler chicks in individual cages, were fed on a balanced diet ad libitum until 10 d old and then given a single meal daily. Blood and pectoral muscle samples were taken from each. Free aspartic acid, threonine, serine, glutamic acid, glycine, alanine, valine, cystine, isoleucine, leucine, phenylalanine, lysine and arginine were determined. 2. Free amino acid concentrations varied greatly between birds. Values for the coefficient of variation ranged from 0.21 for serine in both tissues to 0.571 and 0.749 for valine and lysine in blood and muscle respectively. 3. Many correlations for pairs of amino acids did not seem related to the body weight of chicks.

A comparison of the osmotic pressures along the digestive tract of the domestic fowl and the rabbit.

1. The osmotic pressures of the contents of the alimentary tract from the adult hen and cockerel and rabbit were measured. 2. In the rabbit osmolality of the fluids from the different segments of the digestive tract was similar (331 &/- 12 mOm) and slightly hypertonic to blood plasma (297 &/- 3-12 mOsm). 3. In the hen osmotic pressures were: crop 537, gizzard 312, duodenum 571, proximal jejunum 650, distal jejunum 573, proximal ileum 514 and distal ileum 451 mOsm. Only osmolality of the crop contents was influenced by egg formation. 4. In the cockerel osmotic pressure in the alimentary tract followed the same pattern as the hen and was modified by the time of day. 5. Plasma osmolality in the fowl was about 320 mOsm. Absorption of water across the proximal jejunum is achieved therefore against a gradient of about 330 mOsm in the female and 420 mOsm in the male fowl.

[Influence of Eimeria acervulina duodenal coccidiosis on intestinal absorption of lysine and on the movement of water and electrolytes]. / Influence de la coccidiose duodenale a Eimeria acervulina sur l'absorption intestinale de la lysine et sur les mouvements nets de l'eau et des electrolytes.

The absorption rate of 14C L-lysine and net flux of water and mineral ions (Na+, K+) were studied in 4-week-old male chickens infected with Eimeria acervulina (10(6) sporulated oocysts/chicken). Intestinal coccidiosis significantly decreased absorption rate of 14C-lysine. This effect was particularly pronounced in the jejunum. Net flux of water was also modified: its absorption was decreased in the middle and distal small intestine. In the duodenum a net absorption of water was converted to a net excretion. These effects were accompanied by an increase in tissue water content and in secretion rate of Na+ and K+.

[The effect of methionine, added to the diet of the gravid hen or injected into the egg, on the embryonic and post-natal development of the chick]. / Influence de la méthionine, ajoutée au régime alimentaire de la poule pondeuse ou injectée dans l'oeuf, sur les développements embryonnaire et post-natal du poussin

Chicks from hens consuming a methionine deficient diet have a live weight which is significantly reduced from hatching until 8 weeks of age. Normal growth rate was restored either by methionine supplementation of the hens diet or by injection of 0.5 mg of DL or L methionine. Injection of the D isomer alone was inactive.