Chemical composition and biological value of spray dried porcine blood by-products and bone protein hydrolysate for young chickens.

The chemical composition of spray dried porcine blood by-products is characterised by wide variation in crude protein contents. In spray dried porcine blood plasma (SDBP) it varied between 670-780 g/kg, in spray dried blood cells (SDBC) between 830-930 g/kg, and in bone protein hydrolysate (BPH) in a range of 740-780 g/kg. Compared with fish meal, these feeds are poor in Met and Lys. Moreover, in BPH deep deficits of Met, Cys, Thr and other amino acids were found. The experiment comprised 7 dietary treatments: SDBP, SDBC, and BPH, each at an inclusion rate of 20 or 40 g/kg diet, plus a control. The addition of 20 or 40 g/kg of the analysed meals into feeds for very young chickens (1-28 d post hatch) significantly decreased the body weight (BW) of birds. Only the treatments with 40 g/kg of SDBP and SDBC showed no significant difference in BW as compared with the control. There were no significant differences between treatments and type of meal for feed intake, haematocrit and haemoglobin concentrations in blood. Addition of bone protein and blood cell meals to feed decreased the IgG concentration in blood and caused shortening of the femur and tibia bones. However, changes in the mineral composition of bones were not significantly affected by the type of meal used. The blood by-products, which are rich in microelements, improved retention of Ca and Cu only. In comparison to control chickens, significantly better accretion of these minerals was found in treatments containing 20 g/kg of SDBP or 40 g/kg of SDBC. Great variability in apparent ileal amino acid digestibility in chickens was determined. In this respect, some significant differences related to the type of meal fed were confirmed for Asp, Pro, Val, Tyr and His. In general, the apparent ileal digestibility of amino acids was about 2-3 percentage units better in chickens fed on diets containing the animal by products than in control birds.

Effect of sweet chestnut tannin (SCT) on the performance, microbial status of intestine and histological characteristics of intestine wall in chickens.

1. In experiments carried out with 950 one-day-old male chickens, the effect of tannin supplementation (0, 250, 500 and 1000 mg/kg) on performance, microbial status of chickens small intestine and colon of 28- and 41-d-old chickens, as well as histological changes of jejunum walls at 41 d and carcase quality were determined. 2. Application of 250 or 500 mg of sweet chestnut tannin per kg of feed had an insignificant effect on body weight and feed conversion of 41-d-old chickens (30 and 26%) in comparison to control birds. The highest tannin supplement (1000 mg/kg) reduced final body weight. 3. No effects of tannin supplementation on feed conversion and carcase quality were found. 4. Addition of tannin increased dry matter content of the litter by 88 (Group II) and 77% (Group III) when compared to control. 5. Higher doses of tannins significantly reduced the number of E. coli and coliform bacteria in small intestine of 28-d-old chickens; in other microorganisms great variability of microbial populations in small intestine and colon were observed. 6. The histologies of jejunal walls in chickens of control, II (250 mg/kg) and III (500 mg/kg) groups were similar. The structure was characteristic of correctly developed and functioning tissues and the villi were formed correctly. Tannin applied at the highest dose (1000 mg) slowed down the proliferation rate in the mother-cell zone. Single cells and enterocyte complexes showed the features characteristic of degradation processes. These unfavourable symptoms indicated some disturbances in intestinal wall morphology and function.

Dynamics of yolk sac content absorption and intestine development in ducklings fed mixtures with increasing dietary methionine level.

The experiment was carried out with ducklings fed-control feed mixture (Met level 0.3%) and mixtures supplemented with dl-methionine at the dose of 0.03 (II); 0.07 (III) 0.12 (IV) and 0.18% (V). In 5 h post-hatch (12 birds) and on days 3, 4, 6 always 18 birds were taken out from each treatment and killed, then the yolk sac (YS) and intestine were removed. The weight and chemical composition of YS residues (in them also amino acids) were analysed. Moreover on days 1, 3, 4 and 6, the amino acid pattern of YS residual protein was elaborated as well as length and weight of intestine were recorded. Increased doses of supplemental Met improved body weight gain after 4 days of ducklings life. All determined parameters were not affected by treatment. Development of intestines, yolk sac weight and yolk sac composition (DM, fat, protein, amino acid composition) changed with age; however, without any clear effect from dietary methionine level. No differences between sex and analysed parameters were stated.

Effect of increased methionine level on performance and apparent ileal digestibility of amino acids in ducks.

The experiment was conducted with 960 one-day-old ducklings fed mixtures (I control - 0.28% methionine) additionally supplemented with DL-methionine (DL-Met) at amounts: 0.03% (group II), 0.07% (III), 0.12% (IV) and 0.18% (V). The performance, carcass quality and apparent ileal digestibility of amino acids as the criterions of methionine (Met) effectivity were considered. The analysis of growth and development of ducks as an effect of diversified DL-Met supplements indicate that increased content of this amino acid in the diets has not affected clearly the performance parameters. The body weight of 21-day-old ducklings was significantly affected only by the level of 0.12% of added Met in comparison to control group. On day 42, the differences among groups were negligible; only the addition of 0.12% DL-Met has increased the body weight by 2.4% when compared with control (p > 0.05). Feed conversion estimated for a period of 1-42 days has not been influenced by Met supplementation. The indistinct, however, visible tendency of better ileal amino acids' apparent digestibility (for Asp.a.,Thr, Ser, Glu, Lys) was noted in the groups fed supplemented diets. Application of 0.07% and 0.18% of DL-met, has significantly (p < 0.05) improved the coefficient of cysteine (Cys) apparent ileal digestibility; however, the improvement of Met apparent ileal digestibility has been achieved by the addition of 0.18% Met. The mortality of ducklings in the experiment was very low and varied between 3.15% (II) and 0.0% (groups I and III). In general, application of 0.12% of DL-Met to mixture containing 0.28% Met had positive effect on the productive output of birds and also improved the apparent ileal digestibility of Cys and Met.

Use of active substances of plant origin in chicken diets based on maize and locally grown cereals.

1. A total of 336 Hubbard Hi-Y broiler hybrids were fed from d 1-41 on diets based on maize or wheat and barley which were supplemented (or not) with 100 mg/kg plant extract consisting of capsaicin, cinnamaldehyde and carvacrol. 2. Body weight was not enhanced, but feed conversion improved by 4.2% on the maize diet and 2.0% on the wheat and barley diet. 3. Plant extract addition enhanced the breast muscle proportion of empty body weight by 1.2% in comparison to control birds. 4. The apparent ileal digestibility of nutrients (crude protein, fibre and amino acids) was not significantly better in birds fed on supplemented diets than in the control group. 5. Reduction of E. coli, Clostridium perfringens and fungi and increase of Lactobacillus spp. were observed in the 41-d-old chickens from the supplemented groups. 6. An increase in the lipase activity in pancreas and intestine wall was found in older birds fed on the plant extract supplemented diets.

Dynamics of yolk sac resorption and post-hatching development of the gastrointestinal tract in chickens, ducks and geese.

Under similar environmental conditions, 100 male Shaver-Starbro hybrid chickens, 100 male Mulard cross-line ducklings and 100 male Landaise goslings kept in 30 metabolic cages from the first day of life (10 birds of each species separately per cage) were chosen for the study. The animals were fed semi ad libitum diets with crude protein content and energy density similar to that used for poultry species, avoiding feed residues. During the first 21 days of life they received starter diets and from day 22 to 42 grower diets. Maize accounted for 23-40% and barley constituted 10-18%. Wheat accounted for 20.0% in starter diets and 10-18% in grower diets. Resorption of yolk sac residues, performance, development of the intestinal tract in young chickens, ducklings and goslings were assessed. During the first 5 days of life intensive absorption of yolk sac ingredients was observed. On day 7, residues of the yolk sac were found in more than 30% of chickens compared with approximately 10% in geese. In ducklings residues of the yolk sac were not found. On day 16 unabsorbed yolk sacs were found in approximately 10% of chickens. Liver and pancreas weighed the highest in geese and in ducks; in chickens the weight of these organs was significantly lower (p < 0.01). The relative values calculated to 100 g of metabolic body weight show that the average small intestine in chickens was significantly longer (p < 0.01) than in ducks or geese. The intestinal tract developed earlier in the chicken than in the water fowl.

Aspects of development of digestive activity of intestine in young chickens, ducks and geese.

The experiment comprised 100 chickens, 100 ducks and 100 geese fed diets based on mixed grains of maize, barley and wheat. Nutrient concentrations in the mixtures were in accordance with the requirements of poultry species. The birds were kept in metabolic cages from the 1st up to the 42nd day of life. The measurements of body weight, activity of alpha-amylase and lipase in pancreatic tissue, enzymatic activity of intestinal wall cells, parameters of carbohydrate fermentations, ileal and total amino acids digestibility were conducted on the 1st, 3rd, 5th, 7th, 28th and 42nd day of life or on the 14th, 28th and 42nd day of life. The pancreas alpha-amylase activity in chickens during the whole period was quite constant; in ducks and geese it was very low, but from the 28th day a dynamic increase in the activity of the pancreatic enzymes was observed in these birds. The activity of lipase was low but from the 28th day of experiment an increase was noted and was much higher in waterfowl than in chickens. The highest caecal concentration of SCFA (Short chain fatty acids) (in total high) was noted in chickens; these values were slightly lower in geese and ducks. A high (70%) ileal amino acids digestibility was seen in very young chickens; during the period of 15-42 days this value amounted up to 73%. In geese, the obtained values were 63% and in ducks 43-61%, with a mean of 55%. Faecal digestibility of amino acids had a mean of up to 86% for all species but the digestibility of single amino acids such as cystine, glycine, histidine and tyrosine was diversified and relatively lower than the others.

Development of the gastrointestinal tract and digestibility of dietary fibre and amino acids in young chickens, ducks and geese fed diets with high amounts of barley.

The experiment comprised of 50 chickens, 40 ducks and 30 geese fed a diet containing 40% barley. Birds were kept in metabolic cages from 1 to 42 days of age. A balance trial was carried out during the last week of the bird's life and the apparent digestibility of nutrients was determined. At 21 and 42 days of age 12 animals per species were killed. The absolute length of intestines followed the live weight (LW) of the animals. In relation to metabolic LW (kg(0.67)), the total length was significantly higher in chickens and geese than in ducks at 21 days of age, but identical in the three species at 42 days of age. The absolute and relative weights of intestines were smaller in ducks than in chickens and geese both at 21 and 42 days of age. Dietary fibre was digested better by chickens than by ducks and geese (P<0.01). Ileal digestibility of total amino acids amounted to 76% in chickens, 69% in ducks (P>0.05) and only 56% in geese (P<0.01) with relatively low digestibility of methionine (70, 44 and 52%) and lysine (72, 57 and 41%), respectively. The overall tract-faecal digestibility of total amino acids was evaluated on the level of 86% for all three species and indicates a substantial hind gut synthesis of amino acids.