Effect of diets containing raw and extrusion‐cooked rice bran on growth and efficiency of food utilization of broilers

1. Meat strain chicks were fed on diets containing 600 g rice bran/kg for the 7 to 8 week period required to reach broiler weight.

2. Extrusion cooking of rice bran resulted, in improved chick weight gain and food efficiency for the first two weeks of feeding, but this advantage was lost by the end of the feeding period.

3. Addition of 10 g calcium/kg to the stabilised rice bran diet prevented the decline in performance after two weeks of age, and birds fed on this diet continued to gain at an increasing rate until the end of the experiment.

4. Calcium supplementation of stabilised rice bran diets produced significantly greater gains and superior food utilisation compared to stabilised rice bran diets without added calcium.

5. Calcium supplementation did not affect weight gain of chicks fed on diets containing raw rice bran.

6. Taste panel evaluation of meat from birds fed on diets containing raw rice bran, stabilised rice bran, or no rice bran indicated a significant preference in only one combination tested. Any ‘off flavour could not be related to dietary treatment.     

Effects of different rates of drying cassava root on its toxicity to broiler chicks.

1. The effects of drying cassava root at different rates on its composition and toxicity to broiler chicks were examined. Unpeeled roots from a high-cyanide cultivar of cassava were chipped and dried at 25 degrees C to a moisture content of below 100 g/kg over 24 h for fast-dried meal (FD) or 72 h for slow-dried meal (SD). The meals were incorporated at 250 and 500 g/kg into semi-synthetic diets which were fed to day-old broiler chicks as mash or pellets in separate experiments. 2. The two drying rates produced meals with similar concentrations of polyphenols, but different concentrations of cyanogens, the latter being 38 and 482 mg total cyanide/kg for SD and FD, respectively. The linamarin, acetonecyanohydrin or total cyanide content measurements of pelleted diets were highly correlated. 3. Growth rates of chicks fed on SD-based diets were significantly higher than those of chicks fed on FD-based diets. Compared with a control diet, weight gain of chicks fed on the 500 g FD/kg diet (containing 258 mg total cyanide/kg) was 77% lower, although performance also appeared to be reduced at 142 mg total cyanide/kg. 4. The ratio of water:food intake of chicks was higher in FD than in SD groups, and this was reflected in the high water content of excreta. There was increased bile excretion, the chloretic effect increasing with the cyanogen content of diet. Pancreas weights were lower in FD than in SD groups in experiment 1 (mash diets), but not in experiment 2 (pelleted diets), while there was a significant interaction between drying method and cassava inclusion rate on liver weight in experiment 2, but not in experiment 1. There were no effects on the mortality rate. 5. Pelleting of diets generated high temperatures, but did not significantly alter the cyanogen concentration or the growth of the chicks. 6. Thus, slower rates of drying cassava roots produce meals with lower cyanogen concentration that are, consequently, less toxic to broiler chicks. Cassava root meal of less than 40 mg total cyanide/kg can be fed to broiler chicks at 500 g/kg without any adverse effects.     

Strategies to improve the nutritive value of rice bran in poultry diets. III. The addition of inorganic phosphorus and a phytase to duck diets

1. In the first of 2 experiments ducklings grown from 2 to 19 d were given diets with 0, 200 or 400 g rice bran, with or without a phytase and with 1 or 3 g inorganic phosphorus (Pi) per kg for rice bran-based diets only. In the 2nd experiment rice bran concentrations were 0, 300 or 600 g rice bran per kg with or without a phytase and 1 g Pi/kg. Ducks were grown from 19 to 40 d of age. 2. In experiment 1, a response to phytase was observed for weight gain and food intake on most diets except those with 200 g rice bran (3 g Pi) and 400 g rice bran (1 g P)i/kg. Main effects showed that 400 g rice bran depressed growth rate and food conversion ratio (FCR); increasing Pi depressed food intake, while food phytase increased food intake and growth rate over 2 to 19 d. There were several interactions. Dry matter and P retention were reduced but N digestibility improved when rice bran was increased from 200 g to 400 g/kg at 2 to 10 d of age; apparent metabolisable energy (AME) and calcium retentions were improved, similar results being seen at 10 to 19 d of age. Calcium and P retentions increased with the addition of food phytase and, at 10 to 19 d of age, phytase increased dry matter digestibility. Increasing Pi improved calcium and P retention, but only at 2 to 10 d of age. 3. Tibia ash (g or g/kg) content of bone was lowest on the diet without rice bran and without phytase; Pi concentration had no effect but phytase increased tibia ash on diets with 0 and 200 g rice bran and 1 g Pi/kg. Retention of several minerals in tibia ash declined at the highest rice bran inclusion rate; Pi level and phytase both increased Mg retention. 4. In experiment 2, food intake and growth rate of ducks, but not FCR, declined as rice bran inclusion increased from 0 to 600 g/kg. Phytase improved growth rate but not food intake and FCR on all 3 diets. Dry matter digestibility declined with increasing rice bran inclusion, but AME increased; retention of P and Mg declined but those of Ca and Fe increased. Phytase improved dry matter digestibility and retention of N and P. AME also increased but this was only on diets with 0 and 600 g rice bran/kg. There were reductions of 8% and 10% in P excreted in experiments 1 and 2 respectively when food phytase was added. 5. Tibia ash declined with increasing dietary inclusion of rice bran. Zn and Mn in ash tended to decline and Mg to increase; Ca and P showed no change in concentration in tibia ash. Again, phytase increased tibia ash content in bone. 6. It was concluded that there were a number of unexpected benefits from adding a food phytase to these diets, which resulted in improved nutrient yield and bird performance, although several of the diets appeared to be adequate in available P.     

Strategies to improve the nutritive value of rice bran in poultry diets. II. Changes in oil digestibility,metabolisable energy and attempts to increase the digestibility of the oil fraction in the diets of chickens and ducklings

1. In experiment 1, the effects of age on oil digestibility and apparent metabolisable energy (AME) were measured in chickens and ducklings between 3 and 28 d of age on a diet with 400 g rice bran/kg. In experiment 2, a biosurfactant and a food lipase were added to diets of chickens containing 200 and 400 g rice bran/kg. In experiment 3, chicken diets containing 0 or 400 g rice bran/kg were supplemented with a food lipase (2 concentrations) or a food enzyme or their combination. 2. In experiment 1, oil metabolisability and AME increased substantially as chickens aged. Oil metabolisability was much higher in ducklings, when comparisons were made with chickens of similar age. 3. In experiment 2, lipase or biosurfactant gave no improvement in bird performance. Growth rate and food conversion ratio were, respectively, 23% and 10% better on diets with 200 compared to 400 g rice bran/kg. 4. In experiment 3, there was a significant growth response to lipase plus the enzyme mixture on the diet with 200 g rice bran/kg. On the diet with 400 g rice bran/kg, growth improvement was seen with the enzyme mixture only. 5. In experiment 3, enzyme addition did not increase oil metabolisability or AME. At 4 to 8 d of age AME was higher on the diet without rice bran but oil metabolisability was the same as on the diet with rice bran. At 19 to 23 d of age AME was similar but oil metabolisability was higher on the diet with rice bran than without. Droppings' dry matter was higher on diets without than with rice bran (32.4 vs 27.1%). 6. The response to lipase and the combination of this and a food enzyme suggest that there may be benefit in examining this interaction further although they had no effect on oil metabolisability or on AME. It is concluded that a stable AME for rice bran cannot be provided for chickens until at least 21 d of age.     

Strategies to improve the nutritive value of rice bran in poultry diets. IV. Effects of addition of fish meal and a microbial phytase to duckling diets on bird performance and amino acid digestibility

1. Ducklings were given diets with vegetable protein (VP) and 0 or 600 g rice bran/kg; fish meal (60 g/kg) and a phytase (+,-) were added to the diets (VP + AP). An additional 40 g soyabean meal/kg was added to the diet with rice bran (VP ++). Amino acid digestibility and mineral retention were measured in the lower ileum of ducklings killed at 23 d of age. Acid insoluble ash was used as an inert marker. Trypsin and amylase activities were also measured and weights of the pancreas and small intestine recorded at slaughter. 2. Addition of soyabean meal (VP ++) to the diet with rice bran improved growth rate and food intake compared to the diet without (VP) and gave the same food intake and growth rate as the comparable basal diet (VP) without rice bran. Fish meal improved growth rate on the diets without rice bran and improved food intake on this diet (VP + AP). Rice bran depressed growth rate and food conversion ratio (FCR); protein source affected growth rate, food intake and FCR; phytase increased food intake only. There were several interactions. 3. Determined total amino acid composition of the diets appeared to meet the essential amino acid requirements of ducklings. Rice bran depressed the ileal digestibility of virtually all amino acids and phytase had no direct effect, although there were interactions. Fish meal addition to diets with rice bran improved the apparent digestibility of several essential amino acids as well as that of dry matter and crude protein. 4. Ileal retention of some minerals and tibia ash content were reduced by rice bran. Fish meal and phytase inclusion increased P retention and ash in tibia. 5. Higher intestinal trypsin activity and increased pancreas size were seen in ducklings on diets with rice bran compared to those without. Intestinal amylase activity was reduced in ducklings given rice bran, probably because of its low starch content. 6. The stimulating effect of fish meal on duckling performance was probably caused in part by the improvement in the digestibility of some amino acids. The addition of small amounts of minerals in fish meal may have increased mineral retention. Phytase gave benefits anticipated from our previous work, but also improved lysine and threonine digestibility in diets containing vegetable protein only.     

Effects of Rice Bran Inclusion on Performance and Bone Mineralization in Broiler Chicks

Rice bran, a by-product of the rice industry, is available for animal feeds. However, it has not been a common part of poultry rations in Argentina. Hydrolytic and oxidative rancidity development, phytate content, enzyme inhibitor, and high fiber content are the most important antinutritive factors cited as limiting factors for its use. An experiment utilizing 1-d-old male broiler chicks was conducted to determine the responses of zootechnical and bone mineralization parameters to diets with different concentrations of rice bran. The feed conversion and tibia ash were more sensitive than weight gain to detect antinutritive factors in rice bran. High concentrations of rice bran (in excess of 20%) produced a significant reduction in body weight. Furthermore, feed conversion and bone mineralization variables were impaired by feeding 10% rice bran diets. The adverse effects of rice bran on weight gain, feed conversion, and mineralization in the current studies suggest that rice bran should be included in broiler diets at a level between 10 and 20% if strategies are not used to decrease the antinutritive activity.     

Rice bran lysolecithin as a source of energy in broiler chicken diet

1. Rice bran lysolecithin (RBL) was evaluated in broiler chicken diets. In the first experiment, RBL was included in diet at 0, 0·5, 2, 8 and 32?g/kg and fed to 250 broiler chickens from 0 to 42?d of age. In the second experiment, RBL was fed at 0, 25 and 50?g/kg diet to 405?day-old broiler chickens until 21?d of age, while during the finisher phase (22–35?d of age) chickens receiving each concentration of RBL were given all three concentrations of RBL in a 3?×?3 factorial manner. The diets were isocaloric.

2. Body weight, food consumption and food conversion efficiency were unaffected by feeding RBL, while the weight of pancreas increased at ≥2?g/kg of RBL in diet (experiment 1). In experiment 2, body weight was greater in the chickens receiving RBL at either 25 or 50?g/kg (21?d) and 50?g/kg (35?d of age). At 21?d of age, food consumption was greater at 25 or 50?g RBL/kg diet, while food conversion efficiency improved with 50?g RBL/kg diet.

3. Fat digestibility increased with RBL at 32?g/kg (experiment 1) and ≤25?g/kg (experiment 2). Rice bran lysolecithin increased ready to cook weight at 50?g/kg during starter phase and decreased abdominal fat at 25 and 50?g/kg during finisher phase (experiment 2). Liver and meat fat content were not affected.

4. It is concluded that lysolecithin from rice bran oil could be used as energy supplement in broiler chicken diet.     

Effect of replacing barley with rice bran in finishing diet on productive performance and carcass characteristics of Afshari lambs

Thirty-five male Afshari lambs (3.5 months old), with an average weight of 35 kg were randomly assigned to one of five experimental treatments relating to optimal replacement level of rice bran in lamb finishing diets. The lambs were fed a milled concentrate (3 mm screen) diet supplemented with 15% (DM basis) chopped (5 cm length) lucerne hay and chopped (5 cm length) maize silage or wet (80% moisture) sugar beet pulp. Barley grain in the lambs’ diets was replaced by rice bran at either 0, 15, 30, 45 or 60% of the concentrate mixture on a dry matter basis. Results show that lambs fed 45 and 60% rice bran treatments weighed significantly less than those fed with 15 and 30% and control group (P < 0.05). Average daily gain in lambs fed with concentrate mixtures containing 45 and 60% rice bran were 33 and 47% lower than control, respectively (P < 0.05). Lambs that received diets containing 45 and 60% rice bran, had lower feed intake (P < 0.05) than other groups. Using rice bran in the finishing diet had no significant effect on dressing percentage, tail percentage, abdominal fat and visceral organ weights. These results suggest that barley can be replaced with rice bran up to 30% in the finishing diets of lambs without any adverse effect on lamb performance.     

In vitro bile acid-binding capacity of dietary fibre sources and their effects with bile acid on broiler chicken performance and lipid digestibility

1. A 4 × 2 factorial experiment was conducted to study the effect of feeding diets-containing dietary fibre (DF) sources and a source of bile acid (BA) on growth performance and lipid metabolism. In addition, in vitro BA-binding capacity of fibre sources was investigated.

2. A total of 256 one-d-old male broiler chickens (Ross 308) were assigned to DF sources [maize-soybean meal (control, C), or 30 g/kg of wheat bran (WB), barley bran (BB) or soybean hulls (SH)] and BA (with or without 1.5 g Na-deoxycholate/kg). Each treatment was replicated 4 times with 8 broiler chickens per cage.

3. The highest in vitro BA-binding capacity was observed with BB (8.76 mg/g BB). From 0 to 21 d, with the addition of BA, the average daily feed intake (ADFI) decreased in broiler chickens fed on the C, WB or BB diets, while there was no difference with the SH diet. With added BA, the average daily gain decreased in broiler chickens fed on the C or SH diets, but it did not change in those fed on the other diets. The addition of BA decreased feed conversion ratio (FCR) in broiler chickens fed on the BB or WB diets, but it increased in those fed on the C or SH diets. Interaction results indicated that the apparent ileal digestibility of lipid increased in broiler chickens fed the C and other DF diets with BA compared to those fed the diets without BA. The addition of BA decreased the pancreas lipase activity (PLA) in broiler chickens fed on the C diet compared to those fed the C diet without BA, while no changes observed in those fed the DF diets with or without BA. No interaction was observed in total liver bile acid (TLBA).

4. The WB, BB and SH with little Na-deoxycholate-binding capacity (<10 mg/g of DF) under in vitro conditions had particular effects with BA on the measured criteria in broiler chickens. The magnitude of improvement in digestibility of lipid with the addition of BA depends on the source of fibre used and the addition of BA in DF diets had little effect on growth performance in young broiler chicken diets.

     

Feed preference in pigs: effect of cereal sources at different inclusion rates

The palatability of different cereals was studied in 2 two-way choice (preference) experiments using pigs of 56 d of age and 17 kg of BW. In Exp. 1, the effect of 24 cereals vs. a common reference diet containing white rice on feed preference in pigs was studied. Pigs were offered free choice between the reference diet and a diet with the cereal under study for 4 d. Barley, corn (2 sources), wheat, cassava meal, biscuit meal, rye, sorghum, and 1 source of oats were tested at inclusion rates of 300 and 600 g x kg(-1). Short-grain rice (whole, brown, or extruded white), long-grain white rice (raw and cooked), extruded barley, extruded corn, extruded wheat, oats (2 sources), thick rolled oats, cooked oats, and naked oats (raw, extruded, or micronized) were tested at inclusion rates of 150, 300, and 600 g x kg(-1). Relative preference of cereals (% of total feed intake) was affected by type of cereal and by rate of inclusion. The diets containing extruded rice (150 g x kg(-1)), extruded naked oats (150, 300, and 600 g x kg(-1)), or naked oats (150 and 300 g x kg(-1)) were preferred (P < 0.05) by pigs to the reference diet. However, the reference diet was preferred (P < 0.05) to the diets containing 150, 300, and 600 g x kg(-1) of cooked long-grain rice, oats, or cooked oats, 300 and 600 g x kg(-1) of extruded wheat, wheat, corn, sorghum, or unhulled short-grain rice, and 600 g x kg(-1) of thick rolled oats, extruded corn, rye, extruded barley, micronized naked oats, barley, cassava, or biscuit meal. Extrusion improved (P < 0.05) preference values for corn and naked oats by pigs, but had no effect on barley, rice, or wheat. In Exp. 2, the preferences of pigs for oats and barley were studied using mash and pelleted diets. Diet form did not affect preference in oats diets. However, for barley, greater preference values were obtained when measured in pelleted form compared with mash form. Additionally, direct 2-way choices were also performed between oats and barley diets and between diets presented in mash and pelleted forms. Pigs preferred barley to oats, and preferred diets presented in pelleted form to those presented in mash form. In conclusion, cereal type, inclusion rate, and diet form affected feed preference in pigs. Using cereals with greater preference values may contribute to the formulation of more palatable feeds, which enhance feed intake of piglets at critical stages such as weaning time.     

Effects of heat treatment on the nutritional value of raw soybean selected for low trypsin inhibitor activity

1. Two broiler experimentss and a layer experiments were conducted on Kunitz trypsin inhibitor (Kti) soybeans (SB) of low trypsin inhibitor (TI) activity to determine their nutritive value when included as mash in least-cost poultry diets. 2. Experiment 1 compared chick performance on the Kti or raw SB using a commercial full-fat SB meal (FFSBM) and a solvent extracted SB meal (SBM) as controls during a 20 d experimental period. Broiler experiment 2 compared Kti and raw SB, non-steamed, or steam-pelleted with and without DL-methionine supplementation added to every treatment containing 170 g SB/kg. For each broiler experiment the levels of each SB were 70, 120 and 170 g/kg with the control birds fed only 170 g SB/kg. 3. The layer experiment, compared steam-pelleted Kti and raw SB against a non-steamed Kti and raw SB each fed at two levels (70 and 110 g/kg) x 30 replicates from 29 weeks of age for 19 weeks in a completely randomised design. Production parameters were measured when diets were formulated to contain minimum required specifications and calculated apparent metabolisable energy (AME). At the completion of each trial, 2 broiler birds from each cage and 5 layer birds per treatment were killed, weighed, and their liver and pancreas weighed. 4. Both broiler experiments indicated that production parameters on the Kti SB treatments were significantly lower (P<0.05) than on the two commercial control SB treatments. However, the Kti treatments were superior to the raw SB treatments. 5. Pancreas weight increased with increasing inclusion of both raw and Kti SB, suggesting that a TI was causing the depression in performance. The AME of the Kti SB was similar to that of commercial FFSB meal. After steam conditioning, the raw SB meal AME value of 9.5 MJ/kg dry matter (DM) was improved to 14.1 MJ/kg DM by reduced TI activity, but this AME improvement with TI activity reduction, plus the supplementation with DL-methionine on birds fed the raw SB had no effect (P>0.05) on any parameter evaluated in experiment 2. 6. The layer experiment showed that hens on the Kti SB treatments had significantly greater live weight gain (LWG), egg weight and daily egg mass than birds given raw SB. A reduced food intake (FI) was observed in the Kti treatments but egg mass was generally similar to that on the FFSB control diet, indicating that Kti SB supported excellent egg production at an inclusion of 110 g/kg. The depressed performance observed for broiler chicks suggest that younger birds are more susceptible to the effects of SB TI.     

Interaction between genotype and dietary concentrations of methionine for immune function in commercial broilers

1. Growth, antibody response to sheep red blood cells (SRBC) and resistance to Escherichia coli were measured in broiler female chicks received from 4 (n = 100 in each) commercial genotypes (A, B, C and D) and fed with maize-soybean-deoiled rice bran based diets containing 4 concentrations of methionine (3.91, 4.46, 5.00 and 5.54 g/kg). The diets were fed ad libitum from 1 to 49 d of age. 2. Body weight gain and weight gain/food intake at 2 week intervals, response of broilers to inoculation of 0.5 ml of SRBC (0.5 or 2.5%), 0.1 ml of E. coli (10(-4) dilutions) culture, and 100 microg phytohaemogglutinin-P (PHA-P) at 43 d of age were measured. The responses to SRBC and E. coli inoculation were recorded at 5 d post inoculation (PI), while the responses to PHA-P were recorded at 12 and 24 h PI. 3. Genotype by methionine interaction was not significant for body weight gain, but significant differences in weight gain were observed among different genotypes. Variation in methionine concentration did not influence body weight gain or weight gain/food intake at 1 to 14, or 42 d of age. At 28 d of age, chicks fed on the 3.91 g methionine/kg diet weighted significantly less than those on the other methionine concentrations. Genotype by methionine interaction was observed for food efficiency at 0 to 28 d of age but not at other ages. 4. Antibody titres against SRBC and heart and air sac lesion score to E. coli challenge were not influenced by genotype-methionine interaction. Chicks given higher concentrations of methionine had higher antibody titres and greater cutaneous basophilic hypersensitivity (CBH) response than those given low levels of methionine. Also, variation was observed in expression of CBH response to PHA-P among different genotypes. 5. It may be concluded that, although the commercial broiler chicks do not require more than 3.91 g methionine/kg for optimum growth and food efficiency, the immunity in terms of CBH response and antibody production to SRBC increased with the concentration of methionine in the diet in the majority of genotypes, indicating a higher methionine requirement for immunity than for weight gain.     

Strategies to improve the nutritive value of rice bran in poultry diets. I. The addition of food enzymes to target the non-starch polysaccharide fractions in diets of chickens and ducks gave no response

1. Three experiments were undertaken to test the efficacy of 2 enzymes targeting mainly the non-starch polysaccharides (NSPs) in rice bran. 2. In experiment one, 400 g rice bran/kg depressed chick performance and there was a significant decline in growth rate and food intake with increasing inclusion of rice bran (0, 200, 400 g). Neither enzyme had any benefit. 3. In experiment two, rice bran (inclusion 200 and 400 g/kg), did not alter growth rate, food intake or food conversion ratio of duckling (3 to 17 d of age). Again enzyme addition gave no response. 4. In experiment three, 300 g rice bran/kg stimulated duck (19 to 35 d of age) growth while 600 g rice bran/kg depressed growth but not food intake. Enzymes gave no response. 5. Relative gut viscosity declined with increasing rice bran inclusion as did dry matter in ileal digesta. There were differences between ducklings and chickens. 6. It was concluded that NSPs were not a significant factor in altering the nutritive value of rice bran and the enzymes used were therefore unlikely to be of benefit.     

Comparison of the utilisation of palm kernel meal,brewers' dried grains and maize offal by broiler chicks

1. Palm kernel meal (PKM), brewers dried grains (BDG) and maize offal (MO) were included in broiler diets, each at 100, 150 or 200 g/kg; the diets were fed up to 35 d of age. 2. Overall food intake and weight gain decreased in the order BDG, PKM and MO. There were, however, significant interactions between the test ingredients and dietary concentrations in all the growth responses. Food intakes increased with the dietary concentrations of each test ingredient, but the increase was greater for BDG than PKM or MO. For weight gain, at 100 g/kg, the final body weights of the chicks fed on the diets with BDG and MO were similar, and those of chicks fed on the diet with PKM slightly lower. However, at 200 g/kg, growth rate of chicks fed on the BDG and PKM diets were similar while those of chicks fed on the MO diet was 7% lower. Efficiency of food utilisation was similar at 100 g/kg for all the ingredients and decreased as their concentrations increased; however, the decrease was considerably less for the PKM than for the MO and BDG diets. 3. Broilers fed on the BDG-based diets voided most excreta followed by those fed on the PKM and MO diets; excreta water content was highest from birds fed on the MO diets followed by the PKM and BDG diets. Apparent retention of dry matter was similar with all the test ingredients, but it decreased only significantly at 200 g/kg dietary concentration. The rate of passage was faster with the PKM diets followed by the MO and BDG diets; it was increased at 200 g/kg dietary concentration of the test ingredients.     

The incorporation of whole grain into pelleted broiler chicken diets: production and physiological responses

1. Pelleted diets, incorporating whole or ground triticale or wheat in the pellets, were fed to broiler chickens and the performance, gastro-intestinal development and health of those chickens recorded. 2. The use of whole triticale in the pelleted food produced similar bodyweight responses to when ground triticale was incorporated in the food. Food conversion efficiency was enhanced when whole triticale was used compared to ground triticale and was similar to when an exogenous enzyme was added to the ground triticale diet. The incorporation of whole wheat into the pelleted food produced similar production responses to the use of ground wheat. 3. The gastro-intestinal development of the birds was greater when they were fed the whole grain diet as gizzard weights were increased by the incorporation of whole grain into the diet. Gastro-intestinal development was thought to be related to the presence of large fibre particles in the food. 4. Proventricular dilatation and mortality due to ascites were reduced by feeding pelleted diets containing whole grain, which was possibly related to the early development of the gastro-intestinal tract relative to total body development. 5. It is suggested that the current use of exogenous enzyme additions to broiler diets may be reduced by incorporating whole grain into pelleted diets for broiler chickens.     

Nutritional value of raw and autoclaved kabuli and desi chickpeas (Cicer arietinum L.) for growing chickens.

1. Two experiments were carried out to determine the effect of inclusion of raw (kabuli and desi) and autoclaved (desi) chickpea seeds in wheat-based starter diets in chickens grown to 28 d of age on the performance, digestive organ sizes, nitrogen-corrected apparent metabolisable energy (AMEn), ileal apparent protein and starch digestibilities (APD and ASD) and intestinal alpha-amylase and trypsin activities. 2. In the first experiment, diets were formulated to contain 0, 150, 300 and 450 g/kg of raw kabuli chickpea seeds. Increasing the proportion of seed in the diet negatively influenced body weight gain, food intake and food efficiency. The relative weights of the pancreas, liver and gizzard and the relative lengths of duodenum, jejunum, ileum and caeca were increased significantly when the chickpea seeds were included in the diets. Correspondingly, APD, ASD, alpha-amylase and trypsin activities and AMEn were reduced significantly when the chickpea seed was incorporated in the diets. 3. In the 2nd experiment, diets were formulated to contain 75 and 150 g/kg of raw and autoclaved desi chickpea seeds. Weight gain and food intake of the chicks given desi chickpea diets were significantly reduced compared with those fed on the control diet. Increasing the proportion of seed in the diet negatively influenced body weight gain, food intake and food efficiency. Moreover, a significant increment in the relative weights of liver and pancreas, and in the relative lengths of duodenum, ileum and caeca was observed when the concentration of chickpea seeds in the diets was increased. Feeding autoclaved seeds significantly increased the weight gains and the food intakes. However, food efficiency was not modified by the autoclaving. Relative weights of gizzard and liver and relative lengths of ileum were decreased significantly by the inclusion of autoclaved desi chickpea in the diet. 4. We concluded that the inclusion of kabuli (up to 450 g/kg) and desi (up to 150 g/kg) chickpea seeds produced a negative effect on the performance of the birds, and an increment in the relative weights and lengths of the digestive organs. In addition, the incorporation of kabuli chickpea produced a reduction of protein and starch digestibilities, alpha-amylase and trypsin activities, and AMEn of food compared with the birds given the control diet. Autoclaved treatment of desi chickpea improved the performance of the birds.     

Effects of dietary rosemary, rosemary volatile oil and vitamin E on broiler performance, meat quality and serum SOD activity

1. The current study was conducted to evaluate the effects of dietary supplementation with vitamin E (as alpha-tocopherol acetate), dried rosemary leaves and rosemary volatile oil on the performance, meat quality (measured as sensory variables, pH, colour, malondialdehyde (MDA) level, and bacteria count) and serum superoxide dismutase (SOD) activity in broilers fed on maize-soybean meal based diets. 2. A total of 800 broiler chicks were randomly allocated to 8 dietary treatments, which were set up with 1 control group and 7 experimental groups. The control group (VitE1) was given a basal diet including 50 mg/kg alpha-tocopherol acetate, while the experimental groups were given 5 x 7 g/kg rosemary plant (R1), 8 x 6 g/kg plant (R2), 11 x 5 g/kg plant (R3), 100 mg/kg plant oil (RO1), 150 mg/kg plant oil (RO2), 200 mg/kg plant oil (RO3) or 200 mg/kg alpha-tocopherol acetate (VitE2). 3. Although there were no statistical differences observed for feed consumption, other performance variables including live weight gain, feed efficiency and carcase yield were significantly affected. The addition of rosemary volatile oil had more effect on the performance variables than did the rosemary plant itself. 4. As a measure of meat shelf life, TBA analyses were performed on the meat samples on d 1, 3 and 5 after culling. Meat MDA levels of groups fed diets with rosemary and rosemary volatile oil were significantly lower than that of groups fed diets containing alpha-tocopherol acetate alone. 5. Significant differences were also seen between the control and experimental groups for meat colour and meat pH values as well as for sensory analyses. 6. Microbiological analyses conducted at the end of the experiment showed that E. coli counts were significantly reduced in meat samples from the experimental groups. 7. In conclusion, dietary supplementation with rosemary and its volatile oil improved broiler meat quality. Moreover growth performance was positively affected by the rosemary volatile oil supplementations.     

The dietary effect of different wheat cultivars for broiler chickens.

1. An experiment was conducted to examine the variability in chemical composition of 16 wheat cultivars and to study how this variability affected the performance of broiler chickens given diets containing 650 or 815 g wheat/kg diet during the first 3 weeks of life. Intestinal viscosity, apparent fat digestibility and apparent metabolisable energy were determined with all diets. Intestinal pH and the relative weight of different parts of the intestine were measured in chickens fed on diets with the high wheat inclusion. 2. The 16 wheat cultivars varied in chemical composition, with protein content ranging from 112 to 127 g/kg dry matter, starch content from 658 to 722 g/kg dry matter and non-starch polysaccharides from 98 to 117 g/kg dry matter. The effect of the different wheat cultivars on the measured parameters was most pronounced in chickens fed on diets with 815 g wheat/kg diet (P<0.001). However, significant (P<0.001) differences between cultivars were still present at the lower wheat content. 3. Milling-quality wheats resulted in better performance (P<0.001) than feeding-quality wheats at the high inclusion, whereas such an effect could not be registered in diets at the lower wheat inclusion. These results indicate that some of the feeding wheats are comparable in quality to milling wheats when included at the concentrations which are more common in practical broiler diets. 4. Decreasing the wheat content in the diets resulted in significantly (P<0.001) better performance and considerably (P<0.001) lower intestinal viscosity (jejunum; 2.4 to 5.9 cps, ileum; 4.6 to 10.9 cps) than in chickens fed on diets with the higher wheat inclusion level (jejunum; 9.1 to 38.4 cps, ileum; 20.8 to 82.0 cps). 5. Diets with 815 g wheat/kg influenced pH in the caeca, but not in the ileum and gizzard. The relative weights of the gizzard and ileum differed significantly (P<0.05) between treatments, whereas those of duodenum, jejunum and caeca were not affected by dietary addition of the different wheat cultivars. 6. The present study demonstrated that the chemical composition and the nutritive value of Danish wheats for broilers vary markedly. The results indicated that the non-starch polysaccharide and especially the arabinoxylan content of wheat are important factors in the discussion of the result obtained. Poor correlations were seen between performance and AMEn and care should be taken when using AMEn values alone to predict the nutritive value of wheat and wheat-based diets.     

Effect of formic acid on performance, digestibility, intestinal histomorphology and plasma metabolite levels of broiler chickens

1. The effect of dietary formic acid on performance, digestibility, intestinal histomorphology and plasma metabolite levels of broiler chickens was studied. 2. An experiment with 120 Ross male broiler chickens was conducted from 1 to 42 d of age at the laboratory. There were 4 treatment groups: control (C), 10 mg/kg feed avilamycin (AV) and formic acid at two concentrations, 5 and 10 g/kg feed (FA5 and FA10, respectively). 3. No differences in weight gain, feed intake or feed conversion ratio were observed in male broiler chickens fed on the different diets. 4. An effect of the additives on ileal dry matter (DM) digestibility at 42 d of age was detected with the finisher diets; AV and 10 g/kg of feed formic acid slightly improved ileal DM digestibility compared to the other treatment groups. 5. Jejunum pH was not affected when 5 or 10 g/kg formic acid was added, and the results do not clearly show a positive effect of formic acid on the intestinal histomorphology. 6. No differences were noticed for blood metabolites in the different diets, and the levels of calcium and phosphorus in the plasma were not altered by formic acid addition. 7. In conclusion, when using broiler chickens under conditions of good hygiene, dietary formic acid did not have a clear positive effect on performance, intestinal histomorphology or plasma metabolite levels; however, there was a slight positive effect on the ileal digestibility of nutrients.     

Effect of dietary copper on litter microbial population and broiler performance

Proprietary broiler diets, containing added copper (125 mg/kg) as sulphate, were fed to broilers in 4 trials (32 pens each) over a one year period without a change of litter. Mould counts in the litter of pens containing birds fed the standard diets decreased to 2 X 10(3) propagules per g in trial 4. Those in the pens with birds fed the diets containing supplemental copper decreased to 6 X 10(2) propagules per g. Litter bacterial counts (10(7) organisms/g) were not affected by dietary copper. Litter copper concentrations in pens where the birds were fed supplemented diets increased significantly to more than 600 mg/kg in trial 4. Dietary copper sulphate addition significantly increased broiler weight gains at 7 weeks in trials 3 and 4 (P less than 0.05) and the efficiency of food utilisation was significantly improved in trial 4. The copper content of the chicks' livers remained unchanged. It is suggested that broiler performance may be independent of dietary copper content. Litter copper concentrations and litter microbial alterations may be important factors.