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PubMed2002

Genetic and phenotypic relationships between and within support and demand tissues in a single line of broiler chicken.

1. With commercial selection for increased broiler performance there has been a correlated increase in the incidence of several metabolic disorders. A study was undertaken to investigate the balance between the unselected support tissues (including the heart, liver, spleen and the components of the gastrointestinal tract (GIT)) which drive growth in the selected demand tissues (eviscerated body mass) by assessing the genetic correlations between these traits. 2. Data were collected on 483 broiler birds taken from a commercial male broiler line with pedigree information. 3. Genetic parameters were estimated by restricted maximum likelihood with an individual animal model. Heritability estimates for the production traits ranged between h2 = 0.48 and 0.59 for leg and breast mass, respectively. The support tissues were generally associated with low to moderate heritabilities ranging between h2 = 0.19 for proventriculus to h2 = 0.38 for duodenum mass, although moderately high heritability estimates (h2 = 0.51 to 0.54) were associated with the spleen and gizzard. 4. The genetic correlations between production traits and support organs were generally low, however, heart mass was positively correlated with all carcase components of the lean tissue mass; the genetic correlations ranged between r(g) = 0.55 with breast mass to r(g) = 0.64 with eviscerated body mass. 5. In general, there were strong positive genetic correlations between the different components of the GIT. Organs that have been implicated in the development of metabolic disorders such as ascites (for example, the heart) could theoretically be used in commercial selection indices due to moderate heritabilities (heart: h2 = 0.30) and favourable correlations with commercially important traits.

Animals↗

PubMed2003

Responses of broiler chickens to dietary protein: effects of early life protein nutrition on later responses.

1. A study was conducted with modern broiler chicks to test the effects of early life protein nutrition and sex on responses in growth and body composition to dietary protein at a later age. Effects on the incidence of metabolic disorders were also evaluated. 2. From 11 to 26 d of age (EXP1), birds were given 8 diets varying in balanced protein to energy ratio (BPE ratio) between 0.575 and 1.100 g digestible lysine per MJ AMEn. Birds from two treatment groups in EXP1 (BPE ratio of 0.725 and 1.025 g/MJ, respectively) were subsequently used in a test from 26 to 41 d of age (EXP2). In EXP2, 8 diets were used, varying in BPE ratio between 0.500 and 1.025 g/MJ. 3. Responses in weight gain and feed conversion to BPE ratio in EXP2 changed considerably when BPE ratio in EXP1 was modified, irrespective of sex. Up to 10% improvement in both weight gain and feed conversion in EXP2 was observed if BPE ratio in EXP1 was 0.725 compared with 1.025 g/MJ. With males, however, the effect of treatment in EXP1 on weight gain in EXP2 was present only at high BPE ratios. 4. For the relative gain of breast meat and abdominal fat, but not for carcase, the responses of male broilers to BPE ratio in EXP2 were altered by the BPE ratio in EXP1. With females, responses in composition of the gain to diet in EXP2 were independent of BPE ratio in EXP1. 5. The incidence of metabolic disorders was low, irrespective of treatment in EXP1. The lower BPE ratio in EXP1 increased mortality in EXP2 from 0.8 to 3.6%. 6. Our findings show that broiler responses to dietary protein depend on previous protein nutrition and sex. Effects of early life protein nutrition on incidence of metabolic disorders were not observed. The results strongly suggest that protein levels in grower and finisher diets should not be optimised independently, but simultaneously.

Age Factors↗

PubMed2003

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.

Animal Husbandry↗

PubMed2003

Effects of oat hulls and wood shavings on digestion in broilers and layers fed diets based on whole or ground wheat.

1. An experiment was conducted to study the effects of inclusion of oat hulls in diets based on whole or ground wheat for broilers. Effects of wood shavings on layers were investigated in a further experiment. 2. Inclusion of oat hulls in wheat-based broiler diets did not affect weight gain. Feed conversion efficiency (FCE), corrected for insoluble fibre contents, was improved by oat hull inclusion. 3. Gizzard size increased with inclusion of oat hulls, whole wheat, wood shavings and grit. 4. Starch digestibility was significantly increased by inclusion of oat hulls for broilers, and by wood shavings for layers. 5. Wood shavings and whole wheat did not affect bile acid concentration of gizzard contents. However, the total amount of bile acids in gizzard increased with access to wood shavings due to an increase in the weight of gizzard contents, indicating an increased gastroduodenal reflux. 6. Fibre concentration was considerably higher in the gizzard contents than in the feed. 7. Duodenal particle size decreased with access to grit. No effect of hulls or whole wheat inclusion was found, indicating that all particles are ground to a certain critical size before leaving the gizzard.

Animal Feed↗

PubMed2003

Supplementation of diets containing pea meal with exogenous enzymes: effects on weight gain, feed conversion, nutrient digestibility and gross morphology of the gastrointestinal tract of growing broiler chicks.

1. The potential for the nutritional improvement of pea-based diets by supplementation with a cocktail of exogenous carbohydrases was investigated using growing broiler chicks. 2. Pea meals (grown in the UK) were included in wheat-based diets at 300 g/kg as a partial replacement for an approximately isonitrogenous mixture of wheat and soybean meal. A wheat/soybean meal diet served as a control and each diet was supplemented with a cocktail of alpha-amylase, pectinase and cellulase. The diets were fed to 1-d-old broiler chicks for a period of 21 d. Weight gain and feed conversion were monitored weekly and excreta were collected during the final week in order to determine nutrient digestibility coefficients and metabolisable energy. On d 21, the gastrointestinal (GI) tract was excised and gross morphology measured. 3. Inclusion of pea meal reduced weight gain, feed conversion, nutrient digestibility and also increased the relative sizes of the distal sections of the GI tract. 4. Enzyme addition partially ameliorated the detrimental effects of pea meal inclusion although similar improvements were also noted for birds fed on the control diet. 5. It is concluded that the nutritive value of pea-meal-based diets can be improved by the addition of carbohydrases, and that some pea cultivars show considerable potential as vegetable protein sources for broiler chicks.

Animal Feed↗

PubMed2003

Photorefractoriness in broiler breeders: sexual maturity and egg production evidence.

1. Photorefractoriness was assessed in two lines of broiler breeders. In one trial, male-line and female-line pullets were reared on the floor and transferred to individual cages at 15 weeks. Birds were either maintained on 8-, 11- or 16-h photoperiods or transferred from 8- to 16-h photoperiods at 67 or 124 d. In the second trial, female-line pullets were concurrently housed in the same rearing facilities as trial 1 and transferred to adult floor-pens at 12 weeks. These birds were either maintained on 11- or 16-h photoperiods or transferred from 8- to 11-h or from 8- to 16-h photoperiods at 140 d. 2. In the cages, male-line and female-line birds responded similarly to the lighting treatments, but with the male-line maturing 1 to 2 weeks later than the female-line in each case. Birds on constant 11-h photoperiods matured 3 to 8 d earlier than constant 8-h birds, but 3 weeks earlier than constant 16-h birds. Birds photostimulated at 67 d matured at a similar time to constant 16-h birds, but almost 7 weeks later than those transferred from 8 to 16 h at 124 d. In the floor facilities, constant 11-h birds matured 3 weeks earlier than constant 16-h birds, but almost 2 weeks later than either of the photostimulated groups. Birds transferred from 8 to 16 h matured 4d earlier than those transferred from 8 to 11 h. 3. Caged birds maintained on 16 h or transferred from 8 to 16 h at 67 d laid at least 24 fewer eggs, and had more hens not laying at 58 weeks, than birds maintained on 11-h days or those transferred from 8 to 16 h at 124 d. In the floor-pens, constant 11-h and both photostimulated groups produced about 20 more eggs to 56 weeks of age than the constant 16-h controls. 4. Collectively, these findings indicate that conventionally managed broiler breeders exhibit photorefractoriness. Additionally, a combination of photorefractoriness and controlled feeding appears to prevent broiler breeders from being photoresponsive until at least 10 weeks of age, and to cause some individuals still to be photoperiodically non-responsive at 18 weeks.

Aging↗

PubMed2004

Identification of critical periods for turning broiler hatching eggs during incubation.

(1) Fertile hatchability was superior from a broiler breeder flock at 29 weeks of age than at 68 weeks of age because of decreased mortality at all stages of embryo development. (2) Eggs that were either turned or not turned during the 0 to 7 d, 8 to 14 d and 15 to 18 d periods in the 8 possible combinations showed that the absence of turning from 0 to 7 d of incubation caused a decrease in fertile hatchability and an increase in all stages of embryonic mortality, and an incidence of Malposition II (head in small end of shell) that was more pronounced in a 68-week-old flock than a 29-week-old flock. (3) When eggs from 33- and 35-week-old broiler breeder flocks were either turned or not turned from 0 to 2 d, 3 to 4 d, 5 to 6 d or 7 to 8 d in the 16 possible combinations, the absence of turning from 3 to 8 d, or 0 to 2 d alone or in combination with other time periods reduced fertile hatchability and increased embryonic mortality and percentage of Malposition II. (4) The most critical period for turning commercial broiler hatching eggs during incubation was from 0 to 7 d with the single most critical 2-d period being 0 to 2 d.

Agriculture↗

PubMed2004

Effect of a Chinese herb medicine formulation, as an alternative for antibiotics, on performance of broilers.

1. A total of 720 female broiler chicks was used to test the effects of 4 dietary concentrations of a Chinese herbal medicine (CHM) formulation (0.25, 0.5, 1 and 2g/kg), as an alternative for virginiamycin (VRG), on growth performance in broilers. 2. A total of 72 birds from non-supplemented, VRG and 0.5 g/kg CHM groups was selected and killed and the relative weights of the intestinal segments were assessed. 3. The CHM dietary treatments produced increased body weight gain at 7 to 21 d of age but not at 21 to 28 d of age compared with the non-supplemented and VRG groups. The CHM groups had a higher feed intake and a higher feed conversion ratio (FCR) than the VRG group between 21 and 28 d. 4. The dissection results showed that the liver colour of the birds in the CHM group varied less between animals than that of the VRG and the non-supplemented groups. Neither CHM nor VRG had any significant effects on either liver or intestinal tract weights. 5. It was concluded that the birds of the CHM group had better growth performance from d 7 to 21 but not thereafter. Further experiments are needed to elucidate the mechanisms underlying enhanced growth performance by CHM in broilers.

Animals↗

PubMed2005

Sustained availability of trimethoprim in drinking water to achieve higher plasma sulphonamide-trimethoprim antibacterial activity in broilers.

(1) In order to make trimethoprim (TMP) available to broilers throughout the day, a sustained release formulation (SRF) of the drug in the form of granules was added to the water tank that supplies drinking water. (2) Broilers were initially dosed with sulphachloropiridazine-TMP (SCP-TMP 5:1) and then further medicated throughout the day, achieving in the end a dose of 30 mg/kg each of SCP and TMP (group A). Group B received a preparation with the same dose of SCP and TMP (1:1) as group A, but administered as a single dose without the SRF of TMP. Group C received the customary SCP-TMP 5:1 preparation (30 and 6 mg/kg, respectively). Water tanks were completely consumed in 3 to 4 h. (3) Broilers were bled at different times and concentration of antibacterial activity in serum determined by correlating the composite antibacterial activity of SCP and TMP with actual concentrations of these drugs by means of a microbiological agar diffusion assay. (4) Time vs serum concentrations of activity were higher in group B; the increments in the maximum serum concentration for group B over groups A and C being 39 and 67%, respectively. (5) However, the sustained concentration of activity over time, measured as the area under the cu)rve, was highest in group A. Group B had higher values for area under the curve than group C. (6) An additional dose of TMP to achieve 30 mg/kg of both SCP and TMP improves the serum concentration of this combination over the customary 5:1 proportion. The best values for sustaining antibacterial activity were obtained using a 1:1 ratio as in group A. The use of a SRF as in group A may translate into better clinical results.

Absorption↗

PubMed2004

Influence of phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digestive tract measurements and gut morphology in broilers fed wheat-based diets containing adequate level of phosphorus.

1. The aim of the present study was to examine the influence of microbial phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digesta viscosity, digestive tract measurements and gut morphology in broilers fed on wheat-soy diets containing adequate phosphorus (P). The wheat-soy basal diet was formulated to contain 4.5 g/kg non-phytate P and the experimental diets were formulated by supplementing the basal diet with xylanase (1000 xylanase units/kg diet), phytase (500 phytase units/kg diet) or a combination of phytase and xylanase. 2. Supplemental phytase improved the weight gains and feed efficiency by 17.5 and 2.9%, respectively. Corresponding improvements due to the addition of xylanase were 16.5 and 4.9%, respectively. The combination of phytase and xylanase caused no further improvements in broiler performance. 3. Individual additions of xylanase or phytase resulted in numerical improvements in apparent metabolisable energy (AME), but the differences were not significant. The combination of the two enzymes significantly increased AME. Addition of xylanase and the combination of the two enzymes reduced the viscosity of digesta in all sections of the intestine. Phytase supplementation reduced digesta viscosity in the duodenum and ileum, but not in the jejunum. 4. Enzyme supplementation lowered the relative weight and length of the small intestine. Additions of xylanase and phytase reduced the relative weight of the small intestine by 15.5 and 11.4%, respectively, while the corresponding reductions in the relative length of the small intestine were 16.5 and 14.1%, respectively. The combination of phytase and xylanase had no further effects on the relative weight and length of the small intestine compared with the xylanase group. 5. The addition of phytase increased villus height in the duodenum and decreased the number of goblet cells in the jejunum compared with those on the unsupplemented basal diet. Xylanase supplementation tended to increase goblet cell numbers in the duodenum and decreased crypt depth in thejejunum. The combination of phytase and xylanase increased villus height in the ileum and crypt depth in thejejunum and ileum. 6. In summary, the present results showed that the addition of a microbial phytase, produced by solid state fermentation and containing significant activities of beta-glucanase and xylanase, was as effective as xylanase in improving the performance of broiler chickens fed on wheat-based diets containing adequate levels of P. Improved performance with enzyme supplementation was generally associated with reduced digesta viscosity, increased AME, and reduced relative weight and length of small intestine.

6-Phytase↗

PubMed2004

Uptake and distribution of astaxanthin in several tissues and plasma lipoproteins in male broiler chickens fed a yeast (Phaffia rhodozyma) with a high concentration of astaxanthin.

1. The experiments were conducted to evaluate astaxanthin (Ax) uptake in several tissues and plasma lipoproteins of male broiler chickens fed on Phaffia rhodozyma containing a high concentration of Ax. 2. Male broiler chicks (5 weeks of age) fasted for 16h were given 0 or 45 mg Ax as Phaffia rhodozyma through the crop and blood was collected over the following 24 h. Ax appeared in the plasma at 2 h after administration into the crop. Most (more than 70%) of the Ax was contained in the high density lipoprotein (HDL) fraction in the plasma irrespective of blood sampling times and administration procedure of Ax. 3. Male broiler chicks (2 weeks of age) were fed on a diet containing 0, 50 or 100 mg/kg of yeast Ax for 2 weeks. Of the tissues examined, Ax concentration in the small intestine was highest, followed by subcutaneous fat, abdominal fat, spleen, liver, heart, kidney and skin. The lowest concentration was in the muscles. Ax concentration in the small intestine, subcutaneous fat, abdominal fat, liver and skin rose as dietary content increased, but this was not the case for the spleen, heart, kidney and muscles except for M. pecloralis superficialis. 4. Over 50% of Ax deposited in liver tissues was detected in the microsomal fraction and 15% was in the mitochondrial fraction. In muscles, both fractions of mitochondria and sarcoplasmic reticulum contained Ax.

Animals↗

PubMed2004

Effect of different levels of rice bran processed by various techniques on performance of broiler chicks.

1. Rice bran processed by extrusion cooking, roasting or pelleting and treated with antioxidant was used in broiler starter and finisher diets at various concentrations up to 500 g/kg. 2. Extrusion cooking gave the best performance, followed by roasting, while non-significant differences were observed between raw and pelleted bran. 3. Increasing the amount of rice bran in broiler diets resulted in significantly negative effects on growth performance. Non-significant differences were observed in mortality and dressing percentage due to different processes and concentrations of rice bran in the diet. Organ weights were significantly higher on raw and pelleted rice bran as compared to extruded and roasted bran. Liver and heart weights significantly increased with increasing contents of rice bran above 200g/kg, while pancreas weight increased with an addition of rice bran. 4. Treating the rice bran with antioxidant up to 250ppm had non-significant effects on broiler performance.

Animal Nutritional Physiological Phenomena↗

PubMed2004

Constant photoperiods and sexual maturity in broiler breeder pullets.

1. Broiler breeder pullets were maintained on 10-, 11-, 12-, 13-, 14- or 16-h photoperiods to determine the effect of constant photoperiods on sexual development in broiler breeders. The birds were fed to achieve a 2100 g body weight at approximately 17 or 20 weeks to see if the photosexual response was modified by rate of growth. 2. In both body weight groups, pullets maintained on 10h were the first to reach sexual maturity (50 eggs/100 bird-d), and these and the 11-h pullets matured significantly earlier than any of the other photoperiod groups. Pullets maintained on 13 or 14 h matured latest, at about 3 weeks after the 10-h pullets, though both were only marginally later than the 12- or 16-h birds. These differences in maturation probably reflect the different rates at which photorefractoriness is dissipated in broiler breeders reared on photoperiods that vary in their degree of stimulatory competence. 3. There were no significant interactions among the photoperiods and the ages at 2100 g; faster-growing birds consistently matured about 10 d earlier than conventionally grown pullets.

Age Factors↗

PubMed2005

Mapping of quantitative trait loci affecting organ weights and blood variables in a broiler layer cross.

1. A genome scan was performed to locate genomic regions associated with traits that are known to vary in birds (most commonly broilers) suffering from heart, lung or muscular dysfunction and for weight of the dressed carcass and some internal organs. 2. The F2 population studied was derived from a cross between a broiler and a layer line and consisted of over 460 birds that were genotyped for 101 markers. 3. There was strong support for segregation of quantitative trait loci (QTL) for carcass and organ weights and blood variables. We identified 11 genome-wide significant QTL (most of them for dressed carcass weight) and several genome-wide suggestive QTL. 4. The results point to some genome regions that may be associated with health-related traits and merit further study, with the final aim of identifying linked genetic markers that could be used in commercial breeding programmes to decrease the incidence of muscular and metabolic disorders in broiler populations.

Animals↗

PubMed2005

Effects of chitosan on growth performance and energy and protein utilisation in broiler chickens.

1. Two experiments were conducted to investigate the effects of dietary chitosan on growth performance, energy availability and protein retention in broilers. 2. Experiment 1 was a 42-d growth assay, in which 294 1-d-old male broilers were given one of 7 dietary treatments. A control feed was supplemented with 5 levels of chitosan (0.2, 0.5, 1.0, 3.0 and 5.0 g/kg) or 50 mg/kg chlortetracycline (CTC). 3. Increasing chitosan inclusion gave a nonlinear increase (P< 0.001) in feed conversion efficiency (FCE). Optimal growth and feed conversion were obtained with 0.5-1.0 g/kg chitosan. 4. In experiment 2, 42 1-d-old male broilers (6/treatment) were individually housed but fed on the same diets as in experiment 1. Excreta were collected from d 19-21 and d 40-42. 5. The addition of 0.5-1.0 g/kg chitosan increased nitrogen retention compared with the control group (P< 0.01), while apparent metabolisable energy in the diets was not altered.

Animal Feed↗

PubMed2005

Effect of ochratoxin A on broiler chicks challenged with Salmonella gallinarum.

1. A study was conducted to evaluate the effects of ochratoxin A (OA) on broiler chicks challenged with Salmonella gallinarum. 2. One hundred and seventy-six 1-d-old broiler chicks were divided into two groups of 88 chicks each, with one group fed on a control mash diet and the other given a mash diet containing 2 ppm OA. On d 14, each group was further subdivided into two groups with one group infected with S. gallinarum and the other uninfected. 3. Following S. gallinarum inoculation on d 14, 4 birds from each group were killed at 1, 2, 3, 5, 7, 10, 14 and 21 d post inoculation. 4. S. gallinarum infection caused dullness, depression, weakness, increased thirst, droopy wings, ruffled feathers and greenish-yellow diarrhoea. S. gallinarum infection in the absence of OA caused 11.5% mortality which increased to 28.8% in the presence of OA. 5. Decreased body weight and reduced feed intake were observed in chicks fed on the diet containing OA. S. gallinarum infection also reduced the body weights of chicks, with the effects being more marked in chicks receiving OA. The OA diet led to increased serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, uric acid and creatinine, and decreased levels of total proteins, albumin, globulins, calcium and phosphorus. S. gallinarum infection did not cause significant alteration in any of the serum biochemical parameters. 6. Mortality and the severity of S. gallinarum infection in broiler chicks were increased by the presence of OA in the diet.

Alanine Transaminase↗

PubMed2005

Can testosterone and corticosterone predict the rate of display of male sexual behaviour, development of secondary sexual characters and fertility potential in primary broiler breeders?

1. Genetic selection for growth to enhance production may be associated with stress and with modified physiological and behavioural phenotypes which depress male primary broiler breeder fertility. 2. We hypothesised that male serum testosterone (T) and corticosterone (C) concentrations might correlate with fertility, sexual behaviour, and testicular, comb and wattle size. 3. Cockerels from two genetic strains (A and B) of primary broiler breeder were penned individually with an average of 10 females across 5 age periods (30 to 51 weeks) to evaluate male fertility, behaviour, serum T and C, and comb, wattle and testicular dimensions. 4. Strain A males had higher T at age periods 2, 4 and 5 than Strain B. Both strains had basal concentrations of C, apart from an elevated concentration for Strain B in period 5. 5. Strain B had a weak but significant, positive correlation between sexual behaviour and T and C, while Strain A males with higher C had larger combs and wattles. 6. Neither T nor C correlated with fertility. We conclude that evaluation of these endocrine factors (quantifiable measurements with the potential to correlate with fertility) alone seems insufficient to predict male fertility potential in these strains of primary broiler breeder.

Aging↗

PubMed2005

A mixture of pure cellulase, hemicellulase and pectinase improves broiler performance.

1. The effects of a mixture of pure enzymes (cellulase, hemicellulase and pectinase) and a commercial enzyme, Energex, were examined on performance and metabolisabilities in broiler chicks given a maize-soybean meal diet. Composition of the mixed enzyme was similar to Energex except that protease was not present. 2. Chicks were divided into three groups: control, mixed enzyme and Energex with 7 replicates per group. Male broiler chicks were raised at 25 degrees C in wire-floored cages for 12 d from 15 d of age. Feed and water were offered ad libitum. 3. The Energex group gained significantly more weight and the mixed enzyme group tended to gain more than the control. Feed intakes were similar and thus the feed conversion ratio of Energex was significantly improved while it tended to be improved by the mixed enzyme. 4. The mixed enzyme group showed significant improvement in carcase and muscle weight when compared with the control group. The mixed enzyme group also showed significant improvement in organic matter and crude protein metabolisabilities. In the groups given enzyme, abdominal fat weight tended to decrease. 5. It is concluded that a combination of cellulase, hemicellulase and pectinase is effective in improving organic matter and crude protein metabolisabilities and carcase yield of broilers on a maize-soybean meal diet.

Animal Feed↗