Physiological and health‐related response of broiler chickens fed diets containing raw,full‐fat soya bean meal supplemented with microbial protease

A 2 × 3 factorial study (protease: 0 or 1,5000 PROT/kg and raw full‐fat soya bean meal [RSBM] replacing the commercial SBM at 0, 45 and 75 g/kg of diet) was conducted to examine the performance of broilers. Phytase (2000 FYT/kg) was uniformly added to each diet, each also replicated six times, with eight birds per replicate. Birds were raised in climate‐controlled rooms using sawdust as the bedding material and offered starter, grower and finisher diets. Feed intake (FI) and body weight gain (BWG) were reduced (p < .05) due to increasing levels of RSBM, but feed conversion ratio (FCR; 0–35 days) was unaffected. Over the first 24 days, neither RSBM nor protease supplementation affected (p > .05) mortality, footpad dermatitis or intestinal lesions in birds. At day 24, the weight, length, width and strength of tibia bone were reduced in chickens that received an elevated level of RSBM (75 g/kg of diet), but this was not significant at day 35. At day 24 (p < .05) and 35 (p < .01), Ca concentration in the litter was reduced when the RSBM level was increased in the diet, but P content was not affected. On days 24 (p < .05) and 35 (p < .01), the N content in litter was also increased with increase in dietary RSBM. Protease supplementation increased (p < .05) the uric acid concentration in the litter (at day 35), but the reverse was the case for ammonia concentration. Overall, the results of this study indicate that there are no major health‐related risks, associated with the replacement of commercial SBM with RSBM (≤25%) in broiler diets.     

Effect of an organic acid blend and phytase added to a rapeseed cake‐containing diet on performance,intestinal morphology,caecal microflora activity and thyroid status of broiler chickens

The experiment was carried out on 96 female broilers, allocated to eight groups of 12 birds kept in individual cages. Two basal wheat‐ and soyabean meal‐based diets containing 150 g/kg of rapeseed expeller cake were formulated, differing in the level of P: 7.1 g/kg in diet H or 5.9 g/kg in diet L. Rapeseed cake supplied 3.15 μmol alkenyl glucosinolates per gram of diet. The eight treatments were: basal diets only, basal diets + phytase (1000 U/kg), basal diets + organic acid blend (OA, 6 g/kg), or basal diets + both additives. Diets were fed from day 8 to 28 of life. The results showed that the lower dietary P content and OA supplementation did not significantly affect feed intake or BWG, while both increased (p < 0.001) after phytase supplementation. Tibia ash content as well as tibia ultimate strength were lower (p < 0.001) in birds fed diets L compared with diets H, and increased (p < 0.01) with phytase supplementation of diet L, while OA had no influence on either parameter. Dietary P levels and OA supplementation had no influence on the pH of gut digesta, but the pH of jejunal digesta increased following phytase supplementation (p < 0.01). Morphological measurements of the small intestinal mucosa of chicks indicated that OA added to diet L depressed villi height (p < 0.001) and crypt depth (p < 0.001); both parameters increased after phytase supplementation (p < 0.01). The lower total SCFA as well as acetic, propionic and butyric acid concentrations in caecal digesta indicated lower activity of caecal microflora in birds fed diets L compared with H. OA supplementation had no influence, while phytase supplementation increased the concentration of acetic acid in caecal digesta. Supplementation of diets with either phytase or OA increased thyroid weight by 16% (p < 0.01) and 11% (p < 0.05) respectively. The increase in thyroid weight because of phytase supplementation was greater at the lower dietary P level, and the greatest when both phytase and OA were added to the diet.     

Effects of supplementation of high-dosing Trichoderma reesei phytase in the corn-wheat-soybean meal-based diets on growth performance,nutrient digestibility,carcass traits,faecal gas emission,and meat quality in growing-finishing pigs

We conduct this study to investigate the effects of corn-wheat-soybean meal (SBM)-based diet supplemented with high-dosing Trichoderma reesei phytase on the growth performance, nutrient digestibility, carcass traits, faecal gas emission and meat quality in growing-finishing pigs (29.71–110.58 kg live weight; 70-day-old to 166-day-old). A total of 56 crossbred pigs [(Landrace × Yorkshire) × Duroc] were used in 96-day experiment with a completely randomized block design. The growing period was from day 0 to 42, and the finishing period was from day 43 to 96. Pigs were randomly allocated to one of two treatments with seven replicate pens and four pigs (two barrows and two gilts) per pen and fed corn-wheat-SBM-based nutrient adequate basal diet or the basal diet supplemented with 1500 FTU/kg diet Trichoderma reesei phytase. One phytase unit (FTU) was defined as the amount of enzyme that catalyses the release of one micromole phosphate from phytate per minute at 37°C and pH 5.5. Dietary supplement with Trichoderma reesei phytase had increased body weight on day 96 and average daily gain in days 0–96. Moreover, high apparent total tract digestibility (ATTD) of phosphorus (P) was observed in pigs fed with Trichoderma reesei phytase. However, the carcass traits, faecal gas emission and meat quality of pigs were unaffected by Trichoderma reesei phytase supplementation. In conclusion, supplementation of high-dosing Trichoderma reesei phytase (1500 FTU/kg diet) in the corn-wheat-SBM-based nutrient adequate basal diet increased body weight and the ATTD of P, while no adverse effects were observed on the production characteristics.     

Impact of reduced dietary crude protein levels and phytase enzyme supplementation on growth response,slurry characteristics,and gas emissions of growing pigs

This experiment was carried out to evaluate the effect of reduced dietary crude protein (CP) levels supplemented with or without exogenous phytase on growing pigs. Six dietary treatments arranged in a 3 × 2 factorial arrangements of 3 CP levels (containing 14%, 16%, and 18% CP) supplemented each with or without 5,000 FTU/g phytase enzyme. Thirty growing pigs (average weight of 17.80 ± 0.10 kg) were allotted to the six dietary treatments in a complete randomized design. The final weight, daily weight gain, and feed conversion ratio (FCR) increased significantly with increasing CP levels. While, phytase supplementation improved (p = .044) FCR in pigs. Total solid and volatile solid content of the slurry were higher (p = .001) in pigs fed 14% and 16% CP diets supplemented with phytase when compared with other treatment groups. Concentration of methane gas emitted was lowest (p = .001) in the slurry of pigs fed 14% CP diet with or without phytase and those fed 16% CP diet with phytase supplementation. In conclusion, reduction in dietary CP levels resulted in reduced weight gain and poor FCR. While, reduced CP with phytase supplementation reduced concentration of methane gas emitted.     

Increased iron level in phytase-supplemented diets reduces performance and nutrient utilisation in broiler chickens

1. The effect of different levels of dietary iron on phytase activity and its subsequent effect on broiler performance were investigated in a 3 × 2 factorial arrangement. A total of 360 day-old Ross 308 male broiler chicks were distributed to 6 experimental diets, formulated with three levels of Fe (60, 80 and 100 mg/kg) and two levels of phytase (0 and 500 FTU/kg).

2. Phytase supplemented to mid-Fe diets increased feed consumption more than the non-supplemented diet at d 24. From hatch to d 35, Fe × phytase interaction significantly influenced the feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR). The high-Fe diet supplemented with phytase significantly reduced FI and BWG of broilers than those supplemented with low- or mid-Fe diets. The overall FCR was significantly better in birds fed on the mid-Fe diets with phytase supplementation.

3. A significant improvement in ileal digestibility of N, P, Mg and Fe was observed in birds feed diets containing 60 mg Fe/kg, with significant interaction between Fe and phytase.

4. Phytase improved the bone breaking strength when supplemented to low- or mid-Fe diets, compared to the non-supplemented diets. There was a significant Fe × phytase interaction effect. Tibia Fe content was higher in birds fed on phytase-free diets with high Fe but the reverse was the case when phytase was added and their interaction was significant. High dietary Fe significantly increased the accumulation of Fe in liver.

5. Phytase improved Ca-Mg-ATPase, Ca-ATPase and Mg-ATPase activities in jejunum when supplemented to the diet containing 80 mg Fe/kg.

6. This study indicates that high (100 mg/kg) dietary Fe inhibited phytase efficacy and subsequently reduced the overall performance and nutrient utilisation of broilers.     

Influence of exogenous acid protease in broiler chickens fed corn–soybean meal-based diets

This study was conducted to determine the influence of exogenous acid protease (EAP) on growth performance, blood profiles, excreta noxious gas emissions, ileum digesta viscosity and apparent ileal digestibility in broilers. A total of 600 1-d-old broilers with average initial body weight of 47.0 ± 0.2 g were used in a 5-week feeding trial. The broilers were randomly allotted to 1 of 4 treatments with 10 replicate pens per treatment and 15 birds per cage. Dietary treatments consisted of: CON, basal diets; EAP1, CON + 2,700 exogenous acid protease unite (APU)/kg; EAP2, CON + 5,400 APU/kg; EAP3, CON + 8,100 APU/kg. The body weight gain (BWG) had a linear improvement when chicks fed 8,100 AP/kg diets from d 18 to 35 and overall (p < .05). Lower feed conversion ratio (FCR) was obtained in broilers fed 5,400 APU/kg and 8,100 APU/kg as compared with the CON during overall (p < .05). Birds fed diets supplemented with EAP diet led to a linear increase in the ileal digestibility of crude protein, energy and amino acids (lysine, methionine, cystine, threonine, isoleucine, leucine, histidine and tryptophan) compared with CON group (p < .05). In conclusion, based on our results, we suggest that supplementation with EAP diet was effective in improving growth performance through increasing ileal digestibility of some nutrients (crude protein, energy and amino acids) in broilers.     

Response of broiler chickens to different levels of calcium,non-phytate phosphorus and phytase

1. Five hundred and seventy six-d old Ross 308 broiler chicks (6 cages per diet, 8 birds per cage in 3 × 2 × 2 factorial arrangement) were fed on maize–soybean meal-based diets containing three concentrations of Ca (6, 8 or 10 g/kg), two concentrations of non-phytate phosphorus (NPP) (3 or 4 g/kg) and two levels of exogenous microbial phytase (0 or 500 FTU/kg) from d 0 to 35.

2. Body weight (BW), feed intake (FI) and mortality records were collected. Two birds per replicate were killed at 24 d of age to obtain tibia samples.

3. Increasing Ca level significantly reduced the FI and body weight gain (BWG) between hatch and 10 and 24 d, especially with the phytase-supplemented diets. However, phytase supplementation of the diet containing 4 g NPP/kg improved the FI and BWG at d 10 and 24. At d 24, phytase supplementation improved feed conversion ratio (FCR) of birds that consumed diets containing high NPP. The overall FCR was better in birds offered the phytase-supplemented, medium-Ca diet.

4. There was a significant reduction in length, width and breaking strength of the tibia bone in birds fed on a diet with high Ca and low NPP. Phytase supplementation improved the tibia ash content and bone breaking strength of chicks fed on the diet containing 8 and 4 g/kg Ca and NPP, respectively. The Ca content of the tibia bone was low in birds fed on diets with 6 and 4 g/kg Ca and NPP, respectively, but this was counteracted by phytase supplementation.

5. Birds fed on diets with 4 g/kg NPP had the best carcass percentage and parts yield. Phytase supplementation to high-Ca diets significantly reduced the carcass yield of birds.

6. These results confirmed the detrimental effect of high dietary Ca on phytase activity and subsequent growth and bone development of birds, especially when NPP is in short supply.     

Effects of Source of Inorganic Phosphorus and Phytase Supplementation on Performance, Physiological Parameters and Bone Mineralization in Broilers

The objective of this study was to evaluate the effects of inorganic phosphorus source and phytase addition on performance, nutrient digestibility and bone mineralization in broiler chickens. In Exp. 1, 150 two-day old, male broiler chicks were fed a corn-soybean meal basal diet supplemented with phosphorus provided by dicalcium phosphate, tricalcium phosphate or defluorinated rock phosphate. Five cages containing 10 birds were allotted to each of the three treatments. In Exp. 2, 120 three-day old, male broiler chicks were fed the basal diet from Exp. 1 supplemented with 0, 250, 500, or 1,000 FTU phytase per kg of diet. Six cages containing five chicks were allotted to each of the four treatments. In Exp. 1, there was no difference in weight gain, feed intake or feed conversion as a result of feeding the different sources of inorganic phosphorus. The digestibility of phosphorus was significantly lower (P = 0.01) for chicks fed diets supplemented with tricalcium phosphate than for chicks fed the other two diets.  However, despite the lower digestibility, serum phosphorus levels did not differ among the three treatments. For Exp. 2, feed conversion showed a linear improvement (P = 0.03) with increasing levels of phytase inclusion (days 0 to 33).  Phytase supplementation resulted in linear increases in the digestibility of dry matter (P = 0.02), crude protein (P = 0.04) and energy (P < 0.01).  Chicks fed 1,000 FTU/kg phytase had significantly higher bone calcium (P = 0.05) and bone breaking strength (P = 0.04) than chicks fed the basal diet on day 33. In conclusion, the results of the current study indicated that the performance of birds fed diets supplemented with dicalcium phosphate, tricalcium phosphate or defluorinated phosphate was similar and therefore production costs could be lowered by choosing the cheapest inorganic phosphorus source when formulating diets for poultry. When diets were formulated to meet dietary phosphorus requirements, the growth of broilers was not enhanced with phytase supplementation.  However, increases in feed conversion and bone breaking strength and its potential to impact culling and mortality in broiler operations may be sufficient justification for the routine inclusion of phytase in diets fed to broilers.     

Intrinsic phytase in hybrid rye increases the digestibility of phosphorus in corn and soybean meal in diets fed to growing pigs

An experiment was conducted to test the hypothesis that inclusion of hybrid rye in diets containing corn and soybean meal (SBM) without or with microbial phytase improves the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P because of the intrinsic phytase activity in hybrid rye. Forty-eight growing barrows (initial body weight: 39.5 ± 7.7 kg) were allotted to six diets. A basal diet containing corn and SBM; a rye-based diet; and a diet containing corn, SBM, and rye were formulated. Each diet was formulated without and with microbial phytase (500 units/kg of diet) for a total of six diets. Fecal samples were collected for 4 d following a 5-d adaptation period according to the marker-to-marker procedure. Results indicated that no interactions between diets and concentration of phytase were observed for any of the response criteria measured. The ATTD and STTD of P and the ATTD of Ca differed (P < 0.05) among diets, but regardless of diet, the concentration of P in feces was reduced (P < 0.05) by adding microbial phytase to the diets. As a consequence, microbial phytase increased (P < 0.05) ATTD and STTD of P, and the ATTD of Ca was also increased (P < 0.05) by the use of microbial phytase. Measured values for the ATTD and STTD of P in the diets containing corn, SBM, and hybrid rye without or with phytase were greater (P < 0.05) than values that were predicted based on the ATTD and STTD of P for the corn–SBM and the hybrid rye diet. The observation that STTD predicted from the individual ingredients underestimated the STTD of P in the mixed diet indicates that the intrinsic phytase in hybrid rye resulted in increased digestibility of the P in the corn and SBM included in the corn–SBM–hybrid rye diet. In conclusion, microbial phytase increased the ATTD and STTD of P and the ATTD of Ca regardless of feed ingredients used in diets fed to pigs. In addition, the intrinsic phytase from hybrid rye increased the ATTD and STTD of P in corn and SBM.     

Utilization of unpeeled cassava (Manihot esculenta Crantz) root meal supplemented with or without charcoal by broiler chickens

A 42‐day feeding trial was conducted using 480‐day‐old, male Marshall broilers to study the utilization of unpeeled cassava root meal (UCRM) supplemented with or without 6 g/kg charcoal. The experimental design was laid out in a 3 × 2 factorial arrangement of treatments having three inclusion levels of UCRM (0, 100 and 200 g/kg) with or without 6 g/kg charcoal supplementation. Each treatment consisted of 80 birds replicated eight times with 10 birds per replicate. Main effect of inclusion level of UCRM and supplementation of charcoal showed reduced (p < 0.05) final live weight, weight gain, feed intake and apparent crude protein digestibility of the birds with increasing inclusion levels of UCRM. Birds fed diets supplemented with charcoal showed higher (p < 0.05) final live weight, weight gain and feed intake than birds fed diets without charcoal. Supplementation of charcoal in diet containing 100 g/kg UCRM resulted in improved (p < 0.05) weight gain when compared with birds fed similar diet but not supplemented with charcoal. Broilers fed diet containing no UCRM but supplemented with charcoal had the highest overall (p < 0.05) final live weight and weight gain, while birds fed diet containing 200 g/kg UCRM supplemented with charcoal recorded the poorest (p < 0.05) final live weight and weight gain. Serum glutamate oxaloacetate transaminase (SGOT) and serum thiocyanate concentration increased (p < 0.05) with increasing dietary inclusion levels of UCRM. Dietary supplementation of charcoal resulted in increased (p < 0.05) concentration of serum glucose and cholesterol and reduced (p < 0.05) SGOT concentration. Birds fed diets containing UCRM had high (p < 0.05) serum thiocyanate concentration irrespective of dietary supplementation or not with 6 g/kg charcoal. In conclusion, supplementation of diet containing up to 100 g/kg UCRM with 6 g/kg charcoal showed improved weight gain without any deleterious effect on serum metabolites.     

Evaluating the nutritional value of date pits and demonstrating their application in laying hen diets

This experiment was carried out to study the feeding value of ground date pits (DP) (Phoenix dactylifera L.) with and without enzyme supplementation on laying hens’ performance. Apparent metabolizable energy value of DP was determined by the total collection method using 10 adult Leghorn cockerels. After that, a total number of 144 Lohmann 50‐week‐old LSL‐Lite hens were randomly allocated into six groups consisting of four replicates of six birds, based on a 3 × 2 factorial arrangement of the treatments. Six iso‐caloric and iso‐nitrogenous experimental diets including I‐corn–soya bean meal‐based control, II‐corn–soya bean meal oil‐based control and III‐ corn–soya bean meal‐based diet (180 g/kg DP) were formulated. Each of the diets was supplemented with two levels of an enzyme (0.0 and 0.07 g/kg Natozim Plus). The experiment lasted 10 weeks after 7 days of adaptation. The results revealed that there was no significant difference in feed intake, feed conversion ratio, egg production, egg mass, eggshell weight, eggshell thickness and Haugh unit among the treatments. Dietary inclusion of DP significantly decreased body weight gain (BWG), egg weight and yolk colour score. On the other hand, corn–soya bean meal‐based control diet with vegetable oil significantly increased egg weight and BWG of birds in comparison with other treatments. The serum biochemical metabolites were not affected by DP and enzyme supplementation. Thus, DP can be used as alternative feedstuff in laying hen diets, up to 18% of the diet with little effect on the performance of hens, including egg weight, and also, it had an adverse effect on yolk colour. Eventually, in terms of performance, the results failed to demonstrate any positive effect of Natozim Plus on either the controls or 18% DP diets.     

Effect of low‐ or high‐CP diet with cold‐pressed oil supplementation on growth,immunity and antioxidant indices of growing quail

This study was to investigate the effect of dietary protein levels and supplementation with two cold‐pressed oils on the performance, immunity and antioxidant indices of growing Japanese quails. A 3 × 4 factorial experiment, using 3 dietary crude protein (CP) levels (22%, 24% and 26%) and 4 supplemental herbal oils levels: control without additives, 250 mg marjoram (Mar), 250 mg thyme (Thy) and 125 mg Mar + 125 mg Thy per kg diet. A total of 720 unsexed, 7‐day‐old quail chicks were randomly distributed into twelve treatment groups (4 replicates per group of 15 chicks in each). The live body weight (LBW) on 42 days and body weight gain (BWG) from 7 to 42 days were significantly improved (p < 0.01 and 0.05) in chicks fed 24% or 26% CP compared with those of the 22% CP group. The groups fed diets supplemented with Mar or in combination with Thy oil exhibited significantly better LBW, BWG and feed conversion ratio (FCR) than the control at all periods except BWG from 21 to 42 days and FCR from 7 to 21 days were not significant. Feed intake was gradually decreased with increasing dietary CP level or adding herbal oils during the periods 21–42 and 7–42 days of age. Plasma triglycerides, cholesterol, total lipids and malondialdehyde were decreased by cold‐pressed oils supplementation, but the activity of reduced glutathione and superoxide dismutase was increased (p < 0.01) compared with the control. In conclusion, quails fed a diet containing 24% or 26% CP or diets supplemented with Mar or Thy oils or both exhibited improvement in the performance, lipid profile, immunity and antioxidant capacity without any detrimental impacts on the other studied parameters.     

Phosphorus equivalency of a Citrobracter braakii phytase in broilers

A study was conducted to evaluate the effects of phytase supplementation on growth performance, phosphorus availability, and bone mineralization in broilers. Three hundred fifty Cobb × Cobb 500 slow-feathering male broilers were placed in steel battery cages into 7 treatments with 10 replications of 5 chicks each. The treatments were: a positive control (PC) diet [0.42% nonphytate phosphorus (nPP)], 4 diets containing increases in nPP from dicalcium phosphate (0.14, 0.20, 0.26, and 0.32%), and 2 phytase supplemental levels [500 and 1,000 phytase units ( FYT)/kg] on the diet having 0.14% nPP. All diets contained 0.8% calcium. Growth performance and bone data were regressed against the 4 diets having increased nPP. The equations generated were replaced by the corresponding performance obtained with 2 phytase levels to estimate their nPP bioequivalence. An overall reduction in performance and bone mineralization was observed associated with a reduction in nPP. Linear fits provided the best adjustments for all responses with the exceptions of BW gain (BWG) and feed intake (FI). Adding phytase to the 0.14% nPP diet improved growth performance and bone mineralization (P < 0.001). Average bioequivalence nPP for each phytase level was dependent on the evaluated response with lowest and highest values at 500 FYT supplementation of 0.077 and 0.145 for toe P and femur Ca, respectively, whereas lowest and highest values at 1,000 FYT of 0.143 and 0.194 for BWG and toe ash. Averaging all values for 500 and 1,000 FYT provided estimations of 0.100 and 0.166 nPP, respectively.     

Effects of adding high-dosing Aspergillus oryzae phytase to corn–wheat–soybean meal-based basal diet on growth performance,nutrient digestibility,faecal gas emission,carcass traits and meat quality in growing-finishing pigs

This study tests the effects of supplementation of high-dosing Aspergillus oryzae phytase into the corn – wheat – soybean meal (SBM)-based basal diet on growth performance, nutrient digestibility, faecal gas emission, carcass traits and meat quality in growing-finishing pigs (29.73–110.86 kg live weight; 70-day-old to 166-day-old). A total of 56 crossbred pigs [(Landrace × Yorkshire) × Duroc] were divided into two dietary groups for a 96-day experiment (growing period, days 0 – 42; finishing period, days 43 – 96) with a completely randomized block design. There were seven replicate pens in each dietary group, and each pen has four pigs (two barrows and two gilts). The dietary treatments consisted of a corn – wheat – SBM-based nutrient sufficient basal diet or the basal diet supplemented with 1500 FTU/kg A. oryzae phytase. One phytase unit (FTU) was defined as the amount of enzyme that catalyses the release of one micromole phosphate from phytate/min at 37°C and pH 5.5. Higher average daily gain and lower feed conversion ratio were observed in growing-finishing pigs consuming a high-dosing A. oryzae phytase supplementing diet during days 0 – 42 and 0 – 96. Supplementing high-dosing A. oryzae phytase to the diet of growing-finishing pigs increased apparent total tract digestibility of phosphorus on days 42 and 96. Moreover, growing-finishing pigs fed the diet supplemented with high-dosing A. oryzae phytase had higher carcass back-fat thickness than those fed the control diet. However, the faecal gas emission and meat quality were not affected by high-dosing A. oryzae phytase supplementation. In conclusion, dietary supplementation of high-dosing A. oryzae phytase (1500 FTU/kg) had beneficial effects on the growth performance, apparent phosphorus digestibility and carcass back-fat thickness in growing-finishing pigs.     

Significant effect of NSP‐ase enzyme supplementation in sunflower meal‐based diet on the growth and nutrient digestibility in broilers

The response of broiler chickens to 3 levels of sunflower meal and 2 levels of NSP‐ase enzyme combination (with and without) was investigated in 3 × 2 factorial arrangement under complete randomized design (CRD). A total of 240 Hubbard broiler chicks were fed on practical mash diets having 2950 kcal of ME and 21% CP from 1 to 42 days of age. The BW gain was not significantly reduced when 25% SFM was added in the diets during 1 to 42 days of age. Supplementation of NSP‐ase in broiler diets (day 1–42 overall) demonstrated non‐significant differences (p < 0.05) across the treatments in terms of FI and BWG. The difference in feed:gain at 15% or 20% SFM was observed to be non‐significant. Replacement of SBM with SFM or inclusion of SFM at higher level (25%) increased/deteriorated FCR. The addition of exogenous NSP‐ase showed a significant improvement (p < 0.01) in feed:gain. The improvement was clearly demonstrated when SFM was added to the experimental diet at 15% or even 20%. Supplementation of NSP‐ase at the 25% inclusion level could not, however, sustain the beneficial effect, which was possibly due to excessively high dietary CF. No difference was noted across the treatments regarding carcass response. Relative gizzard weight and intestinal weight were observed to be improved in birds consuming higher levels of SFM (p = 0.00). The digestibility of CF was observed to improve when SFM was used at 20% and 25% in the diets. No improvement in the digestibility of CF was observed with NSP‐ase supplementation, which meant other factors were clearly involved. Supplementation of NSP‐ase improved FCR up to 20% SFM. At 25% SFM, no improvement in the digestibility of CF was observed with NSP‐ase supplementation.     

Effects of phytogenic feed additives,probiotic and mannan-oligosaccharides on performance,blood metabolites,meat quality,intestinal morphology,and microbial population of Japanese quail

ABSTRACT

1. The aim of this experiment was to investigate the effects of ajwain (Trachyspermum ammi) and dill (Anethum graveolens) essential oils (AEO and DEO, respectively), probiotic (PRO) and mannan-oligosaccharides (MOS) on the growth performance, serum metabolites, meat quality, intestinal morphology and microbial populations of Japanese quail.

2. A total of 375 one-day-old Japanese quail were randomly allocated into five treatment groups with five replicates of 15 birds each for a 42 d feeding experiment. The dietary treatments were a basal diet (control) or the same diet supplemented with PRO (0.15 g/kg feed), MOS (2 g/kg feed), AEO (0.25 g/kg feed) or DEO (0.25 g/kg feed).

3. AEO, MOS, and PRO supplementation increased weight gain, while diets supplemented with AEO decreased feed intake (FI), and improved feed conversion ratio from d 1 to 21 (P < 0.05). The relative weight of the gizzard was higher in birds supplemented with AEO compared to control group, while the birds fed MOS diet had the longest intestine (P < 0.05). Ceca length was greater in control, MOS and PRO groups (P < 0.05). Both essential oils decreased malondialdehyde (MDA) concentration of breast meat and percentage of cooking loss in quail (P < 0.05). The villus length (VL) was greater in birds fed diet supplemented with MOS, AEO, and DEO (P < 0.05).The population of E.coli decreased in Japanese quail fed MOS, while Lactobacilli spp. count was increased in the MOS group (P < 0.05).

4. In conclusion, AEO, MOS, and PRO supplementation exhibited a positive effect on growth performance, while lipid peroxidation of the meat decreased in birds fed AEO and DEO diets. The intestinal morphometric indices increased in quail fed the AEO, MOS, and DEO diets. Supplementation with MOS modulated intestinal microbial populations of the Japanese quail.     

Effects of a New Recombinant Phytase on the Performance and Mineral Utilization of Broilers Fed Phosphorus-Deficient Diets

An experiment was conducted with Arbor Acres broiler chickens that were fed 3 experimental diets—a control diet containing an adequate level of available phosphorus (AP) and 2 diets that were deficient in AP but supplemented with phytase at a level of either 500 or 750 phytase units/kg—to assess the effects of a novel microbial phytase supplement in broilers fed AP-deficient diets on growth performance and mineral utilization. Similar average daily gain, feed intake, and feed efficiency (P > 0.05) were obtained among broilers fed different diets. Compared with broilers fed the control diet, broilers fed diets with phytase had greater (P < 0.05) retention of Ca, P, and Zn. Moreover, the levels of Cu, Zn, Mg, and Mn in the tibia bone at 28 d of age, and Zn and Mn at 42 d of age in birds fed diets with phytase exceeded (P < 0.05) those of birds fed the control diet. Supplementation of phytase increased Zn and Mg contents in the plasma at 42 d of age. Birds responded similarly to phytase supplemented at a level of 500 or 750 phytase units/kg in terms of growth performance, mineral retention, and mineral content in the serum and bone. Therefore, with the supplementation of this novel phytase, it is possible to reduce the dietary levels of P and other minerals to below the recommended levels of the Feeding Standard of Chicken in P. R. China (ZB B 43005-86).     

Response of broiler chicks to non-steam- or steam-pelleted diets containing raw,full-fat soybean meal

The objective of this study was to evaluate the effects of steam pelleting of diets containing graded levels of raw, full-fat soybean meal (RSBM) on the chemical properties and feeding values of the diets. Samples of diets with steam- or non-steam-pelleted as well as the mash containing varying levels of RSBM were subjected to detailed chemical analysis. As a result of this study, trypsin inhibitor (TI) concentrations in the diets ranged between 4,153 and 10,484 TIU/g. Amino acid concentrations were higher in the non-steam-pelleted and mash diets than the steam-pelleted diets. A 4 × 2 factorial arrangement (RSBM: zero, 10, 20 or 30%, equivalent to zero, 30, 60, and 90 g/kg of diet, respectively, and non-steam- or steam-pelleted diets) was used while feeding broiler chicks (zero to 14 d of age). Each treatment was replicated 6 times with 8 birds per replicate. As a result of this study, there was no difference (P > 0.05) in mortality of birds among the groups. Feed intake (FI) (P < 0.05) and body weight gain (BWG) (P < 0.001) decreased with increasing levels of RSBM. Birds fed on steam-pelleted diets gained less (P < 0.001) weight than birds on the non-steam-pelleted diets, but the FI was not significantly (P > 0.05) different. The FCR was negatively affected (P < 0.05) by increasing levels of RSBM. There was no interaction effect between RSBM and pelleting method on the FI, BWG, or FCR of birds. The weight of the pancreas (P < 0.001) and duodenum (P < 0.01) increased with a rise in the level of RSBM in diets. Non-steam pelleting increased (P < 0.05) the pancreatic protein content, whereas the activity of chymotrypsin was reduced (P < 0.01) when the RSBM level was increased. Birds fed with RSBM-free diets had thicker muscle, longer villi, wider villus surface area, and higher villus to crypt depth ratios than birds on the other diets, but these differences were not significant. It can be concluded that steam pelleting of diets containing RSBM is inadequate to reduce the adverse impact of TI on chicks.     

Effects of an experimental phytase on performance, egg quality, tibia ash content and phosphorus bioavailability in laying hens fed on maize- or barley-based diets

A 24-week performance trial was conducted to evaluate the efficacy of an experimental phytase on performance, egg quality, tibia ash content and phosphorus excretion in laying hens fed on either a maize- or a barley-based diet. At the end of the trial, an ileal absorption assay was conducted in order to determine the influence of phytase supplementation on the apparent absorption of calcium and total phosphorus (P). Each experimental diet was formulated either as a positive control containing 3.2 g/kg non-phytate phosphorus (NPP), with the addition of dicalcium phosphate (DCP), or as a low P one, without DCP addition. Both low P diets (containing 1.3 or 1.1 g/kg NPP) were supplemented with microbial phytase at 0, 150, 300 and 450 U/kg. The birds were housed in cages, allocating two hens per cage as the experimental unit. Each of 10 dietary treatments was assigned to 16 replicates. Low dietary NPP (below 1.3 g/kg) was not able to support optimum performance of hens during the laying cycle (from 22 to 46 weeks of age), either in maize or barley diets. Rate of lay, daily egg mass output, feed consumption, tibia ash percentage and weight gain were reduced in hens fed low NPP diets. The adverse effects of a low P diet were more severe in hens on a maize diet than in those on a barley diet. Low dietary NPP reduced egg production, weight gain, feed consumption and tibia ash content and microbial phytase supplementation improved these parameters. Hens given low NPP diets supplemented with phytase performed as well as the hens on positive control diets containing 3.2 g/kg of NPP. A 49% reduction of excreta P content was achieved by feeding hens on low NPP diets supplemented with phytase, without compromising performance. Phytase addition to low NPP diets increased total phosphorus absorption at the ileal level, from 0.25 to 0.51 in the maize diet and from 0.34 to 0.58 in the barley diet. Phosphorus absorption increased linearly with increasing levels of dietary phytase. Mean phosphorus absorption was higher in barley diets than in maize diets (0.49 vs 0.39).     

Effects of different dietary phytase activities on the concentration of antioxidants in the liver of growing broilers

One‐hundred and fifty male chickens were used to evaluate the effects of different activities (0, 250, 500, 12 500 FTU/kg) of phytase on their performance and antioxidant concentration in the liver. The chicks were housed in 30 cages and were allocated to six replicates of five dietary treatments. All diets were formulated to be adequate in energy and protein (12.90 MJ/kg metabolizable energy, 214 g/kg crude protein), however, the negative control (NC) was lower in available P compared with the positive control (PC) (2.5 vs. 4.5 g/kg diet). The other three diets were the NC supplemented with phytase at 250, 500 and 12 500 FTU/kg (NC + 250, NC + 500 and NC + 12 500 FTU respectively). The concentration of antioxidants in the liver of the birds was determined using HPLC at 21 days of age. Low P diets (NC) reduced weight gain, however, supplementation with phytase improved weight gain to the extent that it was better than the PC at the 12 500 FTU treatment (p < 0.05). Feed conversion ratio was also improved by the high level of phytase supplement more than other treatments (p < 0.05). Feed consumption was not affected either by dietary phosphorus concentration or by different phytase supplementation. The antioxidant data showed that the unsupplemented diet with low phosphorus (NC) decreased the concentration of coenzyme Q₁₀ and retinol‐linoleate in the liver compared with that of birds on the adequate phosphorus treatment (PC). Phytase supplementation, especially at the higher doses (500 and 12 500 FTU) increased the level of coenzyme Q₁₀ to the same level as the PC treatment. In addition, the highest dose (12 500 FTU) of phytase increased retinol concentration in the liver of chickens compared with those on the NC treatment. The highest inclusion level of phytase increased the α‐tocopherol level in the liver compared with the lower levels of phytase (NC + 250 and NC + 500 FTU).