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Abdallh, Medani
- PublicationDietary hydrolysed yeast cell wall extract is comparable to antibiotics in the control of subclinical necrotic enteritis in broiler chickens(Taylor & Francis, 2019-11-02)
; ; ; ; ; ; 1. The aim of this study was to examine the effect of yeast cell wall (YCW) on performance and physiological responses of broiler chickens under subclinical necrotic enteritis challenge.
2. Six treatments in a 2 × 3 factorial arrangement (non-challenged or challenged plus no supplement, YCW or antibiotics (AB)) was used. Each treatment was replicated eight times with 12 birds per replicate. The treatments included: (1) Positive control (PC; no additive, not challenged); (2) Negative control (NC; no additive, with challenge); (3) YCWN = yeast cell wall (2.0 g/kg diet, not challenged; (4) YCWC = yeast cell wall (2.0 g/kg diet, challenged); (5) ABN = zinc bacitracin 50 ppm + Salinomycin 60 ppm, not challenged); (6) ABC = zinc bacitracin 50 ppm + Salinomycin 60 ppm, challenged).
3. Eimeria challenge at 9 d of age did not affect feed intake (FI), body weight gain (BWG), FCR or liveability at 10 d. The BWG and FCR at 10 d were greater (P < 0.05) in birds fed YCW or AB (AB) diets relative to the PC or NC groups. On 24 and 35 d, FI, BWG, FCR and flock uniformity (28 d) were greater (P < 0.05) in the challenged groups fed YCW or AB diets compared to NC group.
4. Supplementation with YCW ameliorated the negative effects of NE on liver, spleen and bursa weight of birds.
5. Necrotic enteritis challenge decreased (P < 0.05) caecal Lactobacillus and Bifidobacterium spp. counts, and increased ileum lesion score and caecal Clostridium perfirngens counts. This was reversed by the addition of either YCW or AB.
6. Supplementation with YCW and AB resulted to a greater (P < 0.05) dressing percentage and meat yield (35 d).
7. The results indicated that YCW plays a vital role in improving the physiological response and performance of broiler chickens under subclinical necrotic enteritis challenge.
- PublicationEnergy and protein utilisation by broiler chickens fed diets containing cottonseed meal and supplemented with a composite enzyme product(Taylor & Francis, 2020)
; ; ; ; ; 1. The present study examined the potential of new-generation microbial enzymes to improve the utilisation of energy and protein of cottonseed meal (CSM)-containing diets, with the aim of increasing its inclusion level in broiler chickens diets.
2. Four hundred and eighty, one-day-old Ross 308 male broilers were used to assess the utilisation of energy and protein by broiler chickens fed diets containing four graded levels of CSM – none, low (4, 8, 12%), medium (5, 10, 15%) or high (6, 12, 18%) in the starter, grower, and finisher phases, respectively, supplemented with 100 mg/kg of a composite enzyme product (xylanase and β-glucanase).
3. Inclusion of CSM improved (P < 0.01) apparent metabolisable energy (AME), with further improvement (P < 0.001) seen in the enzyme-supplemented diets. Inclusion of CSM reduced (P = 0.002) the metabolisable energy intake (MEI), but this was increased (P < 0.05) with enzyme supplementation.
4. Enzyme addition increased (P < 0.001) the net energy of production (NEp), while heat production (HP) decreased (P < 0.001) with CSM inclusion. More energy was retained as fat (P < 0.05) and protein in birds fed diets with the enzyme, but this was reduced (P < 0.029) by CSM.
5. There was an increase (P < 0.05) in efficiencies of ME use for energy, lipid and protein retention, with higher CSM levels. The enzyme improved (P < 0.013) efficiency of ME use for lipid retention.
6. Feeding diets containing CSM to the broilers enhanced (P < 0.05) protein intake (PI) and protein efficiency ratio (PER). Positive effects (P < 0.05) of enzyme were observed on protein gain (PG) and net protein utilisation (NPU).
7. Results obtained from this study suggested that nutrient utilisation of diets containing CSM by broiler chickens can be improved by enzyme supplementation.
- PublicationEnergy utilization, nutrient digestibility and bone quality of broiler chickens fed Tanzania-type diets in different forms with enzymes(BioMed Central Ltd, 2019)
; ; ; ; A study was conducted to determine the influence of feed form and microbial enzyme supplementation on energy utilization, bone quality, and amino acid and mineral digestibility of broiler chickens. Four hundred and eighty Ross 308, day-old broiler chickens were randomly assigned to eight diets formulated from commonly used ingredients in Tanzania. A 2 (pellet or mash) × 4 (control, Axtra XB, Quantum Blue (QB) and Axtra XB + QB enzyme) factorial array in a completely randomized design having six replicates per treatment (10 birds per replicate) was used. Birds were raised in climate-controlled rooms in a 3-phase" starter (0–10 days), grower (11–24 days) and finisher (25–35 days). Apparent metabolizable energy (AME), metabolizable energy intake, net energy of production, energy retained as protein (REp), and efficiency of metabolizable energy use for energy and protein retention were higher (p < 0.05) in birds fed pelleted diets. The AME and REp was higher (p < 0.05) with enzyme supplementation. Ash content, weight, length, width and breaking strength of tibia bones were highest (p < 0.05) in birds on pelleted diets. Tibia bone traits were improved (p < 0.05) when enzymes were included, particularly in a combination of QB and Axtra XB. However, potassium, magnesium, and zinc contents were highest (p < 0.05) when QB was supplemented. Digestibility of all amino acids was higher (p < 0.05) in birds supplied with pellets and with enzyme supplementation for most amino acids, except for serine. There was a positive interaction (p < 0.05) between feed form and enzymes on lysine and phenylalanine digestibility. Digestibility of Ca, P, K, S, Zn, and Fe was higher (p < 0.05) in birds fed pelleted diets, while those on mashed diets had higher (p < 0.05) digestibility of Cu and B. The digestibility of P, K, and Zn was highest (p < 0.001) when QB was added, while Ca, P, S, and B digestibility was highest when a combination of Axtra XB + QB was applied. Pelleted diets with or without enzymes improved energy utilization, digestibility of amino acids, and minerals, and increased bone strength in broiler chickens.
- PublicationResponses of broiler chickens to dietary yeast and yeast components(University of New England, 2019)
; ; ; ; ; ; Four experiments were conducted to examine the growth promoting effect of different levels of autolyzed whole yeast (WY), yeast cell wall (YCW) and enzymatically hydrolyzed cell wall components, yeast α-mannan (YM) and yeast β-glucan (YG), in broiler chickens. The mechanisms underlying these effects in broilers were determined. The potential of these yeast products as possible alternatives to in-feed sub-therapeutic antibiotics was determined by measuring their effects on broiler performance, meat yield and immune-regulation under mild stress. In the first experiment, lower levels of supplementation of autolyzed WY and YCW (0.5 and 1.0 g/kg) did not have a significant effect on performance, visceral organ weight, digestibility and intestinal enzyme activities in experiments one. However, WY and YCW at 1.5 or 2.0 g/kg had marked improvement in bird performance response for both whole yeast and yeast cell walls.
In experiment two, feeding lower levels of YM (0.05 and 0.10 g/kg diet) to unchallenged did not have significant effect on the parameters considered. However, YM supplemented at 0.15 and 0.20 g/kg diet were superior to the control group in the majority of the parameters recorded (gross performance, protein digestibility and meat yield). Birds fed diets containing YG did not have in effect in most of the parameters considered.
In experiment 3, the effect of autolyzed WY (2.0 g/kg diet), YCW (2.0 g/kg diet), yeast mannan (0.20 g/kg diet), YG (0.20 g/kg diet) and zinc bacitracin (50 ppm diet), Salinomycin (60 ppm diet) was compared with a control group (without supplementation) in broilers under mild stress of Salmonella lipopolysaccharide challenge (LPS). The LPS challenge increased bird rectal temperature and immune response (haematological and serum metabolite), with a resultant decrease in performance, meat yield, flock uniformity and spleen weight. However, supplementation with autolyzed WY, YCW, YM, YG or antibiotics (Salinomycin and zinc bacitracin) improved performance, flock uniformity and meat yield in challenged birds. These improvements were associated to ability of these additives to reduce the level of LPS-induced immune responses. These additives, possibly through different mechanisms, improved most parameters (performance, flock uniformity, haematological indices, plasma metabolites and meat yield) considered.
In a further trial, YCW and zinc bacitracin when supplemented to the diets of birds unchallenged or challenged with Eimeria and Clostridium perfringens showed the growth enhancing and challenge-ameliorating effects. In unchallenged broilers, supplementation of yeast cell wall and bacitracin tended to improve performance relative to the control group. Eimeria and C. perfringens resulted in poorer feed intake, body weight gain, FCR, meat yield and flock uniformity. The challenge also resulted in a higher number of intestinal lesions. There was no effect of the challenge or dietary treatments on the pH of duodenal, ileal, jejunal and caecal digesta. Challenge resulted to an increase in C. perfringens count. The Lactobacillus and the Bifidobacteria caeca count decreased in CP challenged birds. Both YCW and zinc bacitracin supplementation decreased C. perfringens counts and increased Lactobacillus and Bifidobacteria counts. This may be associated to the better performance, meat yield, flock uniformity and lesion score observed in the study. Challenge or supplementation did not significantly influence the mortality of birds.
The results of these studies provided evidence that autolyzed WY (at 1.5-2.0 g/kg diet), YCW (at 1.5-2.0 g/kg diet) and YM (at 0.15-0.20 g/kg diet) exhibited some growth enhancing effects. Furthermore, WY and YCW (both included at 2.0 g/kg diet) as well as YM and YG (both included at 0.20 g/kg diet) showed immunomodulatory controlling abilities which led to improved growth performance in both mildly stressed and disease challenged broiler chickens. - PublicationReplacement value of cottonseed meal for soybean meal in broiler chicken diets with or without microbial enzymes(BioMed Central Ltd, 2020)
; ; ; ; ; ; A 4×2 factorial feeding trial was designed to investigate the effect of replacing soybean meal (SBM) with cottonseed meal (CSM) in wheat/sorghum/SBM-based diets fed with or without microbial enzymes in diets on the performance, visceral organ development and digestibility of nutrients of broiler chickens. Four graded levels of CSM - none (0%), low (4%, 8%, and 12%), medium (5%, 10%, and 15%), and high (6%, 12%, and 18%) of complete diets in starter, grower and finisher, respectively were fed with or without 100 mg/kg of xylanase and β-glucanase blend. Eight isocaloric and isonitrogenous diets were formulated using least-cost method to meet the nutrient specifications of Ross 308 male broilers. Each treatment was randomly assigned to 6 replicates (10 birds per replicate). There were CSM-enzyme interactions (p < 0.05) on feed intake (FI) and weight gain (WG) in the starter phase. Enzyme supplementation improved (p < 0.05) feed conversion ratio (FCR) in the grower and finisher phases, and increased WG in growing and finishing birds. CSM inclusion reduced (p < 0.05) the weight of gizzard and proventriculus in starter chicks, while these organs were bigger (p < 0.05) in the grower phase. The test ingredient decreased (p < 0.05) small intestinal weight in starter and grower birds. The CSM increased the absolute weight of thighs (p < 0.05) while breast meat was increased (p < 0.01) by enzyme addition. Starch digestibility was improved (p < 0.01) by enzyme inclusion and decreased (p < 0.01) by CSM. Enzyme supplementation improved (p < 0.05) the ileal digestibility of gross energy and protein. The results demonstrate that CSM can substitute up to 90% SBM in broiler chicken diets without compromising performance, and the nutritive value of CSM-containing diets can effectively be improved by enzyme supplementation.