Feed Enzymes Research Articles

Effect of feeding sorbent and enzymes on heavy metal toxicity in young steers

Effect of feeding sorbent and enzymes on heavy metal toxicity in young steers

The evaluation of protease enzyme effectivenes in broiler chicken diet containing jack bean seed (Canavalia ensiformis) with different protein level toward internal organ size

This study was conducted with the intention of evaluating the use of the protease enzyme in broiler feed containing jack bean seed (Canavalia ensiformis) with the different levels of protein towards the internal organs of broiler chicken starter. Bird samples used were 24 broilers of the male lohmann strain taken from 120 chickens. The study design used was a factorial completely randomized design (FCRD) with 2 factors treatment and 3 replications (each replication used 2 samples of bird). The first factor was the level of protein (CP 22% and CP 19.5%) and the second factor was the use of enzymes (non-protease and protease). Data were analyzed by using analysis of variance (ANOVA). The result showed that the use of low protein levels in broiler feed containing jack bean seed significantly (P <0.05) increased the percentage of pancreatic weights but could be improved by the use of protease enzymes. Levels of protein treatment did not significantly affect the percentage of heart, liver and bile weights. The use of protease enzymes significantly (P <0.05) decreased the percentage of pancreatic and bile weights but did not significantly affect the percentage of liver and heart weights.

Effect of Different Levels of Direct-fed Microbials Plus Exogenous Fibrolytic Enzymes Additives on the Growth Traits of Dairy Calves

The study was carried out to investigate to determine effects of the different levels of the direct-fed microbials (DFM) plus exogenous feed enzymes (EFE) on the body weights, weight gains, feed efficiency ratio, some behavioral traits as well as fecal consistency index of male Brown Swiss calves. For this purpose, 18 male Brown Swiss calves were allocated to three groups (control, 10 g and 20 g head/day of DFM plus EFE). Weights obtained at weaning time and 6 months of age of the calves in 10 g head/day of DFM plus EFE group were respectively 7.3% and 7.1% heavier than these of animals in control group. The calves in 10 g head/day of DFM plus EFE group in pre-weaning and between birth and 6 months of age periods also had respectively 16.0% and 7.3% higher total weight gains than calves in the control group. Feed efficiency ratio of the calves fed diets with 10 g DFM plus EFE had 64.2% better than that of calves in control group. Average fecal consistency score of the calves fed a diet supplemented with 10 g head/day of DFM plus EFE had the lowest score (P<0.05) (i.e., less scouring) compared to other treatment groups in pre-weaning period as well as between birth and 6 months of age. Furthermore, behavioral activities of the calves were not significantly influenced by DFM plus EFE additives except for the percentage of time spent for lying. The study revealed that the feeding of DFM plus EFE to male Brown Swiss calves until 6 months of age had positive but not statistically significant improvement on the growth traits and feed efficiency ratio. On the other hand, it was concluded that the level of 10 g head/day of the DFM plus EFE additives could be beneficial for reducing incidence of diarrhea in the dairy calves.

The effectiveness of the inclusion of domestic enzymes in the compound feed to increase the egg production of laying hens and the quality of eggs

Compound feed are subject to requirements for their composition, since they use several types of grains that contain anti-nutritive substances that reduce the digestibility and use of nutrients. One of the tasks of domestic poultry farming is to reduce losses by increasing the digestibility and accessibility of feed. Among the most effective ways to solve this problem is to add enzymes to the feed of poultry. The inclusion of enzyme drugs in the composition of compound feed contributes to the inactivation of anti-nutritive substances, which contributes to an increase in the coeffi cient of digestibility of nutrients. The purpose of the work was to establish the feasibility and eff ectiveness of the enrichment of compound feed used in the production technology of chicken eggs with mixtures of enzyme drugs of domestic production of Amylosubtilin G3x, Cellolux-F and Protosubtilin G3x. Three groups of laying hens with 57 heads in each have been formed: a control group and two experimental groups. The duration of the experiment was 420 days. Laying hens of the control group have been received farm compound feed depending on their age. Laying hens of the 1st experimental group have been received compound feed of the control group enriched with the enzymes Amylosubtilin G3x and Cellolux-F depending on the age. In the compound feed of laying hens of the 2nd experimental group enzyme drugs were additionally introduced depending on the age Amilosubtilin G3x and Protosubtilin G3x. Higher egg production rates have been observed in the 1st experimental group – 357,81 eggs, which was 6,48 % higher than in the control group and 1,84 % higher than in the 2nd experimental group. The weight of eggs of laying hens of the 1st experimental group was 1,85 g or 2,97 % more, and the 2nd experimental group was 0,7 g or 1,12 % more than in the control group. The diff erence between the egg weight in laying hens of the 1st and 2nd experimental groups was 1,85 % or 1,15 g. The lowest feed consumption of 1,37 kg for the production of 10 eggs was in the laying hens of the 1st experimental group, which was less than the indicator of the control group by 10,94 and by 4,2 % than in the 2nd experimental group.

Growth performance, organ attributes, nutrient and caloric utilization in broiler chickens differing in growth rates when fed a corn-soybean meal diet with multienzyme supplement containing phytase, protease and fiber degrading enzymes

Growth performance, organ weight, ceca digesta short chain fatty acids (SCFA), jejunal histomorphometry, tibia ash, apparent retention (AR) of components and caloric efficiency were investigated in broiler chicken strains differing in growth rate fed diets with multienzyme supplement (MES). The strains differed in estimated time to reach 2.1 kg BW: 37, 43, 47, and 50 d and were designated C, F, J, and N, respectively. A corn-soybean meal diet was formulated for 2-phase program (starter and grower) and fed without or with MES containing phytase, protease and fiber-degrading enzymes. A total of 640-day-old chicks (42.3 + 0.01 g/bird) were housed in cages (5 cockerels and 5 pullets/cage) and allocated to give 8 replicates/ strain and diet combination. Equal amount of feed was fed based on observed ad-libitum intake of C strain in the starter (d 0–14) and grower (d 15–28). Body weight was monitored, grab excreta samples taken and at completion of allocated feed one bird per cage necropsied for samples. With exception of P, apparent metabolizable energy corrected for nitrogen (AMEn) and ceca digesta acetic acid, there was no (P > 0.05) interaction between strain and MES on examined responses. Strains differed (P < 0.01) on growth, FCR, gizzard weight, tibia ash, breast weight, ceca digesta concentration of lactic, propionic, and isobutyric acid and caloric efficiency. The final body weight (BW) was 1,344, 1,134, 959, and 916 g/bird for C, F, J, and N, respectively. Corresponding caloric efficiency was 4,930, 5,807, 6,680 and 7,199 kcal/kg BW gain, respectively. Birds fed MES had higher BW gain (P < 0.05) in grower phase, larger gizzard, higher AR of CP, crude fat, neutral detergent fiber, and Ca than non-MES birds. In conclusion, growth rate influenced organ attributes, nutrient, and caloric utilization. Enzyme supplementation improved growth in grower phase and nutrient utilization independent of strain, suggesting that effects of feed enzymes are not influenced by inherent growth rate.

Polyenzyme preparations in feeding of monogastric animals

In animal feeding enzyme preparations are mainly used, which are not produced in the body of animals, although in chickens in the first weeks of life and piglets after weaning an insufficient amount of their own proteases and amylases is formed, so their inclusion in feed is also useful. By now highly active enzyme preparations with various specific activities have been created and are being produced. In feeds prepared using traditional raw materials up to 30% of nutrients are not available for digestion by enzymes secreted in the gastrointestinal tract. The inclusion of exogenous enzymes in the feed provides additional use of the indigestible fraction. It is impossible to achieve complete digestibility of feed, although in vitro exogenous enzymes digest almost 100% of the target substrates. The problem is due to the fact that natural feed does not contain pure substrates — they are associated with other substances that limit the availability of enzymes to them. The properties of natural substrates, their concentration and availability even in the same raw material are variable, which excludes reliable prediction of the effectiveness of the action of feed enzymes. Partially these difficulties are overcomed by the use of polyenzyme drugs. It is necessary to further study the specificity of native substrates and factors that increase their availability for the action of enzymes.

Environmentally-friendly enzyme compositions in animal feeding

The realization of the genetic potential of farm animals is first of all determined by the complete feeding, which is determined by its balance in accordance with the needs of animals with a certain physiological state and level of productivity. The study of enzyme compositions in the feeding of mammalian farm animals that promote better digestion of incoming nutrients is an urgent issue. Feed enzymes not only increase the digestibility of individual feed components, but also allow you to increase the rate of input of inexpensive raw materials “rich” in anti-nutritional factors without compromising the health and productivity of the animal. The purpose of the research was to study the use of enzyme compositions in the feeding of cattle and pigs. The results of the study of enzyme compositions in the rations of lactating cows during the period of increasing the milk yield and pigs during the period of rearing and fattening have been presented in the article. The input of enzyme additives with a cellulolytic effect in the rations of cows had the positive effect on the digestibility of nutrients in the feeding ration, milk productivity, and the composition of milk. During the first 100 days of lactation milk with natural fat content was produced from cows of the 1st experimental group by 5,5 % more and from cows of the 2nd experimental group by 13,8 % more than from animals of the control group. In terms of 4 % milk the animals of the 1st experimental group exceeded the control analogues by 7,32 % and in the 2nd group by 18,1 %. The input of 1 kg/t of feed in the diet of the multienzyme composition “Kemzaym W” animals allowed us to get 81,7 kg of additional gain, more profi t compared to the 1st experimental group, where the additional gain was 24,7 kg. The use of the multienzyme composition “Kemzaym W” in the amount of 1 kg/t in the diets of young pigs had the positive effect on the digestibility of raw nutrients, on the increase in live weight and average daily gains, on the yield of meat and the quality of carcasses.

Purification and characteration of xylanase from Aspegillus oryzae VTCC F187

Xylanase is produced by many bacteria and fungi, among which Aspergillus oryzae is considered as a potential source. In this study, a xylanase was isolated and purified from the crude culture filtrate of Aspergillus oryzae VTCC F187 after 7 days of growth on the optimal culture containing 7% corncob and 5% soybean powder under liquid-state fermentation. After two steps purification process including gel filtration chromatography (Sephadex G-75) incorporating with anion-exchange chromatography (DEAE-sephadex), obtained xylanase was purified with the yield and purity of 24.9% and 3.91 fold, respectively. The molecular mass of the purified xylanase determined by SDS–PAGEwas 32 kDa with a specific activity of 1268.0 U/mg towards 1% (w/v) of birch wood xylan. The xylanase displayed its optimum activity at 60°C, pH 6.5, and the enzyme remained active effectively within pH 3.0–5.0 and at the temperature below 37°C. Some substances were tested at concentration of 2% (v/v) such as β-mercaptoethanol, DMSO, Tween 80 and 10 mM NaN3 slightly decreased xylanase activity and reached over 85%. While EDTA 10 mM and SDS at concentration of 2% inhibited more strongly, xylanase activity was only 77.6% and 56.6% comparing with control one, respectively. The biochemical characteristics suggested that the xylanase has a potential application, including use as a feed enzyme or using hydrolysis to produce environmentally friendly Bio-products.

Mandated restrictions on the use of medically important antibiotics in broiler chicken production in Canada: implications, emerging challenges, and opportunities for bolstering gastrointestinal function and health — a review

Chicken Farmers of Canada has been progressively phasing out prophylactic use of antibiotics in broiler chicken production. Consequently, hatcheries, veterinarians, and nutritionists have been mandated to contend with less reliance on the use of preventive antibiotics. A topical concern is the increased risk of proliferation of enteric pathogens leading to poor performance, increased mortality, and compromised welfare. Moreover, the gut harbors several taxa such as Campylobacter and Salmonella capable of causing significant illnesses in humans via contaminated poultry products. This has created an opportunity for research and development of dietary strategies designed to modulate gastrointestinal environment for enhanced performance and food safety. Albeit with inconsistent responses, literature data suggest that dietary strategies such as feed enzymes, probiotics/prebiotics, and phytogenic feed additives can bolster gut health and function in broiler chickens. However, much of the efficacy data were generated at controlled research settings that vary significantly with the complex commercial broiler production operations due to variation in dietary, health, and environmental conditions. This review will summarize implications of mandated restrictions on the preventative use of antibiotics and emerging Canadian broiler production programs to meet processor specifications. Challenges and opportunities for integrating alternative dietary strategies in commercial broiler production settings will be highlighted.

EFEK PENAMBAHAN ENZIM (Amylase, Protease, Xylanase) DALAM PAKAN TERHADAP BERAT TELUR DAN DIAMETER KUNING TELUR PADA ITIK CAMPURAN

The purpose of this research aims to determine the effect of adding enzymes (amylase, protease, xylanase) in feed on egg weight and egg yolk diameter in mixed ducks. The experimental animals used were 24 laying ducks. The design used was a completely randomized design (CRD) with 4 treatments and 6 replications. The four treatments were P0 (Control), P1 (6 ducks with Avizym1502®5gram / kg), P2 (6 ducks with Avizym1502® 10gram / kg), and P3 (6 ducks given Avizym1502). ® 15gram / kg). This treatment is carried out once a day for 9 weeks. Before the treatment, the ducks were adapted for a week. After that, the initial egg weight and yolk diameter were measured at week 0, week 6, and week 9. Data obtained from the results of weighing eggs found an average value of P0 (59.1667 ± 3.9200a) g, P1 5gram / kg (56.1667 ± 2.9268a) g, P2 10gram / kg (60.1667 ± 4.9966a) g, and P3 15gram / kg (67.6667 ± 2.7325ᵇ) g. The results of data from examining the diameter of the egg yolk found an average value of P0 (45.03 ± 1.2956a) mm, P1 5gram / kg (44.35 ± 0.7969a) mm, P2 10gram / kg (45.75 ± 1.5694a) mm, and P3 15gram / kg (48.83 ± 0.7394ᵇ) mm. The data obtained were then analyzed using the ANOVA test which statistically showed that there was a significant difference (P &lt;0.05) between egg weight and yolk diameter in mixed ducks treated with enzymes (amylase, protease, xylanase) in the feed.

PSV-14 The Efficacy of Feeding a Bioactive Peptide in Comparison to Narasin in Growing Pigs in a Commercial System on Growth Performance and Efficiency

Abstract At 8-wk post-weaning, pens of split-sexed pigs (26.0 ± 0.25 pigs/pen; 31.3 ± 0.11 kg; DNA genetics) being housed in a commercial research unit were randomly assigned to one of two dietary treatments to compare the growth performance and efficiency of the system’s commercial nutritional program that included narasin (Skycis™, Elanco Animal Health, Greenfield, IN) at 13.6 g/tonne to a product (2 kg/tonne) containing a combination of bioactive peptides and enzymes (PEP; Peptiva® Optimo, Vitech Bio-Chem Corporation, Orange, CA). Dietary treatments were fed through 4 phases based on feed budgets. Pens were weighed bi-weekly through 59-d on test. There were 12 replications or pens per treatment. Feed was delivered and measured using a Feed Logic system and weigh backs were conducted utilizing a calibrated ruler. Average daily gain and feed intake were calculated on a pen basis. Data were analyzed as a mixed model with dietary treatment, gender, and treatment x gender interaction included. There were no interactions reported (P ≥ 0.0965). During the study pigs performed at or above their commercial counterparts. Overall, body weight, ADG, and ADFI were not impacted by treatment, but pigs fed PEP had an 2.1% improvement in feed efficiency compared to the narasin fed pigs. These results indicate that feeding bioactive peptides plus enzymes may improve feed efficiency without the need of an ionophore in the grower period in a commercial swine facility.

Recombinant production of two xylanase-somatostatin fusion proteins retaining somatostatin immunogenicity and xylanase activity in Pichia pastoris.

Somatostatin (SS) is one of the peptide hormones that regulate the endocrine system in animals. When SS is used to immunize animals, the correspondingly generated anti-SS antibody neutralizes the SS and, therefore, alleviates its growth inhibiting effects. This is of great value to the livestock industry; however, previously developed methods fail to obtain enough recombinant SS in an economical way. Herein, we describe the employment of a commonly used feed enzyme, i.e., xylanase, as a carrier protein for recombinant expression of SS in large quantity. The SS gene was fused to one of the two xylanase genes (XynCDBFV and BsXynC) and recombinantly expressed in Pichia pastoris. The purified xylanase-SS fusion proteins displayed excellent antigenicity and immunogenicity. In addition, they retained the enzymatic activities and thermostability of the xylanases, indicating that they can catalyze hydrolysis of xylan in plant cell wall of the animal feeds and stand the high temperature in feed pelleting. Thus, the xylanase-SS fusion proteins serve as an excellent candidate chimeric bifunctional vaccine-feed enzyme protein retaining both SS immunogenicity and xylanase activity. KEY POINTS: • Somatostatin is expressed in P. pastoris as fusion proteins with two xylanases. • The chimeric proteins retain both immunogenicity and xylanase activity. • The xylanase-SS proteins may serve as bifunctional proteins in livestock industry.

Dietary Arthrospira platensis improves systemic antioxidant potential and changes plasma lipids without affecting related hepatic metabolic pathways in post-weaned piglets

BackgroundThe ability of a high level of dietary Arthrospira platensis, individually or in combination with two exogenous carbohydrate-degrading enzymes (lysozyme and Rovabio®), to improve systemic antioxidant potential and hepatic lipid metabolism was tested in piglets. Forty male post-weaned piglets, sons of Large White × Landrace sows crossed with Pietrain boars, were allocated into 4 groups (n = 10) and fed during 28 days one of the following diets: 1) a control basal diet (cereal and soybean meal); 2) a basal diet with 10% of A. platensis (AP); 3) the AP diet supplemented with 0.005% of Rovabio® (AP + R); 4) the AP diet supplemented with 0.01% of lysozyme (AP + L).ResultsArthrospira platensis decreased BW gain of piglets, regardless the addition of feed enzymes. The majority of plasma metabolites were affected by diets. A. platensis increased total lipids, total cholesterol and LDL-cholesterol, without changing hepatic fatty acid content or modulating, in an expressive manner, the transcriptional profile of lipid sensitive mediators. The antioxidant potential in general, and total carotenoids in particular, were improved by the microalga, regardless lysozyme or Rovabio®.ConclusionsSumming up, A. platensis, individually and combined with feed enzymes, impacts negatively on piglets’ growth but improves the systemic antioxidant potential and changes plasma lipids with a minor modulation on related hepatic metabolic pathways.

Towards a Novel Computer-Aided Optimization of Microreactors: Techno-Economic Evaluation of an Immobilized Enzyme System

Immobilized multi-enzyme cascades are increasingly used in microfluidic devices. In particular, their application in continuous flow reactors shows great potential, utilizing the benefits of reusability and control of the reaction conditions. However, capitalizing on this potential is challenging and requires detailed knowledge of the investigated system. Here, we show the application of computational methods for optimization with multi-level reactor design (MLRD) methodology based on the underlying physical and chemical processes. We optimize a stereoselective reduction of a diketone catalyzed by ketoreductase (Gre2) and Nicotinamidadenindinukleotidphosphat (NADPH) cofactor regeneration with glucose dehydrogenase (GDH). Both enzymes are separately immobilized on magnetic beads forming a packed bed within the microreactor. We derive optimal reactor feed concentrations and enzyme ratios for enhanced performance and a basic economic model in order to maximize the techno-economic performance (TEP) for the first reduction of 5-nitrononane-2,8-dione.

The effect of papain and bromelain enzymes on the growth and feed utilization of post larvae Litopenaeus vannamei

The aim of this research was to evaluate the effect of papain and bromelain enzymes in feed on growth and feed utilization of post larvae Litopenaeus vannamei shrimp. The research was conducted during 23 January to 2 March 2020 at the Fish Hatchery Laboratory, Faculty of Marine and Fisheries, Syiah Kuala University. The completely randomized design consisting of four treatments and three replications were used in this study (A (feed without enzyme); B (feed + 1% papain enzyme); C (feed + 1% bromelain enzyme), and D (feed + 1% papain enzyme + 1% bromelain enzyme)). The shrimp was fed with the tested feed five times on 07.00 AM, 11.00 AM, 03.00 PM, 07.00 PM and 11.00 PM for 42 days. The ANOVA test results showed the addition of papain and bromelain enzymes in the feed had a significant effect on weight gain, daily growth rate and specific growth rate of vannamei shrimp (P<0.05). However, there was no significant effect on its survival, feed conversion and feed efficiency (P>0.05). The best treatment was found in treatment D with the weight gain of 1.15 g, daily growth rate of 0.027 g day-1, specific growth rate of 7.14% day-1, feed conversion ratio of 1.85, and feed efficiency 54.15%, but the highest survival was found at treatment A. It is concluded that the best treatment is a combination between of 1% papain enzyme and 1% bromelain enzyme).

In vitro assays for evaluating phytate degradation in non-ruminants: chances and limitations.

The positive effects of phytases on the environment, animal welfare and animal feed costs have resulted in the continuous development and improvement of these enzymes in the non-ruminant feed market. To test the efficacy of these phytases, a large number of experimental animals are necessary, antagonising the animal welfare aspect of these enzymes. In the present review, we summarise the most prominent available in vitro assays for evaluating phytase enzymes and how far they can reduce the number of in vivo experiments. Several in vitro assays exist that differ in their setup, extent and conditions depending on the animal of interest and the research question. With the in vitro assays described, it is not possible to fully replace in vivo trials. However, for the investigation of phytase effects in feedstuffs, the use of an in vitro assay has several advantages. In vitro assays have the potential to be used for ranking feed enzymes and as screening tools. Applying in vitro protocols will result in a reduction in the number of animals or treatments usually necessary for an in vivo trial, thus acting towards the three Rs. © 2020 Society of Chemical Industry.

The Feed Enzymes Phytase, Protease and Xylanase Affect Pressure at Initial Flow and Do Not Affect Technical Properties During Pelleting of Microalgal Biomass

Lower energy consumption for producing feed pellets is an important part of the economy in the feed mill. The same is if physical pellet quality is degraded. The interest in using of novel ingredients is increasing due to requirements for the sustainable development goals. Defatted microalgae as by-product from biodiesel production is one of many novel ingredients. The purpose of this experiment was to understand how the addition of small amount of enzymes can reduce the flow resistance in the die during pellet discharge, without affecting the physical quality of pellets. Thus, possibly reduce the total consumption of electrical energy during compaction. Three enzymes, phytase, protease, xylanase, and combinations of those were added to defatted Desmodesmus subspicatus microalgae at 3 inclusion levels. Feed enzymes xylanase and phytase helped lowering the flow resistance of the material in the die. Reduction of flow resistance was in average 17 times lover when all three levels of enzyme phytase were used. The same was observed when 0.01% xylanase was added. All feed enzymes and their combination have evidently lowered underwater pellet swelling due to their hydrolytic activity at the surface of the microalgal particles. The hydrolytic activities of the feed enzymes did not affect hardness of the microalgal pellets. Contact angle degree between pellet surface and oil droplet was lowered when xylanase and protease was used at all three dosage levels. However, contact angle degree between pellet surface and water droplets was unaffected by the hydrolytic activity of enzymes.

Antagonistic bacteria of pathogens of intestinal infections and producers of a complex of cellulases as a basis for creating additives that combine the functions of a probiotic and a feed enzyme

Antagonistic bacteria of pathogens of intestinal infections and producers of a complex of cellulases as a basis for creating additives that combine the functions of a probiotic and a feed enzyme

Wybrane dodatki paszowe stosowane w żywieniu świń

The paper provides an overview of the knowledge of the options of the use of selected feed additives in the feeding of sows and young pigs. Feed enzymes, organic acids, probiotics, prebiotics and phytobiotics are the most commonly used feed additives for these technology groups. Nowadays, in pig breeding and farming, it is not possible to achieve high production performance in the herd without the use of specialised feed additives. They are added to the feed ration always in small quantities, and the effects of their use are often clearly noticeable. They improve the flavour and digestibility of the feed, and thereby have a favourable effect on feed intake, piglets weight gain and sows milk yield, boost pig immunity and displace pathogens from the gastrointestinal system, stimulating the growth and development of the beneficial bacterial microflora. Fed to lactating sows, they have a positive effect not only on the sows, but above all on the growth and development of their litters. This allows maximising the weaning weight of piglets and improving their health and weight gain at further fattening stages. All this contributes to improved production performance and should encourage breeders to enrich pig feed with appropriate specialised feed additives.

Effect of â-mannanase supplementation and feed presentation on carcass characteristics and macro-mineral digestibility of growing rabbits fed palm kernel based diets

The influence of â -mannanase supplementation and feed presentation of palm kernel cake (PKC) based diets were assessed on grower rabbits. Twenty crossbred grower rabbits (757.5 ± 65g) of mixed sex aged between eight to ten weeks old were used during the trial in 2 X 2 factorial design conducted in a completely randomized experimental design giving four treatment interactions with five replicates of one rabbit per replicate. The treatments were; T1- diet in mash form without enzyme; T2- diet in pellet form without enzyme; T3- diet in mash form with â-mannanase (0.5g/kg) and T4- diet in pellet form with mannanase (0.5g/kg). The trial lasted for six weeks. The animals were weighed individually at the beginning of the study and weekly thereafter. At the end of the study period the feacal samples were collected and animals were slaughtered and measurements taken from the carcasses. The carcass yield showed no interaction, though full GIT weights (g) were significantly influenced (T1-23.04, T2-17.67, T3-19.99 and T4- 18.74. Enzyme inclusion and feed form elicited significant effects on carcass characteristics, with varying improvements observed. Enzyme inclusion on the mash diet gave lower organ weights compared to other diets. Feed form and enzyme inclusion influenced lengths of the segments of the GIT, with rabbit on Diet 3 having the longest length. Pelleting influenced ileum lengths positively. Rabbits fed pelleted or mash diets whether supplemented or non-supplemented with â-mannanase digested dry matter, calcium, phosphorus and magnesium in the same level. In conclusion, supplementation of diets with â-mannanase and pelleting of diets improved phosphorus digestibility in palm kernel cake based diets. In addition, rabbits feed mash and pelleted rations with addition of â-mannanase had improved loins as opposed to those fed mash and non-supplemented rabbits while other carcass and visceral organ characteristics were not significantly affected.