Total Non-starch Polysaccharides Content Research Articles

Effects of Different Papua New Guinea Sweetpotato Varieties on Performance and Level of Enteric Pathogens in Chickens.

Simple SummaryThe smallholder poultry industry in Papua New Guinea (PNG) has grown rapidly in the last decade. The cost of growing meat birds is high, as feed alone makes up to 80% of the total cost of production in PNG. Sweetpotato is currently used in a poultry feed as a cheaper alternative option compared to the more expensive commercially manufactured stockfeed in PNG. The PNG smallholder poultry production system involves many families who rear multiple batches of meat birds every year. These birds are sold mostly at the farm gate, at local provincial markets, or roadside markets. Consumption of contaminated chicken meat has been identified as one of the important food vehicles for food borne illness. This PNG-based study was conducted to understand whether the inclusion of local sweetpotato in poultry feed can influence the shedding of pathogens such as Clostridium perfringens, Salmonella and Campylobacter without causing negative effects on poultry performance. The results of this study releveled that Campylobacter and Salmonella levels in the broilers fed with the local sweetpotato diets can be influenced with inclusion of enzymes in the feed. In the last decade, research has targeted the evaluation of local feed ingredients for use in monogastric diets to alleviate the high cost of production of livestock at smallholder levels in Papua New Guinea (PNG). The PNG smallholder poultry production system involves many families who rear multiple batches of meat birds every year. This study was conducted to evaluate the levels of enteric pathogens in the caeca of broilers fed with sweetpotato diets with varying levels of non-starch polysaccharides (NSP). Selection of a sweetpotato variety for use in broiler diets should be based on the total NSP content. In particular, varieties with low soluble NSPs are economical to use as Apparent Metabolizable Energy (AME) values are within the desired range for poultry and there is minimal need to include enzymes to improve NSP digestibility. The use of varieties with a low total NSP is also advantageous as the numbers of Clostridium perfringens was lower in broilers fed with these sweetpotato varieties. The level of Campylobacter and Salmonella levels were high in the ceca of birds fed with the sweetpotato varieties with high total NSP. These levels can be reduced with the inclusion of enzymes. This information will assist in the efficient use of local varieties of sweetpotato in PNG by small holder poultry farmers for sustainable poultry production and the commercial industry.

Optimisation of Extrusion for Enhancing the Nutritive Value of Palm Kernel Cake Using Response Surface Methodology

The palm kernel cake (PKC) inclusion level in poultry diets is limited by the high indigestible polysaccharides content. Hence, PKC was subjected to an extrusion treatment to reduce the content of these components. The effects of extrusion on the total non-starch polysaccharides (T-NSP), fibre, monosaccharides, and mannooligosaccharides contents were evaluated according to the response surface methodology (RSM) with various temperatures, screw speeds, hopper speeds, and moisture contents. The optimum conditions observed according to the RSM were a temperature of 178 °C, screw speed of 100 rpm, hopper speed of 5 Hz, and moisture content of 75%. The T-NSP content was significantly reduced (p<0.05), from 63.3 ± 1.85% to 57.6 ± 0.89%, and the crude fibre content decreased (p<0.05) from 16.7 ± 0.68% to 13.5 ± 0.99%. The mannose, glucose, and fructose contents of the PKC increased (p<0.05) 2.9-, 1.9-, and 1.4-fold, respectively. The 1,4-β-D-mannobiose, 1,4-β-D-mannotriose, 1,4-β-D-mannotetraose, and 1,4-β-D-mannopentaose increased (p<0.05) 3.7-, 3.8-, 3.5-, and 32.8-fold, respectively. This study showed that extrusion enhanced the nutritive value of PKC.

Improving the nutritional value of rapeseed cake and wheat dried distillers grains with solubles by addition of enzymes during liquid fermentation

An increased production of biofuel during the last decade with a subsequent increased amount of co-products has led to an interest in utilizing these co-products as inexpensive alternatives to traditional ingredients for pig feed. Biofuel co-products are considered valuable sources of protein but the high amount of fibre resuts in low digestibility in pigs. An in vitro study was conducted to screen several enzyme mixtures, primarily carbohydrases, for their ability to solubilise non-starch polysaccharides (NSP) and protein in rapeseed cake (RSC) and wheat dried distillers grains with solubles (wDDGS) during fermentation. During the first 48h of the experiment, denoted the initial phase, the mixture was fermented and samples were collected at 0, 24 and 48h. Then, backslopping was performed every 24h, where 50% of the mixture was replaced with fresh feed, water and enzyme, until a steady state cycle was reached. Samples were collected at 0, 6, 12 and 24h after the last backslopping. Results on RSC showed a decrease during the initial phase of fermentation in the amount of total NSP (−31%, P<0.001) and insoluble NSP (−42%, P<0.001) in fermented RSC treated with the enzyme mixture composed by β-glucanase+xylanase+pectinase (GluXylPec). Carbohydrates released from the GluXylPec sample of RSC were fermented by the microorganisms present in the mixture, resulting in elevated amounts of lactic acid during the steady state phase (P≤0.05) and acetic acid from 24h of incubation to the end of the study (P<0.01), and reduced pH levels from 24h to the end of the study (P≤0.01) compared to the Control were measured. Protein solubility in RSC increased in samples fermented with GluXylPec (+14% during the initial 48h, P<0.05). Samples fermented with phytase (Phy) showed a higher protein solubility, too (+18% during the initial 48h, P<0.01); and addition of phytase clearly reduced the level of phytate-P in RSC. Although all the enzymatic treatments showed a small reduction of total NSP content in wDDGS in the initial phase (P≤0.01), and three enzymes [GluXylPec (6), CelXyl (9), and Xylmix (7)] reduced the level of soluble NSP in the initial phase (P≤0.05), no increase in protein solubility or organic acid concentration was detected as a result of enzyme addition. For both fermented products, the biggest effect of enzyme addition was observed in the initial phase of fermentation. In conclusion, addition of β-glucanase, xylanase and pectinase during especially the first 48h of liquid fermentation can be a strategy to disrupt NSP and increase protein solubility in RSC. The overall impact of enzymes on wDDGS was more ambiguous, though reduction of total NSP was observed for all enzymes. Addition of phytase resulted in an almost complete reduction of phytate-P in RSC during fermentation.

Enzymatic preparation of mushroom dietary fibre: A comparison between analytical and industrial enzymes

Abstract A comparative study on preparing dietary fibres (DFs) from three mushroom sclerotia, namely, Pleurotus tuber-regium (PTR), Polyporus rhinocerus (PR) and Wolfiporia cocos (WC), using analytical or industrial enzymes (including α-amylase, protease and amyloglucosidase), was conducted. Apart from enzyme activity and purity, their effects on the yield of sclerotial DF as well as its major components, such as β-glucans, chitin and resistant glycogen (RG), were investigated and compared. The activities of all industrial enzymes were significantly lower than those of their corresponding analytical ones, except for the Fungamyl ® Super MA, which had the highest α-amylase activity (6395 U/g). However, this fungal α-amylase was less able to digest the three sclerotial glycogens when compared with the bacterial alternatives. Amongst all tested enzymes, only analytical and industrial amyloglucosidases were found to have significant amount of contaminating cellulase (7.05–7.07 U/ml) and lichenase (4.62–4.67 U/ml) activities, which would cause endo-depolymerization of the β-glucan-type cell wall components (3.39% reduction in glucose residue after RG correction) of the PTR, leading to a marked α-amylase hydrolysis of its otherwise physically-inaccessible cytoplasmic glycogen (20.3% reduction in RG content). Commercial production of the three novel sclerotial DFs, using the industrial enzymes, would be feasible since, in addition to their economic advantage, both the yield (PTR: 81.2%; PR: 86.5%; WC: 96.2% of sample DM) and total non-starch polysaccharide contents (PTR: 88.0%; PR: 92.5%; WC: 91.1% DF-rich materials of DM) of their resulting sclerotial DFs were comparable to the levels of those prepared using analytical enzymes.

Study of the effect of technological processes on starch hydrolysis, non-starch polysaccharides solubilization and physicochemical properties of different ingredients using a two-step in vitro system

The present study evaluated in vitro the effect of technological processes on four cereal grains: maize, wheat, barley and oats and one legume grain: green seeded pea. Processing included extrusion, cooking and grinding (0.8 and 3.0 mm opening), and the parameters evaluated were starch hydrolysis, content of soluble non-starch polysaccharides (NSP) and physicochemical properties: solubility of dry matter (DM), viscosity of the supernatant and water retention capacity (WRC). All samples were submitted to an in vitro digestion that consisted of two steps, gastric (G; pepsin; pH 2; 4 h) and small intestine (SI; pancreatin; pH 7; 4 h) simulation. Prior to incubation, particle size was evaluated in all samples by hand sieving and calculated on a weight basis. Total starch and total NSP analyses were performed on raw samples (0.8 mm). Hydrolysis of starch was evaluated by measuring glucose in the supernatant during the course of SI incubation. Soluble NSP were evaluated in the supernatant at the end of SI incubation. Physicochemical properties were evaluated after G and SI incubation. In raw ingredients (0.8 mm) the hydrolysis of starch at the end of SI incubation (ratio between glucose released in the sample and glucose released in the sample gelatinized) was lower in peas (0.45) than in cereal grains (0.69 in maize; 0.95 in wheat; 0.82 in barley and 0.92 in oats). The highest amounts of soluble NSP were found in barley (19.8 g/kg DM) and oats (13.8 g/kg DM), and were associated with higher viscosities. The WRC in raw samples was positively related to the amount of total NSP after both G ( r 2 = 0.847, P<0.001 for 0.8 mm samples) and SI incubation ( r 2 = 0.773, P<0.001). Technological processing increased starch hydrolysis and solubilization of NSP in all ingredients. The extent of the effect was dependent on the ingredient as well as on the severity of the technological process. Component monosaccharides of soluble NSP were differently affected, while glucose was increased by all the processes, arabinose and xylose required the more extreme conditions of extrusion. Contrary to raw samples, WRC of heat treated ingredients showed a negative relation with total NSP content of the sample after G incubation, which turned out to be a positive relation after SI incubation. It is concluded that technological processing of ingredients promotes higher starch hydrolysis, increases in the amount of soluble NSP and modifications in the physicochemical properties depending on the nature of the feed ingredients.

The wheat variety used in the diet of laying hens influences colonization with the intestinal spirochaete Brachyspira intermedia

This study investigated whether feeding different wheat varieties to laying hens could influence colonization with the intestinal spirochaete Brachyspira intermedia. Fifty ISA-Brown laying hens were divided into two groups. One group were fed a laying-hen diet formulated with wheat variety Westonia, and one were fed the diet incorporating variety Stilleto. Each group was divided into 15 hens experimentally infected with B. intermedia and 10 uninfected controls. The 30 infected hens were housed in individual cages in one room, and the controls were similarly housed in another room. Following administration of cultures of B. intermedia strain HB60 by crop-tube over 3 days, cloacal swabs were taken for spirochaete culture every 3 to 4 days. The water content of caecal faeces, and egg production and body weight were measured weekly. The hens were killed after 4 weeks, the caeca cultured for spirochaetes and the viscosity of the ileal contents measured. A total of 48/120 (40%) of the excreta samples from infected hens fed Westonia contained B. intermedia, compared with 21/120 (17.5%) for Stiletto (P=0.0002). The ileal viscosity of hens fed Westonia also was higher (P=0.048), but viscosity was not clearly related to the non-starch polysaccharide (NSP) content of the wheats. Westonia had a slightly higher total NSP content than Stiletto, but the ratio of soluble to insoluble NSP was lower. Infected hens developed wetter excreta, but neither infection nor diet altered egg production. In conclusion, the wheat variety can influence colonization with B. intermedia, apparently through diet-related alterations in the intestinal microenvironment.

Influence of cereal non-starch polysaccharides on digestion site and gut environment in growing pigs

Five Yorkshire castrates fitted with a post valve T-caecum (PVTC) cannula were used in a 5×5 Latin square design to study the influence of non-starch polysaccharides (NSP) in cereal based diets on site and extent of digestion and gut environment. The cereal part of the control diet was designed to resemble a Swedish slaughter pig feed. Diets H and Hi had a high total NSP content, and by starch dilution, the resulting diets L and Li had a low total NSP content. The insoluble proportion (i) of the total NSP was higher in diets Hi and Li than in the other diets. There was a linear decrease ( P<0.05) in both ileal and total tract digestibility of organic matter (OM), crude protein (CP) and energy with increasing dietary NSP content. NSP solubility had no effect ( P>0.05) on ileal digestibility of nutrients or dietary fibre (DF) components. The total tract digestibility of OM, fat and energy, and of all DF components was increased ( P<0.05) with higher levels of soluble NSP. The total organic acid content and pH in ileal digesta were linearly related ( R 2=0.90). Diets L and Li showed a higher ( P<0.05) proportion of acetic acid in ileal digesta compared to diets H and Hi.

Comparison of two direct bioassays using 3-week-old broilers to measure the metabolisable energy of diets containing cereals high in fibre: Differences between true and apparent metabolisable energy values

1. Nitrogen-corrected apparent and true metabolisable energy contents (AMEN and TMEN) of 12 diets, containing different amounts of maize, wheat, barley and rye, barley with β -glucanase and maize with 0.05 g/kg guar gum were measured using 3-week-old male broilers. 2. The AMEN method involved: 4 d of dietary adaptation, 24 h of starvation, 54 h of ad libitum feeding, 24 h of starvation and daily total droppings collection. TMEN was measured after a 48 h starvation period followed by 2 d of tube-feeding two doses of 15 g of the diets and quantitatively collecting all the droppings after 48 h of starvation. The endogenous energy losses (EELN) were measured after tube-feeding 8 chickens with 30 g of glucose, also over 2 d. 3. The results show that a significant interaction exists between the nature of the diets and the method used to measure metabolisable energy. Differences between TMEN and AMEN values ranged from 1.03 to 1.98 MJ/kg dry matter. These differences were positively correlated with the total pentosan contents of the diet (r = 0.94), the natural logarithm of the viscosities of the water extracts (r = 0.87), the sum of the contents of total pentosans and total β -glucan (r = 0.85), the calculated total non-starch polysaccharide contents (r = 0.79), the neutral detergent fibre contents (r = 0.76) and the total β -glucan contents (r = 0.70). Furthermore, a significant interaction was found between diets and the method used to derive lipid digestibility. The differences between apparent and true lipid digestibility ranged from 0.05 percentage points for the wheat diet to 0.20 percentage points for the rye diet. 4. From the results of this trial, it appears that TMEN overestimates the energy value of high fibre diets.