Effect of xylanase supplementation to a cereal-based diet on the apparent faecal digestibility in weanling piglets

The effect of supplementing a cereal-based diet with xylanase on the apparent faecal digestibility was investigated in weanling piglets (9.7 kg body weight). Xylanase supplementation increased the apparent faecal digestibility coefficients of crude protein, crude fat, crude fibre, organic matter, nitrogen free extract (NFE) and nonstarch polysaccharides (NSP). The increased apparent faecal digestibility coefficients resulted in a higher energy value of the cereal-based diet supplemented with the xylanase.     

Adaptation to the digestion of nutrients of a starch diet or a non-starch polysaccharide diet in group-housed pregnant sows

A trial was conducted with twenty group-housed pregnant sows to study the adaptation in nutrient digestibility to a starch-rich diet or a diet with a high level of fermentable non-starch polysaccharides (NSP) during a time period of 6 weeks. The starch-rich diet was primarily composed of wheat, peas and tapioca, whereas soya bean hulls and sugar beet pulp, which both are highly fermentable NSP sources, were used to formulate the NSP-rich diet. The starch-rich diet and the NSP-rich diet were formulated to contain different levels of starch (298 vs. 78 g/kg) and fermentable NSP (100 vs. 300 g/kg), but a similar level of net energy (NE) (8.36 MJ/kg). The trial consisted of a 1-week adaptation period followed by a 5-week collection period. Weekly apparent faecal digestibilities of dry matter (DM), crude protein (CP), crude fat, ash and NSP were measured by using the acid-insoluble ash marker method. Apparent faecal digestibilities of DM and organic matter (OM) of both diets were similar. Faecal digestibility of CP and crude fat was lower (p < 0.001) whereas that of NSP was higher (p < 0.001) for sows that received the NSP-rich diet. Calculated NE values of both diets were similar. Sows fed the NSP-rich diet produced faeces that contained a lower (p < 0.001) DM content compared with sows that were fed with the starch-rich diet. The quantity of dry faeces was the same on both diets, therefore total faeces production (as-is basis) was higher (p < 0.01) for the sows fed the NSP-rich diet. During the 5-week collection period, no changes were observed in the digestibility of DM, OM and NSP in the NE value of the diets. Digestibilities of CP and fat, however, were lower in week 1 (p < 0.05) compared with weeks 2-5 for both diets. The DM content of the faeces and the quantity of dry faeces did not change from weeks 1-5. Diet by time interaction was not observed for any of the response variables indicating that sows adapt as quickly to a diet with a high level of fermentable NSP as to a starch-rich diet. The present trial shows that, with regard to digestibility of nutrients, pregnant sows completely adapt to a NSP-rich diet (i.e., NSP from sugar beet pulp) in 2 weeks and that the time period necessary to adapt to a starch-rich diet or a diet with a high level of fermentable NSP is similar.     

High-fibre sunflower cake affects small intestinal digestion and health in broiler chickens

1. An experiment was conducted to evaluate high-fibre sunflower cake (HF-SFC); a feed ingredient distinguished by large amounts of crude fibre and insoluble non-starch polysaccharides (i-NSP). 2. Broiler chickens (n = 160) were fed on pelleted maize-based diets free from coccidiostats and antibiotic growth promoters between 15 and 31 d of age. Diets included 0, 10, 20 or 30% HF-SFC. Performance and small intestinal health were assessed. 3. In general, HF-SFC inclusion mediated significant linear increases in ileal digestibility of fat and protein and significant linear decreases in ileal digestibility of dry matter, ash and energy. 4. Weight gain increased linearly with HF-SFC inclusion. Feed conversion was negatively affected by 30% HF-SFC but not by 20% HF-SFC. 5. In the jejunal lumen, inclusion of HF-SFC was associated with significant decreases in colony counts of Clostridium spp. 6. HF-SFC inclusion resulted in significant linear reductions of villus height, thickness of muscularis mucosa, and the circular and longitudinal layers of muscularis in the jejunum. Crypt depth and submucosal thickness were not affected. 7. The data indicate that broiler chickens may thrive on feeds with insoluble fibre contents far exceeding those used in practice, and that HF-SFC exerts some positive effects on digestion and small intestinal health.     

High calcium intake lowers apparent digestibility of energy in veal calves.

Veal calves aged 8 weeks were fed iso-energetic amounts of milk replacers with either a low (7.1 g of calcium/kg of air-dry diet) or a high concentration of calcium (11.6 g of calcium/kg of air-dry diet) for a period of 10 weeks. The extra calcium was added in the form of calcium formiate. Final body weight of the two dietary groups was similar. Faeces were collected during the final week of the trial. The high calcium diet raised faecal dry matter output by 87% and faecal energy by 70%. The extra output of faecal dry matter was composed of 36% and 37% of crude fat and ash, respectively. The extra faecal energy output was for 75% in the form of crude fat. The high versus low calcium intake not only depressed apparent digestibility of total lipids but also that of crude protein, carbohydrates and ash. It is concluded that a high calcium intake by veal calves reduced energy availability without affecting body weight gain.     

Determination of physical characteristics,chemical composition and digestion coefficients of treated lemon pulp with Saccharomyces cerevisiae in goat diet

The aim of this study was to evaluate the effects of processing of lemon pulp with Saccharomyces cerevisiae on physical properties, chemical composition, digestion coefficients and blood parameters. Eight adult male Raeini goats were used in a 28‐day period. The experimental design was a completely randomised design with two treatments and four replicates. The first 21 days were for adaptation, and the last 7 days were for collecting samples. The animals were housed in individual metabolic cages equipped with a urine–faeces separator and were fed with diet containing alfalfa hay (60%) and lemon pulp (40%) at the maintenance level. Collected data were subjected to analysis of completely randomised design. With diet containing processed lemon pulp, functional specific gravity, bulk density, soluble dry matter, percentage of crude protein, neutral detergent fibre (NDF), acid detergent fibre and crude ash were significantly increased and water‐holding capacity, insoluble dry matter, insoluble ash percentage of dry matter, organic matter, crude fat, non‐fibrous carbohydrates and nitrogen‐free extract were significantly decreased (p < 0.05). Digestion coefficient of organic matter in dry matter and metabolisable energy were also decreased in treated lemon pulp (p < 0.05). Compared with untreated lemon pulp, digestibility of crude protein and NDF was higher (p < 0.05), but digestibility of crude fat was lower (p < 0.05). In general, processing of lemon pulp with S. cerevisiae improved the physical characteristics and increased the percentage of crude protein and the digestion coefficients of protein and NDF.     

Digestibility of nutrients in a feed mixture in certain swine helminthiases

The average digestibility coefficients of feed mixture nutrients in pigs infected medium severely to severely by the helminths Ascaris suum and Oesophagostomum dentatum were lower in comparison with the post-dehelminthization condition (dry matter by 3.1%, crude protein by 6.7%, fat by 8.9%, nitrogen-free extracts and fibre by 2.2%, organic matter by 3.1%). The content of total digestible nutrients made 679 g in infected pigs and 708 g in dehelminthized pigs. In the period following the experimental infection of pigs by the helminths Ascaris suum, characterized by the formation of antibodies and adaptation after heavy injury of the organism, the digestibility coefficients of feed mixture nutrients were in comparison with the state prior to infection influenced positively. In two metabolism trials, on the 9th to 13th day after infection the digestibility coefficients increased as follows: of dry matter by 4.8% and 3.6%, crude protein by 8.2 and 4.2%, nitrogen-free extracts and fibre by 2.0 and 3.5% and organic matter by 3.0 and 3.3%. The decrease in fat digestibility coefficients was observed in both cases, by 12.4% and 9.9%. Prior to infection the content of total digestible nutrients was 712 g and 682 g, after infection 731 g and 707 g.     

The effect of exogenous factors on prececal nutrient and amino acid absorption, ascertained from swine with ileo-rectal anastomoses. 3. The effect of crude fiber-rich coarse meal supplements to a basic ration

In digestion trials using pigs fitted with ileo-rectal anastomoses and parallel intact pigs the influence of wheat straw meal (WSM) or grass meal (GM) supplemented on two different levels to a basal diet was examined with regard to nutrient and amino acid digestibility resp. absorption. Both roughages reduced, obviously because of their high cell wall contents, nearly at equal amounts and partly significantly the precaecal as well as the total digestibility of dry matter, organic matter, carbohydrates (= crude fibre + NFE), crude fibre and hemicelluloses (arabinose, xylose). By the roughage supplementations the crude protein digestibility at the terminal ileum was less reduced than at the end of the total digestive tract, the starch digestibility was hardly influenced and that of ether extract mostly increased. In comparison with precaecal glucose and fructose digestibilities it could be shown that the anthrone method is not suitable for determinations of the precaecal digestibility of water soluble carbohydrates. Beside these compounds other substances in the ileum digesta must evidently be dyed by anthrone too. The crude protein digestibility and the amino acid absorption were precaecally hardly or not reduced by WSM supplementations, therefore it can be concluded that it is possible to dilute the energy concentration in diets (e.g. for sows) by addition of WSM without impairing protein digestion and amino acid absorption. The GM supplementations, however, impaired protein digestibility and amino acid absorption of the whole diet, probably caused by the encrusted, possibly heat damaged protein present in the GM itself. When the roughage supplemented diets were fed, the excretion of nitrogen compounds in the faeces was enlarged due to the more intensive bacterial activity in the hind gut and the additional sorption effects to cell wall substances, so that a too low apparent and also true digestibility is made believe. The applicability of the difference method to the calculation of protein and amino acid digestibilities in roughages is very questionable because of their low contents and the missing additivity. The crude fibre and hemicellulose digestibility values calculated by the difference method demonstrate for the both roughages--in spite of high standard deviations--that the precaecal digestibility of crude fibre is about zero and that of the hard lignified hemicellulose fraction in contrast to the predominantly endospermic hemicelluloses of the basal diet is very low. The faecal crude fibre and hemicellulose digestibilities of WSM--especially on the lower supplementation levels--are markedly worse than those of GM.     

云南省反刍家畜主要饲料营养价值评价

通过对云南省 9个牛羊饲养基地县饲料样品的常规营养成份、范氏纤维及干物质体外消化率 ( IVDMD)的测定发现 :1 )用营养成份和 IVDMD等指标进行评定 ,所有牧草以白三叶、红三叶和青苕子的营养价值最高 ;秸秆类粗饲料营养价值由高到低依次为 :蚕豆秆、黄豆秆、玉米秆、稻草和小麦秆 ;2 )饲料中 ADF、NDF含量与 CP、EE含量呈极显著负相关 ( P<0 .0 1 ) ;各结构碳水化合物成份含量与 CF含量都呈正相关 ,其中 ADF、 NDF含量和 C (纤维素 )含量相关极显著 ( P<0 .0 1 )。粗饲料中 ADF、NDF、HC(半纤维素 )、C及 AIA含量与常规成份都有显著的回归关系 ;3)饲料 IVDMD与 CP含量呈极显著正相关 ,与 NDF含量呈极显著负相关 ( | r| >0 .8) ( P<0 .0 1 )。各饲料的 IVDMD与 CP、 EE、 ASH、 NFE、 NDF和 ADL含量之间存在着显著的回归关系 ( P<0 .0 5 ) ,利用回归方程可以用饲料营养成份含量来预测饲料的IVDMD。     

Digestive physiology of captive giant anteaters (Myrmecophaga tridactyla): determinants of faecal dry matter content

Giant anteaters (Myrmecophaga tridactyla) are specialized insectivores and consume mainly ants and termites in the wild. In captivity, giant anteaters are either fed a complete diet, or a combination of a domestic carnivore diet with leaf eater pellets, or a traditional gruel‐type diet. Soft faeces are a frequently encountered problem with this type of feeding. In the present study, we analysed diet and faeces composition, calculated digestibility and measured mean retention time on various diets in eight giant anteaters (total of n = 64 experiments). The results suggest that the digestive physiology of giant anteaters is similar to that of domestic dogs and cats in terms of nutrient digestibility and digesta retention. When testing correlations between faecal dry matter content and other variables, no relationship with dietary crude fibre content or mean digesta retention time could be detected. However, acid insoluble ash intake was significantly and positively correlated with faecal dry matter content. The amount of acid insoluble ash excreted with the faeces was higher than that ingested with the diet offered, indicating that the giant anteaters ingested soil from their enclosure of up to 93 g per day. This finding is consistent with observation of faeces of wild giant anteaters that contain soil or sand most likely due to indiscriminate feeding. It also corresponds to reports that indigestible materials such as peat, soil, chitin or cellulose contribute to a firmer faecal consistency in various carnivore species. Therefore, offering giant anteaters the opportunity to voluntarily ingest soil from their enclosure might be beneficial.     

2种营养水平下不同遗传基础肉牛对日粮养分消化率的比较研究

The experiment aimed to study the difference on the dietary nutrient digestibility of different genetic basis beef cattle during two nutrient levels.Forty-eight heads of different genetic basis beef cattle （Charolais×Simmental-crossbred cattle,Gelbvieh×Simmental-crossbred cattle,Angus×Simmental-crossbred cattle and Limousin×Simmental-crossbred cattle) were introduced，feeding two different nutritional level of diets，adopting 4×2 two factor design，and carrying on the seven days of digestion experiment using endogeny indicator method.The results showed as follows：①From genetic basis，crude protein digestibility in Gelbvieh×Simmental-crossbred cattle was significantly higher than that in Angus×Simmental-crossbred cattle (P＜0.05)，and extremely significantly higher than that in Limousin×Simmental-crossbred cattle（P<0.01）, crude fat digestibility in Gelbvieh×Simmental-crossbred cattle was extremely significantly higher than that in Charolais×Simmental-crossbred cattle and Angus×Simmental-crossbred cattle (P＜0.01).②From nutritional level，the nutrient digestibility of beef cattle in feeding a high nutrition diet were extremely significantly higher than that in feeding a low nutrition diet (P＜0.01).③From the interaction of genetic basis and nutritional level，nutrient digestibility decreased with the increase of nutritional level of diet in Charolais×Simmental-crossbred cattle,Angus×Simmental-crossbred cattle and Limousin×Simmental-crossbred cattle，while Gelbvieh×Simmental-crossbred cattle were on the contrary.The results indicated that genetic basis had significant influences on crude protein digestibility and crude fat digestibility （P＜0.05），nutritional level of diet had significant influences on the digestibility of dry matter，organic matter，crude protein，crude fiber，crude ash and crude fat （P＜0.05），crude protein digestibility were influenced significantly by genetic basis and nutritional level of diet at the same time （P＜0.05）.     

生物纤维饲料对绵羊的饲用价值研究

本试验以绵羊作为研究对象，通过常规养分测定、消化试验和瘤胃降解试验(尼龙袋法)，对生物纤维饲料的常规养分、饲用价值、瘤胃降解特性进行了探讨。结果表明：生物纤维饲料中干物质、粗蛋白、粗脂肪、粗纤维、粗灰分、无氮浸出物、钙和磷的含量分别为：65．61％、21．97％、1．88％、3．00％、7．79％、30．97％、0．85%和1．13％；绵羊对生物纤维饲料的干物质、粗蛋白、粗脂肪、粗纤维、粗灰份、无氮浸出物和能量的消化率分别为74．71％、84．81％、72．24%、72．68％、45．41％、77．52％、77．76％；同时测得生物纤维饲料原样中的消化能为10 100kJ／kg；生物纤维饲料干物质的有效降解率为61．75%，而蛋白质的有效降解率为73．73％。     

Dietary soyabean oil depresses the apparent digestibility of fibre in trotters when substituted for an iso-energetic amount of corn starch or glucose

The aim of the present study was to establish whether the inhibitory effect of fat feeding on fibre digestion has been underestimated due to the substitution of fat for corn starch. A high fat intake has been shown to lower total intestinal tract apparent digestibility of crude fibre in horses but, since fat was substituted for nonstructural carbohydrates, including starch, the specific effect of fat could not be ascertained. The possibility could not be excluded that starch also inhibits fibre digestibility, so that the fat effect observed earlier would have been underestimated. In this study, the intakes of iso-energetic amounts of soyabean oil, corn starch or glucose were compared as to fibre digestibility. Unlike starch, glucose is fully absorbed by the small intestine and, therefore, is not expected to influence fibre fermentation in the caecum and colon. Six trotters were fed rations high in soyabean oil (158 g/kg dry matter), corn starch (337 g/kg dry matter) or glucose (263 g/kg dry matter) according to a 3 x 3 Latin square design. Apparent crude fibre digestibility was similar for the rations with corn starch (mean +/- s.d., 70.7 +/- 3.06% of intake, n = 6) or glucose (71.0 +/- 1.90%), but was significantly depressed by fat feeding (56.5 +/- 7.65%). Similar observations were made for apparent digestibilities of neutral and acid detergent fibre and of cellulose. It was concluded that the addition of fat to the feed ration of horses has a specific inhibitory effect on fibre utilisation and, therefore, reduces the amount of energy provided by dietary fibre.     

Effects of Different Dietary Crude Protein Levels on the Nutrient Absorbability in the Small Intestine of Lambs

This experiment was conducted to study the effects of different dietary crude protein levels on the nutrient absorbability in the small intestine of lambs.Three Kazakh lambs (30 kg body weight) fitted with permanent ruminal,duodenal and ileal fistula were selected.3×3 Latin square design was adopted.A dual-phase marker system with LiCr-EDTA and Yb-Ac as the liquid-phase or particulate-phase digesta flows maker was adopted to measure the true digesta flows at duodenal and ileal fistula,respectively.The results showed that nitrogen intake,total tract apparent digestibility,N deposition,the apparent digestibility of dry matter and organic matter were significantly increased with increasing levels of dietary crude protein (P<0.05),but had no significant effects on intestinal digesta flows (P>0.05).Increasing dietary crude protein levels had significant effects on most part of nutrients of duodenal digesta except fat and purine (P<0.05),while it only significantly effected CP,Ash,dry matter,neutral detergent fibre and acid detergent fiber of ileal digesta flows (P<0.05).In addition,intestinal absorbability of nutrients except for CP,Ash,dry matter,neutral detergent fibre and acid detergent fiber were significantly affected with increasing levels of dietary crude protein(P<0.05).The test provided basis for further study of the effects of dietary CP level on the digestibility and utilization of lamb.     

不同粗蛋白质水平日粮对育肥羊小肠养分吸收率的影响

本研究旨在比较不同粗蛋白质（CP）水平日粮对育肥羔羊小肠养分吸收率的影响。选用体重30 kg左右,安装有瘤胃、十二指肠近端和回肠末端瘘管的3只哈萨克育肥羊为试验动物,采用3×3拉丁方试验设计,采用醋酸镱（Yb-Ac）、锂铬乙二胺四乙酸（LiCr-EDTA）分别作为消化道固相和液相食糜标记物测定小肠食糜流量。结果显示,增加全混合日粮中CP水平可显著提高育肥羊N的进食量、全消化道表观消化率和N沉积（P<0.05）,显著提高干物质（DM）和有机物（OM）的表观消化率（P<0.05）,但对小肠食糜流量无显著影响（P>0.05）;提高日粮CP水平对十二指肠食糜除EE和嘌呤外的营养成分流量均产生显著的影响（P<0.05）,仅对回肠食糜中CP、粗灰分（Ash）、DM、中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）流量的影响显著（P<0.05）,且对CP、Ash、DM、NDF和ADF的小肠吸收率影响显著（P<0.05）。本试验为进一步深入分析增加日粮CP水平对其在育肥羊体内的消化利用奠定基础。     

Comparison of the guaranteed analysis with the measured nutrient composition of commercial pet foods

The purpose of this study was to compare the guaranteed analysis of commercial pet foods to their measured nutrient concentrations. Data were collected regarding the guaranteed and measured concentrations of crude protein, crude fat, crude fibre, moisture and ash of pet foods from annual feed inspection reports from South Dakota (2003–2005), Indiana (2004–2005), Rhode Island, New York and New Jersey (2005–2006). The difference for each nutrient was compared among types of food (dry, canned or treat), intended species, target life‐stages, manufacturers and reporting laboratories. Significant differences between the guaranteed and measured nutrient concentrations were found. For all foods, the mean ± one standard deviation of the difference was 1.5 ± 2.0% for crude protein, 1.0 ± 1.7% for crude fat, ‐0.7 ± 1.3% for crude fibre, ‐4.0 ± 3.3% for moisture, and ‐0.5 ± 1.0% for ash. The difference in crude protein was significantly greater for treats than for other food types. The difference in crude fat was significantly less for dry foods than for other food types. The differences in crude fibre and moisture were significantly less for canned foods than for other food types. Only the differences in crude fibre differed significantly among target species, life‐stages, manufacturers or laboratories. More accurate estimations of the nutrient composition and calculated metabolizable energy content of commercial pet foods can be obtained by making adjustments to the guaranteed analysis. This includes adding 1.5% and 1% to the guaranteed minimums for crude protein and crude fat, respectively, and subtracting 0.7%, 4% and 0.5% from the guaranteed maximums for crude fibre, moisture and ash, respectively.     

Postileal nutrient digestibility in cattle]

Four heifers of an average live weight of 301 kg supplied with ileocaecal re-entrant cannulae received rations consisting of 4 kg hay (variants A und B), 1 kg coarse wheat meal, 0.4 kg molasses, 100 g urea and 30 g mixed minerals per animal and day. After a 14-day preliminary feeding period the ileum digesta was quantitatively collected at the re-entrant cannula over 24 h. 10% of the digesta were used for analysis, the remainder was heated to 37 degrees C and returned. Under consideration of the digesta passage through the colon the 24-hour collection of faeces was started after a 6-hour delay after the first replacement of digesta. Losses of nutrients were calculated from the values analysed from digesta and faeces. No differences could be ascertained between the two hay variants. On an average of the two rations the nutrient losses of the scaffold substances-equivalent to the digestibility in the colon-showed the following values: crude fibre = 10.6%, NDF = 10.4%, ADF = 11.9% and hemicellulose = 7.4%. The losses of the other nutrients, corresponding to their apparent digestibility, had the following values: crude protein = 12.1%, crude fat = 10.7%, N-free extracts = 18.9%, ash = 31.2%, dry matter = 17.5%. The water balance showed that 8.2 l water of the 23.4 l supplied with the ileum digesta were excreted in faeces.     

Energy utilization by swine of nutritive fiber-rich by-products from the milling and food industry

Growing pigs (from 20 to 80 kg body weight) were fed diets containing equal amounts of soybean, pea (pisum sativum), millet and barley hulls as well as a mixture of these fibre sources. The effects of these fibrous components on the digestibility of energy and nutrients were investigated. Although some rations had a similar nutrient composition, important differences in the digestibility of energy could be observed: e.g. soybean hulls and pea hulls had a similar content in crude fibre but differed in the digestibility of energy by a factor 1:2. The difference in the digestibility of energy was even more pronounced between the rations with soybean hulls and millet hulls (factor 1:11, respectively) although the crude fibre and ADF fibre content were similar. Therefore the magnitude of the difference in digestibility of energy shows a considerable variation between the fibre sources. This seems to be caused partially by differences in the chemical nature of the fibrous by-products. Soybean hulls and barley hulls proved to be very well suited for growing pigs (11.4 MJ DE/kg DM and 10.0 MJ DE/kg DM, respectively). The pea hulls showed a mean content of digestible energy (5.6 MJ DE/kg DM) whereas the millet hulls (1.1 MJ DE/kg DM) didn't contribute significantly to the energy supply of the pigs.     

Nutrient digestibility, faecal physicochemical characteristics and bacterial glycolytic activity of growing pigs fed a diet supplemented with oligofructose or trans-galactooligosaccharides

The effect of oligofructose (FOS) or trans-galactooligosaccharides (TOS) inclusion at 10 g/kg diet for growing pigs, at the expense of cornstarch (CON), on growth performance, nutrient digestibilities, and faecal physicochemical parameters was determined. In addition, concentration of volatile fatty acids (VFA) and bacterial -glucosidase, β-glucosidase, β-galactosidase and β-glucuronidase activities in faeces were determined as markers of intestinal microflora metabolic activity. Twelve 35-day-old castrated pigs were allocated to CON, FOS and TOS dietary treatments for an experimental period of 4 weeks. Dietary treatments did not affect animal growth performance. FOS and TOS pigs tended to have a lower faecal output than CON pigs by approximately 6.0% and 1.7% respectively. FOS and TOS did not affect total tract apparent digestibility of dry matter, organic matter, fat, crude protein, crude fiber, ADF and cellulose. Digestibility of carbohydrate components such as nitrogen free extract and NDF was significantly (P ≤ 0.05) higher in TOS pigs compared to CON and FOS. Digestibility of hemicellulose in TOS pigs did not differ from FOS but was significantly higher from CON. The experimental period had a significant effect on most of the parameters determined. There were no significant (P ≤ 0.05) differences between treatments regarding total VFA concentration and faecal bacterial enzyme activities. Nevertheless, an increased saccharolytic activity in the gut of FOS and TOS pigs could be postulated by the trends for apparently higher VFA concentration and bacterial -glucosidase and β-galactosidase activities.     

Models to quantify excretion of dry matter,nitrogen, phosphorus and carbon in growing pigs fed regional diets

Modern pig production contributes to many environmental problems that relate to manure, especially in areas with highly intensive production systems and in regions like Asia where the regulative control is not effective. Therefore, the objective of this study was to use three different pig diets varying in dietary protein, fibre and fat as representative for Danish （DK）, Thai （TH） and Vietnamese （VN） pig production to develop and evaluate different approaches to predict/calculate excretion from growing pigs in comparison with the experimentally determined values. Nine female growing pigs were used in a digestibility and balance experiment. Excretion of dry matter （DM）, nitrogen （N）, phosphorus （P） and carbon （C） of the experimental diets were determined. Due to the highest dietary fibre content, VN had the lowest digestibility of N, P and C （73, 49, and 73%, respectively） compared with the DK and TH pig diets. From the known diet composition using standard table values on chemical and nutrient digestibly, high accuracy （bias） and low variation was found and the results could be used for prediction on chemical composition and excretion in faeces and urine in growing pigs. Calculation based on standard values regarding nutrient retention in the pig body as used in the Danish manure normative system （DMNS） showed likewise to be quite useful for quantifying the total excretion of N and P. Overall, the results demonstrate that simple models that require cheap and normally available information on dietary nutrients can give useful information on nutrient excretion in growing pigs.     

Digestibility and nitrogen retention of diets containing different levels of fibre in local (Mong Cai), F1 (Mong Cai x Yorkshire) and exotic (Landrace x Yorkshire) growing pigs in Vietnam

Total tract digestibility and nitrogen retention of three diets containing different levels of fibre [200, 260 and 320 g/kg neutral detergent fibre (NDF) in dry matter] were determined in three breeds of growing pig at an initial age of approximately 3.5 months. The breeds were local (Mong Cai, MC), F1 crossbred (MC x Yorkshire) and exotic (Landrace x Yorkshire, LY), allocated at random within breed (block) to double 3 x 3 Latin squares. The main fibrous ingredients of the experimental diets were rice bran, cassava residue meal and non-dehulled groundnut cake meal. Digestibility of organic matter (OM), crude protein (CP), NDF, crude fibre, gross energy (GE) and ether extract (EE) decreased as the level of dietary NDF increased (p < 0.001). The r(2) values for the relationship between NDF level and digestibility of OM, CP, GE and EE were 83%, 83%, 80% and 82% respectively. On average, an increase in NDF content of 1% unit resulted in a decrease in OM, CP, GE and EE digestibility of 0.67%, 0.75%, 0.50% and 0.42% units respectively. Digestibility of energy and nutrients was the highest for MC and the lowest for LY (p < 0.01), with intermediate values for F1. There was a negative effect of NDF level on nitrogen (N) retained as a proportion of intake (p < 0.05). Nitrogen retention and utilization were significantly higher (p < 0.001) for LY than for MC and F1 pigs.