Energy evaluation of extruded compound foods for dogs by near-infrared spectroscopy

Near-infrared reflectance spectroscopy (NIRS) was used to predict the chemical composition, apparent digestibility and digestible nutrients and energy content of commercial extruded compound foods for dogs. Fifty-six foods of known chemical composition and in vivo apparent digestibility were analysed overall and 51 foods were used to predict gross energy digestibility and digestible energy content. Modified partial least square calibration models were developed for organic matter (OM), crude protein (CP), ether extract (EE), crude fibre (CF), nitrogen free extracts (NFE) and gross energy (GE) content, the apparent digestibility (OMD, CPD, EED, NFED and GED) and the digestible nutrient and energy content (DOM, DCP, DEE, DNFE and DE) of foods. The calibration equations obtained were evaluated by the standard error and the determination coefficient of cross-validation. The cross-validation coefficients of determination (R) were 0.61, 0.99, 0.91, 0.96, 0.94 and 0.92 for OM, CP, EE, CF, NFE and GE, the corresponding standard error of cross-validation (SECV) being 5.80, 3.51, 13.35, 3.64 and 16.95 g/kg dry matter (DM) and 0.29 MJ/kg DM respectively. The prediction of apparent digestibility was slightly less accurate, but NIRS prediction of digestible nutrient (g/kg DM) and DE (MJ/kg DM) gave satisfactory results, with high R (0.93, 0.97, 0.93, 0.83 and 0.93 for DOM, DCP, DEE, DNFE and DE respectively) and relatively low SECV (11.55, 6.85, 12.14 and 22.98 g/kg DM and 0.47 MJ/kg DM). It is concluded that the precision of NIRS in predicting the energy value of compound extruded foods for dogs is similar or better than by proximate analysis, as well as being faster and more accurate.     

Determining metabolizable energy content in commercial pet foods

This study was conducted to assess the suitability of several equations for the estimation of metabolizable energy (ME) of pet foods. Sixteen canned and 31 dry cat foods and 24 dry dog foods representing the range of energy densities found in commercial adult, growth or all life stage products were evaluated in four separate experiments. In vivo ME was compared with estimates of ME generated by several previously published equations. The results indicated that the equation recommended by Association of American Feed Control Officials provided reasonable estimates of in vivo ME for both canned cat foods and dry dog foods, but proved unsuitable for dry cat foods. Better estimates were generated in each case using other published equations. Of the equations tested, the most accurate equations for estimating ME (kJ/g) without feeding trials were:
for canned cat foods: [(16.32 × protein) + (32.22 × fat) + (12.55 × NFE)];
for dry cat foods: [((GE × 1.209) – 1.911) × 4.184] or [((0.075 × g fat) + 2.766) × 4.184]
for dry dog foods: [GE=(24 × g protein) + (38 × g fat) + (17 × g NFE), then percentage energy digestibility=91.2 – (1.43 × percentage crude fibre in dry matter), then ME=(GE × percentage energy digestibility) – (4.34 × g protein)].
With the exception of high-fibre weight-management diets, the simple equation [((GE × 1.209)–1.911) × 4.184] also reliably predicted ME in dry dog foods.     

Prediction of digestible energy value of extruded dog food: comparison of methods

The proposal of National Research Council (NRC), based on the use of modified Atwater factors, is nowadays the widely used method to estimate digestible energy (DE) content of pet foods. Recently, alternative methods have been suggested for predicting energy content of commercial canine dry food. Factorial equations including food fibre content as estimator, in vitro digestions methods or near-infrared spectroscopy (NIRS) techniques have been considered as good approaches to predict the energy content of dog foods. The aim of this study was to compare the accuracy of some of those estimation methods. Seventeen samples of commercial extruded dog food were used to validate and compare some estimation methods of energy digestibility (Ed, %) and DE value [MJ/kg dry matter (DM)]. The apparent Ed and DE of each food were previously determined by in vivo trials. In vivo Ed and DE of foods ranged from 79.30% to 91.05% and from 16.25 to 21.82 MJ/kg DM, respectively, and their crude fibre (CF) content ranged from 0.72% to 3.28% (in DM base). The % Ed of each sample was estimated by the factorial equation (% Ed = 91.2 - 1.43 x CF %) and by the in vitro digestion method [% Ed(in vitro) = -2.45 + 0.98 organic matter (OM) disappearance(in vitro)%]. The set of samples also was analysed by NIRS, using a calibration equation developed from a set of 69 samples of commercial extruded dog food (0.76 and 0.89 cross-validation r(2) and 2.33 and 0.61 cross-validation SE for Ed and DE respectively). The in vitro method gave better estimations of Ed in vivo than NIRS and factorial methods, although all the methods assessed showed a very good and similar accuracy in the prediction of DE value. These three methods showed a slight better accuracy than that previously proposed by the NRC. To consider constant digestibility values of nutrient content of food can result in bias and error in the estimated energy values. The alternative prediction methods used in this study take into account differences of ingredient composition and availability of nutrients of different extruded dog foods thus could be better systems of valuating energy content in a wider range of different kind of foods than in use method.     

Urinary energy losses in dogs fed commercial extruded foods

Energy and nitrogen losses in the urine were recorded in 134 individual balances with adult (1- to 2-year-old) female Beagles that were fed 23 dry extruded dog foods ranging in crude protein (CP) content from 242 to 360 g/kg dry matter. The energy equivalent of urinary nitrogen was estimated as 33.9 kJ/g N. Both energy losses in the urine corrected for the nitrogen balance, and the metabolizable energy (MEn): digestible energy (DE) ratio were found to be closely related to diet CP content (r : 0.851 and 0.820). The MEn content of extruded dog foods can be accurately calculated from the DE content, either by subtracting 4.59 MJ/kg CP or estimating the MEn/DE ratio from the food CP content by the following equation: MEn/DE=0.98 – 3.44 ± 0.517 × CP (kg/MJ DE).     

Digestibility and metabolizable energy values of processed cassava chips for growing and finishing pigs

Determinations of digestibility of dry matter (DM), digestible energy (DE), and metabolizable energy (ME) in cassava chips with different levels of crude fiber (CF) were measured in growing pigs (20 kg) and finishing pigs (60 kg). The treatments were (1) cassava starch (0% CF), (2) peeled cassava chips (2.5% CF), (3) non-peeled washed cassava chips (3.9% CF), and (4) non-peeled and non-washed cassava chips (5.2% CF). In the growing pigs, peeled cassava chips, non-peeled washed cassava chips, and non-peeled and non-washed cassava chips had DM digestibility of 87.51%, 78.63%, and 73.89%, respectively. Their DE was 3.69, 3.49, and 3.32 Mcal/kg DM, respectively (DE of cassava starch is 3.90 Mcal/kg DM). ME was 3.54, 3.35, and 3.19 Mcal/kg DM, respectively (ME of cassava starch is 3.74 Mcal/kg DM). On the other hand, in the finishing pigs, the digestibility of DM was 89.13%, 80.63%, and 76.13%, respectively. Their DE was 3.72, 3.53, and 3.43 Mcal/kg DM, respectively (DE of cassava starch is 3.91 Mcal/kg DM). ME was 3.57, 3.38, and 3.29 Mcal/kg DM, respectively (ME of cassava starch is 3.75 Mcal/kg DM). These values increased with decreasing CF content, and the peeled cassava chips had the highest values (P < 0.01). These suggest that the digestibility values of DM, DE, and ME of cassava chips is inversely related to the CF content in cassava chips. It is recommended that cassava chips be peeled for better nutrition for growing and finishing pigs.     

果子狸对皮革蛋白粉的消化率测定

８只体重约２ｋｇ的果子狸用于测定其对皮革蛋白的消化率,从而探索皮革蛋白粉作为一种蛋白补充料饲养果子狸的可能性。结果表明,皮革蛋白粉中粗蛋白（ＣＰ）的消化率为７７７１％,粗脂肪（ＣＦ）的消化率为７６０９％,总能（ＧＥ）的消化率为７２１４％,干物质（ＤＭ）的消化率为９０９５％。     

The effect of replacing brewers' grains with barley tea grounds in total mixed ration silage on feed intake, digestibility and ruminal fermentation in wethers

Four wethers were used in a 4 × 4 Latin square to study the feed intake, apparent digestibility, nitrogen balance and ruminal fermentation characteristics when fed total mixed ration (TMR) silages which included wet barley tea grounds (WBTG). The TMR silages were prepared using compound feed including wet brewers' grains (WBG), corn, oat hay, alfalfa hay, dried beet pulp, salt and vitamin-mineral supplement in a ratio of 30.7:15:8:24:10:12:0.15:0.15, respectively, on a dry matter (DM) basis. The WBTG and soybean meal mixture (7:3 on DM basis) were substituted for WBG at ratio of 0% (Control), 5% (LTG), 10% (MTG), and 15% (HTG) on DM of TMR. WBTG addition to the TMR silages increased lactic acid concentration, decreased pH, acetic acid and ammonia-N ( P  < 0.001). Feed intakes and digestibilities for LTG and MTG (except ether extract (EE) digestibility) treatments were not different from the control ( P  > 0.05). However, EE and neutral detergent fiber (NDF) intake, crude protein, EE and NDF digestibility was lower, but the DM and gross energy digestibility was higher for the HTG treatment compared to control ( P  < 0.01). With progressive increases in WBTG concentrations, nitrogen intake, fecal nitrogen and retention nitrogen did not differ, but the urinary nitrogen for MTG and HTG treatments were lower than that of the control ( P  = 0.001). The ruminal total volatile fatty acid concentration and the molar ratios of propionate and butyrate were higher, but the acetate, ratio of acetate to propionate and ammonia-N content were lower for the HTG treatment compared with the control ( P  < 0.05). Therefore, the possible proportion of replacing WBG with WBTG for TMR silage can be 10% or less of the diet DM.     

Basic data on food intake, nutrient digestibility and energy requirements of lorikeets

Although knowledge of the nutrient requirements of pet birds has increased a lot over the last few years, basic data on food and water intake and the energy requirements of nectarivorous species, such as lorikeets, are scarce. Thus, the aim of this study was to try to generate some of these data for lorikeets kept at maintenance. Determination of the daily maintenance energy requirement enables calculation of the daily ration and thus, the appropriate nutrient concentrations in order to maintain body weight. Investigations were carried out with six Goldie's lorikeets (GL; Trichoglossus goldiei: 40-50 g BW; 1-4 years) and six rainbow lorikeets (RL; Trichoglossus haematodus haematodus: 120-140 g BW; 1-12 years). Three of the most commonly used diets/foods (commercial 'lory soup'/apples/pollen: crude ash - 52.9/17.8/18.8; crude protein - 178/32.5/191; crude fat - 52.8/0.89/73.1; crude fibre - 17.9/40.5/30.4; starch - 139/not detectable/127; sugar - 522/859/418 g/kg DM; ME - 13.9/14.6/10.9 MJ/kg DM) were individually offered ad libitum. The measured dry matter (DM) intake (g/100 g BW) corresponded well to the values reported for granivorous bird species of similar body mass. Both lorikeet species achieved an apparent digestibility of organic matter of more than 90% for apples, approximately 82% for 'lory soup' and approximately 55% for pollen. The water content of the food affected the DM content of the excreta; 8% when fed 'lory soup', 2% for apples and approximately 30% when fed pollen. Regression analysis of body weight change relative to energy intake demonstrated constant body mass (assuming no change in body composition) when the daily energy intakes were 860 (GL) or 650 (RL) kJ ME/kg BW(0.75).     

Nutritional value of timothy haylage in Icelandic horses

Four mature Icelandic geldings were used in a balance trial to investigate the effect of stage of maturity of timothy (Pleum pratence L.) haylage fed at maintenance level on coefficients of total tract apparent digestibility (CTTAD), and nitrogen and energy metabolism in a 4 × 4 change-over arrangement of treatments. The content of fibre increased and crude protein content decreased with advancing stage of maturity. Very high CTTAD values were found for DM, OM, CP, CF, NDF and ADF in the first two cuts. Overall, there was a negative relationship between stage of maturity (p < 0.05) and the CTTAD of all measured dietary components. Nitrogen (N) intake, N losses in urine and N balance were affected (p < 0.05) by stage of maturity, while the N losses in the faeces were unaffected. There was a strong correlation (r² = 0.95) between N balance and water intake. Gross energy intake and losses in urine (as % of digestible energy intake) were unaffected by stage of maturity, while the energy balance was affected (p < 0.05). The digestible energy content of the timothy haylage studied ranged from 14.1 to 9.0 MJ/kg DM.

In conclusion, early-cut timothy haylage (stem elongation to flowering) has the energy content required to form the basis of diets for high-performing horses. Late-cut timothy haylage (seeding to late seeding), on the other hand, can be used to fulfil the energy and protein needs of maintenance-fed Icelandic horses.     

Comparative evaluation of net digestive and absorptive efficiency in dogs and cats fed a variety of contrasting diet types

Comparative net digestive and absorptive efficiency was assessed with adult Beagles and domestic cats by apparent digestibility assays. Eight foods were used comprising two canned dog foods; canned cat foods; two samples of semipurified diet; and single samples of experimental dry cat food and fresh mince. Apparent digestibility percentages of crude protein, fat, nitrogen-free extract (NFE) and gross energy were all significantly higher in dogs than cats. Mean values obtained for dogs were (per cent): crude protein 87; fat 92; NFE 70 and energy 89. Respective values for cats were 82, 76, 67 and 79. On average, dogs obtained 11 and 9 per cent more digestible energy and protein per unit food eaten than cats. Most digestibility characteristics of foods measured in cats were significantly correlated with those for dogs and regression equations are presented predicting digestibility in cats from dog data.     

生长育肥兔复合添加剂配方筛选试验

选择年龄相近 ,健康无病 ,体重约 1kg的新西兰白兔 80只 ,根据体重、性别按组间相似的原则分为 4组 ,每组 2 0只。结果表明 ,试兔平均日增重 4组间有明显差异 ,饲料报酬和单位增重的饲料成本 ,以试验 2组和试验 3组最好 ;试验 1 ,2 ,3组试兔干物质、能量和粗蛋白质的消化率均显著高于对照组 (P <0 0 1 ) ,而试验组间无显著差异 (P <0 0 5) ,3个试验组的胴体重和屠宰率都显著高于对照组 (P <0 0 1 ) ,但以试验 2组最高 ;肌肉pH值和系水力各组之间无显著差异 (P <0 0 5)。     

不同品种苜蓿营养成分及体外消化率动态研究

用两级离体消化法测定了3个苜蓿Medicago sativa品种4个不同生育期的体外干物质(DM)和有机物质(OM)消化率.结果表明,DM和OM消化率随着生育期的推移极显著(P<0.01)下降.营养期最高,分别为63.56%和59.77%;盛花期仅为47.64%和45.37%.DM和OM消化率与ADF含量均呈强负相关,r分别为-0.800(P<0.01)和-0.814(P<0.01);与CP含量均呈强正相关,r分别为0.706(P=0.05)和0.743(P<0.01).品种对DM和OM消化率无显著影响(P＞0.05).     

Influence of dirlotapide, a microsomal triglyceride transfer protein inhibitor, on the digestibility of a dry expanded diet in adult dogs

The objectives of this study were to evaluate the effects of dirlotapide, a microsomal triglyceride transfer protein inhibitor, on apparent nutrient digestibility of an expanded dry dog food, on defecation frequency and fecal consistency. Eighteen beagles were randomized to either placebo ( n  = 6) or dirlotapide ( n  = 12). Testing was divided into a 21-day adaptation phase (days −21 to −1) and a 35-day treatment (digestibility testing) phase (days 0–35). During the treatment phase, dogs were administered oral dirlotapide (0.3 mg/kg) or placebo (0.06 mL/kg) once daily. For digestibility testing, feces were collected over two periods for 7 days each starting on days −9 and 28. All dogs were fed a commercial adult dog food throughout the study. Food intake was adjusted to maintain body weight during adaptation, followed by pair-feeding placebo dogs the amount of food ingested by the dirlotapide dogs during the treatment period. Dogs in both groups had reduced food intake and lost similar amounts of body weight during treatment. Dogs receiving 0.3 mg dirlotapide/kg once daily had a small but significant ( P  = 0.018) decrease (6.16 ± 2.22%, mean ± SD) in crude fat digestibility compared with the placebo-treated food-restricted dogs, but no difference in crude protein, dry matter, or energy digestibility was observed. Fecal consistency and volume and defecation frequency were similar between groups. Dirlotapide effectively reduced appetite and energy intake without affecting nutrient digestibility, except for a minimal decrease in fat digestibility.     

日粮纤维水平对猪营养物质表观消化率的影响

为了测定日粮不同纤维水平和品种对猪营养成分表观消化率的影响,试验选用8头4月龄猪,采用4×4拉丁方设计进行试验。4种试验日粮按等能等氮设计,日粮Ⅰ、Ⅱ、Ⅲ、Ⅳ粗纤维水平分别为3%、6%、9%和12%(干物质基础),4个品种分别为莱芜猪(100%)、大莱猪(50%)、大大莱猪(25%)、大约克猪(0%)。在本试验条件下,日粮纤维在较低的范围内(3%~6%)粗蛋白质(CP)消化率随粗纤维含量的增加而提高,赖氨酸、蛋氨酸表观消化率差异不显著,CP在粗纤维含量6%时,消化率最高达到86.90%。不同品种猪对干物质、Ca、P的消化率影响极显著(P＜0.01),但莱芜猪和大约克猪对干物质、CP消化率的影响差异不显著,莱芜猪对NDF的消化率为51.44%,大约克猪为43.51%,两者之间差异极显著(P＜0.01)。NDF和ADF的表观消化率随猪血统中莱芜猪血比例的降低而显著降低,NDF在小肠中已得到有效的分解,本试验结果证实莱芜黑猪具有耐粗饲的特性。不同品种猪对必需氨基酸(EAA)的表观消化率除赖氨酸、苏氨酸、异亮氨酸外影响均不显著。     

Fibre analysis and fibre digestibility in pet foods--a comparison of total dietary fibre, neutral and acid detergent fibre and crude fibre

Six dry dog foods and six dry cat foods with different carbohydrate sources were investigated in digestion trials. Food and faecal samples were analysed for CF, TDF and starch. In dogs, also neutral detergent fibre (aNDFom) and acid detergent fibre (ADFom) were analysed. N-free extract (NfE) was calculated for CF, and similarly for all other fibre analyses. Linear regressions were calculated between fibre intake and faecal fibre excretion. True digestibility was calculated from the regression coefficients [true digestibility in % = (1 - regression coefficient)*100], with the intercept of the equation representing excretion of material of non-food origin. Crude fibre analyses gave the lowest values, and TDF the highest, while ADFom and aNDFom were in between. Variation between diets was lowest in CF and highest in TDF. Total dietary fibre, aNDFom and ADFom in food were positively correlated. Crude fibre in food did not correlate with any other method. The NfE analogue for TDF was closest to the starch content. Methods of fibre analyses in faeces did not agree very well with each other. Crude fibre had the lowest apparent digestibility, followed by ADFom, TDF and aNDFom. For all fibre analyses, there was a significant correlation between fibre intake and faecal fibre excretion. True digestibility was close to zero for CF, with a high uniformity in both species. In dogs, true digestibility of aNDFom was 53%, of ADFom 26% and of TDF 37%; in cats, true digestibility of TDF was 31%. Except for CF, the intercept of the regression equations suggest that faecal excretion of some material of non-food origin is analysed as fibre. A combination of TDF and CF analyses might give good information on the content of total (TDF), unfermentable (CF) and partially fermentable fibre (TDF-CF) in pet foods.     

Digestibility,fecal characteristics,and plasma glucose and urea in dogs fed a commercial dog food once or three times daily

Digestibility, fecal characteristics, and levels of glucose and urea in the plasma were determined in 8 dogs that received 2 different dog foods once or 3 times daily. One dog food (A) was 5 times more expensive than the other (B). Fecal pH and consistency, digestibility of dry matter (DM), organic matter (OM), crude protein (CP), and crude fiber (CF) were determined. Blood samples were taken from 30 min before to 60 min after a meal. Digestibilities of DM, OM, and CP, and fecal consistency were higher, and daily fecal excretion and fecal pH were lower when dogs were fed food A (P < 0.001). The feeding schedule had no effect on plasma glucose and urea. Neither feeding frequency nor food × frequency interactions was significant for the parameters studied.     

Evaluation of low-oligosaccharide, low-phytate whole soybeans and soybean meal in canine foods

Eight mature dogs (19.3 +/- 0.1 kg) were used in an experiment to compare the effects of feeding soybeans containing low concentrations of oligosaccharides and phytate on nutrient availability in complete foods fed to dogs. All foods were formulated to be isonitrogenous and contained low-oligosaccharide, low-phytate soybean meal (LLM); conventional soybean meal (SBM); low-oligosaccharide, low-phytate whole soybeans (LLB); or conventional whole soybeans (WSB) as the protein source. Daily DMI averaged 287 +/- 4 g/d. Fecal outputs were greatest for LLB and WSB, averaging 48.2 g DM/d. Small intestinal DM digestibility ranged from 80.9% (LLM) to 74.0% (LLB) but was unaffected by treatment. Large intestinal DM digestibility did not differ among treatments (P = 0.652). Total-tract DM digestibility was higher (P = 0.020) for LLM (87.0%) than for SBM (84.8%). No difference in total-tract DM digestibility was observed for the two WSB foods (average = 83.3%; P = 0.286). Nitrogen retention did not differ among foods containing LLM and SBM (1.2 g of N/d; P = 0.486) or LLB and WSB (0.9 g of N/d; P = 0.225). Small intestinal N digestibility did not differ among LLM- and SBM-containing foods (80.6%; P = 0.190) or LLB and WSB (69.3%; P = 0.640). Total-tract N digestibility did not differ among foods containing LLM and SBM (83.5%; P = 0.627) or LLB and WSB (76.8%; P = 0.968). Tryptophan digestibility was higher for SBM than for LLM (P = 0.039). Histidine and tryptophan digestibilities were higher in WSB compared with LLB (P = 0.049 and P < 0.001, respectively). No differences in nonessential AA digestibility were observed when comparing soy-based foods. The results of this study demonstrate that LLM, SBM, LLB, and WSB can be effective sources of protein for canine foods and have a high digestibility. Differences in small intestinal digestibility of tryptophan and histidine may require consideration when formulating diets using low-oligosaccharide, low-phytate soybeans or meal.     

氨化处理对豆秸营养价值的影响

本试验研究了用碳酸氢铵对豆秸进行氨化处理,测定了处理前后秸秆主要化学成分变化,并用尼龙袋法测定了其瘤胃干物质降解率。结果表明:与未处理秸秆相比,氨化处理后其粗蛋白质(CP)含量提高66.0%(P<0.01),中性洗涤纤维(NDF)降低4.5%(P<0.01),瘤胃干物质(DM)降解率提高15.3%(P<0.01),但钙磷无显著变化。     

Comparison of feed preference and digestion of three different commercial diets for cats and ferrets

Diet preference and digestibility experiments were conducted using a total of 10 cats and 10 ferrets. The composition of the three different kinds of dry cat feed was as follows (each data are given in dry matter, DM): (i) normal diet (N): 95.3% DM, 33.7% crude protein (CP), 20.4% ether extract (EE), 37.6% nitrogen-free extract (NFE); (ii) 'light diet' (L): 94.2% DM, 31.6% CP, 10.7% EE, 52.2% NFE; (iii) 'veterinary diet' (D): 94.57% DM, 38.7% CP, 9.6% EE, 47.2% NFE. During the period of the preference test, the average daily dry matter intake (calculated with the mean of the three diets: 94.7% DM) was 98.0, 15.0 and 16.7 g DM in cats and 25.0, 7.3 and 8.1 g DM in ferrets. The preference rates of the three different diets, expressed in percentage of their total consumption, were as follows: 60.4% N (54.4 g DM), 12.4% L (12.1 g DM) and 27.2% D (26.6 g DM) in cats, and 46.2% N (11.6 g DM), 29.9% L (7.5 g DM) and 23.9% D (6.0 g DM) in ferrets. This indicates that cats and ferrets have a clear preference for diets of higher fat content. In all three diets, the digestibility of CP was significantly (p < 0.05) lower (70.1 +/- 5.4 vs. 75.9 +/- 5.8) while that of EE was significantly (p < 0.05) higher (95.6 +/- 1.5 vs. 89.4 +/- 5.3) in ferrets than in cats. The average digestible/metabolizable energy (DE/ME) ratio of feeds turned to be 95.6% for cats and 90.6% for the ferrets. From the data one can conclude that the ferret cannot be used as a model animal for cats either for preference or digestibility studies.     

木薯产品营养成分的分析与比较研究

本试验对3种木薯产品及玉米对照样品的主要营养成分包括粗蛋白质、粗脂肪、粗纤维、粗灰分、无氮浸出物、总淀粉、支链淀粉、直链淀粉、氨基酸、非淀粉多糖、矿物质的含量及其体外干物质和淀粉消化率、淀粉颗粒特征等指标进行了比较研究。结果表明,与玉米对照相比,木薯产品粗蛋白质和氨基酸含量较低,蛋白质品质低劣;木薯粒粗脂肪、粗纤维、粗灰分含量均显著高于玉米（P<0.05）;木薯渣无氮浸出物含量显著低于木薯干（P<0.05）,而粗灰分和粗纤维含量均显著高于木薯干和玉米（P<0.05）;木薯干和木薯粒的总淀粉含量与玉米相当,但直链淀粉/支链淀粉比值显著低于玉米（P<0.05）,木薯渣中抗性淀粉含量显著高于其他木薯产品和玉米对照（P<0.05）,玉米淀粉粒形态为不规则多面体,而木薯淀粉粒形态似球形;木薯产品中钙、钾、铁和锰的含量均显著高于玉米（P<0.05）,而磷和锌的含量均显著低于玉米（P<0.05）;玉米中可溶性非淀粉多糖（SNSP）含量显著低于3种木薯产品,且木薯渣中SNSP含量显著高于木薯干和木薯粒（P<0.05）;木薯渣中不溶性非淀粉多糖含量显著高于木薯干和木薯粒（P<0.05）,且其不溶性半乳糖的含量显著高于其他木薯产品及玉米（P<0.05）;木薯粒干物质和淀粉消化率均显著高于木薯干、木薯渣和玉米（P<0.05）,木薯渣干物质和淀粉消化率均显著低于玉米和木薯干（P<0.05）。本研究结果对木薯产品在饲料中的应用有一定的指导意义。