Functional properties,antioxidant activity and in-vitro digestibility characteristics of brown and polished rice flours of Indian temperate region

The present investigation was aimed to study functional properties,antioxidant activity and in-vitro digestibility characteristics of brown and polished flours obtained from four rice cultivars(SR-4,K-39,Mushq Budij and Zhag)of Kashmir.Brown rice flours had higher total dietary fibre(3.08%-3.68%),oil absorption(116.0%-139.0%),emulsion capacity(4.78%-9.52%),emulsion stability(87.46%-99.93%)and resistant starch content(6.80%-9.00%)than polished flours.However,polished flours presented greater water absorption(102.0%-122.0%),foaming capacity(8.00%-13.63%),apparent amylose(19.16%-22.62%),peak(2260.0-2408.0 cP),trough(1372.0-1589.0 cP)and breakdown(714.0-978.0 cP)viscosities than their brown counterparts.Brown rice flours depicted highest total phenolic content(4.40-6.40 mg GAE/g)and inhibition of lipid peroxidation(19.50%-33.20%).However,equilibrium starch hydrolysis percentage(C∞)and predicted glycemic index of brown rice flours were lower than their polished counterparts.Among rice cultivars,brown Zhag flour had the highest total dietary fibre(3.68%),emulsion capacity(9.52%),emulsion stability(99.93%),resistant starch(9.00%),DPPH radical scavenging activity(85.45%)and inhibition of lipid peroxidation(33.20%),respectively.Emulsion capacity and emulsion stability were positively correlated with protein content of rice flours.However,peak,trough,breakdown and setback viscosities were negatively correlated with protein and fat contents of rice flour.The present investigation will be helpful in identifying nutritive role of rice flours from studied cultivars in human diet.

In-vitro digestibility,protein digestibility corrected amino acid,and sensory properties of banana-cassava gluten-free pasta with soy protein isolate and egg white protein addition

Soy protein isolate and egg white protein were added to cassava-banana gluten-free pasta and the effects on the nutritional quality,digestibility properties,protein digestibility corrected amino acid(PDCAA),and sensory acceptance of the pasta was observed.Banana-cassava composite flour(75:25)was blended with soy protein isolate or egg white protein at the following rates:0,5,10,and 15 g/100 g flour.Cooked pasta samples were analysed for total phenolic content(TPC),antioxidant activity,amino acid profiles,protein content,starch digestibility,protein digestibility and protein digestibility corrected amino acid score(PDCAAS).Addition of both proteins decreased starch digestibility,increased protein digestibility,improved the balance of the amino acid profile,and PDCAAS whereas only soy protein isolate enhanced the TPC and antioxidant capacity of the banana-cassava pasta.An egg white protein-fortified banana-cassava pasta had better customer acceptance and purchase intent than soy protein isolate inclusion.

Pelleting and particle size reduction of corn increase net energy and digestibility of fiber,protein,and fat in corn-soybean meal diets fed to group-housed pigs

Background Reduction of the particle size of corn increases energy digestibility and concentrations of digestible and metabolizable energy.Pelleting may also reduce particle size of grain,but it is not known if there are interactions between particle size reduction and pelleting.The objective of this experiment was to test the hypothesis that particle size reduction and pelleting,separately or in combination,increase N balance,apparent total tract digestibility(ATTD)of fiber and fat,and net energy(NE)in corn-soybean meal diets fed to group-housed pigs.Methods Six corn-soybean meal-based diets were used in a 3×2 factorial design with 3 particle sizes of corn(i.e.,700,500,or 300μm)and 2 diet forms(i.e.,meal or pelleted).Pigs were allowed ad libitum access to feed and water.Twenty-four castrated male pigs(initial weight:29.52 kg;standard diviation:1.40)were allotted to the 6 diets using a 6×6 Latin square design with 6 calorimeter chambers(i.e.,4 pigs/chamber)and 6 periods.Oxygen consumption and CO_(2)and CH_(4)productions were measured during fed and fasting states and fecal and urine samples were collected.Results Regardless of particle size of corn,the ATTD of gross energy(GE),N,and acid-hydrolyzed ether extract(AEE),and the concentration of NE were greater(P<0.05)in pelleted diets than in meal diets.Regardless of diet form,the ATTD of GE,N,and AEE,and the concentration of NE were increased(linear;P<0.05)by reducing the particle size of corn,but the increase was greater in meal diets than in pelleted diets(interaction;P<0.05).Conclusions Both pelleting and reduction of corn particle size increased nutrient digestibility and NE,but increases were greater in meal diets than in pelleted diets.

Amino acid and mineral digestibility,bone ash,and plasma inositol is increased by including microbial phytase in diets for growing pigs

Background The effect of microbial phytase on amino acid and energy digestibility is not consistent in pigs,which may be related to the phytase dosage or the adaptation length to the diet.Therefore,an experiment was conducted to test the hypotheses that increasing dietary phytase after an 18-day adaptation period:1)increases nutrient and energy digestibility;2)increases plasma P,plasma inositol,and bone ash of young pigs;and 3)demonstrates that maximum phytate degradation requires more phytase than maximum P digestibility.Results Data indicated that increasing inclusion of phytase[0,250,500,1,000,2,000,and 4,000 phytase units(FTU)/kg feed]in corn-soybean meal-based diets increased apparent ileal digestibility(AID)of Trp(quadratic;P<0.05),and of Lys and Thr(linear;P<0.05),and tended to increase AID of Met(linear;P<0.10).Increasing dietary phytase also increased AID and apparent total tract digestibility(ATTD)of Ca and P(quadratic;P<0.05)and increased ATTD of K and Na(linear;P<0.05),but phytase did not influence the ATTD of Mg or gross energy.Concentrations of plasma P and bone ash increased(quadratic;P<0.05),and plasma inositol also increased(linear;P<0.05)with increasing inclusion of phytase.Reduced concentrations of inositol phosphate(IP)6 and IP5(quadratic;P<0.05),reduced IP4 and IP3(linear;P<0.05),but increased inositol concentrations(linear;P<0.05)were observed in ileal digesta as dietary phytase increased.The ATTD of P was maximized if at least 1,200 FTU/kg were used,whereas more than 4,000 FTU/kg were needed to maximize inositol release.Conclusions Increasing dietary levels of phytase after an 18-day adaptation period increased phytate and IP ester degradation and inositol release in the small intestine.Consequently,increasing dietary phytase resulted in improved digestibility of Ca,P,K,Na,and the first 4 limiting amino acids,and in increased concentrations of bone ash and plasma P and inositol.In a corn-soybean meal diet,maximum inositol release requires approximately 3,200 FTU/kg more phytase than that required for maximum P digestibility.

Standardized ileal digestibility of amino acids in soybean meal fed to non-pregnant and pregnant sows

Background Two studies were designed to determine standard ileal crude protein(CP)and amino acid(AA)digestibility of soybean meal(SBM)from different origins fed to non-pregnant and pregnant sows.Seven solvent-extracted SBMs from soybeans produced in the USA,Brazil,and China were selected.In Exp.1,eight different diets were created:a nitrogen(N)-free diet and 7 experimental diets containing SBM from different origins as the only N source.Eight non-pregnant,multiparous sows were arranged in an 8×8 Latin square design(8 periods and 8 diets).In Exp.2,the diet formula was the same as in Exp.1.Eight gestating sows(parity 3)were assigned to 4 different diets in a replicated 4×3 Youden square design(three periods and four diets)in mid-gestation and again in late-gestation stages.Results When fed to non-pregnant and late-gestating sows,the standardized ileal digestibility(SID)of CP and most AAs from different SBM were not significantly different(P>0.05).When fed to mid-gestating sows,the SID values for Arg,His,Lys,Phe,Cys,Gly,Ser,and Tyr in SBM 1 were lower than in SBM 4 and 5(P<0.05),whereas SID for Leu from SBM 5 was higher than in SBM 1 and 4(P<0.05).SID values for Ile,Ala,and Asp from SBM 4 were lower than in SBM 1 and 5(P<0.05).Sows had significantly greater SID values for Lys,Ala,and Asp during mid-gestation when compared with late-gestation stages(P<0.05).Mid-gestating sows had greater SID value for Val and lower SID value for Tyr when compared with non-pregnant and late-gestating sows(P<0.01),whereas non-pregnant sows had significantly greater SID value for Met when compared with gestating sows(P<0.01).Conclusions When fed to mid-gestating sows,the SID values for most AAs varied among SBM samples.The SID values for Lys,Met,Val,Ala,Asp,and Tyr in SBM were affected by sow gestation stages.Our findings provide a cornerstone for accurate SBM use in sow diets.

Modulation of starch digestibility using non-thermal processing techniques:A review

Obesity and type 2 diabetes are widespread throughout the world, especially in developed countries. Starch is an important part of human staple food, the modulating of starch digestibility is conducive to reducing postprandial blood glucose levels and alleviating the chronic disease caused by high caloric intake. The digestion properties of starch are correlated with its structural features, including crystallization, amylose/amylopectin ratio, non-starch components, etc. Among the modified methods applied to regulate starch digestibility, non-thermal processing techniques(NTPT) receive extensive attention due to the characteristics of safety, environmental friendliness and high efficiency. The influence and mechanism of NTPT on the digestion properties of starch are discussed in this review, including ultrasounds, high pressure, γ-irradiation, etc. NTPT induces the alternation of morphological and structural characteristics of native starch, changing their sensitivity to enzymes. The effects of NTPT on the digestibility of starch are highly related to the processing parameters and structure characteristics of native starch. The review shows that NTPT is an effective way to modulate the digestion properties of starch and prevent people from suffering from chronic diseases such as obesity and type 2 diabetes.

Oils with different degree of saturation:effects on ileal digestibility of fat and corresponding additivity and bacterial community in growing pigs

Background Oils are important sources of energy in pig diets.The combination of oils with different degree of saturation contributes to improve the utilization efficiency of the mixed oils and may reduce the cost of oil supplemented.An experiment was conducted to evaluate the effects of oils with different degree of saturation on the fat digestibility and corresponding additivity and bacterial community in growing pigs.Methods Eighteen crossbred(Duroc×Landrace×Yorkshire)barrows(initial body weight:29.3±2.8 kg)were surgically fitted with a T-cannula in the distal ileum.The experimental diets included a fat-free basal diet and 5 oil-added diets.The 5 oil-added diets were formulated by adding 6%oil with different ratio of unsaturated to saturated fatty acids(U:S)to the basal diet.The 5 oils were palm oil(U:S=1.2),canola oil(U:S=12.0),and palm oil and canola oil were mixed in different proportions to prepare a combination of U:S of 2.5,3.5 and 4.5,respectively.Results The apparent and standardized ileal digestibility(AID and SID)of fat and fatty acids increased linearly(P<0.05)as the U:S of dietary oils increased except for SID of fat and C18:2.The AID and SID of fat and fatty acids differed among the dietary treatments(P<0.05)except for SID of unsaturated fatty acids(UFA)and C18:2.Fitted one-slope broken-line analyses for the SID of fat,saturated fatty acids(SFA)and UFA indicated that the breakpoint for U:S of oil was 4.14(R^(2)=0.89,P<0.01),2.91(R^(2)=0.98,P<0.01)and 3.84(R^(2)=0.85,P<0.01),respectively.The determined SID of fat,C18:1,C18:2 and UFA in the mixtures was not different from the calculated SID of fat,C18:1,C18:2 and UFA.However,the determined SID of C16:0,C18:0 and SFA in the mixtures were greater than the calculated SID values(P<0.05).The abundance of Romboutsia and Turicibacter in pigs fed diet containing palm oil was greater than that in rapeseed oil treatment group,and the two bacteria were negatively correlated with SID of C16:0,C18:0 and SFA(P<0.05).Conclusions The optimal U:S for improving the utilization efficiency of mixed oil was 4.14.The SID of fat and UFA for palm oil and canola oil were additive in growing pigs,whereas the SID of SFA in the mixture of two oils was greater than the sum of the values of pure oils.Differences in fat digestibility caused by oils differing in degree of saturation has a significant impact on bacterial community in the foregut.

A Simulative Study on Effects of Climate Warming on Nutrient Contents and In Vitro Digestibility of Herbage Grown in Qinghai-Xizang Plateau

The increasing trend of air temperature along with the climate warming has been accepted gradually by scientists and by the general public. Qinghai_Xizang Plateau, a unique geographic unit due to high_altitude climate, is one of the most susceptible regions to climate warming. Its ecosystem is very fragile and sensitive to climate change. In order to get a better understanding of the impacts of climate warming on the nutrient contents of herbage grown in Qinghai_Xizang Plateau, a simulative study was implemented at Daban Moutain by using temperature differences resulted from sites selected at different altitudes and nutrient contents and in vitro digestibility were determined for assessing the quality of the grown herbage. There were significant downtrends in crude protein (CP), ether extract (EE) and nitrogen free extract (NFE) contents of herbage along with the increase of temperature. It had a positive correlation between temperature and content of acid detergent fibre (ADF), acid detergent lignin (ADL) in herbage. In vitro digestibility of herbage decreased along with the increase of temperature. The results of this study indicated that climate warming significantly influence nutrient contents and in vitro digestibility of herbage grown in Qinghai_Xizang Plateau. It is suggested that the future climate warming especially the gradual rise of the night temperature could cause negative effect on herbage quality grown in Qinghai_Xizang Plateau by decreasing CP, EE, and NFE contents and increasing some indigestible ingredients such as crude fibre (CF), neutral detergent fibre (NDF), ADF, and ADL. This, consequently, decreases the ruminant assimilation ability.

Effect of Graded Levels of Fiber from Alfalfa Meal on Nutrient Digestibility and Flow of Fattening Pigs

The fiber level and composition have an important effect on nutrient digestibility of swine diets. Little information is known about the effects of fiber level and composition from alfalfa meal on nutrient digestibility of fattening pigs fed a corn-soybean meal-based diet. The objective of this experiment was to determine the effects of alfalfa fiber on the growth performance, intestinal nutrient flow and apparent total tract digestibility（ATTD） of nutrients in fattening pigs. 24 barrows（Duroc×（Large White×Landrace）, body weight=（60.6±0.7） kg） were randomly allotted to 4 treatments with 6 replicates of 1 pig per replicate. The pigs were provided a control diet or a diet containing 5, 10 or 20% of alfalfa meal during a 14-d experiment period. Average daily gain（ADG） and the ATTD of dry matter（DM）, organic matter（OM）, crude protein（CP）, neutral detergent fiber（NDF）, acid detergent fiber（ADF） and gross energy（GE） reduced linearly as the level of alfalfa meal in the diet increased（P〈0.01）. The total tract flow of DM, OM, CP, NDF, ADF, and GE increased with the increase in dietary alfalfa（linear, P〈0.05）. Growth performance and nutrient digestion were not affected by inclusion of 5% alfalfa meal in the diet（P〉0.05）. A multiple linear regression analysis, taking into account both soluble and insoluble fiber intake, explained approximately 70% of the variation in the ATTD of DM, OM, NDF, and GE（P〈0.01）. In conclusion, alfalfa meal should be limited to less than 5% of the diet in fattening pigs to maximize growth performance and nutrient digestion. Soluble and insoluble fiber from alfalfa meal has the differential roles in nutrient digestion, which may help explain the main variation observed in nutrient digestibility. These findings suggest that knowledge of specific fiber components is necessary to accurately predict the effects of dietary fiber on nutrient digestibility.

Nutritional value of a partially defatted and a highly defatted black soldier fly larvae (Hermetia illucens L.) meal for broiler chickens: apparent nutrient digestibility,apparent metabolizable energy and apparent ileal amino acid digestibility

Background: The study aimed to determine the apparent total tract digestibility coefficients(ATTDC) of nutrients, the apparent metabolizable energy(AME and AMEn) and the amino acid(AA) apparent ileal digestibility coefficients(AIDC)of a partially defatted(BSFp) and a highly defatted(BSFh) black soldier fly larvae meal. The experimental diets were: a basal diet and two diets prepared by substituting 250 g/kg(w/w) of the basal diet with BSFp or BSFh, respectively.Results: Significant differences were found between BSFp and BSFh meals for ATTDC of the nutrients: BSFp resulted more digestible than BSFh, except for ATTDC of CP which did not differed between meals, while a statistical trend was observed for ATTDC of DM and EE. The AME and AMEn values were significantly(P < 0.05) different between the two BSF meals, with higher levels for BSFp(16.25 and 14.87 MJ/kg DM, respectively). The AIDC of the AA in BSFp ranged from 0.44 to 0.92, while in BSFh they ranged from 0.45 to 0.99. No significant differences were observed for the AA digestibility(0.77 and 0.80 for BSFp and BSFh, respectively), except for glutamic acid, proline and serine that were more digestible in the BSFh meal(P < 0.05).Conclusions: Defatted BSF meals can be considered as an excellent source of AME and digestible AA for broilers with a better efficient nutrient digestion. These considerations suggested the effective utilization of defatted BSF larvae meal in poultry feed formulation.

Effects of dietary yeast β-glucan on nutrient digestibility and serum profiles in pre-ruminant Holstein calves

This study aimed to investigate the effects of dietary supplementation of yeast 13-glucan on the nutrient digestibility and serum profiles in pre-ruminant Holstein calves. Forty-two neonatal Holstein calves （（39.6＋4.2） kg） were randomly allotted to six groups, and each was offered one of the following diets： a basal diet （control） or the basal diet supplemented with 25, 50, 75, 100 or 200 mg of yeast 13-glucan kg-~ feed （dry matter basis）. The basal diet consisted of a milk replacer and a starter feed. The trial lasted for 56 d. Two digestibility trials were conducted from d 14 to 20 and from d 42 to 48. Blood samples were collected on d 0, 14, 28 and 42 for serum profile analyses. On d 56, three calves from each group were slaughtered, and intestinal samples were collected to assess the villous height, crypt depth and mucosal thickness. Although feed intake was not affected by dietary treatment （P〉0.05）, the average daily gain （ADG） and gain-to-feed ratios were higher （P〈0.05） for the calves fed 75 mg of yeast β-glucan kg^-1 feed than those in the other groups. The supplementation of yeast β-glucan at 75 mg kg^-1 feed increased the apparent digestibility of dry matter （DM）, crude protein （CP）, ether extract （EE）, and phosphorus （P） （P〈0.05） and the ratio of intestinal villous height to crypt depth （V/C） （P〈0.05） when compared with the control group. No effects of yeast β-glucan on the serum concentrations of total protein （TP）, albumin （ALB）, serum urea nitrogen （SUN） and glucose （GLU） were observed （P〉0.05）. Compared with the control group, supplementation of yeast β-glucan decreased （P〈0.05） the serum concentrations of triglycerides （TG） and total cholesterol （TC）. The serum concentration of immunoglobulin G （IgG） and immunoglobulin M （IgM） increased quadratically （P〈0.05）, whereas the serum concentration of immunoglobulin A （IgA） was unaffected by dietary treatments （P〉0.05）. The supplementation of yeast β-glucan stimu- lated the enzymatic activity of alkaline phosphatase （ALP） （P〈0.05） compared with the control group. The lysozyme （LYZ） concentration increased quadratically （P〈0.05） with increasing yeast β-glucan levels. The results suggested that dietary supplementation of yeast 13-glucan at 75 mg kg^-1 feed improved nutrient digestibility, enhanced immunity by increasing the immunoglobulin concentration and stimulating ALP, and exerted no adverse effects on metabolism in pre-ruminant calves.

Effects of a novel bacterial phytase expressed in Aspergillus Oryzae on digestibility of calcium and phosphorus in diets fed to weanling or growing pigs

In 2 experiments, 48 weanling （initial BW： 13.5 ± 2.4 kg, Exp. 1） were used to determine effects of a novel bacterial 6-phytase and 24 growing pigs （initial BW： 36.2 ± 4.0 kg, Exp. 2） expressed in Aspergillus oryzae on the apparent total tract digestibility （ATTD） of phosphorus and calcium in corn-soybean meal diets fed to weanling and growing pigs. In Exp. 1 and 2, pigs were randomly allotted to 6 dietary treatments using a randomized complete block design and a balanced 2 period changeover design, respectively. In both experiments, 6 diets were formulated. The positive control diet was a corn-soybean meal diet with added inorganic phosphorus （Exp. 1：0.42 and 0.86% standardized total tract digestible phosphorus and total calcium, respectively; Exp. 2：0.32 and 0.79% standardized total tract digestible phosphorus and total calcium, respectively）. A negative control diet and 4 diets with the novel phytase （Ronozyme HiPhos, DSM Nutritional Products Inc., Parsippany, N J） added to the negative control diet at levels of 500, 1,000, 2,000, and 4,000 phytase units （FYT）/kg were also formulated. In Exp. 1, the ATTD of phosphorus was greater （P 〈 0.01） for the positive control diet （60.5%） than for the negative control diet （40.5%）, but increased （linear and quadratic, P 〈 0.01） as phytase was added to the negative control diet （40.5% vs. 61.6%, 65.1%, 68.7%, and 68.0%）. The breakpoint for the ATTD of phosphorus （68.4%） was reached at a phytase inclusion level of 1,016 FYT/kg. In Exp. 2, the ATTD of phosphorus was greater （P〈 0.01） for the positive control diet （59.4%） than for the negative control diet （39.8%） and increased （linear and quadratic, P〈 0.01） as phytase was added to the negative control diet （39.8% vs. 58.1%, 65.4%, 69.1%, and 72.8%）. The breakpoint for the ATTD of phosphorus （69.1%） was reached at a phytase inclusion level of 801 FYT/kg. in conclusion, the novel bacterial 6-phytase improved the ATTD of phosphorus and calcium in both weanling and growing pigs. The optimum level of inclusion for this phytase is 800 to 1,000 FYT/kg of complete feed to maximize ATTD of phosphorus and calcium in weanling and growing pigs

Chemical composition,energy and amino acid digestibility in double-low rapeseed meal fed to growing pigs

Background： The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition. And a precise understandin9 of the nutritional value of an ingredient is beneficial for the accurate diet formulation and reduction of feed costs. This study was conducted to determine the chemical composition, dicjestible energy （DE） and metabolizable enercjy （ME） content, and apparent ileal digestibility （AID） and standardized ileal dicjestibility （SID） of amino acids （AA） for growincj pigs. Thirteen solvent-extracted double-low rapeseed meal （DLIRSM） samples were obtained from the main double-low rapeseed producing areas in China. Methods： The DE and ME contents of the 13 DLRSM samples were measured in cjrowin9 pigs （six pigs per DLRSM sample, average initial body weicjht （BW） =48.3 kg）. The AID and SID of AA of 10 DLRSM samples were determined in 12 crossbred barrows （average initial BW = 35.3 kcj） by using two 6 x 6 Latin square designs. Each Latin square comprised one N-flee diet and 5 DLRSM test diets. Results： The chemical composition of DLRSM varied among samples, and the coefficient of variation was greater than ]0 % for ether extract （EE）, neutral detergent fiber （NDF）, acid detergent fiber （ADF）, calcium （Ca）, and total 91ucosinolates. The AA content of DLRSM varied among samples especially for lysine （Lys） and methionine （Met）. On a dry matter （DM） basis, the apparent total tract digestibility （ATFD） of gross energy （GE）, the DE and ME and the ME：DE ratio of DLRSM averaged 62.39 %, 2862 kcal/k9 and 2723 kcal/kcj, and 94.95 %, respectively. The mean value of S1D of Lys was 70.52 % which varied from 66.54-76.54 %. The SID of crude protein （CP）, Met, and threonine （Thr） averaged 72.81%, 82.41%, and 69.76 %, respectively. Conclusions： There was great variability in chemical composition especially in the concentration of EE, NDF and ADF, but no significant differences in energy content of the DLIRSM samples were observed. In addition, the AID and SID of all AA were relatively similar amoncj DLRSM samples except for that of Lys.

Effect of lactic acid bacteria and propionic acid on conservation characteristics,aerobic stability and in vitro gas production kinetics and digestibility of whole-crop corn based total mixed ration silage

This study was conducted to evaluate the effect of lactic acid bacteria and propionic acid on the fermentation quality, aer- obic stability and in vitro gas production kinetics and digestibility of whole-crop corn based totalmixed ration （TMR） silage. Total mixed ration was ensiled with four treatments： （1） no additives （control）; （2） an inoculant （Lactobacillus plantarum） （L）; （3） propionicacid （P）; （4） propionic acid＋lactic acid bacteria （PL）. All treatments were ensiled in laboratory-scale silos for 45 days, and then subjected to an aerobic stability test for12 days. Further, four TMR silages were incubated in vitro with buffered rumen fluid to study in vitro gas production kinetics and digestibility. The results indicated that all TMR silages had good fermentation characteristics with low pH （〈3.80） and ammonia nitrogen （NH3-N） contents, and high lactic acid contents as well as Flieg points. Addition of L further improved TMR silage quality with more lactic acid production. Addition of P and PL decreased lactic acid and NH3-N contents of TMR silage compared to the control （P〈0.05）. After 12 days aerobic exposure, P and PL silages remained stable, but L and the control silages deteriorated as indicated by a reduction in lactic acid and an increase in pH, and numbers of yeast. Compared to the control, addition of L had no effects on TMR silage in terms of 72 h cumulative gas production, in vitro dry matter digestibility, metabolizable energy, net energy for lactation and short chain fatty acids, whereas addition of PL significantly （P〈0.05） increased them. L silage had higher （P〈0.05） in vitro neutral detergent fiber digestibility than the control silage. The results of our study suggested that TMR silage prepared with whole-crop corn can be well preserved with or without additives. Furthermore, the findings of this study suggested that propionic acid is compatible with lactic acid bacteria inoculants, and when used together, although they reduced lactic acid production of TMR silage, they improved aerobic stability and in vitro nutrients digestibility of TMR silage.

Use of the N-alkanes to Estimate Intake, Apparent Digestibility and Diet Composition in Sheep Grazing on Stipa brevifl ora Desert Steppe

The application of n-alkane as markers to estimate herbage intake, apparent digestibility and species composition of diet consumed by grazing sheep was studied. Six local Mongolian sheep were used to determine dry matter （DM） intake, apparent DM digestibility and species composition of diet during summer, autumn and winter. Animals were orally dosed twice daily with n-alkane gelatin capsules containing 60 mg C32-alkane as an external marker. Diet composition was estimated by comparing the odd-chain n-alkanes pattern profile （C27-C31） of the consumed plant species with the n-alkanes fecal concentrations of grazing animals, using a non-negative least squares algorithm called EATWHAT software package. The alkane pair C32：C33 and C33 alkane were used to estimate DM intake and diet apparent DM digestibility, respectively. The results showed that daily dry matter intake of the sheep were 1.77, 1.61 and 1.18 kg d-1 in summer, autumn and winter, respectively. Apparent DM digestibility, crude protein （CP）, metabolizable energy （ME） and neutral detergent fiber （NDF） intake of diet consumed by sheep decreased significantly （P〈0.01） from summer to winter, with no evident changes in ADF and ADL intake. Diet composition indicated Artemisia frigida Willd was the most dominant diet component, contributed 79.68, 68.12 and 86.26% of sheep＇s diets in summer, autumn and winter, respectively. Cleistogenes songorica Ohwi and Convolvulus arnmannii Desr were the important components of the diet. Although Stipa breviflora Griseb is one of the main plant species in the study area, the sheep rarely choosed it. The study indicated that CP and ME in diet consumed by sheep were deficient in winter. Therefore, appropriate supplementation strategies should be indispensable during this period.

The effects of dietary fiber level on nutrient digestibility in growing pigs

The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 x 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease （P =0.] O） as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased （P 〈0.0]） when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased （P 〈0.01）. The digestible energy and metabolizable energy content of diets decreased （P 〈0.01） as the total dietary fiber increased.

Dynamics of methanogenesis,ruminal fermentation and fiber digestibility in ruminants following elimination of protozoa: a meta-analysis

Background: Ruminal microbes are vital to the conversion of lignocellulose-rich plant materials into nutrients for ruminants.Although protozoa play a key role in linking ruminal microbial networks,the contribution of protozoa to rumen fermentation remains controversial; therefore,this meta-analysis was conducted to quantitatively summarize the temporal dynamics of methanogenesis,ruminal volatile fatty acid(VFA) profiles and dietary fiber digestibility in ruminants following the elimination of protozoa(also termed defaunation).A total of 49 studies from 22 publications were evaluated.Results: The results revealed that defaunation reduced methane production and shifted ruminal VFA profiles to consist of more propionate and less acetate and butyrate,but with a reduced total VFA concentration and decreased dietary fiber digestibility.However,these effects were diminished linearly,at different rates,with time during the first few weeks after defaunation,and eventually reached relative stability.The acetate to propionate ratio and methane production were increased at 7 and 11 wk after defaunation,respectively.Conclusions: Elimination of protozoa initially shifted the rumen fermentation toward the production of more propionate and less methane,but eventually toward the production of less propionate and more methane over time.

Effects of Lactobacillus plantarum and fibrolytic enzyme on the fermentation quality and in vitro digestibility of total mixed rations silage including rape straw

The aim of the current study was to investigate the effects of a lactic acid bacteria inoculant（Lactobacillus plantarum, LP）, fibrolytic enzyme（EN）, combination of LP and EN（LP＋EN） on fermentation quality, nutritive characteristics and in vitro digestibility of total mixed ration（TMR） silages containing 0, 7.5 and 15.0%（on dry matter basis） of rape（Brassica campestris L.） straw（RS）（denoted as CTMR, LTMR and MTMR, respectively）. After ensiling for 60 days, TMR silages without additives were well preserved, but MTMR had higher p H than CTMR and LTMR. There were no differences in other parameters of fermentation quality, microbial composition, nutrition and in vitro digestibility between CTMR and LTMR except for yeast and mold number and crude protein（CP） content. CTMR and LTMR silage had higher CP content, in vitro neutral detergent fiber digestibility（IVNDFD） and in vitro acid detergent fiber digestibility（IVADFD）, lower acid detergent fiber（ADF） content than MTMR silage. LP and EN decreased p H and increased dry matter（DM） recovery of TMR silages. LP＋EN improved the fermentation quality, nutritive characteristics and in vitro digestibility of TMR silages, showed by lower p H, ADF content, higher lactic acid content, in vitro dry matter digestibility（IVDMD） and IVNDFD. Therefore, It was suggested that TMR silage contained 7.5% RS on a DM basis and treated with LP＋EN can be as a useful feed for ruminant.

Effects of Dietary Soy Isoflavones on Feed Intake,Growth Performance and Digestibility in Juvenile Japanese Flounder(Paralichthys olivaceus)

An 8-week feeding trial was conducted to investigate the effects of dietary soy isoflavones on feeding intake,growth performance,and digestion of juvenile Japanese flounder(Paralichthys olivaceus).Four isonitrogenous(49% crude protein) and isoenergetic(20.1 MJ kg-1) diets were formulated to contain four graded levels of soy isoflavones,namely,0,1,4 and 8 g soy isoflavones in 1 kg of diet.Each diet was randomly fed to triplicate tanks of fish(Initial average weight:2.58 g ± 0.01 g),and each tank was stocked with 35 fish.No significant difference was observed among diets with levels of 0,1 and 4 g kg-1 soy isoflavones in feed intake,weight gain,feed efficiency ratio(FER),proximate composition of fish whole body and apparent digestibility coefficients(ADC) of nutrients and energy(P>0.05).However,high dietary soy isoflavones level(8 g kg-1) significantly depressed weight gain,FER,whole-body crude lipid content of fish and ADC of nutrients(P<0.05).These results indicate that high level of dietary soy isoflavones(above 4 g kg-1) significantly depresses growth responses and FER of Japanese flounder.However,as the content of soy isoflavones in soybean meal is around 1 to 3 g kg-1,the adverse effects might be neglected when soybean products are used as a fish feed ingredient.

Effects on Growth Performance and Feed Digestibility of Hainan Black Pigs by Adding Lysine in Low Protein Diet

[Objective] The paper was to study the effects on growth performance and feed digestibility of Hainan black pigs by adding lysine in low prntein diet. [Method] A tntal of 36 Hainan black pigs with the body weight of （46.34±3.06） kg were randomly divided into three groups： con- trol group （protein level 15%, lysine level 0.83%）, experimental grnup 1 （protein level 13%, 0.83%）, and experimental group II （protein level 13%, lysine level 1.03）, each group had three replicates of four pigs. The trial lasted 35 d. [Result] The growth performance of Hainan black pig in grnup II had no significan! difference with that in contrail group （P〉0.05）. The apparent digestibility of chide protein and phosphorus of Hainan black pigs in Group II increased significantly （P〈0.05）, which were increased by 10.08% and 11.85% respectively compared to the control group; the apparent digestibility of calcium was increased, but the difference was not signifieant （P〉0.05）. [Conclusion] It will not reduce the growth performance of Hainan blaek pig when the protein level of diet is reduced by 2% and Ihe lysine level is increased to 1.03%. It is recommended that the diet can be used in the production of llainan black pig.