Influence of diet complexity on productive performance and nutrient digestibility of weanling pigs

The effect of diet complexity on coefficient of total tract apparent digestibility (CTTAD) and growth performance was studied in piglets from 21 to 62 d of age. There were five experimental prestarter diets (21–41 d of age) with similar net energy and total indispensable amino acids content. The negative control diet contained 400 g raw maize, 40 g fish meal (FM) and 70 g lactose (LAC)/kg and the positive control diet contained 400 g cooked maize, 100 g FM and 140 g LAC/kg. The other three diets were similar to the positive control diet but the cooked maize was substituted by raw maize or contained 40 g FM/kg or 70 g LAC/kg, respectively. Each treatment was replicated six times (six pigs per pen). For the starter period (42–62 d of age), half of the pens of each of the prestarter treatments was sorted into two groups and fed either a standard soybean meal–raw maize–lard diet or a diet with similar nutrient profile that included 200 g cooked maize, 50 g FM, 13 g LAC, 20 g soy protein concentrate and 10 g soybean oil/kg in substitution of lower cost ingredients. Dietary treatment did not affect piglet performance at any age, but incidence of diarrhoea during the prestarter period, was higher in piglets fed the negative control diet than in piglets fed any of the other diets (P<0.05). At 30 d of age (prestarter period), the CTTAD of organic matter and gross energy were lower (P<0.001) for pigs fed the negative control diet than for pigs fed the other diets, but that of crude protein was not affected. At 50 d of age (starter period), dietary treatment did not affect the CTTAD of any dietary component. It is concluded that the use of high levels of high quality ingredients in the diet did not improve growth performance of piglets at any age. From 21 to 41 d of age, the incidence of diarrhoea was reduced and the CTTAD of dietary components was increased when the more complex diets were fed. The inclusion of high levels of high quality ingredients in the diet to maximize performance of young pigs might not be justified under all circumstances.     

The interaction between lactose level and enzyme supplementation and form of barley processing on performance, digestibility and faecal volatile fatty acid concentration of weanling pigs fed barley-based diets

A 2×3 factorial arrangement was used to investigate the interaction between lactose level (170 g/kg versus 275 g/kg), enzyme supplementation (with or without endo-1,3 (4)-β-glucanase) and toasting (raw barley versus toasted barley) in barley-based diets (250 g/kg) on piglet performance and diet digestibility postweaning. One hundred and forty-four weaned piglets (24 days old, 6.5 kg live weight) were blocked on the basis of live weight and were assigned to one of six dietary treatments (n = 6) for 21 days as follows: (1) 170 g lactose/kg and barley (250 g/kg), (2) 275 g lactose/kg and barley (250 g/kg), (3) 170 g lactose/kg and toasted-flaked barley (250 g/kg), (4) 275 g lactose/kg and toasted-flaked barley (250 g/kg), (5) 170 g lactose/kg and barley (250 g/kg) plus β-glucanase, (6) 275 g lactose/kg and barley (250 g/kg) plus β-glucanase. There was an interaction (P<0.05) between lactose level and β-glucanase supplementation on average daily gain (ADG), food conversion ratio (FCR) and coefficient of total tract apparent digestibilities (CTTAD) of dry matter (DMD), organic matter (OMD) and nitrogen (N). Pigs offered 170 g lactose/kg and β-glucanase supplementation had an improved FCR and ADG compared to the treatment based on 170 g lactose/kg and unsupplemented barley. However, β-glucanase supplementation at 275 g lactose/kg had no significant effect on FCR and ADG compared to the 275 g lactose/kg and unsupplemented barley. Pigs offered diets containing 170 g lactose/kg plus β-glucanase had a significantly higher CTTAD for DMD, OMD and nitrogen compared to the 275 g lactose/kg plus β-glucanase diet. However, there was no significant effect of lactose level in the unsupplemented diets. Pigs offered high lactose diets showed significantly increased total VFA concentration, molar proportions of butyric acid and reduced acetic acid compared to those offered low lactose diets. Pigs offered β-glucanase supplemented diets showed reduced (P<0.05) total VFA concentration compared to unsupplemented diets. In conclusion, β-glucanase supplementation improved diet digestibility and pig performance compared to the unsupplemented diet at the low lactose level only. There was no response of β-glucanase supplementation at the high level of lactose.     

Effects of deoxynivalenol (DON) on growth performance, nutrient digestibility and DON metabolism in pigs

Wheat infected naturally withFusarium, contaminated mainly with 18.53 mg DON per kg, was added to a total constant wheat proportion of 400g/kg diet. Control and DON contaminated feed was fed for 11 weeks underad libitum and restrictive feeding conditions to 48 pigs of both sexes, which were randomly divided into 4 groups. Effects on performance (live weight range between 26 and 100kg), duration of feed intake and blood parameters were investigated. Parallel to this study, a balance study was carried out to examine the effects on nutrient digestibility and DON metabolism. The group fed the DON contaminated rationad libitum consumed 15% less feed and gained 14% less live weight compared to thead libitum control group, while the feed to gain ratio was unaffected. Under restrictive feeding conditions (DON and control) pigs exhibited 33%, 25% and 10% lower feed consumption, live weight gain and feed to gain ratio, respectively, than the control group fedad libitum. Metabolizability of energy, digestibility of organic matter, crude protein, crude fat and N-retention were significantly increased by 4, 3, 6, 11 and 10%, respectively, in the DON group of the restrictively fed pigs. In average up to 43.2% of the ingested DON, as the parent toxin in both groups, was eliminated with the urine and up to 3.0% with faeces. DON fed animals needed more time to consume the restrictive ration than the control group. Presented at the 26^th Mykotoxin-Workshop in Herrsching, Germany, May 17–19, 2004. Financial support Deutsone Forschungsgemeingschaft     

Effects of fibre level and dietary mannanoligosaccharides on digestibility,caecal volatile fatty acids and performances of growing rabbits

The current experiment with 3 trials aimed to study the effect of two levels of dietary fibre – high fibre (HF; 323 g aNDFom/kg) and low fibre (LF; 248 g aNDFom/kg) – and the effect of mannanoligosaccharides (MOS) addition (1 g/kg) to the LF diet (LFM) on the performances and health status of growing rabbits, digestibility and caecal fermentative characteristics. In the growth trial 132 rabbits of both sexes were used (11 cages with 4 rabbits per treatment) from weaning (32 days of age) to slaughter (67 days of age). Rabbits fed HF diet showed a significantly higher weight gain and live weight at 67 days than rabbits fed LF diet (2032 g vs. 1935 g) (P<0.05). Feed and digestible energy intake increased with dietary fibre level (P<0.05). During the growing period rabbits fed HF diet had a feed intake 26% higher than those fed LF diet. Feed efficiency ratio was worse in HF animals (0.334 vs. 0.385; P<0.05). Addition of MOS to LF diet did not affect growth performance parameters (P>0.05). Mortality and morbidity rate were not affected by treatments. In the digestibility 24 rabbits from 46 to 51 days of age trial were used. The HF diet resulted in a significant (P<0.05) decrease in digestibility of dry matter, organic matter and protein while the aNDFom digestibility was not significantly different between diets (P>0.05). Supplementation with MOS had no effects on digestibility (P>0.05). In the 3rd trial the caecal traits were measured in 30 rabbits with 46 days of age that received the experimental diets in the previous 14 days. Caecal production of total volatile fatty acids (VFA), acetate and propionate were significantly higher (P>0.05) on rabbits fed HF diets than on rabbits fed LF diets. The total VFA concentration increased 64% (from 5.01 to 8.20 mmol/100 ml) and acetate increased 73% (from 3.73 to 6.44 mmol/100 ml). Butyrate production was not different between diets (P>0.05). Fibre level did not affect proportions of VFA and caecal contents and caecal weights. Addition of MOS to LF diet did not affect any caecal trait (P>0.05). It was concluded that the reduction of dietary fibre level increases feed digestibility but worsens rabbit growth performances. Supplementation of low fibre diet with 1 g MOS/kg is not enough to reduce its negative effects on growth performances.     

Effects of deoxynivalenol and sodium meta-bisulphite on nutrient digestibility in growing pigs

ABSTRACT

Deoxynivalenol (DON), a mycotoxin synthesised by the Fusarium, is known to affect the growth of pigs. This effect can be attenuated with sodium meta-bisulphite (SBS). The aim of this study was to evaluate the effect of SBS with antioxidant blend on nutrient digestibility in pigs fed a diet contaminated naturally with DON. Six crossbred castrated pigs fitted surgically with single-T cannulas in the distal ileum received one of four barley-corn-soybean diets with or without SBS. After 8 d of feeding, faeces and ileal digesta were collected for 2 d. Apparent ileal digestibility (AID) of the dry matter (DM), energy, nutrients and DON, and apparent total tract digestibility (ATTD) of DM, acid detergent fibre (ADF), neutral detergent fibre (NDF), energy and DON were evaluated. The AID of phosphorus, calcium and some amino acids was increased (p < 0.05) in the DON diets whereas the ATTD of DM and energy tended to decrease (p = 0.064 and p = 0.071). SBS reduced the AID of DM, energy, ADF, ether extract, phosphorus and DON (p < 0.05) but had no effect on the ATTD of DM, energy, fibre or DON. These results show that DON improved the AID of some nutrients but tended to reduce the ATTD of energy, which could explain, although anorexia is the main effect of DON on live weight gain, the reported negative effect of DON on pig growth. Finally, SBS with antioxidant blend had reduced AID of some nutrients and intestinal absorption of DON.     

The effects of seaweed extract inclusion on gut morphology, selected intestinal microbiota, nutrient digestibility, volatile fatty acid concentrations and the immune status of the weaned pig

An experiment (complete randomised design) was conducted to investigate the effects of Laminaria hyperborea and Laminaria digitata seaweed extract inclusion on gut morphology, selected intestinal microbiota populations, volatile fatty acid concentrations and the immune status of the weaned pig. Twenty-eight piglets (24 days of age, 6.5 ± 1.4 kg live weight) were assigned to one of four dietary treatments for 7 days and then sacrificed: (T1) basal diet (control); (T2) basal diet and 1.5 g/kg L. hyperborea seaweed extract; (T3) basal diet and 1.5 g/kg L. digitata seaweed extract; and (T4) basal diet and 1.5 g/kg of a combination of L. hyperborea and L. digitata seaweed extract. The seaweed extract contained both laminarin and fucoidan. Digesta samples were taken from the caecum and colon to measure the enterobacteria, bifidobacteria and lactobacilli populations and for volatile fatty acid analysis. Tissue samples were taken from the duodenum, jejunum and ileum for morphological examination. Blood samples were taken to determine the cytokine gene expression profile and to measure the phagocytotic capacity of the blood. Pigs offered diets containing L. hyperborea seaweed extract had less bifidobacteria in the colon (P < 0.05) and lactobacilli in the caecum (P < 0.05) and colon (P < 0.001). The inclusion of L. digitata seaweed extract resulted in lower populations of enterobacteria in the caecum and colon (P < 0.01), bifidobacteria in the caecum (P < 0.05), and lactobacilli in the caecum (P < 0.05) and colon (P < 0.001). Pigs offered the combination of L. hyperborea and L. digitata seaweed extracts had less enterobacteria (P < 0.05) and lactobacilli (P < 0.01) in the caecum and colon. Pigs offered the L. digitata-supplemented diet had a reduced villous height in the duodenum and jejunum (P < 0.05). The inclusion of the L. digitata seaweed extract increased the molar proportion of butyric acid in the colon (P < 0.05). There was a significant reduction in the ammonia concentration in the colon with the inclusion of L. hyperborea (P < 0.01) and L. digitata (P < 0.05) seaweed extracts. An increase in the expression of the Interleukin-8 mRNA was observed on day 6 with the supplementation of the combination of L. hyperborea and L. digitata seaweed extract (P < 0.05). The inclusion of L. hyperborea seaweed extract resulted in an increase in total monocyte number (P < 0.05). In conclusion, the supplementation of L. hyperborea and L. digitata seaweed extract alone and in combination reduced the enterobacteria, bifidobacteria and lactobacilli populations in the caecum and colon, while only marginal effects on the immune response was observed.     

Effects of extrusion of corn on growth performance,nutrient digestibility and short-chain fatty acid profiles in the hindgut of weaned piglets

Abstract

The experiment was conducted to investigate the effects of different inclusion levels of extruded corn on growth performance, nutrient digestibility and short-chain fatty acids profiles in the hindgut of weaned piglets. Ninety weaning piglets (28 d of age; 8.21 ± 0.69 kg BW) were allotted to one of five dietary treatments only substituted for unprocessed corn at varying levels (0, 1/4, 2/4, 3/4, 4/4) with extruded corn in a 28-d experiment. On day 28, 30 piglets were killed to measure concentrations and molar ratios of short-chain fatty acids in the hindgut. From day 0 – 14, digestibility of DM, N and GE was increased linearly and diarrhea frequency was decreased due to the increasing inclusion levels of extruded corn. From day 14 – 28, digestibility of GE and N was enhanced linearly due to the increasing proportion of extruded corn. On day 28, as proportion of extruded corn increased, the level of butyrate in the caecum and colon was increased linearly and the relative proportion of propionate was reduced. Results indicated that increasing proportions of extruded corn had no effect on growth performance, but significantly improved digestibility of N and energy at day 10 of trial and may be advantageous to the intestinal health of piglets.     

Effects of extrusion of corn on growth performance, nutrient digestibility and short-chain fatty acid profiles in the hindgut of weaned piglets

The experiment was conducted to investigate the effects of different inclusion levels of extruded corn on growth performance, nutrient digestibility and short-chain fatty acids profiles in the hindgut of weaned piglets. Ninety weaning piglets (28 d of age; 8.21 +/- 0.69 kg BW) were allotted to one of five dietary treatments only substituted for unprocessed corn at varying levels (0, 1/4, 2/4, 3/4, 4/4) with extruded corn in a 28-d experiment. On day 28, 30 piglets were killed to measure concentrations and molar ratios of short-chain fatty acids in the hindgut. From day 0-14, digestibility of DM, N and GE was increased linearly and diarrhea frequency was decreased due to the increasing inclusion levels of extruded corn. From day 14-28, digestibility of GE and N was enhanced linearly due to the increasing proportion of extruded corn. On day 28, as proportion of extruded corn increased, the level of butyrate in the caecum and colon was increased linearly and the relative proportion of propionate was reduced. Results indicated that increasing proportions of extruded corn had no effect on growth performance, but significantly improved digestibility of N and energy at day 10 of trial and may be advantageous to the intestinal health of piglets.     

Effects of insoluble dietary fibre differing in lignin on performance, gut microbiology, and digestibility in weanling piglets

The study aimed to investigate the effects of insoluble dietary fibre differing in lignin content on performance and parameters of gut microbiology in 48 weanling piglets (8.5 kg mean body weight) fed common diets ad libitum. Fibre sources tested were wheat bran (low lignin) and pollen from Chinese Masson pine (Pinus massoniana) as model of fibre rich in lignin, added to diets as follows: no addition (control), 3.0% wheat bran, 1.27% pine pollen and 2.55% pine pollen. In colonic chyme, bacterial colony counts remained unaffected by treatment, but ammonia contents were reduced by fibre additions (up to -38%). The effects on ammonia were best explained by added cellulose and lignin. Fibre additions reduced apparent (faecal) digestibility of dry matter (DM) and crude protein (CP) up to -3.5 and -4.3% units with cellulose and lignin being the major determinants for changes in CP digestibility.     

Effects of dietary iron levels on growth performance, hematological status, liver mineral concentration, fecal microflora, and diarrhea incidence in weanling pigs

An experiment was conducted in weanling pigs (Landrace x Yorkshire x Duroc) to evaluate the effects of dietary iron levels on growth performance, hematological status, liver mineral concentration, fecal microflora, and diarrhea incidence. One hundred and forty-four piglets (initial BW 5.96 +/- 0.93 kg) were randomly allotted to one of the four dietary treatments on the basis of their body weights. The basal diets for each phase (phase 1: days 0 to 14; phase 2: days 15 to 28) were formulated to contain minimal Fe and then supplemented with gradient levels of Fe (0, 50, 100, and 250 mg/kg) from ferrous sulfate. Feces were collected on days 14 and 28 and used for the analysis of microbial count and trace minerals. Eight piglets from each treatment (two piglets per pen) were bled at 0, 7, 14, 21, and 28 days to determine their hematological and plasma Fe status. In addition, two piglets from each pen (eight piglets per treatment) were killed at days 14 and 28 to determine liver mineral concentrations. Pigs fed supplemental 250 ppm Fe showed lowest overall average daily gain (linear, p = 0.036). Diarrhea incidence was linearly increased (p < 0.001) with supplemental Fe level. On days 14, coliform population in normal feces was increased (p = 0.036) linearly with supplemental Fe level, and there were higher (p = 0.043) coliform population and lower (p < 0.001) Bifidobacterium spp. in the diarrhea feces. Supplemental Fe linearly (p < 0.05) improved the total red blood cells, hemoglobin, plasma, and liver (p = 0.109) Fe status of pigs and also increased (linear and quadratic, p < 0.001) the fecal excretion of Fe on days 14 and 28. It is concluded that increasing the dietary iron levels in piglets improved their hematological status and liver Fe content; however, higher dietary Fe levels might also be associated with the increased diarrhea incidence.     

Responses of feeding prebiotics on nutrient digestibility, faecal microbiota composition and short-chain fatty acid concentrations in dogs: a meta-analysis

The effects of prebiotics on digestibility, short-chain fatty acid (SCFA) concentrations and bacterial populations in the faeces and immunity in dogs were evaluated by meta-analyses. Overall, data from 15 published studies containing 65 different treatment means of 418 observations from different breeds of dogs were included in the data set. Feeding of prebiotics to dogs did not affect the nutrient intake (P > 0.10), nor did prebiotics change (P > 0.10) the digestibility of dry matter (DM) and fat. However, crude protein (CP) digestibility tended to decrease quadratically (P = 0.06) with increasing dosages of prebiotics, although the degree of prediction was low (R(2) = 0.33). The concentration of total SCFA (P = 0.08; R(2) = 0.90) tended to increase linearly, whereas concentration of acetate (R(2) = 0.25), propionate (R(2) = 0.88) and butyrate (R(2) = 0.85) increased quadratically with increasing dosage of prebiotics in the faeces of dogs. The numbers of beneficial bifidobacteria (P < 0.01; R(2) = 0.62) increased quadratically, but lactobacilli (P < 0.01; R(2) = 0.66) increased linearly with increasing supplementation of prebiotics. The changes in healthy bacterial numbers were affected by the interaction of initial bacterial numbers and dose of prebiotics; bacterial numbers increased relatively more when initial bacterial numbers were low. Dietary composition did not influence the response of prebiotics on lactobacilli and bifidobacterial numbers in this study. The numbers of pathogenic Clostridium perfringens and Escherichia coli were not affected by prebiotics. Prebiotics did not affect the serum immunoglobulin (Ig) concentrations such as IgG, IgA and IgM in dogs. Although prebiotics may tend to have an adverse effect on CP digestibility, prebiotics at doses up to 1.40% food intake (DM basis) might increase the beneficial bacterial populations and SCFA concentrations in the faeces of dogs. Thus, the feeding of prebiotics has a great prospective to improve the intestinal health of dogs.     

Betaine increases net portal absorption of volatile fatty acids in Iberian pigs

Betaine is an osmolyte with the potential to increase volatile fatty acids (VFAs) production and hence improve intestinal health.The present study investigated how betaine affects portal and arterial concentrations and net portal absorption (NPA) of VFA in growing Iberian pigs. Eight 30 kg BW Iberian growing barrows with indwelling catheters in portal vein, ileal vein and carotid artery were randomly assigned to a control diet or a diet supplemented with 0.5% betaine. Para-aminohippuric acid was infused into the ileal vein as a marker to determine portal blood flow using the dilution method. Blood samples were simultaneously taken from the carotid artery and portal vein at −60, 60, 120, 180, 240, 300 and 360 min after feeding 1 200 g of the diet. The NPA of VFA (acetate, propionate, butyrate, valerate, isobutyrate and caproate) was determined by multiplying the porto-arterial plasma concentration differences by portal plasma flow. Betaine increased NPA of acetate (1.44 fold; P < 0.001) and total VFA (0.55 fold; P < 0.001) while decreased NPA of propionate (−0.38 fold; P < 0.05) and valerate (−1.46 fold; P < 0.05) compared with control pigs. Estimated heat production potentially derived from NPA of VFA accounted for 0.20–0.27 of metabolizable energy for maintenance. Acetate and propionate accounted for most of the total VFA estimated heat production (0.83–0.89). Regarding bacterial communities, betaine apparently did not change the DNA abundance of fecal total bacteria, Lactobacillus, Bifidobacterium, Enterobacteriaceae, Bacteroides and the Clostridium clusters I, IV and XIV. In conclusion, betaine increased portal appearance and NPA of VFA, contributing to cover maintenance energy requirements.     

Effects of feeding high- and low-fibre fractions of air-classified,solvent-extracted canola meal on diet nutrient digestibility and growth performance of weaned pigs

The dietary energy value of solvent-extracted canola meal (CM) is limited by its relative high fibre content. The fibre-rich hull of canola is denser than the oil-free cotyledons, so these seed components partially fractionate in a stream of air. Air classification thus separates CM into a low-fibre, light-particle fraction and a high-fibre, heavy-particle fraction of interest for feeding monogastric and ruminant species, respectively. Crude fibre (CF), acid detergent fibre (ADF) and neutral detergent fibre (NDF) in light-particle fraction were reduced by 96, 34 and 28% compared with CM (83 CF, 165 ADF, 238 NDF g/kg, as-is). Brassica (B) napus, Brassica juncea, or their fractions were evaluated feeding 288 weaned pigs (7.1 kg) for 37 d as a 2 × 3 factorial with 12 replicate pens per treatment. Wheat-based diets including 200 g of test feedstuff/kg provided 10.5 and 10.0 MJ net energy (NE)/kg and 1.27 and 1.15 g standardised ileal digestible lysine/MJ NE and were fed for 9 and 28 d, respectively. Pen feed added, orts, and individual pig body weight were measured weekly to calculate average daily feed intake (ADFI), average daily gain (ADG), and feed efficiency (G:F). Pen faecal samples were collected on d 16 and 17 to calculate diet apparent total tract digestibility coefficients (CATTD) of dry matter (DM), gross energy (GE), crude protein (CP) and digestible energy (DE) value. Pigs fed B. juncea had 3 and 2% higher (P<0.001) CATTD of DM (0.82 vs. 0.79) and GE (0.84 vs. 0.82) than pigs fed B. napus. Feeding the light-particle fraction increased (P<0.001) CATTD of DM (0.82 vs. 0.79), GE (0.84 vs. 0.82), and CP (0.79 vs. 0.77) by 4, 3 and 3% compared with CM, respectively. For the entire trial, pigs fed B. juncea consumed 33 g/d less (P<0.001) feed (723 vs. 756 g/d), had 0.02 higher (P<0.05) G:F (0.735 vs. 0.718 g:g), but ADG (503 vs. 514 g/d) was not different (P>0.05) compared to pigs fed B. napus. Feeding pigs the light-particle fractions did not affect (P>0.05) ADFI (741 vs. 736 g/d), increased (P<0.05) G:F 0.02 (0.739 vs. 0.721 g:g) and tended to increase (P=0.07) ADG (519 vs. 501 g/d) by 18 g/d compared to CM. In conclusion, air classification of canola meal increased diet nutrient digestibility, but only modestly increased G:F of weaned pigs due to dietary fibre reduction.     

Effects of dietary zinc on performance, nutrient digestibility and plasma zinc status in Cashmere goats

Thirty-six 1.0-year-old Liao Ning Cashmere goat wethers (BW = 22.01 ± 0.59 kg) were used to determine the effects of dietary zinc (Zn) level on the performance, nutrient digestibility and plasma Zn status during the cashmere fiber growing period. The goats were randomly divided into four groups that were fed a basal diet containing 22.3 mg Zn/kg dry matter (DM) with 0, 15, 30 or 45 mg Zn/kg DM as reagent grade ZnSO₄·7H₂O. The experiment lasted 60 days including a 7-day metabolism trial. Both average daily gain (ADG) and feed efficiency were improved (P < 0.05) by Zn supplementation and were higher (P < 0.05) for the treatment groups supplemented with 30 and 45 mg Zn/kg DM compared with 15 mg Zn/kg DM. Zn supplementation had no influence on the length and diameter of cashmere fiber (P > 0.05). Digestibility of DM, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) did not differ among treatments (P > 0.05). Plasma Zn concentrations were increased (P < 0.01) by Zn supplementation and were higher (P < 0.05) for the treatment groups supplemented with 30 and 45 mg Zn/kg DM compared with 15 mg Zn/kg DM. Zn apparent absorption rate and apparent retention rate were decreased (P < 0.05) by Zn supplementation, but did not differ among Zn supplemented treatments (P > 0.05). In conclusion, a control diet containing 22.3 mg Zn/kg DM was inadequate for achieving optimal growth performance in Cashmere goats, and the recommended level of dietary Zn for such goats is 52.3 mg/kg DM during the cashmere fiber growing period.     

健康与腹泻仔猪粪样中挥发性脂肪酸和菌群区系的比较

[目的]本试验通过对比健康与腹泻仔猪粪样挥发性脂肪酸( Volatile fatty acid,VFA)以及菌群的差异,初步探讨腹泻对仔猪后肠环境的影响.[方法]采集腹泻和健康仔猪粪样,气相色谱测定挥发性脂肪酸浓度;提取粪样总细菌核酸,利用变性梯度凝胶电泳(Denaturing gradient gel electrophoresis,DGGE)和Real-time PCR技术定性、定量分析总细菌和梭菌Ⅳ菌群.[结果]与健康仔猪相比,腹泻仔猪粪样中乙酸含量有升高的趋势,支链脂肪酸(Branched chain fatty acid,BCFA)含量显著降低(p＜0.05),总VFA、丙酸和丁酸含量有降低的趋势,但差异均不显著;乙酸占总挥发酸比例显著升高(p＜0.05),而丙酸及BCFA占总挥发酸比例则显著降低(p＜0.05),丁酸占总挥发酸比例有降低趋势.PCR-DGGE指纹技术分析表明:腹泻发生后,仔猪粪样中总细菌和梭菌Ⅳ菌群在DGGE图谱上并没有特异性的条带消失或出现,但相似性分析显示,腹泻仔猪样品趋于归类于同一簇.Real-time PCR定量分析显示:仔猪腹泻后,粪样中的总细菌和梭菌Ⅳ菌群的数量显著下降(p＜0.05);而大肠杆菌和乳酸杆菌的数量变化不显著.[结论]与健康仔猪相比,腹泻仔猪粪样挥发性脂肪酸组成发生改变,并且微生物区系中的一些菌群也发生变化.     

The effect of feeding expeller-pressed canola meal on growth performance and diet nutrient digestibility in weaned pigs

The effects of feeding increasing levels of expeller-pressed (EP) canola meal in substitution for soybean meal as an energy and amino acid source were evaluated in 240 weaned pigs with an initial body weight of 7.3 ± 0.6 kg. Five pelleted wheat-based diets containing 0, 50, 100, 150 or 200 g EP canola meal/kg were formulated to contain 10.0 MJ net energy (NE)/kg and 1.18 g standardised ileal digestible (SID) lysine/MJ NE and were fed for 4 wk starting 1 wk after weaning at 19 days of age. Expeller-pressed canola meal was added at the expense of soybean meal and the diets were balanced for NE using canola oil and for amino acids using crystalline lysine, methionine, threonine and tryptophan. Increasing inclusion of EP canola meal linearly reduced (P<0.001) the apparent total tract digestibility of energy, dry matter and crude protein and the digestible energy content of diets. From 0 to 28 days on trial, increasing inclusion of EP canola meal did not affect body weight gain, feed intake and feed efficiency. In conclusion, up to 200 g EP canola meal/kg can replace soybean meal in diets formulated to equal NE and SID amino acid content and fed to nursery pigs starting 1 wk after weaning without reducing growth performance.     

Effects of fermentation products of Ganoderma lucidum on growth performance and immunocompetence in weanling pigs

The purpose of this study was to test fermentation, for its products of a Chinese medicinal mushroom, Ganoderma lucidum, cultured by submerged fermentation for its effect on growth performance and immunocompetence in weanling piglets. In Experiment 1, 72 weanling piglets were allotted to one of four treatments receiving these fermentation products (GLF, expressed as amount of β-glucans) at 0 (control), 50, 100, and 150 mg/kg feed for 4 weeks. The results showed that at a supplementation level of 50 mg/kg feed, GLF caused the best growth performance, the highest pseudorabies antibody titre, and a decrease of blood glucose level. It was also demonstrated that GLF up-regulated the cell-mediated immune response related cytokines (IL-2, IFN-γ, and TNF-α) expression in different lymphoid tissues. After challenging with porcine circovirus (PCV) type 2 (Experiment 2), a supplementation with 50 mg GLF per kg feed also inhibited PCV-2 virus amplification, and ameliorated lymphocyte depletion in different lymphoid tissues. Conclusively, feed supplemented with GLF at 50 mg/kg could be beneficial to counteract the physiological stress in weanling piglets.     

Effects of fermentation products of Ganoderma lucidum on growth performance and immunocompetence in weanling pigs

The purpose of this study was to test fermentation, for its products of a Chinese medicinal mushroom, Ganoderma lucidum, cultured by submerged fermentation for its effect on growth performance and immunocompetence in weanling piglets. In Experiment 1, 72 weanling piglets were allotted to one of four treatments receiving these fermentation products (GLF, expressed as amount of beta-glucans) at 0 (control), 50, 100, and 150 mg/kg feed for 4 weeks. The results showed that at a supplementation level of 50 mg/kg feed, GLF caused the best growth performance, the highest pseudorabies antibody titre, and a decrease of blood glucose level. It was also demonstrated that GLF up-regulated the cell-mediated immune response related cytokines (IL-2, IFN-gamma, and TNF-alpha) expression in different lymphoid tissues. After challenging with porcine circovirus (PCV) type 2 (Experiment 2), a supplementation with 50 mg GLF per kg feed also inhibited PCV-2 virus amplification, and ameliorated lymphocyte depletion in different lymphoid tissues. Conclusively, feed supplemented with GLF at 50 mg/kg could be beneficial to counteract the physiological stress in weanling piglets.