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1.
Two maize based diets containing 2.3 g phytic P and 38 mg Zn/kg (P+) or 1.3 g phytic P and 25 mg Zn/kg (P−) were formulated. A third diet (P+/Phytase) was P+ supplemented with 3-phytase (500 FTU/kg). Each of these three basal diets, supplemented or not with 15 mg Zn/kg, was given during 20 days to weaned piglets and to 1-day-old chicks. Chicks fed the P− diets were removed from the data set because of an abnormally low feed intake.

In piglets, added Zn increased bone (P < 0.05) and plasma Zn (P < 0.01) irrespective of the basal diet (basal diet × Zn, P > 0.05). Supplementing P+ with phytase was more efficient in improving these indicators of Zn status than replacing P+ by P−. In chicks, supplemental Zn improved Zn status in a higher extent when added to P+ than to P+/Phytase (basal diet × Zn, P < 0.05). Phytase increased Zn status in a lesser extent than 15 ppm supplemental Zn. More Zn was soluble in gizzard than in stomach which corresponded to the differences in pH (4.2 vs 5.0). Phytase increased soluble Zn in stomach (P < 0.05) but not in gizzard. These results suggest a higher availability of Zn in chicks than in piglets in the absence of phytase. This may explain the higher efficacy of phytase for improved Zn availability in piglets than in chicks.  相似文献   


2.
A digestibility trial on piglets was conducted to study the effect of an enzyme complex derived from Trichoderma longibrachiatum (Roxazyme G2) supplemented to a rye-based diet on apparent ileal digestibility of amino acids and NSP-constituting sugars. Enzyme supplementation at 200 mg kg− 1 increased (P < 0.05) the digestibility of total amino acids from 67.1 to 70.8. As the dietary concentration of Roxazyme G2 increased from 0 to 100 mg/kg, the ileal digestibility of the NSP constituents gradually increased. No further increase was observed with the supplementation level of 200 mg/kg. The improvement in the digestibility of arabinose + xylose (685%, P < 0.05) was much higher than that of the remaining sugars (110%, P < 0.05). The apparent ileal digestibility of galactose was positively influenced by Roxazyme G2 but it remained negative in all dietary treatments, presumably due to the high concentration of galactose in endogenous secretions. It is concluded that Roxazyme G2 effectively degrades non-starch polysaccharides in upper digestive tract and marginally improves amino acid availability in young pigs.  相似文献   

3.
High moisture corn (HMC) can undergo fermentation during storage that may improve its nutritional value for pigs. Stored HMC used in this study contained (n = 4) 75% dry matter (DM), and, on a DM basis, 63.8% starch, 0.5% mono and disaccharides, 9.9% protein, 19 mM acetic acid, 18 mM lactic acid (LA), 1.25 × 107 cfu g− 1 of LA producing bacteria, 2.88 g kg− 1 total phosphorus (P), and 1.26 g kg− 1 soluble P. The soluble P content was higher than in freshly harvested HMC (0.27 g kg− 1 DM) and indicates P release during storage. Studies were aimed at altering the nutritional value of stored HMC by controlled fermentation or steeping. Changes in LA content were not affected (P > 0.05) by addition of exogenous Lactobacillus and Bacillus bacteria. Steeping of HMC with phytase (Ronozyme) was examined at four inclusion levels (0, 500, 750, 1000 FTU kg− 1) and at either 21 °C or 37 °C. At 37 °C added phytase released virtually all phytate P within 6 h irrespective of the level (levels increased by 1.44 g P kg− 1 DM); at 21 °C, the increase was maximized at 1.2 g P kg− 1 DM after 24 h. The feeding value of HMC for pigs can be altered by steeping with exogenous phytase and does not appear to require microbial inoculants.  相似文献   

4.
The aim of this work was to test the hypothesis that a moderate zinc deficiency induces intestinal alterations in weaned piglets. A diet based on maize and soybean meal was formulated without supplemental zinc (33 ppm, zinc-deficient) or with added zinc (113 ppm, control). These diets were pair-fed for 18 or 27 d to intra-litter pairs of piglets weaned at 21 d of age. The feed intake and growth, plasma concentrations of zinc and alkaline phosphatase (ALP) activity, and morphometry, enzyme activities and the microflora of the mid-jejunum were investigated. Feed intake and growth were similar between diets and diarrhoea was not observed. By contrast, plasma zinc and ALP activity were much lower in zinc-deficient piglets at slaughter (P < 0.001). The weight of organs was unaffected, except colonic tissue that was lighter in piglets fed the zinc-deficient diet (P < 0.05). Neither villus-crypt intestinal architecture nor mucosal enzyme activities were altered. Jejunal counts of lactic acid bacteria and coliforms tended to be higher in the zinc-deficient pigs (P ≤ 0.10). In conclusion, feeding a diet moderately deficient in zinc for 18–27 d induced limited intestinal alterations in weaned pigs.  相似文献   

5.
Four groups of six 21 days-old piglets were used to evaluate the effect of a prebiotic or probiotic on the intestinal fermentative activity. In each group, piglets received one of the following diets: basal diet (C); basal diet supplemented with xylo-oligosaccharide (C-XOS); basal diet supplemented with Saccharomyces cerevisiae (C-SC); and basal diet supplemented with xylo-oligosaccharide and S. cerevisiae (C-XOS + SC).

The short chain fatty acids in the colon of piglets were decreased with the inclusion of S. cerevisiae in the diet (P < 0.01). The xylanolytic activity was higher (P < 0.05) in the small intestine of piglets fed C-XOS + SC diet, but no significant differences were found in the caecum and colon. In the caecum contents, the cellulolytic activity was increased (P < 0.05) by the C-XOS and C-SC diets, but remained similar when the diet was supplemented with the two additives combined.  相似文献   


6.
Value-added processing of cereals produces high-value fractions for food and bio-processing application and by-products that are used in animal nutrition to reduce feed costs. Wheat by-products contain arabinoxylans that might limit nutrient digestibility. Effects of xylanase supplementation (0 or 4375 U/kg feed) on energy digestibility were studied in a wheat control and by-product diets (30% millrun, middlings, shorts, screenings, and bran) in a 2 × 6 factorial arrangement. The wheat control diet was formulated to contain 3.34 Mcal digestible energy (DE)/kg and 2.8 g apparent digestible lysine/Mcal DE, and included 0.4% chromic oxide as a marker for digestibility. Twelve ileal-cannulated pigs (32.5 ± 2.5 kg) were each fed seven of 12 diets. Faeces and then digesta were each collected for 2 d, and diet digestibility values are reported. Wheat had higher ileal and total-tract energy digestibility than by-products (P < 0.01). Xylanase improved energy digestibilities for by-products (P < 0.001) but not for wheat. Among by-products, ileal energy digestibility was lowest for middlings (62%), then bran < screenings < millrun, and highest for shorts (66%). Xylanase improved (P < 0.05) ileal energy digestibility of millrun by 19% to 76%. Total-tract energy digestibility of millrun improved from 72 to 79% (similar to wheat) with xylanase (P < 0.05). In summary, xylanase improved energy digestibility in the selected wheat by-product diets, indicating that arabinoxylans in wheat by-products limit nutrient digestibility.  相似文献   

7.
We report a study on crossbred growing pig ((Duroc × Pietrain) × Large White) that measured the effect of tropical conditions on respiration rate (RR), skin temperature (ST), rectal temperature (RT) and productivity and determined the efficacy of two simple cooling methods. The experiment was a randomized complete block design using 120 growing pigs. The factors were cooling system and pen design. The effects of two cooling systems (water bath (WB) and sprinkling (S)) were evaluated and compared with a control (CON). Cooling systems were tested in pens with (Y) or without an additional outdoor yard (NY). The pens were similar to those used in small-scale pig keeping in South-East Asia. The inside pen size was 2.5 × 3 m, the yard was 2.5 × 2 m. The same experimental design was used in two blocks: one block was in the wet season with average ambient temperature (T) of 27.5 °C and average relative humidity (RH) of 74.7% and the other was in the dry season with average T of 28.7 °C and average RH of 62.8%. In each block a batch of 60 pigs was reared in 12 pens (five pigs per pen). Pigs had free access to feed and water. Results showed that cooling and pen type significantly affected most parameters. The bath and S reduced RR by 4.2 and 5.2 min− 1, respectively (P < 0.01), and ST by 0.3 and 0.4 °C, respectively, (P < 0.05). Rectal temperature was not influenced by any treatment. The bath significantly reduced number of defecations and urinations in the resting area in pens NY (P < 0.001). A yard reduced the number of excretions in the resting area (P < 0.01). There were significant interaction effects of cooling and pen type on lying, lateral lying, and huddling (P < 0.01; P < 0.001; P < 0.01, respectively). Daily weight gain was 6 g d− 1 more with WB and 50 g d− 1 more with S (P < 0.05). The biggest daily weight gain was achieved when S was combined with a pen NY (P < 0.01).

We conclude that the physiologic and behavioral responses and hence productivity of group-housed growing pigs raised under tropical climate conditions benefited from the simple cooling systems tested and were affected by the presence of a yard. A fall in the high respiration rate indicated that cooling with the bath or sprinkling alleviated the pigs' heat stress.  相似文献   


8.
Aim of the study was to investigate the growth performance of weaned piglets fed either a medicated or not medicated diet supplemented with either a blend of formic and lactic (64/36) acids (FL, 11 kg/ton) or a microencapsulated blend of organic acids and flavors (T) (1 kg/ton, Tetracid®S, EU patent 1391155B1,Vetagro srl, Italy). 480 three-week old SCAAPAG × Goland piglets were fed four diets (4 pens of 30 piglets per diet): FL or T with or without the medication (M) comprising colistin 180 ppm + amoxicillin 600 ppm for the 1st phase and chlortetracycline 1000 ppm + sulphadiazine 1250 ppm + trimetoprim 250 ppm for the 2nd phase. The piglets received a two-phase diet (I:18% CP, 1.3% Lys, 7.5% CF and 2600 kcal/kg NE; II:18% CP, 1.2% Lys, 5.6% CF and 2400 kcal/kg NE). All data were analysed by ANOVA. After 49 days, animals fed the medicated diets had higher feed intake (+ 24.5% for group FL + M vs FL − M and + 22.3% for group T + M vs T − M; P < 0.01) and lower mortality (overall 1.2% for the medicated diets fed animals vs 9.2% for the non-medicated ones). Final weights were: 26.8 ± 1.0 kg, 25.7 ± 0.8 kg for FL + M, T + M, 20.9 ± 0.7 kg, 21.6 ± 0.8 kg for FL − M and T − M, respectively (P < 0.05). The medication resulted in maintaining animals in good health status. The microencapsulation technique allowed to lower the acids dose to be included in the feed by ten fold at least maintaining the same effects that a high dose can give without medication.  相似文献   

9.
Forty multiparous cows (599 kg ± 18 kg BW) were fed with a basal diet (19.6% CP, 35% RUP, and 1.7 Mcal kg− 1 NEl) with alfalfa, corn silage and concentrate (49% forage: 52% concentrate). After calving, cows were randomly assigned to the treatments, which consisted in four levels of ruminally protected methionine (RPM): 0, 8, 16 and 24 g d− 1 of Mepron®M85 (Degussa Co.). Experiment was conducted for 120 days with measurements of milk production, composition, body weight, body condition score and DM intake every 15 days (3 consecutive days) starting on day 5 postpartum. Data were analyzed with the repeated measures model (four treatments in 8 periods through lactation). No treatment effects were detected on DM intake (20.38 ± 2.51 kg d− 1), body weight (599.78 ± 19.78 kg), body condition score (2.51 ± 0.19 units) and milk fat. However, milk production and protein yield were increased with addition of RPM (P < 0.01). Milk production responded quadratically to methionine level. Holstein cows with a mean production of 35 kg d− 1 milk require addition of ruminally protected methionine (16 g d−1) to improve milk production.  相似文献   

10.
A study was carried out to investigate whether adding a starter culture or a formic acid containing-product to fermented liquid feed of suboptimal microbial quality could improve the characteristics of the mixture and the gastrointestinal ecology and growth performance of piglets. Four experimental diets were prepared: Feed and water were mixed in the ratio 1:2.5 (w/w) in four closed tanks. Diet 1) Three times daily, 50% of the mixture stored in the tank was removed and then replaced with an equal amount of fresh feed and water, (FLF), positive control; Diet 2) Three times daily, 95% of the mixture stored in the tank was removed and then replaced with an equal amount of fresh feed and water. Escherichia coli K12 (1 × 106/g) was added every morning (COLI); Diet 3) as the COLI treatment and added Lactobacillus plantarum VTT E-78076 (1 × 106/g) every morning (+PLANTARUM); and Diet 4) as the COLI treatment and added 0.26 g AIV/KemiSile 2 plus/100 g mixture three times daily (+ACID). One hundred and sixty weaners were used. On day 14, one littermate from each pen was killed and the gastrointestinal tract removed. The remaining piglets were used to measure the effect of the experimental diets on growth performance during the first six weeks post-weaning. The +ACID diet had lower numbers of lactic acid bacteria and Enterobacteriaceae, higher numbers of yeasts, and lower concentration of lactic acid and acetic acid than the COLI and +PLANTARUM diets. Feeding the +PLANTARUM and the +ACID diets increased daily weight gain during the six weeks post-weaning (P ≤ 0.02) compared to feeding the COLI diet. The +ACID group showed the highest numerical daily feed intake in all periods. The gain/feed during the six weeks post-weaning tended to be lowest in the COLI group (P < 0.10). The counts of lactic acid bacteria able to grow at 20 °C were lowest in the stomach (P ≤ 0.003) and distal small intestine (P ≤ 0.06) of the +ACID group. The counts of yeasts able to grow at 37 °C in the stomach were highest in the +ACID (P ≤ 0.01) and FLF groups (P ≤ 0.09). The number of yeasts able to grow at 20 °C in the stomach and distal small intestine was highest in the FLF fed piglets, followed by the +ACID group. This study showed that addition of L. plantarum VTT E-78076 or AIV/KemiSile 2 plus to fermented liquid feed of suboptimal microbial quality improved growth performance without affecting the gastrointestinal ecology of piglets substantially.  相似文献   

11.
This study was conducted to determine the effects of dietary supplementation with a Chinese herbal ultra-fine powder on growth performance, serum metabolites and intestinal health in early-weaned piglets. Sixty piglets weaned at 21 days of age were randomly assigned to one of the 3 treatment groups, representing supplementation with 0 or 2 g/kg of the powder, or 0.2 g/kg of colistin to maize- and soybean meal-based diets (n = 20 per group). Dietary supplementation with the powder increased ADFI and ADG, improved the gain/feed ratio, and reduced the incidence of diarrhea in the weaned piglets (P < 0.05), compared with the non-additive group. In contrast to colistin, the Chinese herbs decreased (P < 0.05) serum levels of triglycerides and glucose and increased (P < 0.05) serum concentrations of ferrum and phosphorus. Collectively, these findings indicate that the Chinese herbal powder is safe and effective in preventing the weaning-associated intestinal dysfunction and improving the growth performance in piglets.  相似文献   

12.
In a previous study, ornithine addition to an arginine-deficient diet did not improve whole-body arginine status in enterally-fed piglets; however, the metabolic fates of the supplemental ornithine were not studied. This experiment determined the metabolic fates of the supplemental ornithine and whether ornithine metabolism was affected by the addition of -ketoglutarate. Male piglets (n = 20, 1.8 kg), fitted with gastric catheters for diet and isotope infusion, portal vein catheters for isotope infusion and femoral vein catheters for blood sampling (d 0), received 2 d of a complete diet, followed by 5 d of 1 of 4 test diets: the arginine-deficient diet (basal), or the basal diet with either -ketoglutarate [ +  - KG; 4.6 mmol/(kg d)], ornithine [ + Orn; 9.2 mmol/(kg d)] or both [ +  - KG/ + Orn; 4.6 mmol/(kg d)  - ketoglutarate + 9.2 mmol/(kg d) ornithine]. Piglets received primed, constant infusions of [1-14C]ornithine infused intragastrically (either d 5 and d 7) to determine ornithine kinetics, and [guanido-14C]arginine intragastrically to measure arginine flux (d 6). Piglets receiving the ornithine-containing diets had a higher intragastric ornithine flux (P < 0.0001) and ornithine oxidation (P < 0.05). Ornithine supplementation did not increase arginine synthesis, although the ornithine supplemented piglets had a greater conversion of ornithine to proline (P < 0.0001). The fates of supplemental ornithine in piglets fed an arginine-deficient diet appear to be oxidation and proline synthesis; this was not affected by the presence of -ketoglutarate.  相似文献   

13.
The objective of this study was to study the effect of fibrolytic enzyme (FE) inclusion on nutrient digestibility and growth performance of Awassi lamb fed on a high concentrate diet. Thirty weaned Awassi lambs (initial body weight = 20.4 ± 3.0 kg) were fed a high concentrate diet (with or without the addition of FE (15 lambs/treatment)) for 60 d in a completely randomized design. The diet contained 17, 7, 58.5, 15, and 2.5% wheat straw, wheat bran, barley grain, soybean meal and minerals, respectively. Lambs were fed ad libitum twice daily at 08:00 and 15:00 h. Dry matter, OM, CP, and NDF intakes were all similar (P > 0.05) for lambs fed diet with or without the FE and averaged 1078, 941, 171, and 432 g/d, respectively. Metabolizable energy intake was also not affected (P > 0.05) by the enzyme supplementation and averaged 2.87 Mcal/d. Dry matter, OM, CP, and NDF digestibilities were all unaffected (P > 0.05) by the enzyme inclusion and averaged 64.8, 67, 65.7 and 60.4%. Final body weight, average daily gain, and feed to gain ratio were all unaffected (P > 0.05) by the FE inclusion and averaged 34.9 kg, 222 g/d, and 5.4, respectively. In summary, FE treatment of high concentrate diet for lambs had no effect on nutrient intake or any of the growth performance parameters. Therefore, supplementing such diets with FE for fatting Awassi lambs is not recommended.  相似文献   

14.
A 2 × 2 factorial experiment was used to investigate the interaction between dietary crude protein (CP) concentration (200 vs 140 g/kg) and inulin supplementation (0 vs 12.5 g/kg) on nitrogen (N) excretion and intestinal microflora from 16 boars (n = 4, 74.0 kg live weight). The diets were formulated to contain similar concentrations of digestible energy and lysine. Pigs offered the high CP diets had a higher excretion of urinary N (P < 0.01), faecal N (P < 0.01) and total N (P < 0.001) than the pigs offered the low CP diets. Inulin supplementation increased faecal N excretion (P < 0.05) and decreased urine: faeces N ratio (P < 0.05) compared to the inulin free diets. There was no significant effect (P > 0.05) of dietary treatment on N retention. There was an interaction (P < 0.05) between dietary CP concentration and inulin supplementation on caecal E.coli. Pigs offered the diet containing 200 g/kg CP plus inulin decreased the population of E.coli compared to the inulin supplemented 140 g/kg protein diet. However, CP concentration had no significant effect on the population of E.coli in the unsupplemented diets. Inulin supplementation increased caecal bifidobacteria (P < 0.01) compared to the inulin free diets. In conclusion, inulin supplementation favourably altered N excretion and lowered the population of E.coli at high CP concentrations.  相似文献   

15.
Six Murray Grey × Hereford yearling steers were used to determine the effect of two cooling treatments (ENV) (day cooled (0600–1400) or night cooled (1400–2200), and two dietary treatments (DIET) – control (CON) no added fat or added fat (FAT) – on rectal temperature, respiration rate and dry matter intake (DMI). Cattle were exposed to 2 d of thermoneutral conditions followed by four hot days in a controlled climate facility. This was replicated 6 times. Steers were given a 10 d rest in outside pens between each replication. Sprinklers (2.84 L min− 1; 5 min on, 20 min off) and fans (continuous; 2 m s− 1) were used when ambient temperature (TA) ≥ 28 °C. Rectal temperature (5 min intervals) and respiration rate (hourly) were measured for 12 × 24 h periods on hot days (2 per replication). Individual DMI over two time periods (PER) (period 1; 0600–1500, and period 2; 1500–0600) and daily metabolisable energy (ME) intakes were also recorded. Steers fed FAT had greater (P < 0.05) DMI then the CON steers during day cooling. However, there were no DIET or PER differences for DMI during night cooling. DMI of FAT and CON fed steers during night cooling was similar to the DMI of the FAT fed steers during day cooling. Overall DMI was greater during night cooling (DMI from both diets pooled). There were PER differences for DMI, with more (P < 0.05) feed consumed during period 2 irrespective of ENV or DIET. ME intake was 22.9% greater (P < 0.05) for the FAT fed steers during day cooling then for the CON fed steers. There were no DIET effects on ME intake during night cooling. DIET had no effect (P > 0.05) on respiration rate however differences were seen for rectal temperature. Mean rectal temperature for the FAT steers was lower (P < 0.05) than the mean of the CON steers, however there were no within ENV differences. Day cooled cattle had a higher (P < 0.05) respiration rates (71.8 breaths/min; bpm) than the night cooled steers (65.3 bpm). There were no differences for rectal temperature. However, day cooled steers had lower (P < 0.05) rectal temperature and respiration rate than the night cooled steers during the day — which corresponded with the day cooling period. Night cooling appears to be beneficial in lowering mean rectal temperature and respiration rate, and in maintaining DMI. There is no suggestion that feeding fat will replace the need for supplementary measures to alleviate heat exposure of confined cattle. However feeding fat may be worthwhile in maintenance DMI when combined with strategies involving day cooling.  相似文献   

16.
The hypothesis that increase in dietary phytin amplifies phytin binding to protein thereby reducing protein digestion, which is alleviated by phytase, was tested. A 2 × 2 factorial arrangement of dietary treatments was used to investigate the response of growing pigs to supplemental phytase (0, or 1200 units/kg) in low- or high-phytin P diets (2.2 or 3.9 g/kg). Eight crossbred barrows (28–30 kg) were canulated and assigned to crates using a double, 4 × 4 Latin Square design. Pigs were fed each of the 4 diets at 3 times metabolic BW (0.09  BW kg 0.75) for 7 d. Ileal digesta was collected for 12 h on d 6 and d 7 by attaching plastic bags to the cannula. Feed and ileal digesta were analyzed for N, energy and P. Phytase had no effect on apparent ileal digestibility (AID) of N or AAs. The AID of some AAs was higher in the high-phytin diet, which contradicts the hypothesis that higher phytin content would have a negative impact. In contrast, the AID of P was depressed by high dietary phytin (P < 0.01) and increased by phytase (P < 0.01) more so at the higher dietary phytin resulting in a phytin × phytase interaction (P < 0.01).  相似文献   

17.
The effect of xylo-oligosaccharides (XOS), a probiotic culture of Saccharomyces cerevisiae (SC) and the combined administration of XOS and SC on the piglet intestinal microbiota was investigated. Twenty four weaned piglets were fed during 4 weeks with one of the following diets: (BD) basal diet; (BD + XOS) basal diet supplemented with xylo-oligosaccharides (20 g kg− 1); (BD + SC) basal diet supplemented with S. cerevisiae (6 × 109 CFU kg− 1); and (BD + XOS + SC) basal diet supplemented with xylo-oligosaccharides and S. cerevisiae. Samples from the ileum, caecum and colon were collected and analysed for total anaerobes growing in XOS or glucose, xylose and arabinose (GXA) containing media. Specific primers were used to evaluate differences in Bifidobacterium and Lactobacillus populations and ERIC PCR to fingerprint the intestinal microbiota.

The lowest number of culturable bacteria was obtained from the ileum of animals fed BD + XOS. The highest PCR titres with Lactobacillus group-specific primers in BD and BD + SC were obtained in the caecal contents. In XOS-supplemented diets the PCR titres were increased or maintained, from the caecum to the colon. Bifidobacteria were not detected in any samples using genus-specific primers. In the dendrogram from ERIC PCR, the piglets fed with XOS diets presented the highest similarity between samples and probiotic reference strains.  相似文献   


18.
We explored the applicability of the 13C bicarbonate dilution technique for determination of energy expenditure (EE) in young bulls in comparison to whole body indirect calorimetry (IC). Twelve bulls of a F2 German Holstein x Charolais cross (4.5 months, 332 ± 16 kg BM) received a diet providing 1000 kJ ME d− 1 kg BM− 0.75 and 4.3 g crude protein d− 1 kg BM− 0.75. Bulls were housed in respiration chambers and received an intravenous bolus of NaH13CO3 (A: 3 μmol kg BM− 1 (n = 2), B: 7 μmol kg BM− 1 (n = 4), C: 17.5 μmol kg BM− 1 (n = 6), 99 at.% 13C) into the jugular vein to measure EE. Simultaneously, EE was determined by IC. After the 13C administration blood samples and breath gas were collected from the animals in the respiration chamber during a 24-h period (7.00–7.00 h). The recovery of 13C in breath CO2 (% of 13C dose) was irrespective of NaH13CO3 dose (A: 69.7 ± 2.7%, B: 70.5 ± 4.5%, C: 75.0 ± 4.9%; P > 0.05). Only small amounts of 13C were excreted in urine (3.4 ± 2.6%) and feces (2.0 ± 1.3%). The EE determined by the 13C bicarbonate method using breath and blood 13C recovery rates as correction factors was not different from that measured by IC (816 ± 81 [blood] or 827 ± 101 [breath] vs. 820 ± 90 kJ d− 1 kg BM− 0.75). Bland–Altman analysis showed a 95% confidence interval for EE of ± 99 and ± 109 kJ d− 1 kg BM− 0.75 based on blood and breath 13C recovery, respectively. In conclusion, the 13C bicarbonate dilution method is appropriate to obtain reliable estimates of EE in young bulls using blood CO2 or breath CO2 under standardized experimental conditions, i.e. in the fasting state.  相似文献   

19.
L.Y. Yue  S.Y. Qiao   《Livestock Science》2008,115(2-3):144-152
This study was conducted to determine the effects of low-protein diets supplemented with crystalline amino acids (AA) on performance and intestinal development in barrows (n = 32) over 2 weeks after weaning at 18 ± 1 day. Four maize-soybean meal based diets providing 0.93 g standardized ileal digestible lysine/MJ ME were prepared. The treatments were a control diet containing 23.1% CP (crude protein) and three low-protein diets (21.2, 18.9, and 17.2% CP, respectively), which were supplemented with crystalline AA to achieve an ideal AA pattern. Piglets were raised individually and had free access to feed and water. Average daily gain (ADG) and average daily feed intake (ADFI) were measured weekly. Severity of diarrhea was monitored twice per day. Blood from all piglets was taken for determining serum urea nitrogen on d 0, 7, and 14 and serum free AA concentration on d 14. At the end of the experiment, all piglets were killed to measure morphology of the small intestine and disaccharidase activities. Reducing CP level did not affect ADFI (P > 0.10) but resulted in poorer (linear, P < 0.05; quadratic, P < 0.05) ADG and feed:gain ratio (F:G) over the 2-week study period. However, most of the effect of dietary CP was due to the significant deterioration of performance with the 17.2% CP diet. Faecal consistency was improved linearly (P < 0.01) with dietary CP decrease. Reducing dietary CP from 23.1 to 17.2% resulted in a linear (P < 0.001) and quadratic (P < 0.001) decrease in serum urea nitrogen levels on d 7 and 14. Serum arginine (P < 0.001), glutamine (P < 0.05), and proline (P < 0.05) concentrations were decreased in pigs fed the 17.2% CP diet compared with those fed the control diet on d 14. Villous height was decreased (P < 0.05) in the duodenum and jejunum by the reduction of dietary CP. As dietary CP declined, lactase and sucrase activities were reduced (P < 0.01) in the proximal jejunum. In conclusion, reducing CP concentration from 23.1 to 17.2% led to decreased growth performance associated with morphological changes of the gut and reduced disaccharidase activities in the small intestine. But reducing dietary CP from 23.1 to 18.9% did not affect intestinal morphology and disaccharidase activities.  相似文献   

20.
The aim of this work was to evaluate the influence of a coarse ground cereal and two fibrous ingredients incorporated in the diet on the physicochemical properties of digesta and productive parameters of pigs during the first stage of the growing period. A total of 96 pigs (initial body weight, BW, 15 kg) were distributed into four experimental treatments: the control diet (CT) consisted of corn, barley and soybean meal milled to pass through a 2.5 mm screen; the coarse corn diet (CC) was prepared by milling the corn to a coarser particle size (4.0 mm screen); the sugar beet pulp diet (SBP) and the wheat bran diet (WB) were prepared by replacing some of the corn for sugar beet pulp (80 g/kg) or wheat bran (100 g/kg) respectively, in order to contain a higher amount of non-starch polysaccharides (NSP). Three experimental periods were considered (7, 21 and 42 days) during which body weight (BW) and voluntary feed intake were assessed. At the end of each period eight animals per diet were slaughtered. Weight of the gastrointestinal tract and its compartments (full and empty) was recorded and the contents were sampled. Digesta samples were analysed for water concentration, water retention capacity (WRC), ammonia and short-chain fatty acids concentration (SCFA). Histological study of the proximal colon tissues was also performed. In general, the different parameters evaluated showed differences between the experimental periods, but few interactions were recorded. Animals fed CC, SBP and WB diets presented a lower feed intake (P ≤ 0.009) compared to CT fed animals. Compared to the control diet, coarse grinding of corn provoked an increase in the colonic digesta content (P = 0.032). Similarly, animals fed the SBP diet compared to CT animals, showed an increase in the contents (P = 0.009) of hindgut, and in the concentration of water in the digesta (P ≤ 0.011). Compared to CT diet the SBP diet lowered the ammonia concentration in the hindgut contents (P ≤ 0.045) and increased the concentration of SCFA in the distal colon (P ≤ 0.025). Animals fed the SBP diet also showed a lower number of lymphoid nodes in the colonic mucosa compared to the other diets (P ≤ 0.043). Minor modifications were observed associated with the incorporation of wheat bran in the diet, but colonic water from WB fed animals showed a tendency to increase cytolytic capacity. The results confirm major changes in the voluntary intake and physicochemical properties of digesta as affected by the incorporation in the diet of a fibrous ingredient or coarse grinding of cereals.  相似文献   

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