2. Broiler chickens were given, either ad libitum or intermittently, a phosphorus deficient pelleted diet containing either coarsely or finely ground oat hulls and either no enzyme or a phytase added from 10 d of age, in a 2 × 2 × 2 factorial arrangement. Ad libitum feeding consisted of continuous access to feed in a room with 18 h of light and 6 h of complete darkness, whereas birds on intermittent feeding had restricted access to feed from 7 d of age, with 4 1-h feeding bouts/d and one 2-h feeding bout/d from d 14.
3. Performance, characteristics of the anterior digestive tract and phosphorus retention were assessed in experiment 1, while in experiment 2, birds were observed during 4-h periods to quantify different behaviours.
4. Intermittent feeding and phytase improved performance, but intermittent feeding did not improve the efficacy of the enzyme added. Ad libitum fed broiler chickens ate and drank on average twice per hour, and spent close to three-quarters of their time resting. Apart from an increased standing and feed searching activity for intermittently fed birds compared to ad libitum fed birds during the last hour before feed was presented, no differences in activity was detected.
5. It was concluded that broiler chickens quickly adapt to intermittent feeding without reduction in final body weight and with improvements in feed efficiency, but without improving the efficacy of dietary phytase. Only small changes occur in the behaviour of intermittently fed birds compared to ad libitum fed birds. 相似文献
2. A total of 320-d-old chicks (Ross 308, average BW 44.0 ± 3.4 g) were randomly allotted to 4 dietary treatments on the basis of initial body weight (BW). The dietary treatments were negative control (NC; basal diet), positive control (PC; basal diet + 15 mg avilamycin/kg diet) and AMP-A3 (basal diet supplemented with 60 or 90 mg/kg AMP-A3). The NC diet was considered as 0 mg/kg AMP-A3 treatment. Experimental diets were given in two phases: starter phase (d 0–21) and finisher phase (d 22–35).
3. The overall BW gain and retention of dry matter (DM), gross energy (GE; d 19–21) and crude protein (CP; d 19–21 and d 33–35) were greater in birds fed on the PC and 90 mg/kg AMP-A3 diets than in birds fed on the NC diet. Also, an increase in dietary AMP-A3 linearly improved BW gain and retention of DM, GE (d 19–21) and CP (d 19–21 and d 33–35).
4. Birds fed on the PC and 90 mg/kg AMP-A3 diets had fewer excreta coliforms (d 21 and d 35), total anaerobic bacteria (TAB) and Clostridium spp. (d 35) and ileum and caecum coliforms (d 35) than birds fed on the NC diet. In addition, birds fed on the diet supplemented with increasing levels of AMP-A3 had linearly reduced excreta TAB (d 35), Clostridium spp. and coliforms (d 21 and d 35) and ileum and caecum coliforms (d 35).
5. Birds fed on the PC and 90 mg/kg AMP-A3 diets had greater villus height of the duodenum, jejunum and ileum than birds fed on the NC diet. Moreover, birds fed on increasing levels of AMP-A3 diet had increased (linear) villus height of the duodenum, jejunum and ileum.
6. These results indicate that 90 mg/kg AMP-A3 has the potential to improve growth performance, nutrient retention and intestinal morphology and to reduce harmful microorganisms in broilers and can be used as a potential antimicrobial growth promoter. 相似文献
2. The first study was a 3 × 2 factorial experiment, with 3 dietary treatments (control (CON), CON + DFM and CON + antibiotic growth promoter) with and without challenge. Chicks were fed experimental diets from 1 to 28 d, while the challenge was provided by vaccinating with 10 times the normal dose of commercial coccidial vaccine on d 9. In a second experiment, two groups of 1 d-old broilers, housed on built-up litter (uncleaned from two previous flocks), were fed the same CON and CON + DFM diets from 1 to 21 d.
3. The challenge in the first experiment reduced performance, but no differences were observed among dietary treatments from 8 to 28 d. The challenge reduced the ileal epithelial flux for D-glucose, L-lysine, DL-methionine and phosphorus on d 21. Epithelial flux for D-glucose, L-lysine and DL-methionine were increased by DFM. Ileal trans-epithelial electrical resistance (TER) was increased in challenged broilers fed DFM, although this was not observed in unchallenged birds as indicated by a significant interaction.
4. Ileal mucin mRNA expression and colon TER were increased, and colon endotoxin permeability was reduced by DFM on d 21 in the second experiment.
5. It was concluded that the addition of DFM in the diet improved the intestinal integrity of broiler chickens raised under experimental conditions designed to provide increased intestinal microbial challenge. 相似文献
2. A total of 192 broiler chickens were randomly assigned to 4 groups: an uninfected control group and three groups inoculated with either 1 × 102, 1 × 104 or 1 × 105 sporulated oocysts of E. acervulina by gavaging at 21 d. There were 4 replicate pens (2 male and 2 female) per group.
3. Plasma xanthophyll (PX) and skin yellowness (SY) were measured in live birds weekly. At 42 d of age, SY was measured in the breast and abdomen after chilling and in the breast 24 h post-processing on refrigerated carcasses.
4. In general, in all challenged treatments, and for the duration of the study, the average PX decreased by 0.02 μg/ml (R2 = 61.6%) for every 1000 inoculated oocysts, whereas PX increased by 1.26 μg/ml/d in uninfected birds.
5. The average SY in live birds from 21 to 42 d of age decreased by 0.019 b*/every 1000 oocysts administered, while SY of uninfected controls increased by 0.57 b*/d. It was also noted that in all treatments females had a greater SY (6.17 b*) than males for the duration of the study. The SY of the breast and abdomen was correlated (r = 0.76) in chilled carcasses. Breast SY in 24 h refrigerated carcasses was greater in the control group and for female birds.
6. Oocyst excretion was different between inoculated treatments only on 7 d post-inoculation (PI). Coccidia lesion scores in the duodenum averaged 1+ in infected birds and 2+ in birds given the highest oocyst dose. 相似文献
2. One-day-old broiler chicks were randomly distributed into 24 cages (6 replicate cages; 8 birds/cage) and were inoculated with 0 or 1 mg/kg body weight E. coli-LPS (d 4 and 9) and 0 or 500 mg YCW/kg feed, resulting in a 2 × 2 factorial arrangement of treatments. Experimental diets did not include coccidiostats, in-feed antibiotics or enzymes.
3. On d 21, the inoculation of E. coli-LPS reduced weight gain and feed intake and increased feed conversion ratio (FCR) of birds, an effect maintained until 28 d. In contrast, chickens given diets with YCW improved the FCR at both 21 and 28 d of age.
4. E. coli-LPS challenge reduced the relative weight of bursa of Fabricius, except when chickens were given YCW, which resulted in an interaction. Supplementation of broiler diets with YCW exacerbated the cellular immune response as measured by the delayed cutaneous hypersensitivity response test.
5. The results of this study suggested a benefit on feed efficiency when YCW was added to diets fed to broiler chickens challenged with E. coli-LPS. Part of the mode of action of YCW might be related to better maintenance of immune status in response to microbial challenge. 相似文献
2. In Trial 1, 7-d-old broilers were placed 4 per cage in 48 cages and fed either ad libitum or intermittently on a diet with 50 g/kg of either oat hulls or cellulose, with or without 1000 FTU phytase, in a 2 × 2 × 2 factorial arrangement. Ad libitum fed birds had two 4-h dark periods with 1-h light in between, while intermittently fed birds in addition had restricted access to feed through four 1 h feeding bouts.
3. In Trial 2, 144 broiler chickens were divided amongst 12 pens which were intermittently fed on the same diets as in Trial 1 in a 2 × 2 factorial arrangement. At 34 d of age, after 16 h feed withdrawal, birds were fed for 1 h, followed by dissection of 4 birds per treatment every hour for 9 h. Contents from different segments of the digestive tract were collected quantitatively to assess dry matter (DM) and starch flow.
4. In Trial 1, phytase improved performance and nutrient availability, while oat hulls and intermittent feeding improved some measures of nutrient availability. Intermittent feeding augmented the effect of phytase on myo-inositol hexakisphosphate (IP6) degradation in the anterior digestive tract.
5. In Trial 2, birds filled up their crop and slowly passed these contents on to lower segments of the digestive tract. Already 1 h after commencement of feeding, the entire length of the small intestine was filled with DM, and no significant changes in DM content were observed before 4–5 h later, when the small intestine gradually became emptied. The tendency for a higher initial load of DM and starch in birds without oat hulls seems to support the hypothesis that one important function of the gizzard is feed-flow regulation.
6. In conclusion, the anterior digestive tract seems to have an important regulative function in broiler chickens when stimulated by intermittent feeding or structural components. More research is needed in order to elucidate the role of the crop and gizzard for phytase function. 相似文献
2. Treatments consisted of two cereals (maize- or wheat-based diets) and three levels of SKEO)0, 250 and 500 mg/kg).
3. Feed intake (FI) and body weight gain (BWG) decreased in broilers fed on the wheat-based diets compared to the control diet. Dietary supplementation of 500 mg/kg SKEO increased FI and BWG. Dietary SKEO supplementation was effective in improving FI and BWG only in wheat-based diets and was effective in improving feed conversion ratio (FCR) in both diets.
4. Dietary supplementation of 500 mg/kg SKEO caused a significant decrease in plasma cholesterol and triglycerides. Also, plasma low-density lipoprotein concentration was decreased in broilers fed on 250 and 500 mg/kg of SKEO. Plasma cholesterol levels in birds fed on the wheat-based diets were lower than in those fed on maize-based diets.
5. Dietary supplementation of 500 mg/kg SKEO increased caecal population of Lactobacillus and reduced total bacterial and Escherichia coli count. Caecal population of Lactobacillus decreased in broilers fed on the wheat-based diets.
6. Digesta viscosity was increased in broilers fed on the wheat-based diets and decreased in broilers fed on 500 mg/kg SKEO compared to the control diet. Dietary SKEO supplementation was effective in reducing digesta viscosity values only in wheat-based diets.
7. Villus height of the duodenum and jejunum decreased in broilers fed on the wheat-based diets. Dietary supplementation of 500 mg/kg SKEO increased villus height and villus height-to-crypt depth ratios and decreased crypt depth of the duodenum compared to the control diet.
8. It can be concluded that dietary SKEO supplementation was effective in improving FI, BWG and FCR values in wheat-based diets. 相似文献
2. In each group of birds the concentration of plasma GH was inversely related to age. The mean prolactin concentration was highest in the youngest (20‐d‐old) birds.
3. The concentration of plasma GH in the intermittently‐fed birds deprived of food for 24 h (depleted birds) was significantly higher than that in the controls at 33, 56 and 83 d of age. The mean GH concentration in the intermittently‐fed birds 24 h after refeeding (repleted birds) was less than that in the depleted ones.
4. The overall mean concentration of plasma prolactin in the depleted birds was significantly less than that in the control and repleted birds.
5. These results are consistent with the effects of fasting on GH and prolactin secretion and demonstrate that growth retardation in the intermittently‐fed birds was not due to impaired GH secretion. 相似文献
2. A 4 × 4 × 4 factorial design (batch × device × bird type + age) was employed. Ten bird cadavers per bird type and age were tested with each of the 4 devices (N = 160 birds). All cadavers were examined post-mortem to establish the anatomical damage caused.
3. NMCD, MARM and MZIN demonstrated killing potential, as well as consistency in their anatomical effects. NMCD had the highest killing potential, with 100% of birds sustaining the required physical trauma to have caused rapid death.
4. The MPLI was inconsistent, and only performed optimally for 27.5% of birds. Severe crushing injury was seen in >50% of MPLI birds, suggesting that birds would die of asphyxia rather than cerebral ischaemia, a major welfare concern. As a result, the MPLI are not recommended as a humane on-farm killing device for chickens.
5. This experiment provides important data on the killing potential of untried novel percussive and mechanical cervical dislocation methods, informing future studies. 相似文献
2. From d 1 to 21 (starter phase), an equivalent number of birds were fed either a normal protein (NP) diet or a LP diet fortified with Gly. From d 22 to 42 (grower phase), an equivalent number of birds from each starter diet were distributed to one of the following dietary groups: (i) an NP diet during the starter and grower phases (NPNP), (ii) an NP diet during the starter phase and a LP diet during the grower phase (NPLP), (iii) an LP diet during the starter phase and an NP diet during the grower phase (LPNP) or (iv) LP diets during both phases (LPLP).
3. Commencing from d 22, an equivalent number of birds from each dietary group were exposed to (i) 23 ± 1°C throughout (unheated), (ii) 34 ± 1°C for 7 h each day from 10:00 to 17:00 (cyclic heat) or (iii) 34 ± 1°C throughout (constant heat).
4. Feeding the LP diet during the starter phase resulted in feed intake (FI), weight gain (WG), feed conversion ratios (FCR) and energy efficiency ratios (EER) similar to those for the NP diet. The birds fed the LP diet had a significantly higher protein efficiency ratio (PER) compared with the birds fed the NP diet.
5. During the grower phase, there were significant diet × temperature interactions for F, WG, FCR, PER, EER, villus height, crypt depth and caecal Clostridia. The birds fed the NPLP and LPLP diets had lower FI, WG and EER, higher FCR, shorter villus height and crypt depth and higher caecal Clostridia compared with the birds fed LPNP and NPNP diets under constant heat stress. However, feeding birds the NPLP and LPLP diets resulted in FI, WG, EER, FCR, morphology parameters and caecal Clostridia equivalent to the birds fed LPNP and NPNP diets, as well as improved PER, under unheated and cyclic heat stress conditions.
6. In conclusion, our results indicate that Gly-fortified LP diets can be fed to broilers under normal and acute heat stress environmental conditions without any adverse effects on performance. However, the use of such LP diets can be detrimental to broilers under chronic heat stress conditions. 相似文献
2. Treatments established were (1) birds fed 8% tallow from 21 to 49 d (TTT); (2) birds fed 8% tallow from 21 to 37 d and 8% sunflower oil from d 38 to 49 (TSS); (3) birds fed 8% sunflower oil from 21 to 37 d and 8% tallow from d 38 to 49 (STT); (4) birds fed 8% sunflower oil from 21 to 41 d and 8% tallow from d 42 to 49 (SST); (5) birds fed 8% sunflower oil from 21 to 49 d (SSS). Birds from each group were slaughtered on d 21, 29, 38, 40, 42, 44, 46 and 49.
3. The polyunsaturated fatty acids (PUFAs) proportion in the SSS group reached maximum values at d 40 and fitted a quadratic response. This group also showed a decrease in saturated fatty acids (SATs) and monounsaturated fatty acids (MUFAs) of lower intensity than the PUFA increase. The highest synthesis of SAT + MUFA was found in the SSS and TSS groups, whereas these had the lowest body-to-dietary PUFA ratio.
4. A high and quadratic increase in the MUFA proportion was observed during the first 10 d of feeding with the tallow-enriched diet at the expenses of the proportion of PUFA that quadratically decreased (minimum values at d 38).
5. Lipogenic and desaturation capacity decreased with age.
6. The TSS group increased tissue PUFA content faster that the SST group decreased PUFA content after the change in diet which indicates that the earlier feeding has to be taken into consideration for obtaining higher or lower changes in quality parameters.
7. The melting point of the SSS group showed a lower response to the dietary treatment in the initial period when compared to the TTT treatment.
8. The TTT, STT, SST and TSS groups showed similar fat accumulation, and changes in lipid oxidation were related to the day of dietary sunflower oil supplementation.
9. Based on the results, it would be possible to determine the most appropriate dietary programme and optimum slaughter age to obtain chicken meat with the desired quality characteristics. 相似文献
2. Body weight (BW), feed intake (FI) and mortality records were collected. Two birds per replicate were killed at 24 d of age to obtain tibia samples.
3. Increasing Ca level significantly reduced the FI and body weight gain (BWG) between hatch and 10 and 24 d, especially with the phytase-supplemented diets. However, phytase supplementation of the diet containing 4 g NPP/kg improved the FI and BWG at d 10 and 24. At d 24, phytase supplementation improved feed conversion ratio (FCR) of birds that consumed diets containing high NPP. The overall FCR was better in birds offered the phytase-supplemented, medium-Ca diet.
4. There was a significant reduction in length, width and breaking strength of the tibia bone in birds fed on a diet with high Ca and low NPP. Phytase supplementation improved the tibia ash content and bone breaking strength of chicks fed on the diet containing 8 and 4 g/kg Ca and NPP, respectively. The Ca content of the tibia bone was low in birds fed on diets with 6 and 4 g/kg Ca and NPP, respectively, but this was counteracted by phytase supplementation.
5. Birds fed on diets with 4 g/kg NPP had the best carcass percentage and parts yield. Phytase supplementation to high-Ca diets significantly reduced the carcass yield of birds.
6. These results confirmed the detrimental effect of high dietary Ca on phytase activity and subsequent growth and bone development of birds, especially when NPP is in short supply. 相似文献
2. A low-crude protein (CP) diet was formulated to meet the requirements of all amino acids (AA) supplied by the control diet except for Val, Ile, Arg and Gly. The other experimental diets were obtained by the isolated or combined supplementation of the studied AA in the low-CP diet.
3. Growth, serum parameters and litter characteristics were taken in both of the experiments. Carcass measurements were taken in Experiment 2.
4. In the starter and grower phases, low-CP diets without supplementation resulted in birds with a poorer weight gain and feed conversion than those of the birds that received the control diet.
5. In the starter phase, individual supplementation with Val and Gly, but not Ile and Arg, restored the weight gain of the birds, while diets with the addition of Val + Gly, Val + Ile + Arg, Val + Ile + Gly and Val + Ile + Arg + Gly restored their feed conversion.
6. In the grower phase, weight gain was re-established at the same rate as the control diet for the diets supplemented with Val + Ile, Val + Ile + Arg, Val + Ile + Gly and Val + Ile + Arg + Gly. However, the feed conversion was restored only in birds that received the diet supplemented with all studied AA.
7. The supplementation of Val and Gly in low-CP diets was sufficient to avoid adverse effects in the performance and serum parameters of broilers in the starter phase. However, birds in the grower phase required the combined supplementation of Val, Ile, Arg and Gly, to prevent compromised performance. 相似文献
2. A total of 240 one-d-old male White Pekin ducks were allotted to 5 experimental treatments and each treatment contained 6 replicate pens with 8 ducks per pen. Ducks were reared in raised wire-floor pens from hatch to 21 d of age. At 21 d of age, growth performance and intestinal morphology were determined.
3. The weight gain and feed intake of Pekin ducks increased and feed/gain of these birds decreased linearly or quadratically as dietary threonine increased from 5.0 to 8.2 g threonine/kg. Compared to ducks fed on diets containing 5.0 g threonine/kg, ducks given diets containing 7.4 g threonine/kg had higher villus height in duodenum, jejunum and ileum.
4. The threonine requirements for weight gain of White Pekin ducks from hatch to 21 d of age was estimated to be 6.72 g/kg when dietary crude protein concentration was 189.8 g/kg and threonine supply was critical for maintaining intestinal structure of these birds. 相似文献
2. The results showed that Zn-Met improved the growth performance of squabs. The average daily and average weekly weight gain was significantly greater in squabs treated with Zn-Met than in the control group.
3. The group given 2 and 10 mg supplemental Zn-Met had heavier thymus, spleen and bursa of Fabricius than the control group at d 28.
4. Maternal antibody titres against Newcastle disease haemagglutination inhibition and alpha-naphthyl acetate esterase were significantly higher in squabs treated with supplemental 2 and 10 mg Zn-Met compared to the control group at d 14 and d 28.
5. Additionally, the squabs given supplemental 2 mg Zn-Met exhibited significantly higher Bacillaceae, Lactobacillus, Enterococcus and Bifidobacterium populations at d 14 and d 28, but lower Escherichia coli populations at d 28 compared to the control group. On the contrary, Lactobacillus, Enterococcus and Bifidobacterium populations were significantly decreased with 10 mg Zn-Met at d 28.
6. This study indicates that supplementation with Zn-Met has a positive effect on growth performance, immune function and regulation of intestinal flora in pigeons. An inclusion level of 2 mg seems to be better than 10 mg Zn-Met per day per bird. 相似文献
2. Phytase supplemented to mid-Fe diets increased feed consumption more than the non-supplemented diet at d 24. From hatch to d 35, Fe × phytase interaction significantly influenced the feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR). The high-Fe diet supplemented with phytase significantly reduced FI and BWG of broilers than those supplemented with low- or mid-Fe diets. The overall FCR was significantly better in birds fed on the mid-Fe diets with phytase supplementation.
3. A significant improvement in ileal digestibility of N, P, Mg and Fe was observed in birds feed diets containing 60 mg Fe/kg, with significant interaction between Fe and phytase.
4. Phytase improved the bone breaking strength when supplemented to low- or mid-Fe diets, compared to the non-supplemented diets. There was a significant Fe × phytase interaction effect. Tibia Fe content was higher in birds fed on phytase-free diets with high Fe but the reverse was the case when phytase was added and their interaction was significant. High dietary Fe significantly increased the accumulation of Fe in liver.
5. Phytase improved Ca-Mg-ATPase, Ca-ATPase and Mg-ATPase activities in jejunum when supplemented to the diet containing 80 mg Fe/kg.
6. This study indicates that high (100 mg/kg) dietary Fe inhibited phytase efficacy and subsequently reduced the overall performance and nutrient utilisation of broilers. 相似文献
2. CSM was fermented with Bacillus subtilis, Aspergillus niger and A. oryzae for 7 d. A total of 300 one-d-old male Ross 308 broiler chickens were used in a 42-d experiment in which the birds were randomly allotted to one of 5 dietary treatments (containing 0%, 10% and 20% CSM or FCSM) in a completely randomised design. Birds were reared on litter floor and had free access to feed and water during the experiment.
3. Results indicated that the fermentation process significantly reduced crude fibre and free gossypol, while it increased crude protein content and lactic acid bacteria (LAB) count in CSM.
4. The use of FCSM instead of CSM significantly improved growth performance of broilers. The abdominal fat yield in treatments containing FCSM was significantly lower than in the other treatments. The increase in the population of LAB in the crop and decrease in the population of coliforms in the ileum of birds fed on diets containing FCSM were more significant than in other birds. Villi in the duodenum and jejunum of the birds fed on diets containing FCSM were significantly higher than for the other experimental groups.
5. The positive effects of diets containing FCSM on growth performance and intestinal health of broiler chickens showed that this processed source of protein can serve as an appropriate alternative for SBM in diets for broiler chickens. 相似文献
2. A 2 × 3 × 2 factorial experiment consisted of a positive control diet with adequate Ca and a negative control diet (Ca concentration reduced by 30%), three concentrations of WS (0, 75 and 150 mg/kg diet), and two concentrations of 1, 25 (OH)2 D3 (0 and 0.5 μg/kg diet).
3. A total of 600 male one-d-old Ross 308 broiler chicks were randomly distributed into 60 floor pens, with 10 birds each. Each treatment was replicated 5 times (50 birds). Diets were given ad libitum from one to 42 d of age. On d 21 and 42, one bird per replicate was killed and tibiae were removed.
4. Dietary treatments did not affect feed intake and feed conversion. The maximum body weight gain (2475 g) was noted in birds fed on a diet adequate in Ca and supplemented with 75 mg/kg WS.
5. The Ca and P retentions were significantly higher in birds that were given a diet with 30% less Ca. Supplementation of 150 mg/kg WS significantly improved Ca retention in birds receiving a negative control compared to those given a positive control diet (83.0% vs. 66.3%). Ca retention was significantly improved with the addition of 0.5 μg/kg 1, 25 (OH)2 D3 to the diet containing 75 mg/kg WS, regardless of dietary Ca concentration (79.5 vs. 73.3 and 77.9 vs. 68.9).
6. On d 21, birds that received WS had significantly higher tibia Ca compared to those of controls. No significant effects on tibia Ca were noted at 42 d. Birds given a negative control diet supplemented with 75 mg/kg WS and 0.5 μg/kg 1, 25 (OH)2 D3 displayed a similar tibia Ca compared to those given only 150 mg/kg WS. Dietary supplementation of 1, 25 (OH)2 D3 significantly increased tibia Ca and tibial mineralised zone width in birds at 42 d of age.
7. Tibia shear force and stiffness were significantly increased by supplementation of WS. Administration of 1, 25 (OH)2 D3 resulted in a significantly lower width of the proliferative zone at 21 d of age. Reduction of the Ca supply significantly reduced the mineralised zone and cortical thickness at this age.
8. The present study showed that WS supplementation improved Ca retention, bone calcification and mechanical properties with no adverse effects on performance. Also, synergistic effects of WS and 1, 25 (OH)2 D3 were observed on Ca retention and bone calcification. 相似文献
2. A total of 160 Hy-Line Brown layers (45 weeks old) were randomly assigned into 4 treatments on the basis of laying performance. Each treatment had 4 replicates with 10 birds each.
3. Dietary treatments were basal diet supplemented with 0 (control), 2.5, 5.0 and 7.5 g/kg diet G. procumbens during 56-d feeding period.
4. Serum (d 21, 42 and 56) and egg yolk (d 28, 42 and 56) cholesterol and triglycerides concentrations were linearly reduced with increasing dietary concentrations of G. procumbens.
5. Increasing dietary concentrations of G. procumbens linearly reduced the excreta total anaerobic bacteria (d 28), Clostridium sp. and Escherichia coli (d 28 and 56) populations.
6. Overall egg production and egg mass were linearly increased, and overall feed efficiency was linearly improved with increase in dietary G. procumbens.
7. Dietary increasing concentrations of G. procumbens linearly improved egg yolk colour (d 28 and 56) and breaking strength of eggs (d 56).
8. The results obtained in the present experiment indicate that dietary supplementation with G. procumbens could reduce the egg yolk cholesterol, suppresses harmful excreta microflora and improves layers performance. 相似文献
2. Two treatments were used in this study: control (C) and C + 0.5 g/kg extract of Siberian Larch (Larix sibirica) per kg feed, containing 85% DHQ. The diets were fed over 2 feeding phases, a grower phase from 7 to 28 d of age and a finisher phase from 28 to 35 d of age. The birds were reared under the breeder’s recommended conditions.
3. In general, there were no effects of DHQ on growth performance of broiler chickens. However, the results of this experiment showed that there can be changes in the redness colour of the breast meat when DQH is fed. No negative effects of feeding DHQ at 0.5 g/kg diet were observed in this study.
4. Supplementation of poultry diets with DHQ under standard industry-rearing conditions did not improve the performance or any of the studied variables, except an increase of redness index of the breast fillets. Feeding DHQ at different doses and/or under more challenging conditions, e.g. heat stress, may, however, bring positive responses. 相似文献