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1.
The experiment was conducted to investigate the influence of different levels of zinc (Zn) on cashmere growth, plasma testosterone and Zn profile in male Cashmere goats. Twenty‐eight male Liaoning Cashmere goats, 3 years old and body weight at 56.2 ± 2.45 kg, were assigned to four groups. The animals were fed a basal diet containing of 45.9 mg Zn/kg dry matter (DM) basis and supplemented with 0, 20, 40 or 80 mg Zn (reagent grade ZnSO4·7H2O) per kg DM for 90 days. There was no significant effect on growth and diameter of cashmere fibre for Zn supplemented in diets. However, the length and growth rate of wool were improved (p < 0.05) with dietary Zn. The length and growth rate of wool were higher (p < 0.05) for the groups supplemented with 40 or 80 mg Zn/kg DM compared with that of 20 mg Zn/kg DM treatment group. Plasma testosterone concentration was increased for Zn supplemented in diets, and the testosterone concentration was higher (p < 0.05) in goats fed on the diet supplemented with 40 or 80 mg Zn/kg DM compared with those fed on basal diet. Plasma Zn concentrations increased (p < 0.05) with increasing dietary Zn and supplemented with 40 and 80 mg Zn/kg DM groups improved plasma Zn concentration (p < 0.05) more than 20 mg Zn/kg DM group. Fibre Zn content was higher (p < 0.05) in groups supplemented with 40 or 80 mg Zn/kg DM compared with control group, but no difference between Zn‐supplemented groups (p > 0.05). The activity of plasma alkaline phosphatase was increased (p < 0.05) due to dietary Zn supplementation; however, no difference was found between supplemented treatment groups (p > 0.05). In conclusion, Zn content (45.9 mg Zn/kg DM) in control diet was insufficient for optimal wool growth performance, and we recommended the level of dietary Zn for such goats is 86 mg/kg DM during the breeding season and cashmere fibre growing period.  相似文献   

2.
Two experiments were conducted on sheep to determine the effect of dietary supplementation with zinc and a medicinal plant mixture on haematological parameters and microbial activity in the rumen and large intestine. In Experiment 1, 24 male lambs were randomly divided into four groups: One group was fed an unsupplemented basal diet (control), and three groups were fed a diet supplemented with 70 mg Zn/kg diet in the form of Zn sulphate (ZnSO4), a Zn‐chelate of glycine hydrate (Zn‐Gly) or a Zn‐proteinate (Zn‐Pro), for five months. The ruminal content was collected separately from each lamb, and batch cultures of ruminal fluid were incubated in vitro with mixture of medicinal plants (Mix) with different roughage:concentrate ratios (800:200 and 400:600, w/w). Bioactive compounds in Mix were quantified by UPLC/MS/MS. In Experiment 2, four sheep were fed a diet consisting of meadow hay and barley grain (400:600, w/w), with Zn‐Gly (70 mg Zn/kg diet), Mix (10% replacement of meadow hay) or Zn‐Gly and Mix (Zn‐Gly‐Mix) as supplements in a Latin square design. Mix decreased total gas (p < 0.001) and methane (p < 0.01) production in vitro. In Experiment 1, caecal isobutyrate and isovalerate concentrations varied among the dietary treatments (p < 0.01). The isovalerate concentration of the zinc‐supplemented groups in the distal colon was higher (p < 0.001) compared with the control. In Experiment 2, the molar proportion of isobutyrate was the highest in the faeces of the sheep fed the diet with Zn‐Gly‐Mix (p < 0.01). The plasma zinc concentration was higher in the groups fed a diet supplemented with zinc (p < 0.001). The haematological profile and antioxidant status did not differ between the dietary groups (p > 0.05). The diets containing medicinal plants and organic zinc thus helped to modulate the characteristics of fermentation in ruminants.  相似文献   

3.
The interaction effect of whole wheat feeding and mannanoligosaccharides supplementation on growth performance, haematological indices and caecal microbiota of cockerel chicks were investigated using 250‐day‐old cockerel chicks previously reared for 7 days pre‐experimental period. Birds were fed with commercial chick mash during the pre‐experimental period. At the expiration of this period, 192 chicks were selected on weight equalization basis and assigned into 24 pens. Each treatment consisted of six pens, while each pen housed eight birds. Four wheat–soya bean‐based experimental diets were formulated in a 2 × 2 factorial arrangement of diets having two wheat forms (ground and whole wheat grain) each supplemented or not with 1 g/kg MOS/kg feed. Whole wheat feeding (irrespective of MOS supplementation) showed reduced (p < 0.05) feed intake. Birds fed whole wheat diet supplemented with MOS recorded the highest (p < 0.01) final live weight, weight gain and the best (p < 0.05) feed conversion ratio. Haemoglobin concentration, packed cell volume and red blood cell count of the chicks were not affected (p > 0.05) by dietary treatment. However, dietary supplementation with MOS resulted in increased (p < 0.05) WBC counts. The caecum content of chicks fed with MOS‐supplemented whole wheat diets recorded the least (p < 0.01) salmonella counts. In conclusion, combination of whole wheat feeding and MOS supplementation showed improved growth performance, gut microbiota and indications of improved health status of cockerel chicks.  相似文献   

4.
This study aimed to determine the effect of different dietary levels of a Chlorella by‐product (CBP) on the growth performance, immune response, intestinal microflora and intestinal mucosal morphology of broilers. In total, 480 one‐day‐old broiler chickens were randomly allotted to four dietary treatments with four replicated pens consisting of 30 chicks. The basal diet was formulated to be adequate in energy and nutrients. Three additional diets were prepared by supplementing 25, 50 or 75 g/kg of CBP to the basal diet. The diets were fed to the broilers ad libitum for 35 days. Result indicated that increasing inclusion level of CBP improved BW gain (linear, p < 0.05). There was no effect of inclusion level of CBP in diets on total cholesterol, triglyceride, aspartate aminotransferase and alanine aminotransferase levels during the 35 days. Plasma IgG, IgM and IgA concentrations increased (linear, p < 0.05) with inclusion level of CBP in diets. Supplementation of CBP in the diets increased (linear, p < 0.05) the concentrations of Lactobacillus in the caecal content and decreased (linear, p < 0.05) the concentrations of Escherichia coli and Salmonella in the caecal content. Villus height increased (linear and quadratic, p < 0.05) with inclusion level of CBP in diets. Crypt depth increased (quadratic, p < 0.05) with inclusion level of CBP, and a decreased villus height: crypt depth ratio (quadratic, p < 0.05) was observed as inclusion level of CBP in diets increased. The results of the current experiment indicate that dietary supplementation of CBP improves growth performance of birds. Dietary CBP has improving Lactobacillus spp. concentrations in the gastrointestinal tract, plasma immunoglobulin concentrations and intestinal mucosal morphology.  相似文献   

5.
A study with finishing lambs assessed the effect of dietary inclusion of Prosopis laevigata pods (PLPs) on performance, carcass characteristics, meat traits and fatty acid profile of subcutaneous fat. Twenty‐one Rambouillet lambs (27.0 ± 3.0 kg BW) were assigned to one of three experimental diets with 0, 150 and 300 g PLP/kg DM. Evaluation of growth performance lasted 49 days. The experimental design was completely randomized and analysed with a mixed model. Lambs fed diets with 0, 150 and 300 g PLP had similar growth performance. Lambs fed diets with 300 g PLP/kg DM had better (p < 0.05) carcass yield and classification, less (p < 0.05) fat deposition and lower lightness (L*) value (p < 0.05) in meat than lambs fed diets with 0 and 150 g PLP/kg DM. Saturated fatty acids (palmitic and stearic) decreased (p < 0.05) and unsaturated fatty acids (oleic and linoleic) increased (p < 0.05) in subcutaneous fat of lambs fed diets with 150 and 300 g pods as compared with lambs not fed PLP. Prosopis laevigata pods are a safe feedstuff that can replace a third of conventional ingredients and reduce feed costs in growing lambs. Addition of PLP reduced (p < 0.05) total feed cost by 21%.  相似文献   

6.
This study investigated the influence of pre‐pelleting inclusion of whole wheat (WW) and exogenous enzyme supplementation on growth performance, coefficient of apparent ileal nutrient digestibility (CAID) and apparent metabolizable energy (AME) in broilers fed wheat‐based pelleted diets. A 2 × 3 factorial arrangement of treatments was used with two methods of wheat inclusion [622 g/kg ground wheat (GW) and 250 g/kg WW replaced GW (wt/wt) pre‐pelleting (PWW)] and three enzymes (xylanase, phytase and xylanase plus phytase). A total of 288, one‐day‐old male broilers (Ross 308) were individually weighed and allocated to 36 cages (8 broilers/cage), and the cages were randomly assigned to the six dietary treatments. Birds fed PWW diets gained more (p < 0.05) weight than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on feed intake (FI). Phytase alone increased (p < 0.05) FI compared to xylanase or the combination. Whole wheat inclusion increased (p < 0.05) the gain‐to‐feed ratio (G:F). Feeding xylanase plus phytase and phytase‐added diets resulted in the greatest and lowest G:F, respectively, with xylanase supplemented diets being intermediate. Birds fed PWW diets had greater (p < 0.05) relative gizzard weights than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on the CAID of nitrogen (N), starch and fat. Combination of xylanase and phytase resulted in greater (p < 0.05) digestibility of N, starch and fat than that of individual additions. Feeding PWW diets resulted in greater (p < 0.05) AME values than GW diets. Combination of xylanase and phytase increased (p < 0.05) the AME compared to the diets with individual additions of xylanase or phytase. The current results suggest that the influence of pre‐pelleting WW inclusion and exogenous enzymes on nutrient digestibility and broiler performance is not additive.  相似文献   

7.
The response of broiler chickens to 3 levels of sunflower meal and 2 levels of NSP‐ase enzyme combination (with and without) was investigated in 3 × 2 factorial arrangement under complete randomized design (CRD). A total of 240 Hubbard broiler chicks were fed on practical mash diets having 2950 kcal of ME and 21% CP from 1 to 42 days of age. The BW gain was not significantly reduced when 25% SFM was added in the diets during 1 to 42 days of age. Supplementation of NSP‐ase in broiler diets (day 1–42 overall) demonstrated non‐significant differences (p < 0.05) across the treatments in terms of FI and BWG. The difference in feed:gain at 15% or 20% SFM was observed to be non‐significant. Replacement of SBM with SFM or inclusion of SFM at higher level (25%) increased/deteriorated FCR. The addition of exogenous NSP‐ase showed a significant improvement (p < 0.01) in feed:gain. The improvement was clearly demonstrated when SFM was added to the experimental diet at 15% or even 20%. Supplementation of NSP‐ase at the 25% inclusion level could not, however, sustain the beneficial effect, which was possibly due to excessively high dietary CF. No difference was noted across the treatments regarding carcass response. Relative gizzard weight and intestinal weight were observed to be improved in birds consuming higher levels of SFM (p = 0.00). The digestibility of CF was observed to improve when SFM was used at 20% and 25% in the diets. No improvement in the digestibility of CF was observed with NSP‐ase supplementation, which meant other factors were clearly involved. Supplementation of NSP‐ase improved FCR up to 20% SFM. At 25% SFM, no improvement in the digestibility of CF was observed with NSP‐ase supplementation.  相似文献   

8.
Zinc-amino acid complexes for swine   总被引：3，自引：0，他引：3  
Two experiments were conducted to determine the effect of sources of dietary zinc on gain, feed conversion and blood and bone traits of swine. In the first experiment 96 pigs were used in a 28-d study. The pigs were fed diets with no supplemental Zn or with either 9 or 12 ppm supplemental Zn from zinc sulfate (ZnSO4), zinc methionine (ZnMet) or zinc methionine with picolinic acid (ZnMet w/PA), each with or without 5% added corn oil. There were differences (P less than .05) in average daily gain (ADG) and average daily feed intake (ADFI) between the pigs fed the two organic Zn sources, with those fed ZnMet w/PA showing the better gains and feed conversion. However, neither organic Zn source resulted in pig performance that was different from either the diet with no supplemental Zn or the diets supplemented with Zn from ZnSO4. In the second experiment the same dietary Zn sources and treatments were fed as in Exp. 1 except that corn oil was deleted as a variable. No differences in ADG, ADFI, feed/gain (F/G) or in changes in serum Zn or Cu were observed among treatments during either the 21-d nursery or the 56-d growing periods. During the subsequent 56-d finishing period ADG and ADFI were greater (P less than .01) for pigs fed the Zn-supplemented diets than for those fed the diets without supplemental Zn. There were no differences among treatments in F/G during the finishing period. Zn content of bone ash was lower (P less than .01) in the non-Zn-supplemented pigs. These data suggest that the Zn sources used are of similar biological value and do not support the theory that picolinic acid aids Zn absorption.  相似文献   

9.
Growth, apparent nutrient digestibility, ileal digesta viscosity, and energy metabolizability of growing turkeys fed diets containing malted sorghum sprouts (MSP) supplemented with enzyme or yeast were investigated using 120, 28‐day‐old male turkeys. Six treatments were laid out in a 3 × 2 factorial arrangement of treatments with three dietary inclusion levels of MSP (0, 50, and 100 g/kg) and supplemented with 200 mg/kg yeast (Saccharomyces cerevisiae) or 200 mg/kg of a commercial enzyme. The experiment lasted for the starter (day 28–56) and grower phases (day 57–84) of the birds. Each treatment group consisted of 20 turkeys replicated four times with five birds each. Data were analysed using analysis of variance while polynomial contrast was used to determine the trends (linear and quadratic) of MSP inclusion levels. Irrespective of dietary supplementation with enzyme or yeast, final body weight (BW), total BW gain, and feed intake for turkey poults from day 29–56 was reduced (p < 0.05) with increasing inclusion level of MSP. Dietary supplementation with yeast resulted in increased (p < 0.05) feed intake while enzyme supplementation improved (p < 0.05) feed conversion ratio of the poults. Turkeys fed enzyme‐supplemented MSP diets had higher (p < 0.05) BW gain than their counterparts fed yeast‐supplemented MSP diets. Apparent ash digestibility reduced linearly (p < 0.05) with increasing inclusion levels of MSP. Apparent metabolizable energy (AME) did not vary significantly (p > 0.05) with MSP inclusion levels . Enzyme supplementation reduced (p < 0.05) ileal viscosity but had no effect (p > 0.05) on AME. Inclusion of MSP resulted in poor growth performance. This confirms earlier studies that utilization of MSP by poultry is rather poor. Supplementation with enzyme or yeast did not lead to any appreciable improvement in performance of turkeys in this study.  相似文献   

10.
The bioavailability of trace elements in fishmeal diets is influenced by their chemical forms and dietary anti‐nutritional factors. In formulated fish feed, supplemented organically bound minerals may be more bioavailable than inorganic minerals. A 10‐week feeding trial was undertaken with rainbow trout (Oncorhynchus mykiss) to determine whether the inclusion of organically bound selenium (Se) and zinc (Zn) improved uptake and assimilation of these elements compared to commonly used inorganic forms. The three diets tested included a control diet, no added Zn or Se; an organic Se‐yeast and Zn‐proteinate supplemented diet; and an inorganic sodium selenite and Zn‐sulphate supplemented diet. The endpoints tested were apparent digestibility, whole body levels, tissue distribution and Se‐ and Zn‐dependent enzyme activities. Digestibility of residual Se in the basal diet was 54.2 ± 1.0% and supplemented Se‐yeast was significantly more digestible than selenite (p < 0.05). Digestibility of residual Zn was 21.9 ± 2.0% and no significant difference was found between the treatments (p = 0.89). Whole body Se was raised by both Se sources and to a greatest extent by Se‐yeast (p < 0.001). Zn‐sulphate, and to a lesser extent Zn‐proteinate, both raised whole body Zn (p < 0.05). Dietary Zn in the basal diet was found to be above requirements, yet Zn‐sulphate had a significantly greater retention than Zn‐proteinate in those tissues that responded to Zn supplementation. Se‐yeast significantly raised Se in all tissues to a greater extent than selenite, except in the pyloric caeca and liver where the greatest increases were by selenite. Only Se‐yeast elevated Se‐dependent thioredoxin reductase activity (p < 0.05) and neither forms of Se affected glutathione peroxidise activity (p = 0.059). Alkaline phosphatase and carboxypeptidase B were not affected by Zn supplementation (p = 0.51 and p = 0.88 respectively). In all aspects, Se‐yeast was found to be a highly bioavailable form of Se in comparison to selenite. Because of its superior bioavailability, organically bound Se would be a preferred Se source for supplementation of fishmeal trout diets than selenite.  相似文献   

11.
Sorghum dried distiller's grains with solubles (S‐DDGS) are distillation extract residues from the ethanol fuel industry. In this experiment, two hundred 42‐day‐old rabbits were randomly allocated to five experimental diets containing 0 g/kg (control), 75, 150, 225 and 300 g/kg S‐DDGS. The experiment lasted for 4 weeks. No difference was found in the average daily feed intake (ADFI; p > 0.05). With increasing sorghum inclusion, the average daily gain (ADG) was linearly (p < 0.001) and quadratically (p = 0.039) reduced, while, conversely, the feed conversion ratio (FCR) linearly (p < 0.001) increased. Increasing the amount of S‐DDGS in the diet linearly decreased (p < 0.001) the apparent total tract digestibility (ATTD) of dry matter (DM), organic matter (OM), crude protein (CP) and ash. Carcass weight, carcass yield, heart and liver weights were linearly decreased by an increase in the amount of S‐DDGS added to diets (p < 0.001), but no difference was observed between the 0, 75 and 150 g/kg S‐DDGS groups (p > 0.05). Serum IL‐6, IL‐10 and SIgA linearly increased (p = 0.008) with increasing levels of S‐DDGS in the diet. Rabbits fed 0, 75 and 150 g/kg of S‐DDGS had similar IL‐6 and IL‐10 levels. Statistically significant differences in SIgA were observed between rabbits fed control diets and feed mixtures containing S‐DDGS (p < 0.01). To conclude, S‐DDGS can safely be added up to 75 g/kg, to the diet of rabbits. Increasing dietary S‐DDGS inclusion may decrease the growth performance, nutrient digestibility and carcass traits, and activate immune responses.  相似文献   

12.
A 42‐day feeding trial was conducted using 480‐day‐old, male Marshall broilers to study the utilization of unpeeled cassava root meal (UCRM) supplemented with or without 6 g/kg charcoal. The experimental design was laid out in a 3 × 2 factorial arrangement of treatments having three inclusion levels of UCRM (0, 100 and 200 g/kg) with or without 6 g/kg charcoal supplementation. Each treatment consisted of 80 birds replicated eight times with 10 birds per replicate. Main effect of inclusion level of UCRM and supplementation of charcoal showed reduced (p < 0.05) final live weight, weight gain, feed intake and apparent crude protein digestibility of the birds with increasing inclusion levels of UCRM. Birds fed diets supplemented with charcoal showed higher (p < 0.05) final live weight, weight gain and feed intake than birds fed diets without charcoal. Supplementation of charcoal in diet containing 100 g/kg UCRM resulted in improved (p < 0.05) weight gain when compared with birds fed similar diet but not supplemented with charcoal. Broilers fed diet containing no UCRM but supplemented with charcoal had the highest overall (p < 0.05) final live weight and weight gain, while birds fed diet containing 200 g/kg UCRM supplemented with charcoal recorded the poorest (p < 0.05) final live weight and weight gain. Serum glutamate oxaloacetate transaminase (SGOT) and serum thiocyanate concentration increased (p < 0.05) with increasing dietary inclusion levels of UCRM. Dietary supplementation of charcoal resulted in increased (p < 0.05) concentration of serum glucose and cholesterol and reduced (p < 0.05) SGOT concentration. Birds fed diets containing UCRM had high (p < 0.05) serum thiocyanate concentration irrespective of dietary supplementation or not with 6 g/kg charcoal. In conclusion, supplementation of diet containing up to 100 g/kg UCRM with 6 g/kg charcoal showed improved weight gain without any deleterious effect on serum metabolites.  相似文献   

13.
The present study evaluated the development of pulmonary hypertension and right ventricular failure in broiler chickens reared at high altitude (2100 m) as affected by dietary intake of n‐3 and n‐6 fatty acid sources. Flax oil and soy oil were used as sources of n‐3 and n‐6 fatty acids, respectively, either with or without α‐tocopheryl acetate. A total of 192 day‐old broiler chicks (Ross 308) were used in a completely randomized design using isoenergetic and isonitrogenous experimental diets. Results showed that dietary flax oil significantly (p < 0.05) improved feed conversion ratio during 21–42 days of age. However, body weight gain did not significantly differ among the experimental groups in entire trial. Birds received flax oil had significantly higher serum concentration of nitric oxide (NO) but they had lower serum concentration of malondialdehyde when compared with their counterparts fed with soy oil. Liver and abdominal fat weights were significantly (p < 0.05) reduced by substitution of soy oil for flax oil. The right‐to‐total ventricle weight ratio (RV/TV) and mortality from pulmonary arterial hypertension (PAH) were significantly (p < 0.05) decreased in birds that received flax oil. In conclusion, n‐3 fatty acids could significantly reduce RV:TV and PAH mortality in birds by increasing circulatory level of NO and suppressing hepatic lipogenesis.  相似文献   

14.
As alterations of dietary electrolyte balance (DEB) can influence amino acid metabolism via changes the ions incur in their configurations, performance and immunological responses of broiler chicks might be affected. So, the current study was carried out to investigate the effects of different levels of sulphur amino acids (SAA) and DEB on performance, jejunal morphology and immunocompetence of broiler chicks. A total of 360 1‐day‐old male Ross 308 broiler chicks were randomly assigned to nine experimental treatments with four replicates of 10 birds each. Experimental treatments consisted of three levels of SAA (100, 110, and 120% of NRC recommendation, provided by methionine supplementation in diets with the same cysteine level) and three levels of DEB (150, 250, and 350 mEq/kg) that were fed during the entire of trial in a 3 × 3 factorial arrangement. Results showed that the relative weights of intestine and abdominal fat were decreased markedly (p < 0.001) with increasing levels of SAA and DEB respectively. Antibody titre against sheep red blood cell was neither individually nor in combination influenced by supplementation of SAA or DEB. Nevertheless, a decrease in DEB level led to a suppression in heterophile (p < 0.05) and an increase in lymphocyte counts (p = 0.06); consequently, heterophile to lymphocyte ratio was significantly decreased (p < 0.05) by decremental levels of DEB. Albumin to globulin ratio was increased after inclusion of at least 10% SAA (p < 0.001) and 150 mEq DEB/kg in the diet (p = 0.11). Although feeding high‐DEB level led to a remarkable decrease in villus height (p < 0.01) and goblet cell numbers (p < 0.001), supplementing the highest level of SAA improved the height of jejunal villus. During the entire trial period, average daily feed intake (ADFI) was increased by incremental SAA levels (p < 0.05). However, inclusion of 150 mEq/kg led to not only a remarkable increase (p < 0.0001) in both ADFI and average daily weight gain (ADWG) but also to improved (p < 0.001) feed conversion ratio (FCR) both during the growing and over the entire trial periods. The present findings indicated that inclusion of low DEB decreased the heterophile to lymphocyte ratio and improved both the albumin to globulin ratio and intestinal health indices. The best growth performance was obtained with 150 mEq DEB/kg in the diet for each level of SAA.  相似文献   

15.
The objective of this study was to evaluate the effects of dietary supplementation with zinc oxide nanoparticles (ZnO‐NPs) on the performance, egg quality, Zn retention, immunity responses, superoxide dismutase activity (SOD), egg malondialdehyde (MDA) content, and serum parameters in laying hens in the late phase of production. A total of 288 laying hens at 64 weeks of age were randomly assigned to 4 treatments with 6 replicates, and 12 birds within each group. Experimental diets included a corn‐soybean meal‐based diet (without Zn supplementation) and a basal diet supplemented with 80 mg/kg of Zn‐oxide, ZnO‐NPs, and Zn‐methionine. The results indicated that egg production and egg mass were significantly higher in the Zn‐methionine and ZnO‐NPs groups (p < .05). Also, eggshell thickness and shell strength increased in the ZnO‐NPs group as compared with the other groups (p < .05). Moreover, Zn supplementation decreased egg loss (p < .05). There were significant differences among treatments in Zn deposition in tibiotarsus, liver, pancreas, eggs, and excreta (p < .01). Antibody titre, heterophil (%(, and phytohemagglutinin (PHA) were significantly higher in birds fed with Zn‐supplemented diets (p < .05). In treatments supplemented with ZnO‐NPs and Zn‐methionine, the SOD activity in the liver, pancreas, and plasma was greater as compared with the other treatments (p < .05). The MDA content in eggs was significantly reduced in groups supplemented with Zn (p < .01). Moreover, dietary Zn supplementation significantly affected serum total protein, albumin, glucose, alkaline phosphatase activity, carbonic anhydrase activity, and Zn level (p < .05). In conclusion, this study demonstrated that dietary supplementation with ZnO‐NPs can improve the performance of laying hens. Therefore, ZnO‐NPs can enhance zinc absorption in the intestine of aged layers and can be a more suitable source of zinc than regular Zn‐oxide in diets.  相似文献   

16.
This study assessed the effects of feeding high peanut meal diets of reduced crude protein (CP) content supplemented with essential amino acids (EAA) on growth performance, carcass traits, biochemical indices in plasma, and nitrogen (N) retention of male and female Lingnan Yellow broilers from day 22 to day 42 of age. Each of four dietary treatments (19%, 18%, 17% or 16% CP, dietary CP level reduced by the reduced dietary peanut meal) contained six replicate pens with 35 birds of each sex (males and females with equal number), separately (1680 in total). The three diets with reduced CP were supplemented with 5 EAA to meet the requirements and provide the same levels as in the 19% CP diet. Average daily gain decreased and feed:gain ratio was worse in both sexes with reduced CP% (linear, p < 0.05). Dressing percentage increased as CP% decreased in males (linear, p < 0.05) and thigh muscle percentage reduced slightly in females (linear, p < 0.05). Abdominal fat percentage of males fed the 17% CP was the lowest (quadratic, p < 0.05). The plasma metabolic indices, concentrations of triglycerides and malondialdehyde, showed linear responses to reduced CP% (p < 0.05) with triglycerides increasing while malondialdehyde decreased. Plasma uric acid increased in females (linear, p < 0.05), but not in males, as CP% decreased. Efficiency of N retention increased and N excretion strikingly decreased with lower CP diets (p < 0.001), and both variables showed significant (p < 0.05) linear and quadratic effects. It is concluded that there was a limit to which dietary CP of broilers could be reduced without adverse effects. Dietary CP could be reduced to 17% for males and 18% for females (or 18% when fed together) between day 22 and day 42, if diets are supplemented with synthetic EAA.  相似文献   

17.
Three studies were conducted to examine the effects of zinc concentration or source in diets of finishing beef steers. In Exp. 1, 108 (British x Continental) beef steers were supplemented with concentrations of added zinc (as ZnSO4) at 20, 100, or 200 mg/kg of dietary DM. No differences (P > 0.10) were noted among treatments for ADG or gain:feed for the 112-d finishing period. However, a linear (P < 0.10) decrease was noted in daily DMI with increasing zinc concentrations for the overall finishing period. No differences (P > 0.10) were noted in hot carcass weight; dressing percentage; longissimus muscle area; percentage of kidney, pelvic, and heart fat; or marbling score. There were, however, quadratic increases in s.c. fat thickness (P < 0.05) and yield grade (P < 0.01) with added zinc. In Exp. 2, 12 beef steers were used to examine effects of added dietary zinc on serum concentrations of cholesterol and fatty acid profiles. No differences (P > 0.10) were observed in cholesterol or fatty acids among the supplemental zinc levels. In Exp. 3, 84 Brangus- and Angus-sired steers were fed a steam-flaked corn-based diet containing 30 mg of supplemental zinc per kilogram of dietary DM from one of the following sources: 1) ZnSO4, 2) Zn amino acid complex, or 3) a zinc polysaccharide complex. No differences (P > 0.10) were noted for the overall 126-d trial for ADG, DMI, or gain:feed ratio. Percentage kidney, pelvic, and heart fat was increased (P < 0.10) in steers supplemented with ZnSO4 vs the average of Zn amino acid and Zn polysaccharide complexes. However, s.c. fat thickness was greater (P < 0.10) in steers supplemented with Zn amino acid and Zn polysaccharide complexes vs ZnSO4. Serum zinc concentration did not differ (P > 0.10) among zinc sources. Supplemental zinc concentration in finishing diets did not seem to influence feedlot performance and had a minimal impact on carcass quality. Either the organic or inorganic source can be included in finishing diets without affecting feedlot performance.  相似文献   

18.
The major objective of this research was to establish the main and interactive effects of corn type and extent of grinding on broiler performance including carcass characteristics. A completely randomized experimental design with a 2 (corn type) × 2 (fine and coarse) factorial arrangement, each with six replicates of 45 male Ross chicks, was applied. Experimental diets, containing dent or hard corn, were formulated with two extents of grinding (3.00 or 6.00 mm screens) for three growing phases. In comparison with dent corn, the hard corn increased body weight (BW) gain and thigh muscle yield (p < 0.05), while decreasing feed conversion ratio (p < 0.01) and abdominal fat deposition (p < 0.05), some aspects of which were age‐dependent and appeared to vary with extent of grinding. Coarser grinding increased the weight of proventriculus (p < 0.01), gizzard (p < 0.05) and small + large intestine (p < 0.10) relative to BW, particularly towards market size. These results suggest that feeding hard corn or large‐particle‐size corn have some favourable effects on growth performance or gastrointestinal development for finishing broilers.  相似文献   

19.
The objective of this study was to evaluate the effects of inorganic phosphorus source and phytase addition on performance, nutrient digestibility and bone mineralization in broiler chickens. In Exp. 1, 150 two-day old, male broiler chicks were fed a corn-soybean meal basal diet supplemented with phosphorus provided by dicalcium phosphate, tricalcium phosphate or defluorinated rock phosphate. Five cages containing 10 birds were allotted to each of the three treatments. In Exp. 2, 120 three-day old, male broiler chicks were fed the basal diet from Exp. 1 supplemented with 0, 250, 500, or 1,000 FTU phytase per kg of diet. Six cages containing five chicks were allotted to each of the four treatments. In Exp. 1, there was no difference in weight gain, feed intake or feed conversion as a result of feeding the different sources of inorganic phosphorus. The digestibility of phosphorus was significantly lower (P = 0.01) for chicks fed diets supplemented with tricalcium phosphate than for chicks fed the other two diets.  However, despite the lower digestibility, serum phosphorus levels did not differ among the three treatments. For Exp. 2, feed conversion showed a linear improvement (P = 0.03) with increasing levels of phytase inclusion (days 0 to 33).  Phytase supplementation resulted in linear increases in the digestibility of dry matter (P = 0.02), crude protein (P = 0.04) and energy (P < 0.01).  Chicks fed 1,000 FTU/kg phytase had significantly higher bone calcium (P = 0.05) and bone breaking strength (P = 0.04) than chicks fed the basal diet on day 33. In conclusion, the results of the current study indicated that the performance of birds fed diets supplemented with dicalcium phosphate, tricalcium phosphate or defluorinated phosphate was similar and therefore production costs could be lowered by choosing the cheapest inorganic phosphorus source when formulating diets for poultry. When diets were formulated to meet dietary phosphorus requirements, the growth of broilers was not enhanced with phytase supplementation.  However, increases in feed conversion and bone breaking strength and its potential to impact culling and mortality in broiler operations may be sufficient justification for the routine inclusion of phytase in diets fed to broilers.  相似文献   

20.
The effects of dietary supplementation of zinc (Zn) sources and concentrations were investigated on growth performance, absorption into tissues, fecal excretion, nutrient retention, and intestinal morphology in broilers fed a corn-soybean meal basal diet. A total of 525 one-day-old chicks (Ross 308) were assigned based on body weight to seven dietary treatments. There were five replicate pens for each treatment and 15 broilers per replicate pen. The dietary treatments included a basal diet (control, without supplementing Zn), and basal diet supplemented with Zn, as inorganic zinc sulfate (ZnS; 110 mg/kg); organic Zn-methionine (ZnM; 110 mg/kg); hot-melt extruded (HME) 25 zinc sulfate (27.5 mg/kg); HME50 zinc sulfate (55 mg/kg); HME75 zinc sulfate (82.5 mg/kg); or HME100 zinc sulfate (110 mg/kg) for 35 days in two phases (d 1–21, phase I and d 22–35, phase II). Bodyweight and feed efficiency of broiler chicks fed diets supplemented with increasing dietary concentrations of HME-Zn improved linearly during the study period (P<0.05). Compared to the control treatment, the ZnS, ZnM, and HME diets increased Zn concentrations in the serum and liver. Inorganic ZnS supply resulted in the highest Zn concentration in excreta. Increasing supplemented Zn content in diets as HME linearly increased Zn concentration in the excreta, serum, liver, and tibia. Broiler chicks fed diets supplemented with increasing concentrations of HME increased villus height (VH; linear and quadratic) of the jejunum and VH of the ileum (linear). Increasing concentrations of dietary Zn supplied as HME resulted in linearly enhanced dry matter, gross energy, and nitrogen retention of broilers on day 21. These results suggest that dietary HME-Zn at a lower level (55 ppm) shows the same growth performance as common ZnSO4 at 110 ppm.  相似文献   

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