饲粮锌水平对肉鸡血锌、组织锌及含锌酶含量的影响

为研究饲粮中不同锌水平对某些含锌酶活性及血、胰和胫骨锌含量的影响,试验选择1日龄健康AA肉鸡公雏300只,随机分为5个处理组,各处理组锌的含量分别为30、60、90、120、150 mg/kg。结果表明:(1)21日龄时,120、150 mg/kg锌组血锌含量显著增加(P<0.05),与对照组相比,分别提高了56.75%和91.45%;150 mg/kg锌组胰锌含量显著增加(P<0.05),与对照组相比,提高了130.77%;90、120、150 mg/kg锌组胫骨锌含量显著增加(P<0.05),分别比对照组提高14.16%、19.50%和26.61%。42日龄时,150 mg/kg锌组血锌含量显著增加(P<0.05),比对照组提高77.25%;60、90、120 mg/kg锌组胰锌含量显著增加(P<0.05),分别比对照组提高194%、198%和212%;120、150 mg/kg锌组胫骨锌含量显著增加(P<0.05),分别比对照组提高37.80%和43.29%。(2)21日龄时,120、150 mg/kg锌组心肌金属硫蛋白(MT)含量显著增加,分别比对照组提高9.79%和32.17%;90、120、150 mg/kg锌组骨骼肌MT含量显著增加,分别比对照组提高54.55%、57.02%和90.91%。42日龄时,心肌和骨骼肌中的MT含量没有表现出显著的差异。(3)21日龄时,150 mg/kg锌组肝脏铜锌超氧化物歧化酶(CuZn-SOD)活性显著提高,42日龄时,150 mg/kg锌处理组肝脏CuZn-SOD活性显著低于其他处理组。在本试验条件下,饲粮中添加硫酸锌可以显著提高肉鸡血清、胰脏、胫骨组织中的锌沉积,并对肝脏CuZn-SOD活性有一定的影响。     

小麦型日粮添加木聚糖酶和植酸酶对肉鸡生长性能、回肠氨基酸表观消化率及常量元素沉积的影响

本文旨在研究小麦型日粮中添加木聚糖酶和植酸酶对肉鸡生长性能、回肠氨基酸表观消化率及矿物元素沉积的影响。试验选择1日龄科宝白羽肉仔鸡850只,随机分成5组,每组5个重复,每个重复34只鸡。一共有5种日粮,即低磷日粮、高磷日粮、低磷日粮+2000 IU/kg木聚糖酶、低磷日粮+500 FTU/kg植酸酶,低磷日粮+2000 IU/kg木聚糖酶+500 FTU/kg植酸酶,试验进行21 d。低磷组较高磷组显著降低了肉鸡的日增重、日采食量及趾骨灰分含量(P <0.05),与低磷组相比,木聚糖酶组显著降低了肉鸡的料比(P <0.05),而植酸酶组显著提高了肉鸡日增重、日采食量、趾骨灰分及饲料利用率(P <0.05)。复合酶组显著提高了15种氨基酸回肠表观消化率(P <0.05)。与低磷组相比,木聚糖酶组显著提高了表观消化能和可消化代谢能及回肠氮消化率(P <0.05),而植酸酶显著提高了氮沉积及回肠氮消化率(P <0.05),复合酶组显著提高了代谢能、可消化代谢能及氮沉积量(P <0.05)。植酸酶和复合酶组较高磷组显著提高了磷表观消化率和沉积量(P <0.05),但低磷组较高磷组显著提高了钙的表观消化率(P <0.05),植酸酶酶和复合酶组较其他3组显著提高了钾的沉积量(P <0.05)。结论 :小麦型日粮同时添加植酸酶和木聚糖酶对肉鸡生长和消化的影响要优于单独添加这两种酶。     

Growth response, nutrient and mineral retention, bone mineralisation and walking ability of broiler chickens fed with dietary inclusion of various unconventional mineral sources

Growth response, nutrient and mineral retention, bone mineral content and walking ability of broiler chicken fed dietary inclusion of various unconventional calcium sources were studied using 160-day-old broilers. Four isonitrogenous, isocaloric diets balanced for Ca and P were formulated such that oyster shell, snail shell, wood ash and limestone were used as main non-phytate (Ca from other sources apart from plant) calcium sources. Each dietary treatment consisted of 40 birds replicated four times with 10 birds per replicate. A single diet was fed to the broilers throughout the duration of the study which lasted for 8 weeks. Broilers fed diet containing oyster shell as calcium sources recorded the highest (p < 0.05) feed intake of 5863.30 g, while those fed diet containing limestone consumed the least intake (p < 0.05) of 5432.56 g. Occurrence of lameness and evidences of gaits were highest (p < 0.05) for broilers fed diet containing wood ash. Lowest (p < 0.05) Ca and ash retention were recorded for broiler fed diet containing wood ash as Ca sources. Similar tibia ash values were recorded for broilers fed oyster shell, snail shell and limestone. Wood ash inclusion resulted in a low Ca availability hence its inclusion in feeds for broilers should be discouraged.     

Impact of manganese amino acid complex on tissue-specific trace mineral distribution and corpus luteum function in gilts

Functional corpora lutea (CL) are required for pregnancy establishment and gestational maintenance in swine, and CL function is susceptible to environmental influences. Manganese (Mn) could be critical in regulating CL function since it is a component of the antioxidant enzyme Mn superoxide dismutase (MnSOD) as well as enzymes involved in cholesterol and steroid hormone synthesis. We hypothesized that a more bioavailable dietary Mn source would increase Mn content in the CL thereby influencing luteal function during the mid-luteal phase of the estrous cycle. Postpubertal gilts (n = 32) were assigned to one of four gestation diets. The control diet (CON) met or exceeded National Research Council (2012) requirements and was formulated to contain 20 parts per million (ppm) of added Mn in the form of Mn sulfate. Three additional diets included 20 (treatment [TRT]1), 40 (TRT2), or 60 (TRT3) ppm of added Mn from a Mn–amino acid complex (Availa-Mn; Zinpro Corporation) instead of Mn sulfate. Dietary treatment began at estrus synchronization onset and continued through 12 days post estrus (dpe) of the ensuing estrous cycle. Blood samples were collected at estrus onset, which was assigned as 0 dpe, as well as 4, 8, and 12 dpe. Gilts were euthanized and tissues were collected at 12 dpe. Serum progesterone (P₄) increased (P < 0.01) from 0 to 12 dpe but was unaffected by dietary treatment (P = 0.15) and there was no effect of the interaction between day and treatment (P = 0.85). Luteal Mn content increased (P ≤ 0.05) by 19%, 21%, and 24% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Luteal P₄ concentrations decreased (P = 0.03) 25%, 26%, and 32% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Relative to CON gilts, CL calcium content decreased (P = 0.02) by 36%, 24%, and 34% for TRT1, TRT2, and TRT3 gilts, respectively. Collectively, these data support the hypothesis that feeding a more bioavailable Mn source increases Mn accumulation in CL tissue. If and how this influences CL function may be related to altered luteal P₄ concentrations.     

钠水平及种类对肉鸡生长性能、胴体性状及血清矿物质水平的影响

文章旨在评估日粮钠水平及种类对肉鸡生长性能、胴体性状及血清矿物质水平的影响.试验选择平均初始体重一致的白羽肉仔鸡832只,随机分为8组,每组4个重复,每个重复26只鸡.试验日粮采用4×2因子设计,即日粮钠水平分别为1.5、2.4、3.3和4.2 g/kg,以小苏打和硫酸钠两种形式添加,试验共进行42 d.结果:1～10...     

Impact of trace mineral source on beef replacement heifer growth,reproductive development,and biomarkers of maternal recognition of pregnancy and embryo survival

Trace minerals are known to play important roles in early embryo development. The study objective was to determine effects of trace mineral source on heifer reproductive performance. Beef heifers (n = 129) were randomly assigned to one of two treatments. From weaning through breeding, all heifers were individually fed a basal diet supplemented with cobalt (Co), copper (Cu), manganese (Mn), and zinc (Zn) either from organic sources (COMP; Cu, Mn, and Zn amino acid complexes and Co glucoheptonate; Availa-4, Zinpro Corporation, Eden Prairie, MN) or inorganic sources (INORG; Cu, Mn, and Zn hydroxychlorides; Intellibond C, M, and Z, Micronutrients, Indianapolis, IN) and Co as CoSO₄. Blood samples and a reproductive tract score (RTS) were collected to determine pubertal status. All animals were synchronized and artificially inseminated. Pregnancy status was determined by lymphocyte gene expression, circulating concentrations of pregnancy-associated glycoproteins (PAGs), and by transrectal ultrasonography after artificial insemination. Embryonic loss was defined as when a previously pregnant animal was subsequently diagnosed not pregnant. Data were analyzed using the MIXED procedure in SAS. Puberty (P = 0.44), pelvic area (P = 0.74), RTS (P = 0.49), and estrus expression (P = 0.82) were not influenced by treatment. There was no effect of treatment (P = 0.37) or treatment by time (P = 0.19) on pregnancy, but there was a tendency (P = 0.13) for decreased embryonic loss among COMP heifers (27 ± 6%) compared to INORG heifers (38 ± 6%). There was a treatment by pregnancy status by time interaction (P < 0.01) on circulating PAG concentrations with PAG concentrations tending (P = 0.08) to be greater on day 25 among heifers in the COMP treatment compared to heifers in the INORG group. In summary, source of trace mineral did not affect puberty, RTS, pelvic area, or overall pregnancy success, but feeding complexed trace minerals tended to increase circulating PAG concentrations and embryo survival.     

不同配比油脂对肉鸡脂类代谢的影响

以肉鸡为动物模型,探讨了日粮中添加不同配比油脂后对其脂肪代谢的影响。648只1日龄AA肉仔鸡,随机分为6组,每组6个重复,每个重复18只鸡,试验期为42 d。CON组为对照组(饲喂基础日粮),SO组为正对照组(日粮中添加豆油),LO组为负对照组(日粮中添加猪油),COP、COC、COV组分别在日粮中添加以棕榈油为主的配比油脂、以椰子油为主的配比油脂、多种植物油配比的油脂。结果表明:42 d,各组腹脂重、皮下脂肪厚度与肌间脂肪厚度、胸肌含脂率、腿肌含脂率均无显著性差异(P>0.05);SO、COP组总甘油三酯含量低于COV组(P<0.05);COP组血清低密度脂蛋白胆固醇含量低于LO组(P<0.01)与CON组(P<0.05);COP组血清高密度脂蛋白胆固醇与低密度脂蛋白胆固醇含量的比值高于LO、COC、COV组(P<0.01),SO组显著提高(P<0.05);SO组肉鸡血清中总脂酶活性高于CON组(P<0.05),肝脏中COP、COC、COV组脂蛋白脂酶、肝脂酶与总脂酶活性都显著提高(P<0.01或P<0.05)。结论:配比油脂组与豆油组在不影响脂肪沉积的情况下,改善了肉仔鸡的体脂分布,且对脂质代谢具有很好的调节作用,其中豆油组与以棕榈油为主的配比油脂组效果较好。     

氨基酸微量元素螯合物替代无机微量元素饲喂黄羽肉鸡的研究

文章研究了氨基酸微量元素螯合物替代饲粮中无机微量元素对肉鸡生产性能、饲粮养分代谢率和粪中微量元素含量的影响。选用300只0日龄广西快大型黄羽肉鸡(雌性),随机分为5组,每组6个重复,每个重复10只鸡,进行为期63d的饲养试验。对照组,饲喂基础饲粮,其Fe、Cu、Mn、Zn分别由硫酸亚铁、硫酸铜、硫酸锰和氧化锌提供,添加水平为Fe100mg/kg、Cu20mg/kg、Mn120mg/kg、Zn120mg/kg;试验组分别用12.5%、25.0%、37.5%和50.0%的蛋氨酸螯合铁、铜、锰、锌替代基础饲粮各相应无机微量元素的25%、50%、75%和100%。试验表明:与对照组相比,用不同比例蛋氨酸螯合物(铁、铜、锌、锰)替代相应无机盐可一定程度提高肉鸡的生产性能,改善饲粮养分利用率,提高养殖效益,降低粪中微量元素的排泄量,尤以37.5%的蛋氨酸微量元素螯合物替代饲粮中75%的相应无机微量元素效果良好。     

Effect of dietary citric acid on the performance and mineral metabolism of broiler

The objective of this study was to investigate the effect of dietary citric acid (CA) on the performance and mineral metabolism of broiler chicks. A total of 1720 Ross PM3 broiler chicks (days old) were randomly assigned to four groups (430 in each) and reared for a period of 35 days. The diets of groups 1, 2, 3 and 4 were supplemented with 0%, 0.25%, 0.75% or 1.25% CA by weight respectively. Feed and faeces samples were collected weekly and analysed for acid insoluble ash, calcium (Ca), phosphorus (P) and magnesium (Mg). The pH was measured in feed and faeces. At the age of 28 days, 10 birds from each group were slaughtered; tibiae were collected from each bird for the determination of bone mineral density, total ash, Ca, P, Mg and bone‐breaking strength, and blood was collected for the measurement of osteocalcin, serum CrossLaps^®, Ca, P, Mg and 1,25(OH)₂Vit‐D in serum. After finishing the trial on day 37, all chicks were slaughtered by using the approved procedure. Birds that were fed CA diets were heavier (average body weights of 2030, 2079 and 2086 g in the 0.25%, 0.75% and 1.25% CA groups, respectively, relative to the control birds (1986 g). Feed conversion efficiency (weight gain in g per kg of feed intake) was also higher in birds of the CA‐fed groups (582, 595 and 587 g/kg feed intake for 0.25%, 0.75% and 1.25% CA respectively), relative to the control birds (565 g/kg feed intake). The digestibility of Ca, P and Mg increased in the CA‐fed groups, especially for the diets supplemented with 0.25% and 0.75% CA. Support for finding was also indicated in the results of the analysis of the tibia. At slaughter, the birds had higher carcass weights and higher graded carcasses in the groups that were fed the CA diets. The estimated profit margin was highest for birds fed the diet containing 0.25% CA. Birds of the 0.75% CA group were found to have the second highest estimated profit margin. Addition of CA up to a level of 1.25% of the diet increased performance, feed conversion efficiency, carcass weight and carcass quality, but only in numerical terms. The addition of CA up to 0.75% significantly increased the digestibility of macro minerals, bone ash content, bone mineral density and bone strength of the broiler chicks. It may, therefore, be concluded that the addition of 0.75% CA in a standard diet is suitable for growth, carcass traits, macromineral digestibility and bone mineral density of broiler chicks.     

肉鸡日粮钙源及其消化代谢研究进展

越来越多的人认识到钙源品质变化对肉鸡胃肠道pH、磷和氨基酸消化率、外源酶功效和胃肠道微生物种群的影响.本综述的目的是描述肉鸡饲料成分钙消化、代谢,重点介绍可能影响消化率的因素.但文献报道的钙消化和代谢的可重复性仍然存在局限性.未来使用玉米型日粮对回肠钙表观消化率系数进行评估,将钙与非植酸磷比例大于1:1的日粮适应期定为...     

Bioavailability of methionine hydroxy analog-free acid relative to DL-methionine in broilers

Three experiments were conducted to determine and validate the relative bioefficacy of the liquid form of hydroxy analog (liquid MHA‐FA) to that of DL‐methionine (Met) in male broilers. In experiments 1 and 2, 945 and 550 male broilers were fed either a Met‐deficient basal diet, or the basal diet supplemented with four and five equimolar levels of each Met source, respectively. In experiment 3, 1232 male broilers were fed either a Met‐deficient basal diet, or the basal diet with three levels (low, moderate, or high) of liquid MHA‐FA or DL‐Met at 65% of the liquid MHA‐FA level. Growth performance improved in all trials, regardless of the Met source, relative to those broilers fed the basal diet. In experiments 1 and 2, the bioefficacy estimates for liquid MHA‐FA relative to DL‐Met on a product basis were: 50% and 64% for weight gain, 51% and 59% for the feed conversion ratio, and 54% and 48% for breast‐meat yield, respectively. In experiment 3, there were no differences between the DL‐Met or liquid MHA‐FA treatments, and the broilers fed liquid MHA‐FA were 68% as efficient on a product basis as those fed DL‐methionine for weight gain. The results from these three trials indicate that the bioefficacy of liquid MHA‐FA relative to DL‐methionine is 57% on a product basis on average across all criteria tested.     

日粮维生素A水平对肉鸡组织CaBP基因表达影响的研究

采用完全随机试验设计,将192只8日龄健康AA雄性肉鸡称重后随机分为4个处理组,每处理组6个重复,每个重复8只。在以玉米和豆粕为主要原料的基础日粮中分别添加VA1500,3000,15000和45000U/kg构成试验日粮,试验期5周。应用SYBR GreenI实时定量RT-PCR技术测定肉鸡胫骨、十二指肠组织中CaBP基因表达量,研究不同VA水平对肉鸡组织CaBP基因表达的影响。结果表明:随着日粮VA添加量的增加,十二指肠CaBP基因表达降低,当VA水平增加至15000,45000U/kg时,CaBP基因表达量有降低趋势(P>0.05),其中以45000U/kg添加组的CaBP基因表达量最低。虽然日粮VA水平对肉鸡胫骨组织中CaBP基因的表达影响较小,但当添加水平为45000U/kg时胫骨组织中CaBP基因表达量有降低的趋势。说明过量VA对骨骼代谢影响的机制之一是过量VA降低了与钙、磷代谢有关的CaBP的基因表达,进而影响钙、磷代谢和骨骼发育。     

Effects of Phytase Addition with or Without a Trace Mineral Premix on Growth Performance,Bone Response Variables,and Tissue Mineral Concentrations in Commercial Broilers

Microbial phytase has been shown to increase the availability of Ca, P, ME, amino acids, and trace minerals in diets of broilers. By increasing the availability of trace minerals, phytase may be able to replace the trace mineral premix in diets for broilers. Therefore, a 43-d floor pen study that included diets with and without phytase and with and without supplemental trace minerals was conducted to evaluate this possibility. The Ca and nonphytate P concentrations were decreased by 0.10% in diets with phytase. Growth performance was not affected in chicks fed diets with or without the trace minerals, but adding phytase had positive effects on growth performance. Removal of the trace minerals had a negative effect on bone strength. Removal of the trace minerals, addition of phytase, or both had variable effects on tissue trace mineral concentrations.     

Effects of dietary betaine on growth performance,fat deposition and serum lipids in broilers subjected to chronic heat stress

We evaluated the effects of supplementing betaine on growth performance, fat deposition and lipid metabolism status in broilers kept under chronic heat stress. Five hundred and forty chicks were randomly divided into six groups and the two normal temperature groups were held at normal ambient temperature and fed the basal diet (CONT) and basal diet plus 0.1% betaine, respectively. Heat stressed (HS) broilers were held at 32 ± 1°C from days 22 to 42 and fed the basal diet containing variable levels of betaine. Broilers were examined at days 28, 35 and 42 for body weight, feed consumption, fat deposition and serum lipids. The CONT and betaine‐supplemented groups showed higher (P < 0.01 or P < 0.05) feed consumption, body weight gain, and lower feed : gain ratio compared with the HS‐CONT group. Meanwhile, heat stress increased abdominal, intermuscular and subcutaneous fat deposition, whereas the supplemental betaine significantly decreased those compared with the HS‐CONT group. Additionally, betaine supplementation significantly decreased triglyceride, free fatty acids, low‐density lipoprotein cholesterol and high‐density lipoprotein cholesterol compared with HS‐CONT. Chronic HS reduces broiler production performance. However, betaine can reverse these negative effects partially and thus improve carcass composition by changing lipid metabolism.