蛋氨酸锌螯合物的生化性质及其在养鸡业中的应用

对蛋氨酸锌的结构、理化性质及在动物体内的生化特性进行了综述。并与无机锌添加剂作了比较。从引用的试验数据可以看出。蛋氨酸锌能促进家禽的生长。提高产蛋能力和免疫功能。是一类具有广泛应用前景的矿物质添加剂。     

不同用量锌肥基施对南粳46农艺性状与产量的影响

通过田间试验,研究基施不同用量的锌肥对水稻南粳46农艺性状与产量的影响。结果表明,在有效锌含量为1.49 mg/kg时,水稻基施硫酸锌0.5~2.0 kg/667 m^2,可以不同程度地提高水稻产量,尤其是当硫酸锌用量为1.5~2.0 kg/667 m^2时,水稻增产极显著,增产幅度为9.32%~10.17%,增效148.50~160.30元/667 m^2。     

不同土壤条件下追施锌肥对小麦产量及品质的影响

为探讨不同土壤条件下追锌肥对小麦产量及品质的影响,在中国农业科学院进行盆栽试验,以津强8号为供试材料进行研究。试验设黑土（A1）、潮土（A2）、红土（A3）3种土壤和不追肥（B1,对照）、拔节期追锌肥（B2）2个处理。结果表明：在3种土壤条件下,子粒产量表现为黑土>潮土>红土,土壤处理间差异显著。追施锌肥比对照显著提高了穗长、穗粒数、千粒重。黑土结合追锌处理,小麦株高、穗长、穗粒数、千粒重均达到最大值,且显著高于其他处理组合。小麦子粒蛋白产量表现为黑土>潮土>红土,土壤处理间差异显著。追施锌肥的小麦子粒蛋白产量显著高于不追施锌肥处理。     

Wheat plants invest more in mycorrhizae and receive more benefits from them under adverse than favorable soil conditions

Soil chemistry and biota heavily influence crop plant growth and mineral nutrition. The stress-severity and optimal resource allocation hypotheses predict mutualistic symbiotic benefits to increase with the degree of metabolic imbalance and environmental stress. Using two cross-factorial pot experiments with the same biologically active calcareous soil, one time highly saline and nutrient-deficient, and the other time partially desalinated and amended with mineral soil fertilizer, we explored whether these general predictions hold true for zinc (Zn) nutrition of bread wheat in mycorrhizal symbiosis. Increased arbuscular mycorrhizal (AM) fungal root colonization positively correlated with plant Zn nutrition, but only when plants were impaired in growth due to salinity and nutrient-deficiency; this was particularly so in a cultivar-responsive to application of mineral Zn fertilizer. Evidence for direct involvement of AM fungi were positive correlations between Zn uptake from soil and frequency of fungal symbiotic nutrient exchange organelles, as well as the quantitative abundance of AM fungi of the genera Funneliformis and Rhizophagus, but not Claroideoglomus. Combined partial soil desalination and fertilization swapped the dominance ranking from Claroideoglomus spp. to Funneliformis spp. Positive growth, nitrogen, and Zn uptake responses to mycorrhization were contingent on moderate soil fertilization with ZnSO₄. In agreement with the predictions of the stress-severity and optimal resource allocation hypotheses, plants limited in growth due to chemically adverse soil conditions invested relatively more into AM fungi, as evident from heavier root colonization, and took up relatively more Zn and nitrogen in response to mycorrhization, than better growing and less mycorrhized plants. It thus appears that crop plant cultivar-dependent mycorrhization and Zn fertilizer-responsiveness may reinforce each other, provided that there is bioavailable Zn in soil and plant growth is impaired by suboptimal chemical soil conditions.     

Efficacy of male scent glands and urine in masking poison bait odour in female house rats, Rattus rattus

Experiments were carried out to possibly reduce bait shyness of female house rats by masking the poison (rodenticide-Zn₃P₂) with male pheromonal gland secretions, i.e. preputial/cheek glands and urine. The poison bait mixed with the extract of preputial and cheek glands, and urine was found to be effective in masking poison bait shyness. Preputial and cheek gland extracts cumulatively mixed with poison bait increased the poison bait consumption and consequently the mortality of female rats. The results reveal that among three pheromone sources, preputial gland extract was the most effective followed by urine and cheek gland extract. The results further reveal that the urine and glandular secretion from male origin may have the ability to increase the poison bait acceptance in female rats probably by altering the taste memory by pheromone odours.     

种公羊锌摄入量与精液品质的关系研究

以成年小尾寒羊种公羊为对象,采用随机区组试验设计,将10只种公羊随机分成5组,分别饲喂锌含量不同的日粮,研究日粮锌水平及补饲时间与种公羊精液品质的关系。A组:对照组,饲喂锌含量39.69 mg/kg的基础日粮;B组:基础日粮+Zn 40 mg/(d.头)(锌含量48.12 mg/kg);C组:基础日粮+Zn 60 mg/(d.头)(锌含量53.83 mg/kg);D组:基础日粮+Zn 80 mg/(d.头)(锌含量59.55 mg/kg);E组:基础日粮+Zn 100 mg/(d.头)(锌含量65.26 mg/kg)。结果表明:①各试验组间射精量差异不显著(P>0.05)。②鲜精活率,A组与其余各组之间均差异极显著(P<0.01);B组与C、D组差异极显著(P<0.01),与E组差异不显著(P>0.05);其余各组均差异不显著(P>0.05)。③精子密度,A组与其余各组之间均差异极显著(P<0.01);B组与D组差异显著(P<0.05),与C、E组差异不显著(P>0.05);C、D两组间差异不显著(P>0.05);D、E两组间差异显著(P<0.05)。④不同锌水平各组间精子畸形率均差异极显著(P<0.01)。⑤精液pH值,A组与其余各组之间均差异极显著(P<0.01);B组与C组差异不显著(P>0.05),与D、E组差异显著(P<0.05);C、D、E 3组间差异不显著(P>0.05)。⑥缺锌公羊补锌2个月后精液品质能够达到较好水平。     

Trace metals and animal health: Interplay of the gut microbiota with iron,manganese, zinc,and copper

Metals such as iron, manganese, copper, and zinc are recognized as essential trace elements. These trace metals play critical roles in development, growth, and metabolism, participating in various metabolic processes by acting as cofactors of enzymes or providing structural support to proteins. Deficiency or toxicity of these metals can impact human and animal health, giving rise to a number of metabolic and neurological disorders. Proper breakdown, absorption, and elimination of these trace metals is a tightly regulated process that requires crosstalk between the host and these micronutrients. The gut is a complex system that serves as the interface between these components, but other factors that contribute to this delicate interaction are not well understood. The gut is home to trillions of microorganisms and microbial genes (the gut microbiome) that can regulate the metabolism and transport of micronutrients and contribute to the bioavailability of trace metals through their assimilation from food sources or by competing with the host. Furthermore, deficiency or toxicity of these metals can modulate the gut microenvironment, including microbiota, nutrient availability, stress, and immunity. Thus, understanding the role of the gut microbiota in the metabolism of manganese, iron, copper, and zinc, as well as in heavy metal deficiencies and toxicities, and vice versa, may provide insight into developing improved or alternative therapeutic strategies to address emerging health concerns. This review describes the current understanding of how the gut microbiome and trace metals interact and affect host health, particularly in pigs.     

花石头河沿岸5种草本植物对锌富集的影响

[目的]为了探索生长在长期受选矿废水污染土壤上的草本植物对锌的富集与转移特征。[方法]通过对花石头河沿岸3个样区土壤和5种草本植物根部、茎叶进行采样处理与分析测试,研究重金属锌在植物体内的富集和转移特征。[结果]随着土壤锌含量的增加,植物体内锌含量也增加,土壤锌含量与植物全株锌含量、根部锌含量之间表现为0.01水平显著的正相关关系,但与茎叶之间不存在显著性相关关系。5种草本植物根部锌富集系数(EF)为0.941,茎叶EF值为0.464,光叶蕨、紫茎泽兰根部EF值超过1。在山坡上、公路边和河边3个采样区,山坡上5种草本植物的EF值最高,河边采样区各植物的EF值均较低,且它们之间的差异呈0.05水平显著性负相关。5种草本植物的锌转移系数(TF)大小顺序为三叶鬼针草>青蒿>紫茎泽兰>光叶蕨>野牡丹。对于3个采样区,植物中TF大小顺序为山坡上>公路边>河边。土壤锌含量与植物锌的TF呈0.05水平显著性负相关关系,即土壤锌含量越高,植物体内锌的转移系数越低。[结论]土壤中锌含量严重超标时抑制草本植物对锌的富集和转移。     

Supplementation of diets for gestating sows with zinc amino acid complex and gastric intubation of suckling pigs with zinc-methionine on mineral status, intestinal morphology and bacterial translocation in lipopolysaccharide-challenged early-weaned pigs

Eighty male pigs from 20 litters were used to evaluate dietary addition of 250 mg/kg of Zn from zinc amino acid complex (ZnAA) to sows during the last trimester of gestation and gastric intubation of 40 mg Zn from soluble zinc methionine (ZnMet) to suckling pigs at birth and on day 7 and 14 (weaning) on small intestinal morphology, Zn status and bacterial translocation in early-weaned pigs. At weaning, pigs were challenged with an intramuscular injection of saline without or with 120 μg/kg BW of lipopolysaccharide (LPS; from Escherichia coli O26:B6) and were euthanized 24 h later prior to collection of intestinal lymph nodes and small intestinal sections. Zinc concentration in serum 7 days after birth and at weaning were higher in pigs from ZnAA-supplemented sows and those receiving gastric intubation with ZnMet (P = 0.05 and P < 0.0001, respectively). Post-weaning liver tissue concentrations for Zn (P < 0.0001) and Fe (P = 0.04) were higher and for Cu lower (P < 0.0001) in pigs intubated with ZnMet. Pigs from ZnAA-supplemented compared with control-fed sows tended (P < 0.1) to have increased villi height and villus:crypt ratio in the jejunum and higher (P = 0.1) goblet cell counts in the ileum. Goblet cell counts of ZnMet-intubated (P = 0.03) and LPS-challenged pigs (P = 0.05) were also higher in the jejunum. Supplementation of ZnAA to gestating sows increased (P = 0.04) E. coli colony forming unit counts in the small intestinal mesenteric lymph nodes of early-weaned pigs. In conclusion, dietary addition of ZnAA to gestating sows and gastric intubation of ZnMet improved Zn status of suckling pigs.     

Clinical observations of cattle and buffalos with experimentally induced chronic copper poisoning

The susceptibility of cattle and buffalos to chronic copper poisoning (CCP) was compared by using cattle (n = 10) and buffalo (n = 10) steers distributed into two copper supplemented (n = 6) and two control (n = 4) groups. Supplemented animals received 2 mg copper (Cu)/kg body weight daily for one week, with an additional 2 mg weekly until the end of the experiment (day 105). Three liver biopsies (day 0, 45, and 105) were obtained for mineral analyses; clinical examinations and blood samples were obtained every 15 days. Three supplemented cattle and two buffalos with typical manifestations of CCP died. There were no differences in the frequency of mortality between cattle and buffalos; hepatic copper concentration was higher in cattle than buffalos. These findings suggest that buffalos and cattle might be equally susceptible to CCP. However, buffalos accumulate less liver copper than cattle and have a lower threshold of hepatic Cu accumulation, which leads to clinical manifestation of CCP.