Chemical contamination of the cervical mucus in cows in relation to pregnancy and age factors]

Applying the method of absorption atom spectrometry (AAS), the contamination of cervical mucus by chemical elements (Cd, Pb, Hg, Cr, Cu, Zn) was demonstrated in the oestrus period of cows in different ecological agricultural regions of the North Moravian region. The results of observation revealed only a statistically significant difference (P less than 0.05) in Cd contents in the test groups; test group mean = 0.015 micrograms.g-1 Cd, control group mean = 0.006 micrograms.g-1. Cr findings in cervical mucus are of priority importance, the same applies to Cu findings. Zinc was found to be an element influencing negatively the conception of cows. The Zn values in cervical mucus of nonpregnant cows were demonstrated to be significantly higher (P less than 0.01) (conception--group = 0.841 micrograms.g-1, conception + group = 0.219 micrograms.g-1 Zn. So called sum of chemical elements: Cd + Pb + Hg + Cr + Cu + Zn was proposed and evaluated as a picture of the total contamination of cervical mucus. This characteristic was also influenced by the Zn findings in the group of pregnant and nonpregnant cows. Zn: Cd antagonism in cervical secretions of barren and pregnant cows was statistically highly significant (P less than 0.01). Chemical elements in cervical mucus were determined for the first time in a digested sample of cervical secretion. The correlation coefficients used for the cows (n = 99) from a contaminated region showed that the content of chemical elements in cervical secretion was not influenced by the age of cows. The content of chemical elements in cervical secretion was not increasing with the age.     

Levels of toxic elements--Cd, Pb, Hg, Cr, Cu, Zn--in the blood and placenta of cows during parturition and in newborn calves

It was demonstrated that mother's blood and the blood of new-born calves were contaminated by toxic elements in exposed and non-exposed area. The average Cd and Zn levels differed at high statistical significance (P less than 0.01) in the mothers blood from non-exposed regions in comparison with the average Cd and Zn levels from exposed region. The average residues of toxic elements in breeding cows placenta from the exposed and non-exposed regions were not statistically different. The average Zn content in new-born calves from non-exposed regions differ highly statistically significantly in comparison with the average Zn content in the blood of new-born calves from heifers of the exposed region. The transplacental ratio (TPx) of a toxic element in cow placenta during parturition was expressed from the average ratio of toxic element content in mother's blood: toxic element content in placenta: the toxic element content in blood of newborn calf, while the content of toxic element in mother's blood during parturition was expressed by a value equal to one. TPx in parturition period was expressed by mathematical formula TPx = 1 : Xp : Xk, where Xp = toxic element content in placenta, Xk = content of the toxic element in blood of new-born calf. TPPb, Hg, Cr, Cu, Zn values were not statistically different between the groups of breeding cows from exposed and non-exposed regions. TPCd in the group comprising 14 first-calves from the exposed region (TPCd = 1:0.89:2.59 in comparison with TPCd of six cows from non-exposed region, where TPCd = 1:0.29: 0.70;, differed statistically highly significantly (P less than .01). High statistical differences (P, less than 01) TPCd between these groups were explicitly affected highly statistically significantly (P less than .01) by different average Cd content in the blood of fourteen first-calves, compared with the average Cd content in blood of six cows from non-exposed region, in which the Cd value in blood during parturition was higher by 10(-1).     

Isolation of pathogenic strains of Haemophilus somnus from the female bovine reproductive tract.

The prevalence of Haemophilus somnus in the genital tract of slaughtered and live cows in southern Ontario was investigated. The vagina and uterus of slaughtered cows were swabbed separately. Live cows were examined and sampled in two field surveys: Centre A and Centre B. In the former, aspirated mucus secretions and in the latter, specimens obtained by guarded swabbing were examined bacteriologically. Haemophilus somnus was isolated from 28 genital tracts of 461 slaughtered (6.1%), and seven of 199 live (3.5%) cows during the centre B survey. The isolates were recovered from both normal and diseased reproductive tracts. Fourteen strains isolated from genital organs were examined for pathogenicity in vivo to test the occurrence of pathogenic isolates. In the initial stage of the in vivo study on pathogenicity, each of the fourteen isolates was examined on one calf using an intracisternal inoculation. Subsequently, one pathogenic and one nonpathogenic strain were inoculated into five calves each to statistically confirm their pathogenic potential. Of 14 genital isolates of H. somnus examined in an intracisternal calf assay, six (43%) caused a fatal peracute neurological disease, while eight were nonpathogenic. A comparative pathological study of pathogenic and nonpathogenic isolates showed that the former caused a severe fatal suppurative meningoencephalitis whereas the latter caused no lesions whatsoever or a mild leukocytic leptomeningitis. The salient data obtained in this study indicate that there are pathogenic strains of H. somnus in the genital tract of apparently normal cows as well as of those with inflammatory disease.     

重庆东北脐橙主产区土壤重金属含量分析

研究区除As、Pb含量明显低于中国土壤元素背景值和三峡库区元素背景值外,其余重金属元素的含量均高于上述土壤背景值。这表明该区土壤中重金属含量相对较高,特别是其中Cd的富集系数最高,是造成研究区土壤重金属污染的主要因素,表明该区土壤受人类活动影响较大。根据土壤综合污染指数,与土壤分级标准相比较,该区土壤总体尚清洁,仅部分地区受到Cd轻度污染。     

Effects of long-term dietary cadmium chloride on tissue, milk, and urine mineral concentrations of lactating dairy cows.

The effects of long-term consumption of 1 and 5 ppm of Cd on Cd, Cu, Fe, and Zn concentrations in milk and a variety of tissues of first-lactation dairy cows was investigated. Thirty-six Holstein heifers were allocated to three groups and fed similar diets differing only in the concentration of Cd (.25, 1, and 5 ppm) for a 394-d period before calving. One- and 5-ppm Cd concentrations were achieved using CdCl2. Liver, kidney cortex, and muscle were biopsied from one-half of the heifers of each group before Cd supplementation and again from the same heifers within 5 d after parturition. Colostrum and milk were sampled throughout the 150 d of lactation. Urine was sampled after an average of 450 d of Cd exposure. At slaughter (after an average of 554 d), 11 tissues were sampled from 12 cows representing all treatment groups. During the first 394 d, Cd accumulated in kidney and liver with increasing dietary concentrations of Cd but did not further increase by 554 d. However, by 554 d Cd had also accumulated in the adrenal glands, ovaries, spleen, and uteri of cows consuming 5 ppm of Cd. Dietary Cd did not influence the concentration of Cd, Cu, Fe, or Zn in colostrum or milk. However, urine pH, Zn, and K were lower in cows consuming 5 ppm of Cd. Liver Cu was reduced by 1 and 5 ppm of Cd at both 394 and 554 d.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of metabolic alkalosis on colostrum and milk quality of cows and on the health status of their newborns

The investigation was carried out on 12 cows and their calves. At the time of 3 months before parturition and 7 days after parturition metabolic alkalosis one provoked with the high protein feed. The laboratory investigations dependent of determinations on the rumen content the pH, NH3, volatile fatty, acids, the protozoa, bacteria, total gas CO2 and CH4. On the arterial and venous blood on determination the pH, BE, sO2, pO2, HCO3 and coefficient of consumption of the oxygen, and on the venous blood the levels of Na, K, Mg, Ca, P, total proteins, albumins and globulins, cholesterol, glucose, bilirubin, alkaline phosphatase and urea. In the colostrum and in milk one determined the pH, potential acidosis--degree SH, proper weight, proteins, dried mas of milk, time of coagulation in the presence of rennin, Na, K, Ca, Cl, total fats and their composition with different fatty acids. No existed truly changes of clinical signs, only feces was sickly. The metabolic alkalosis of cows decreased the consumption of oxygen across the tissue, deficient of the energy, disorders of water-electrolyte and acid-base balances. The calves form cows with metabolic alkalosis delivered also with metabolic alkalosis, with the symptoms of achondroplasia and degeneration of the liver and other organs. Metabolic alkalosis of cows influenced on the quality of colostrum and milk. The colostrum gained from cows with alkalosis caused of disturbance of gastrointestinal tract and diarrhea presence.     

奶牛蹄叶炎与血浆中矿物元素含量的相关性分析

采集15头健康奶牛和36头蹄叶炎患病奶牛血浆样品,检测其Fe、Zn、Cu微量元素和Mg、Ca、P常量元素的含量及钙磷比,结果表明：2组间Fe、Cu、Mg、Ca和P矿物元素含量及钙磷比无显著性差异（P〉0.05）,患病牛Zn含量却显著低于健康牛（P〈0.05）。因此,奶牛血浆中Zn含量与蹄叶炎发病显著相关,Zn含量可能会作为蹄叶炎发病的监测指标,也可用于奶牛蹄叶炎的早期诊断和防治。     

Associations between periparturient disorders and reproductive efficiency in Holstein cows in northern Mexico

Interrelationships among parity, twinning, retained placenta, abortion, metritis, cystic ovaries, milk fever and postpartum reproductive events were investigated in Holstein cows in northeast Mexico. Data were from 6565 lacations from a large commercial dairy herd. Path analysis was used to model the direct and indirect effects of these variables. The risk of reproductive disorders in cows having a particular periparturient complication was assessed by odds ratio analysis. Milk fever was dropped out of the restricted model, mainly because of the low lactational incidence of this disease (0.5%).

The most important implied cause and effect relationships among the periparturient events were twinning causing retained placenta and retained placenta causing metritis (odds ratio = 5.2 and 4.7, respectively; P * 05). Excluding abortion, most reproductive disorders and twinning increased the days from parturition to first estrus (from 4.4 to 9.2 days), the days from parturition to conception (from 1.3 to 21.4 days), the services per conception (from 0.28 to 0.5) and the calving interval (from 14.7 to 21.3 days). Only in associations between retained placenta and reproductive parameters were the indirect components an important part of the total causal association.     

Biologic quality of colostrum and calves from dairy cows injected with zinc during pregnancy]

The effects of an administration of the Zindep inj. preparation (Biotika) were evaluated in pregnant dairy cows as exerted on specific weight, total protein (TP) content, total immunoglobulin (IgC) and albumin (ALB) contents in colostrum. These parameters were also followed: calf's health, live weight, leucocyte (Lc) counts, T-lymphocyte (T-Ly) counts, contents of TPs, IgCs and ALBs in the blood serum of calves. Zinc concentrations were determined in colostrum, milk and calf blood serum. Our observations included 16 dairy cows in the seventh month of pregnancy in the second lactation and their calves in the winter feeding season. Eight experimental dairy cows were treated with the Zindep preparation in form of an injection to the neck muscles at a dose of 3 mg Zn/kg live weight in the mid-seventh month of pregnancy. Blood samples were taken from v. jugularis from all calves before their first drinking, on days 5, 15 and 30 of age. Colostrum, and/or milk samples were obtained by drawing of the colostrum or milk from the udder quarters within 60 minutes after parturition, on days 5 and 15 of lactation. Zn levels at birth were 16.48 +/- 2.67 mumol/l in experimental calves and 13.84 +/- 3.19 mumol/l in control calves. Zincaemia decreased slightly in both groups on days 5 and 15 of age, but it was insignificantly higher in calves coming from Zindep-treated dairy cows. Zn levels in the blood serum on the 30th day of age were 18.45 +/- 2.44 mumol/l in experimental animals and 15.73 +/- 3.11 mumol/l in control animals. Zn content in the colostrum of experimental cows was 2.40 +/- 0.42 mg/l and in the control it was 1088 +/- 0.52 mg/l (P < 0.05). On day 5 of lactation, Zn amounts in the milk of experimental dairy cows decreased to 0.95 +/- 0.12 mg/l and to 0.76 +/- 0.10 mg/l in the control (P < 0.01). Zn levels in the milk of experimental cows on day 15 of lactation were 0.95 +/- 0.13 mg/l and in the milk of control group they were 0.82 +/- 0.14 mg/l. Colostrum specific weight from zinc-treated cows was 1,067.86 +/- 0.75 g/cm3 and 1,056.8 +/- 13.53 g/cm3 in the control. TP and IgC concentrations were 137.81 +/- 38.11 g/l and 110.13 +/- 29.91 U ZST, respectively, in the colostrum of experimental group, and 105.98 +/- 32.02 g/l and 85.53 +/- 25.42 U ZST, resp., in control animals.(ABSTRACT TRUNCATED AT 400 WORDS)     

Colostral immunoglobulin concentrations in Holstein and Guernsey cows.

OBJECTIVE: To compare the concentration of IgG in colostrum between Holstein and Guernsey cows and among cows of various lactations. DESIGN: Cross-sectional cohort study. SAMPLE POPULATION: Colostrum samples from 77 Holstein and 24 Guernsey cows. PROCEDURE: Colostrum samples were obtained from 101 cows. Colostral IgG concentration was determined, using a radial immunodiffusion assay. Regression analysis was used to determine the effect of breed and lactation number on colostral IgG concentration. Survival analysis and t-tests were used to compare the proportion of colostrum samples that would provide 100 g of IgG for various volumes of colostral intake. RESULTS: Guernsey cows produced 36.4 g of IgG/L of colostrum more than that of Holstein cows. Cows in the third or greater lactation produced 19.5 g of IgG/L of colostrum more than that of first-lactation cows. The IgG concentration of colostrum produced by second-lactation cows did not differ significantly from that produced by first-lactation cows. The colostral IgG concentration of these Holstein and Guernsey cows was higher than values that have been reported elsewhere. CONCLUSIONS AND CLINICAL RELEVANCE: Volume of colostrum needed to meet IgG intake goals is probably lower for Guernsey cows than Holstein cows. Colostrum from first-lactation cows was adequate in IgG content. The practice of discarding colostrum from first-lactation cows on the basis of inadequate IgG content was not justified in this study.     

Pathological changes in the reproductive organs of cows and heifers culled because of infertility

The reproductive organs of 20 Estonian Holstein Breed (EHF) cows and three heifers, culled because of infertility, were studied by palpation per rectum and ultrasonography. In addition, pathoanatomical and pathohistological studies were carried out after slaughtering. The pathohistological study revealed that small cysts often (12 animals) existed in culled cows, whose diameter was less than 2.5 cm. These cysts were frequently accompanied by changes in secondary and Graafi follicles, rete ovarii, ovarian stroma, and the endometrium. Three cows had follicular cysts in the ovaries, which were 25-35 mm in diameter. Two cows revealed luteal cysts in the ovaries; one of them had vaginal prolapse. Four animals (one heifer and three cows) manifested tumours or tumour-like malformations: ovarian endosalpingiosis, germ and stromal cell tumour, oviductal myolipoma, and haemangiosarcoma in the uterine blood vessels. One heifer had been culled because of two abscesses in the vaginal wall close to the cervix and another had chronic endometritis. The research findings indicate that the most common cause of infertility in the culled cows was cystic degeneration in ovaries (85%), accompanied by pathological changes elsewhere in the reproductive organs. We claim that these changes are responsible for the low pregnancy rate after the treatment of ovarian cysts. The second most common reason was genital tumours (15%). In heifers, infertility is rare and its causes are heterogeneous.     

Colostrum and milk performance,and blood immunity indices and minerals of Holstein cows receiving organic Mn,Zn and Cu sources

Effects of supplementing the basal diets with Mn, Zn and Cu, as sulphate, glycine or methionine salts, on colostrum and milk performance, some blood immunity indices and blood minerals of pre- and post-partum Holstein cows were accessed. Forty cows in different groups received: 1) a diet without supplementary Mn, Zn and Cu (control), 2) a diet containing Mn, Zn and Cu sulphates, 3) a diet containing Mn, Zn and Cu glycine, or 4) a diet containing Mn, Zn and Cu methionine with 10 cows per group from d 60 before calving (dry period) to d 100 of lactation. Dry matter intake (DMI), dry matter digestibility (DMD), colostrum and milk performance, milk somatic cell count (SCC), blood and milk total antioxidant capacity (TAC), immunoglobulin M (IgM) and immunoglobulin A (IgA), and blood Mn, Zn and Cu were determined. Dietary supplementation with Mn, Zn and Cu as methionine, glycine or sulphate salts had positive effects on DMD, DMI, colostrum and milk performance, milk SCC, and blood Mn and Zn. Addition of Mn, Zn and Cu in diets could increase (P < 0.05) blood and milk TAC and blood IgA and IgM in the cows and their new-born calves. There were no differences in DMI, DMD, colostrum and milk yields, milk SCC, blood Mn (except d 50 postpartum), Zn and Cu and TAC (except d 50 postpartum) among the organic and inorganic minerals-supplemented groups (P > 0.05), however, the blood concentrations of IgA (except d 1 postpartum) and IgM in the cows supplemented with organic Mn, Zn and Cu were higher (P < 0.05) than those in the cows receiving the sulphate sources of minerals. Overall, dietary supplementation of Mn, Zn and Cu as methionine, glycine or sulphate salts can improve colostrum and milk performance, blood Zn and Mn and immunity indices in Holstein cows and their new-born calves. Moreover, the organic sources of Mn, Zn and Cu have advantage over the sulphate forms in terms of the blood immunoglobulins.     

Über die Bedeutung von Mycoplasmen als Sterilitätsursache beim Rind*

A review of the literature is presented on the strains of Mycoplasma isolated from the bovine genital tract and their relationship to infertility. Although Mycoplasmas have frequently been isolated from the genital organs of bulls, no typical clinical symptoms have been observed and no detrimental effects on spermatozoa have been shown. Mycoplasmas can be transmitted to cows by artificial insemination. In contrast to bulls, Mycoplasmas have been described as causing inflammatory changes such as cervicitir, endometritis and salpingitis in cows. Salpingitis, which may lead to obstruction of the oviduct, has the most serious consequences of later infertility. The author's own observations on the occurrence of Mycoplasmas in the herds in one area are briefly described. Prophylactic and therapeutic measures against genital Mycoplasma infections in cattle are also given.     

Risk factors for postpartum endometritis and the effect of endometritis on reproductive performance in dairy cows in Korea

The objectives of this study were to determine the risk factors for postpartum endometritis by evaluating several reproductive factors in individual cows, and to determine the effect of endometritis on the subsequent reproductive performance in dairy herds in Korea. The data, including health status, parity and body condition score (BCS) of cows, and calving date, were collected from 320 cows in eight dairy herds calving from January 2001 to October 2002. We used logistic regression to evaluate the effects of these factors on endometritis. A stepwise procedure, used to obtain the appropriate model with alpha=0.05, revealed that retained placenta, metabolic disorders and parity are the important risk factors for endometritis. The mean intervals from calving to first service and conception were prolonged (P<0.01) by 23 and 36 days, respectively, in the endometritis group compared to the non-endometritis group. The first service conception rate was lower (P<0.05) in the endometritis group (47.6%) than in the non-endometritis group (62.6%). The number of services per conception was higher (P<0.05) in the endometritis group (1.9) than in the non-endometritis group (1.6). We conclude that retained placenta, metabolic disorders and cow parity are strongly correlated with the development of postpartum endometritis, which decreases reproductive performance in dairy herds in Korea.     

朊蛋白在奶牛生殖系统表达的定位

用免疫组织化学方法对奶牛生殖系统中朊蛋白进行定位研究,结果表明:在雌奶牛卵巢、子宫阜、子宫呈阳性,输卵管呈弱阳性。雄奶牛睾丸、附睾呈现弱阳性,其他器官为阴性。这说明在这些组织中有正常的PrP存在,为探索Prion致病机理、感染途径提供基础数据,也为朊病毒是否可以垂直传播提供了基础数据。     

Yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus) as zoomonitors of environmental contamination at a polluted area in Slovakia

Background

Free-living wild rodents are often used as zoomonitors of environmental contamination. In the present study, accumulation of cadmium (Cd), copper (Cu), iron (Fe), and zinc (Zn) in critical organs of yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus) trapped in a polluted area in Nováky, Slovakia was investigated.

Methods

Yellow-necked mice (n = 8) and bank voles (n = 10) were collected using standard theriological methods for wood ecosystems. All animals were adult males in good physical condition. The concentrations of Cd, Cu, Fe, and Zn in the liver, kidney, and bone were determined by atomic absorption spectrophotometry.

Results

The highest concentrations of Cd and Zn were found in the bone of both species while Cu and Fe accumulated mainly in kidney or liver. Significant higher concentrations of Cd and Cu were detected in the liver of bank voles than in yellow-necked mice. Similar significant higher levels of Cd and Zn were found in the bone of bank voles. In contrast, significant higher concentrations of Cu and Fe were present in the kidney of yellow-necked mice.

Conclusions

In the yellow-necked mouse and bank vole, bone seems to accumulate Cd and Zn following prolonged exposure. On the contrary, kidney and liver store Cu and Fe after a long-term environmental exposure. In the present study, bank voles seemed to be more heavy metal loaded zoomonitors than yellow-necked mice.     

Relationship between stress levels of the antepartum cow and her newborn calf

We investigated the relationship of the stress levels of the dam before and after delivery to that of her offspring soon after birth. Eight pregnant cows were penned 7 days before calving. Blood was taken from the jugular vein of cows at ?7, 1, 2 and 3 days from calving. Blood was also taken from newborn calves at 6 h and 1 and 2 days after birth. Concentrations of cortisol and immunoglobulin G in blood and colostrum were examined. Pearson's correlation coefficient showed that the higher the plasma cortisol concentration of a cow before calving, the higher that of its calf after birth (all P < 0.01). In addition, path analysis demonstrated that the direct effect of the plasma cortisol concentration of the dam before calving on the plasma cortisol concentration of her calf after birth was 0.971 (P < 0.01). However, the colostrum cortisol concentration correlated with neither plasma cortisol concentrations of cows before calving nor that of calves after birth. Unlike cortisol, a clear correlation of immunoglobulin G concentrations in plasma and colostrum was not observed between cows and calves. The results indicate stress is transferred from a cow to her newborn calf not by way of the colostrum but through the placenta.     

藏中矿区家畜组织中重金属分布与放牧环境关系研究

以藏中矿区土壤、牧草、家畜组织为对象,探讨土-草-畜系统中Cu、Zn、Pb、Cd这4种重金属分布情况与饲养环境的相关性。通过设立研究点的方法,采集矿区饲养环境中的土壤、牧草、家畜(牦牛、藏羊)组织进行含量检测。结果表明:藏中矿区及周边土壤中重金属Cu、Zn、Pb、Cd这4种元素均高于我国二级土壤限量值,Cu含量达限量值的2倍以上,Cd超标最严重。牧草、家畜组织体内重金属含量出现超标现象,牧草含量的分布顺序为Zn>Pb>Cu>Cd,这与土壤中重金属含量表现一致。牦牛体内Zn元素含量与远离矿区家畜(CK)相比差异显著(P<0.05),Cd含量与对照(CK)相比差异显著(P<0.05)。Cu、Zn存在超标现象,Cd、Pb两者存在差异但均未超标。矿区牦牛肉中Cu和牧草中Cu含量呈极显著的相关关系(P=0.836,P<0.01);牦牛肉中Zn含量与土壤和牧草中的Zn含量呈显著的相关关系(土壤P=0.631,牧草P=0.667,P<0.05);牦牛肉中Pb含量与牧草中Pb含量呈显著的相关关系(P=0.520,P<0.05);藏羊肉中Cu含量与牧草中Cu含量呈极显著相关关系(P=0.756,P<0.01)。矿区可食牧草中重金属向牦牛和羊肌肉迁移系数变化较大,迁移系数在0.19%~44.61%之间。     

Ultrastructural and Rheological Properties of Bovine Vaginal Fluid and its Relation to Sperm Motility and Fertilization: a Review

The tubular genital organs of the mammalian female reproductive tract provide different luminal microenvironments that can act as an aid or a barrier to gamete transport and the first steps of embryonic development. The mechanism of sperm transport through the genital tract has not been fully established but, first of all, sperm cells encounter and need to overcome mucous-like secretions to reach the site where fertilization occurs. One of these secretions, vaginal fluid, is a complex biological product, which is mainly derived from cervical mucus. In this review, we focus on recent studies that describe the relationships between the ultrastructural and rheological properties of bovine vaginal fluid and sperm motion. In the light of this, we propose bovine vaginal fluid as a morphofunctional model for the study of sperm transport in mammals.     

水牛初乳和常乳中锌、铁、铜含量的动态变化

 采用火焰原子吸收分光光度法对摩本杂水牛（摩拉水牛×德宏水牛）初乳和常乳中Zn、Fe、Cu等三种微量元素含量进行测定。结果表明,在第1 、2 d的初乳中Zn含量显著高于其余几天的初乳和常乳（P<0.05）,第3 d开始Zn含量接近常乳,在3 d至90 d之间稍有波动,但差异不显著（P>0.05）。Fe和Cu含量随泌乳进行逐渐降低,其在初乳中的含量均高于常乳,常乳之间差异不显著（P>0.05）。其中第1 d初乳中Fe含量显著高于第7 d （P<0.05）,而与其余几天初乳相比差异不显著（P>0.05）,第1、2 d初乳中Fe含量均显著或极显著高于常乳（P<0.05）;第1 d初乳中Cu含量显著高于第3、5 d的初乳（P<0.05）,与第2、7 d相比差异不显著（P>0.05）,第1、2 d初乳中Cu含量极显著高于常乳（P<0.01）。研究显示水牛初乳中Zn、Fe、Cu等三种微量元素的含量大都高于常乳,反映了乳腺在初乳期矿物质的分泌特点。