玉树牦牛12项血液生理生化指标的测定

对80头玉树牦牛的12项血液生理生化指标进行了测定。结果为：血红蛋白（Hb）86．41±13．07g／L,红细胞压积（PCV）0．46±0．034L／L,全血钾（BK）34．01±4．57mmol／L,红细胞钾（EK）67．24±9．45mmol／L,血清钾（SK）6．25±1．23mmol／L,血清钠（SNa）141．7±8．15mmol／L,血清总钙（STCa）2．3±0．52mmol／L,血清游离钙（SFCa）0．644-0．38mmol／L,血清结合钙（SBCa）1．63±0．37mmol／L,血清游离钙百分率27．82±7．3％,血清总蛋白87．3±11．3g／L,全血铁28．95±4．37mmol／L。公牦牛与母牦牛组各项指标均无差异显著;成年牦牛与牦牛犊之间除血清总蛋白外,其余各项指标均无显著差异。     

柴达木黄牛四项血清钙指标测定

对８５头柴达木黄牛的上项血清钙指标测定结果表明，犊牛的血清游离钙含量和淳离钙百分率显著地高于成年牛（Ｐ〈０．０１），而血清结合钙含量显著地低于成年牛（Ｐ〈０．０１）。     

饲粮不同磷水平对三黄鸡钙磷代谢和养分消化率的影响

为了探讨不同日粮磷水平对三黄鸡磷吸收及养分利用的影响,试验选择60日龄体重约1．5kg的三黄肉鸡40只,分为4个组,每组5个重复,每个重复2只鸡（一个代谢笼）。日粮磷水平分别为：A组TP=0．4％,B组TP=0．6％,C组TP=0．8％,D组TP=1．0％（钙：有效磷均为2：1）,其中B组为对照组。试验结果表明：血清AKP活性和钙的消化率不随日粮磷水平变化而差异变化（P〉0．05）,但日粮磷水平在0．8％时,血清AKP活性显著降低而钙的消化率达到最高。血清磷随日粮磷增加而增加,血清钙随日粮磷增加而下降（P〈0．01）。磷的消化率随日粮磷水平的改变发生显著变化。     

热应激对荷斯坦种公牛精液品质的影响及机理

用5头荷斯坦种公牛研究了热应激对其生理常值，精液品质，血清生化指标，精清生化指标的影响。结果表明：（1）热应激可造成种公牛精液品质显著下降，使原精活力，冻精活动，精子密度，活精子百分数和顶体完整率分别比春季下降3．13％（P＜0．01），1．11％（P＜0．01），34．8％（P＜0．01），15．0％（P＜0．01）和17．8％（P＜0．01），精子畸形率比春季上升25．5％（P＜0．01）。（2）夏季慢性热应激使荷斯坦种公牛的直肠温度和呼吸频率极显著高于春，米，立3个非热应激季节（P＜0．01）。（3）夏季荷斯坦种公牛血清睾酮，T3，皮质醇和促黄体素的含量分别为3.41ng/L,1.29ng/L,5.05ng/L和45.11ng/L，与非热应激季节相比，均处于较低的水平。（4）热应激可降低血糖和血清钠，钾，钙，镁水平（P＜0．01），使血清GPT，GOT处于最高水平（P＜0．01）。（5）夏季荷斯坦公牛精清睾酮含量仅为4.31ng/L，极显著低于非热应激季节（P＜0．01）。（6）热应激造成荷斯坦种公牛精清钾，钙，镁处于最低水平（P＜0．01），精清ALP，ACP处于最高水平（P＜0．01），使精清钠由春季至夏季呈显著下降趋势。上述结果显示：热应激使体内微环境发生了显著变化，抑制了下丘脑－垂体－睾丸轴的功能，从而影响了精子的生成和贮存。     

肉仔鸡低钙磷日粮添加植酸酶的研究

选取160只1日龄AA肉仔鸡,随机分成4组,研究在低钙、磷日粮和正常钙、磷日粮中添加植酸酶对肉仔鸡生产性能及钙、磷利用的影响。结果表明：植酸酶显著提高了肉仔鸡的日增重和采食量,并且以采食低钙、磷加酶日粮的肉仔鸡增重效果最为明显（P＜0．01）;显著降低了采食低钙、磷日粮肉仔鸡的料重比（P＜0．05）。采食低钙、磷加酶日粮肉仔鸡的胫骨灰分、钙含量和血清总钙、无机磷浓度显著提高（P＜0．05）;但采食正常钙、磷加酶日粮肉仔鸡上述胫骨与血清指标变化不大,表明植酸酶促进了肉仔鸡对低钙、磷日粮中钙和磷的吸收利用。     

莫河双峰驼羔血清钙和磷指标测定

对青海省海西州莫河驼场３６峰双峰驼羔的血清总钙、游离钙、结合钙、游离钙百分率和血清无机磷指标测定结果分别为２．６５±０．１７ｍｍｏｌ／Ｌ,１．３１±０．２１ｍｍｏｌ／Ｌ,１．３４±０．１３ｍｍｏｌ／Ｌ,４９．１５±６．１４％和２．３３±０．４５ｍｍｏｌ／Ｌ。     

热应激蛋鸡适宜钙磷水平研究

选用36周龄新扬州鸡产蛋母鸡600只,按2×2因子安排的完全随机设计分为4组（高钙低磷组、高钙高磷组、低钙低磷组、低钙高磷组）,每组5个重复,分别饲喂不同钙磷水平的玉米-豆粕型日粮,在热应激条件下（8：00～18：00维持36．5±3℃,其余时间29．1±3℃）饲养42d（包括14d预饲期、28d试验期）,研究饲粮不同钙磷水平对热应激产蛋鸡生产性能、蛋品质、血液生化指标的影响。高钙高磷组平均产蛋率不同程度高于其它3组（P〉0．05或P〈0．05）,蛋比重、蛋壳强度、蛋壳厚度、蛋壳比例等蛋品质指标也均显著高于其它3组（P〈0．05）,各组间血清中钙、磷、碱性磷酸酶水平差异不显著（P〉0．05）。研究结果表明,热应激条件下,饲粮钙磷水平分别为3．5％、0．32％,二者比例约11：1时,蛋鸡生产性能、蛋品质质量及血液生化指标最为理想。     

杜洛克杂种仔猪四项血清钙指标的研究

对青海省湟中县多巴镇猪场的20头杜洛克(父本)杂种仔猪的四项血清钙指标进行了测定。结果为:杜洛克二元杂交仔猪,血清总钙,2.40±0.12mmol/L;血清结合钙,1.57±0.20mmol/L;血清游离钙,0.85±0.19 mmol/血清游离钙百分率,35.27±7.64%。杜洛克三元杂交仔猪,血清总钙,2.45 0.24mmol/L;血清结合钙,1.66±0.13mmol/L;血清游离钙,0.80±0.22mmol/L;血清游离钙百分率,32.12±6.64%。且公、母仔猪间四项钙指标差异不显著(P>0.05)。     

高锌对艾维菌肉鸡血液病理学的系统研究

试验将1日龄艾维菌肉鸡健雏200只随机分为4组,分别喂以基础日粮（Zn 100mg／kg,A组）、高锌日粮Ⅰ（Zn1500mg／kg,B组）、高锌日粮Ⅱ（Zn2000mg／kg,C组）和高锌日粮Ⅲ（Zn2500mg／kg,D组）,试验期为7周。结果表明：B组血清碱性磷酸酶（AKP）活性显著升高（P〈0．05）,D组显著降低（P〈0．05）;血清碱性磷酸酶的同工酶亦受到不同程度的影响;谷丙转氨酶（GPT）、淀粉酶（AMY）活性各试验组显著升高（P〈0．05）;肌酸激酶（CK）活性在试验初期升高,中期不同程度降低（P〈0．05）,试验结束时与对照组无显著差异（P〉0．05）;血清总蛋白（TP）、球蛋白（GLB）含量随锌水平的升高而升高,白蛋白（ALB）含量下降,但均与对照组比较差异不显著（P〉0．05）;血清锌含量随饲料锌水平增高而显著升高（P〈0．05）;血清中钙、磷含量则与饲料锌水平呈负相关。     

阴离子型日粮及补Ca对围产期奶牛代谢与健康及其生产性能的影响

将36头干奶后期中国荷斯坦奶牛随机分为对照组、试验Ⅰ组、试验Ⅱ组（每组12头）．分别饲喂常规日粮、阴离子型日粮及在此基础上朴Ca日粮，探讨其对奶牛体内代谢状况、健康状况及生产性能的影响。与饲喂常规日粮相比，饲喂阴离子型日粮可降低奶牛尿液pH值（P〈0．01）和血液HCO2^-浓度（P〉0．05）；增加奶牛产后12h（P〈0．05）、2d（P〈0．05）血清总钙含量．对血清无机磷、镁含量没有显著影响；明显降低奶牛亚临床性低血钙率（33％）、胎衣不下率（33％）和乳房水肿率（17％）；增加牛奶乳糖率（P〈0．05），对其他奶成分和奶产量没有显著影响（P〉0．05）。在阴离子型日粮中补Ca后．与饲喂阴离子型日粮相比．除增加奶牛产后血清镁含量外（P〈0．05）．对其他各项指标没有明显影响。     

巴贝斯虫病水牛血清钙镁浓度变化与染虫率的关系

自水牛巴贝斯虫病非疫区购买的无任何血液原虫寄生的健康水牛犊２头，人工摘除脾脏后，用从疫区采集的饥饿镰形扇头蜱叮咬感染，观察巴贝斯虫的消长与血清钙、镁浓度的变化，结果发现二者关系密切，其中钙离子浓度与红细胞染虫率呈负相关，镁离子浓度与红细胞染虫率呈正相关，这一发现为进一步研究水牛巴贝斯虫病及在体内外研究巴贝斯虫的生长繁殖均具有重要意义。     

Colostral transfer of gamma glutamyl transpeptidase in calves

Serum gamma glutamyl transpeptidase (GGT) levels in blood samples taken from normal calves which bad suckled colostrum were much higher than those found in healthy adult cattle. Levels of over 60 times the normal adult level were observed. These high levels of GGT took approximately 5 weeks to decline to adult values. Calves which appeared to have not received or absorbed colostrum had GGT levels which would be considered normal in adult cattle. A calf with serum gamma globulin levels which indicated an intermediate amount of colostrum absorption had a level of GGT which was intermediate between that expected for normal adult cattle and that found in calves which had more fully absorbed colostrum. The mean GGT level observed in colostrum from 6 newly-calved cows was over 800 times the mean serum GGT level of the same 6 cows. It therefore appears most likely that GGT is concurrently absorbed with colostrum by calves and this gives rise to the very high levels seen in normal calves.

Calves with very high levels of serum GGT also had raised levels of alkaline phosphatase (AP) which slowly declined but never reached normal adult levels within the 53-day period of observation.

It therefore appears that high levels of both GGT and AP are achieved by calves at the time of colostrum absorption and it is concluded that clinical interpretation of serum GGT and AP levels in young calves is closely dependent upon parallel knowledge of their serum gamma globulin levels.     

Colostral transfer of gamma glutamyl transpeptidase in calves

Serum gamma glutamyl transpeptidase (GGT) levels in blood samples taken from normal calves which bad suckled colostrum were much higher than those found in healthy adult cattle. Levels of over 60 times the normal adult level were observed. These high levels of GGT took approximately 5 weeks to decline to adult values. Calves which appeared to have not received or absorbed colostrum had GGT levels which would be considered normal in adult cattle. A calf with serum gamma globulin levels which indicated an intermediate amount of colostrum absorption had a level of GGT which was intermediate between that expected for normal adult cattle and that found in calves which had more fully absorbed colostrum. The mean GGT level observed in colostrum from 6 newly-calved cows was over 800 times the mean serum GGT level of the same 6 cows. It therefore appears most likely that GGT is concurrently absorbed with colostrum by calves and this gives rise to the very high levels seen in normal calves. Calves with very high levels of serum GGT also had raised levels of alkaline phosphatase (AP) which slowly declined but never reached normal adult levels within the 53-day period of observation. It therefore appears that high levels of both GGT and AP are achieved by calves at the time of colostrum absorption and it is concluded that clinical interpretation of serum GGT and AP levels in young calves is closely dependent upon parallel knowledge of their serum gamma globulin levels.     

Acute phase proteins in cattle after exposure to complex stress

Stressors such as weaning, mixing and transportation have been shown to lead to increased blood concentrations of acute phase proteins (APP), including serum amyloid A (SAA) and haptoglobin, in calves. This study was therefore undertaken to assess whether SAA and haptoglobin levels in blood mirror stress in adult cattle. Six clinically healthy Holstein cows and two Holstein heifers were transported for four to six hours to a research facility, where each animal was housed in solitary tie stalls. Blood samples for evaluation of leukocyte counts and serum SAA and haptoglobin concentrations were obtained before (0-sample) and at 8, 24 and 48 hours after the start of transportation. Upon arrival the animals gave the impression of being anxious, and they appeared to have difficulty coping with isolation and with being tied on the slippery floors of the research stable. Serum concentrations of SAA and haptoglobin increased significantly in response to the stressors (P < 0.01 and 0.05 at 48 hours, respectively). Additionally, the animals had transient neutrophilia at 8 and 24 hours (P < 0.05). In conclusion, the results of the study suggest that SAA and haptoglobin may serve as markers of stress in adult cattle.     

Determinants and Utility of the Anion Gap in Predicting Hyperlactatemia in Cattle

The objectives of this study were to investigate the determinants of the anion gap (AG) in cattle and to evaluate the utility of AG in detecting hyperlactatemia in sick neonatal calves and adult cattle. The AG was calculated as AG = ([Na+] + [K+]) - ([Cl^-] + [HCO₃]), with all values in mEq/L. The AG of healthy neonatal calves (n = 16) was 29.6 ± 6.2 mEq/L (mean ± SD), and the blood L-lactate concentration ranged from 0.5 to 1.2 mM/L. The AG was significantly (P > .05) correlated with serum phosphate (r = .66) and creatinine (r = .51) concentrations. The AG of neonatal calves with experimentally induced diarrhea (n = 16) was 28.6 ± 5.6 mEq/L, and the blood L-lactate concentration ranged from 1.1 to 2.9 mM/L. The AG was significantly correlated with blood L-lactate concentration (r = .67), serum phosphate concentration (r = .63), creatinine concentration (r = .76), and blood pH (r = -.61). The AG of adult cattle with abomasal volvulus (n = 41) was 20.5 ± 7.8 mEq/L, and the blood L-lactate concentration ranged from 0.6 to 15.6 mM/L. The AG was significantly correlated with blood L-lactate concentration (r = .60), serum phosphate concentration (r = .71), creatinine concentration (r = .65), albumin concentration (r = .47), total protein concentration (r = .54), blood pyruvate concentration (r = .67), and blood pH (r = -.41) but not plasma β-OH butyrate concentration. The results indicate that the AG in cattle is only moderately correlated with blood L-lactate concentration and is similarly correlated with serum phosphate and creatinine concentrations in neonatal calves and adult cattle, as well as with serum albumin and total protein concentrations in adult cattle. Anion gap determination is of limited usefulness in predicting blood L-lactate concentration in sick cattle, whereas the correlation between AG and serum creatinine concentration in sick cattle suggests that an increased AG should alert the clinician to the potential presence of uremic anions.     

Experimental reproduction of winter dysentery in lactating cows using BCV -- comparison with BCV infection in milk-fed calves

Infection models were developed for adult cows and for young calves using the same strain of bovine coronavirus (BCV), which for the first time allows experimental reproduction of winter dysentery (WD) in seronegative lactating cows. The cattle were infected through direct contact with an experimentally inoculated calf. All experimental cattle shed faecal BCV with development of diarrhoea, being profusely watery with small amounts of blood in the most severely affected animals, including both cows and calves. The cows, in contrast to the calves, showed depressed general condition and appetite leading to a marked decrease in milk yield. Further age-associated differences were a shorter incubation period in the two youngest calves, but with milder fever and milder decrease in white blood cell counts. These findings shed light on the apparent epidemiological differences between WD and calf BCV diarrhoea suggesting that, (1) the same strains of BCV cause natural outbreaks of calf diarrhoea and WD, (2) seronegative cows are more severely affected by the infection than seronegative conventionally reared calves, and (3) unaffected general condition in diarrhoeic calves may lead to underestimation of the occurrence of calf diarrhoea in WD outbreaks.In response to infection, all cattle produced early interferon type 1 in serum and, except for one calf, in nasal secretions. A finding not previously reported is the detection of interferon type 1 responses in bovine milk. All cattle developed high IgM antibody responses and long-lasting IgA antibody responses both systemically and locally. The serum IgM antibody responses came earlier in most of the calves than in the cows. Prolonged IgM antibody responses were detected in serum and milk, while those in nasal secretions were much shorter. BCV-specific IgA was present in nasal secretions from all cattle throughout the 6 months follow-up. The IgA antibody response in serum was detected up to 17 months post-infection and the duration showed an age-related variation indicating a more prominent IgA memory in the adult cattle and in the older calves than in the younger ones. BCV-specific IgG was detected in all cattle during the experimental period of up to 22 months. In conclusion, WD was reproduced in seronegative lactating cows. The cows showed a more severe general diseases than seronegative calves infected concurrently. Very long-lasting IgA antibody responses were detected both systemically and locally.     

大豆黄酮对奶牛血清钙、磷及葡萄糖水平的影响

为研究大豆黄酮对奶牛血清钙、磷和葡萄糖水平的影响,40头胎次、产奶量、泌乳期相近的中国荷斯坦奶牛随机分成4组(n=10),试验组奶牛日粮中分别添加45mg/kg、60mg/kg和75mg/kg的大豆黄酮,在试验前及试验开始后第10d、20d和30d采颈静脉血,测定四组奶牛血清钙、磷和葡萄糖水平。结果表明:与对照组相比较,Dal组中血清钙、磷和葡萄糖变化均不显著;Da2组血清钙在第30d时显著高于对照组(P<0.05);Da3组第10d和20d时血清钙水平显著高于对照组(P<0.05),第30d时血清钙水平极显著高于对照组(P<0.01),而血糖水平显著高于对照组(P<0.05)。     

Serum 25-hydroxyvitamin-D concentrations in beef cattle herds in which ruptures of the Achilles tendon had occurred

The frequency of skeletal disorders including ruptures of the Achilles tendon has increased during the last years in Swedish beef cattle herds, especially in intensively raised calves. The serum concentrations of 25-hydroxyvitamin-D, calcium and inorganic phosphorus were analysed in 7 affected and 3 control herds. None of the animals in affected herds had detectable amounts of serum-25-OH-D₃ (≤ 2 ng/ml) while the control animals had a concentration of 36.1 ng/ml (least squares mean). Calcium and inorganic phosphorus were also significantly lower in the affected herds (P ≤ 0.001). In 1 herd the animals were randomly divided into 4 groups and treated in one of the following ways: Orally with vitamin AD₃E or D₃, intramuscularly with D₂ or D₃. The effect of treatment on serum Ca and P_i was measured 1 month later and was found to be equally high in the 4 groups.