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【目的】了解硫酸头孢喹肟乳房注入剂(干乳期)对健康奶牛的正常体温、日产奶量、奶中体细胞数和乳房内菌群的影响。【方法】选用初产和经产健康泌乳期奶牛各6头,所选奶牛在试验前30日内未全身性或乳房内给予任何抗生素,奶牛正常饲养管理,日粮和饮水中不含有任何抗菌药物。给药前1和0日统计记录各试验奶牛的直肠温度、日产奶量(早、中、晚3次产奶量的加和)、检测每个乳区采集奶样的体细胞数,并对给药前0日的奶样进行病原菌分离鉴定。4个乳区分别单次给予硫酸头孢喹肟乳房注入剂(干乳期)。给药后的第1、3、5、7、10天分别统计记录每头奶牛的日产奶量,给药后的第12 h、3、5、7、10天分别采集奶样进行体细胞检测,同时检查直肠温度;给药后的第10天,采集奶样进行病原菌分离鉴定。比较奶牛用药前后直肠温度、日产奶量、牛奶体细胞数和奶中病原菌的变化。整个试验期间连续观察给药奶牛是否出现红、肿、热、痛等临床症状。【结果】给药前1天、0天和最后一次给药后的第1、3、5、7、10天,试验奶牛的日产奶量平均值分别为28.8、27.7、28.1、28.7、28.8、29.2和29.6 kg,卡方检验显示无显著性差异(P0.05);各时间点采集的奶中体细胞数大都维持在30—50万个/m L之间;各时间点测得的奶牛直肠温度平均值分别为38.3、38.4、38.3、38.3、38.3、38.2和38.3℃,无显著性差异(P0.05);病原菌检测结果显示,在给药前0日采集的奶样中,分离到大肠杆菌8株、链球菌5株和葡萄球菌7株,给药后第10天采集的奶样中大肠杆菌、链球菌和葡萄球菌各分离到1株,明显减少,且没有增加新的病原菌。【结论】硫酸头孢喹肟乳房注入剂(干乳期)对奶牛正常体温、产奶量和奶中体细胞数等没有不良影响,该制剂用于奶牛是安全的。 相似文献
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建立了高效液相色谱法(HPLC)测定牛奶及牛可食性组织中咪唑苯脲(IMD)残留.牛奶或已匀浆组织先用β-葡萄糖苷酶水解,组织用盐酸超声提取,再用提取液萃取,牛奶直接用提取液提取.用乙腈-戊烷磺酸钠水溶液作为流动相,经高效液相色谱C18柱分离后用紫外检测器检测.咪唑苯脲质量浓度在0.01~10.00μg/mL的范围内呈现良好的线性关系,相关系数大于0.999;组织加标样品检出限为0.01μg/g,定量限为0.02μg/g.在定量限、最高残留限量、2倍最高残留限量添加水平下的平均回收率为80.02%~114.72%,批内相对标准偏差为0.83%~10.92%,批间相对标准偏差为7.45%~12.69%.表明该检测方法简单、灵敏、可靠,适用于牛奶及牛组织中咪唑苯脲残留的分析. 相似文献
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气相色谱法检测牛奶中五氯苯酚残留量 总被引:1,自引:0,他引:1
建立了气相色谱-电子捕获检测器测定牛奶中五氯苯酚残留量的检测方法.样品经丙酮提取,乙酸酐衍生化,衍生物采用气相色谱-电子捕获检测器进行检测.结果表明,五氯苯酚衍生物响应信号与其质量浓度在5.00~500.00μg/L范围内线性关系良好,相关系数r2为0.999;在5、10和50μg/kg添加水平下,牛奶中待测物平均回收率分别为77.6%、87.2%和86.3%,相对标准偏差(RSD)小于9.6%;检测限为2μg/kg,定量限为5μg/kg.方法适合于牛奶中五氯苯酚残留检测. 相似文献
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盐酸环丙沙星在奶牛患子宫内膜炎时乳汁中的药动学及残留 总被引:3,自引:2,他引:3
研究通过子宫内灌注盐酸环丙沙星,采用内标法以反相高效液相色谱法测定了4头患子宫内膜炎的奶牛乳汁中盐酸环丙沙星的药物浓度,用MCPKP房室分析程序处理乳中药物浓度-时间数据。研究表明,患牛子宫内给药的血样药时数据经MCPKP处理符合一级吸收一室开放模型。乳样中主要药动学参数为:Ka为0.091 25 h-1,tmax为19.17 h,Cmax为0.018 25 靏mL-1,AUC为1.032 mg(Lh)-1,T1/2Ka为8.25 h,T1/2K为24.64 h。弃奶期为4 d。 相似文献
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Yue GENG Jing MA Ran JIA Li-qin XUE Chuan-jiang TAO Chong-jiu LI Xiao-dong MA Yan LIN 《农业科学学报》2013,12(2):305-313
The long-lasting application of representative herbicide atrazine (ATR) has given rise to the accumulation of its residues in the groundwater. To investigate the impact of long-term ATR use on groundwater safety, the residues of ATR and its metabolites, desethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HA) were monitored in groundwater and top soil at the major corn growing region of Qian'an and Gongzhuling in Jilin Province, China. The residues of the target compounds were analyzed by UPLC-MS/MS. The limits of detection (LODs) of ATR, DEA, DIA, and HA were 0.5, 0.5, 5, and 0.5 ng L?1 in groundwater and 0.33, 0.33, 3.3, and 0.33 μg kg?1 in soil. The target compounds were found in 94% of groundwater samples and 100% of soil samples. The compounds detected most frequently in groundwater were ATR (89%), DEA (64%) and HA (17%), whereas in soil were ATR (97%), DEA (36%) and HA (97%). DIA was not detected in any determined groundwater and soil sample. Average residues were 106.8 ng L?1 for ATR, 0.9 ng L?1 for DEA and 0.3 ng L?1 for HA in groundwater, whereas 11.1 μg kg?1 for ATR, 0.4 μg kg?1 for DEA and 7.8 μg kg?1 for HA in soil. ATR residues detected in groundwater samples were below standards for drinking water quality (GB5749-2006, 2 μg L?1), while the total residues of ATR and its chloro-s-triazine metabolites (DEA and DIA) were below current WHO (World Health Organization) guideline value (GV, 0.1 mg L?1). In addition, concentrations of HA in groundwater were determined below current WHO GV (0.2 mg L?1). The results indicated that ATR is safe to be used in Jilin Province under the current application scheme. However, total residues of ATR and DEA were detected in nearly all wells, thus, it is necessary to pay attention on groundwater monitoring for ATR and its metabolites. 相似文献
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Milk Yield of Holstein Cows Induced into Lactation Twice Consecutively and Lactation Curve Models Fitted to Artificial Lactations
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Jesus Mellado Edgar Sepulveda Jose E Garcia Alvaro Rodriguez Maria A De Santiago Francisco G Veliz Miguel Mellado 《农业科学学报》2014,13(6):1349-1354
Nineteen multiparous barren Holstein cows were subjected to an induction of lactation protocol for 21 d administering estradiol cypionate (2 mg kg−1 of body weight (BW) d−1, on day 1 to 14), progesterone (0.10 mg kg−1 of BW, on day 1 to 7), flumethasone (0.03 mg kg−1 of BW, on day 18 to 20) and recombinant bovine somatotropin (rbST; 500 mg per cow, on day 1, 6, 16 and 21). At the end of lactation and with a minimum of a 2-mon dry period, the same cows were again hormonally induced into lactation. Cows in both lactations were not artificially inseminated, they were milked 3 times daily and received rbST throughout lactation. Mean accumulated milk yield at 305 d in milk (DIM) did not differ between the first and second induced lactations ((9 710 ±1 728) vs. (9 309±2 150) kg; mean±SD). Total milk yield ((12 707±3 406) vs. (12 306±4 218) kg; mean±SD) and lactation length ((405±100) vs. (410±91) d; mean±SD) were not different between the first and second induced lactations. In a second study, 15 empirical models including exponential, power law, yield-density, sigmoidal and miscellaneous models were compared for their suitability by modeling 12-mon (n=334), 18-mon (n=164) and 29-mon (n=22) lactation cycles of Holsteins cows induced into lactation and treated with rbST throughout the lactation. Hoerl (Y= ab1/xxc), Wood (Y=axb exp(cx)) and Dhanoa (Y=ax(bc)exp(cx)) models were equally suitable to describe 12-mon lactations. An exponential model with five parameters (Y=exp(a+bx+cd2+e/x)) showed the best fit for milk yield for 18-mon lactations. The rational model (Y=a+bx/1+cx+dx2) was found to produce the closest fit for 29-mon lactations. It was concluded that, with the protocol used in the present study, multiparous cows respond favorably to a second cycle of induced lactation, with milk yield similar to that experienced during the first cycle. Thus, dairy producers might be able to lengthen the productive life of infertile high producing cows with a renewal of artificial lactation, which would imply an overall reduction in voluntary culling of cows. Also, various equations used to describe the lactation curves demonstrated the potential for fitting monthly milk records of Holstein cows with prolonged lactations and induced hormonally into lactation. 相似文献
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[目的]了解新疆地区奶牛和蛋鸡生产中常用抗生素类药物在牛奶和鸡蛋中的残留情况.[方法]按照新疆地区奶牛和蛋鸡生产中抗生素类药物的使用方法及剂量进行投放,采集牛奶及鸡蛋样品进行检测.[结果]青霉素钾在牛奶中的残留规律为停药1 d>5 d>3 d;头孢噻呋钠在牛奶中的残留规律为停药3 d>1 d>5 d;链霉素在牛奶中的残留规律为停药1 d>3 d>5 d;长效土霉素在牛奶中的残留量在停药1~11 d一直维持在175 μg/kg左右;停药1和3 d,酒石酸泰乐菌素在鸡蛋中的残留量为2 μg/kg左右;头孢噻呋钠在鸡蛋中的残留规律为停药7 d>5 d>3 d>1 d;环丙沙星在鸡蛋中的残留规律为停药11 d>7 d>5 d>1 d>3 d.[结论]除了长效土霉素外,其他药物在休药期内的残留量均低于中国和欧共体(EEC)规定的标准残留限量. 相似文献
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[目的]探讨奶牛头胎产犊日龄对其产奶量的影响。[方法]以宁夏平吉堡奶牛场一分场系谱资料比较完整的50头奶牛头胎产犊记录为资料,对奶牛头胎产犊日龄与305 d泌乳量进行相关分析。[结果]50头奶牛头胎产犊日龄与305 d泌乳量的相关系数为0.4482,达显著水平(P<0.05),即奶牛头胎产犊日龄与305 d泌乳量呈中等正相关。305 d泌乳量(y)与产犊日龄(x)之间的回归方程为y=8.173x+11.460。在744~887 d之间产犊的奶牛,其305 d泌乳量随头胎产犊日龄的增加而增大,可以预测该时期内奶牛的产奶量。[结论]奶牛头胎产犊日龄对其305 d泌乳量有较大影响。 相似文献
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加速溶剂萃取-超高效液相色谱串联质谱法测定大米中三环唑残留 总被引:1,自引:1,他引:0
建立了加速溶剂萃取结合超高效液相色谱串联质谱测定大米中三环唑残留的分析方法。大米中的三环唑经加速溶剂萃取仪萃取,中性氧化铝柱净化,采用超高效液相色谱串联质谱仪定量分析。结果表明,三环唑在2.0~100.0 ng/mL范围内具有良好的线性关系。本方法检出限为0.10μg/kg,回收率为78.2%~85.1%,相对标准偏差为5.6%~7.6%。此方法操作简便、快速、灵敏、精确,适于大米中三环唑残留量的分析测定。 相似文献
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产犊月份对荷斯坦牛产奶量的影响 总被引:1,自引:0,他引:1
以西安草滩第二牛场的荷斯坦牛为研究对象,选择2~4胎产奶量记录完整的健康母牛共587头,其中2胎217头,3胎196头,4胎174头,主要探讨产犊月份对产奶量的影响。将所有产奶数据校正到305d产奶量,用Excel进行统计分析,做出全年产奶量的整体分布曲线。对12个月份和4个季节的产奶量分别采用单因素方差分析,确定各月份和不同季节的影响效果。结果表明,冬季12、1、2月份和早春的3月份产犊的母牛305d产奶量最高,显著或极显著高于其他月份,属高产奶量月份;夏季6、7、8月份产犊的母牛305d产奶量最低,显著或极显著低于其他月份,属低产奶量月份;春季4、5月份和秋季9、10、11月份产犊的母牛305d产奶量处于中等水平,显著或极显著低于冬季和早春,但显著或极显著高于夏季,属中等产奶量月份。产犊月份对产奶量的影响效果表明,在保证全年牛奶供求基本平衡的前提下,适当调整在高产月份产犊,对提高奶牛群体产奶量具有重要意义。 相似文献
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【目的】研究乳房炎奶牛单剂量乳房灌注1%恩诺沙星(50 ml/头)后乳中药物浓度的变化规律。【方法】采用HPLC法测定乳中恩诺沙星及其代谢产物环丙沙星的浓度,用统计矩原理处理药物浓度—时间数据。【结果】在给药区恩诺沙星和代谢产物环丙沙星均于给药后2h左右乳中浓度达到最高值,分别为(13.16±3.10)μg?ml-1和(2.79±0.94)μg?ml-1,然后逐渐下降;12 h后检测不到恩诺沙星,24 h已检测不到环丙沙星。对于非给药区,恩诺沙星给药后1h左右乳中浓度达到最高值(0.19±0.02)μg?ml-1,然后逐渐下降;6 h后检测不到恩诺沙星,而代谢产物环丙沙星于给药后4 h乳药浓度可达最高峰(0.51±0.07)μg?ml-1,24 h已检测不到乳药浓度。给药区代谢物环丙沙星的消除半衰期较恩诺沙星长,平均为(1.67±0.20)h,平均滞留时间(MRT)亦长。在本试验条件下,建议临床休药期不少于3 d。【结论】恩诺沙星吸收较迅速 ,代谢较快、清除较快 ,表明恩诺沙星与环丙沙星在乳中不会形成残留。 相似文献
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原料奶生产环节微生物污染分析及防控措施研究 总被引:1,自引:0,他引:1
【目的】研究原料奶生产环节微生物菌落总数的变化规律,确定防控微生物污染的有效措施。【方法】通过测定原料奶生产各环节微生物菌落总数,分析微生物污染的变化规律,在此基础上研究不同奶牛乳房清洗消毒方式、舍弃奶量、贮存温度、运输条件等对原料奶中微生物菌落总数的影响,进而获得有效防控微生物污染的措施。【结果】奶站设备的卫生状况是造成不同奶站原料奶中微生物菌落总数存在明显差异的原因,奶牛乳房卫生状况、设备的卫生状况及贮存运输条件是造成同一奶站不同环节微生物存在明显差异的原因。温水清洗后擦干再用质量分数0.1% KMnO4溶液消毒奶牛乳房并擦干后,原料奶中菌落总数由未清洗时的2.65×104 cfu/mL降低到2.56×103 cfu/mL。舍弃奶量超过40 mL时,原料奶菌落总数小于1.00×103 cfu/mL,并趋于稳定。相同贮存时间下于0~4 ℃条件下贮存奶样中的微生物菌落总数增长较缓慢。4 927次收奶记录中的1 054 次微生物抽检记录显示,奶温越高、运输距离越长原料奶中微生物菌落总数越多。【结论】采取改善奶站设备卫生水平、温水清洗擦干后消毒奶牛乳房并擦干、机械挤奶前舍弃多于40 mL奶、将原料奶快速冷却至0~4 ℃贮存以及缩短运输距离、减少贮运温度波动等措施,均可有效控制原料奶的微生物污染。 相似文献
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A total of 12 mature healthy Holstein dairy cows of the nearly body weight (580±30) kg, milk yield (22.5±2.8) kg in the early stages of lactation were selected in this experiment. The cows were randomly divided into 2 groups, every group had 6 cows, every group had 6 repeats, and every repeat had 1 cow. Added 20 g protected methionine in earlier lactating cow food every day. The results showed that protected methionine increased milk yield by 10.83%, testing group milk yield was significantly different than that of control (P〈0.05); protected methionine increased milk fat by 5.98%, testing group milk fat was significantly different than that of control (P〈0.05); Milk protein increased by 2.15%, but bad insignificantly different (P〉0.05); dry matter of milk had the tendency of decrease, but had insignificant difference (P〉0.05). 相似文献
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Jian-bo CHENG Cai-yun FAN Xian-zhi SUN Jia-qi WANG Nan ZHENG Xing-kai ZHANG Jun-jie QIN Xiu-min WANG 《农业科学学报》2018,17(3):657-663
This experiment was conducted to evaluate the effects of Bupleurum extract(BE) on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were randomly assigned to 1 of 4 treatments. The treatments consisted of 0, 0.25, 0.5, and 1.0 g of BE kg–1 dry matter. Supplementation with BE decreased(P0.05) blood urea nitrogen(BUN) contents and increased blood total protein(TP) and albumin(ALB) levels compared with control cows, but it had no effects(P0.05) on blood glucose(GLU), nonesterified fatty acid(NEFA), total triglyceride(TG), low-density lipoprotein cholesterol(LDL-C), and high density lipoprotein cholesterol(HDL-C). Compared with control cows, cows fed BE had higher(P0.05) superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) activity. However, supplementation with BE had no effect(P0.05) on total antioxidant capacity(T-AOC) or malondialdehyde(MDA) levels. The immunoglobulin(Ig) A and G contents increased(P0.05) in cows fed 0.25 or 0.5 g of BE kg–1. Interleukin(IL)-2 and IL-4 levels were higher(P0.05) in cows fed 0.5 and 1.0 g of BE kg–1, and IL-6 was significantly elevated(P0.05) in cows fed 0.5 g of BE kg–1. There were no treatment effects(P0.05) on the CD4+ and CD8+ T lymphocyte ratios, CD4+/CD8+ ratio, or tumor necrosis factor-α(TNF-α) level among the groups. These findings suggest that BE supplementation may improve protein metabolism, in addition to enhancing antioxidant activity and immune function in heat-stressed dairy cows. 相似文献
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奶牛乳铁蛋白基因启动子区PCR-RFLP分析与乳房炎的相关性 总被引:7,自引:0,他引:7
采用CMT方法检测奶牛的乳房炎发病情况.筛选 90头分别设为对照组(健康奶牛)、隐性乳房炎组 (试验组Ⅰ )和临床乳房炎组(试验组Ⅱ),每组 30头.检测每头奶牛的NAGase活性,并用限制性片段长度多态性 (RFLP)分析技术,检测乳铁蛋白(Lf)基因启动子区域的RFLP多态性.结果表明:不同组别的奶牛之间NAGase活性差异显著 (P<0. 01),且Lf基因启动子区域存在RFLP多态性,说明该多态性与乳房炎存在一定关系,可能是奶牛乳房炎的一个分子标记. 相似文献