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991.
An N-balance experiment was conducted to test the hypothesis that d-Methionine (d-Met) has the same bioavailability and efficacy as l-Methionine (l-Met) when fed to weanling pigs. A Met-deficient basal diet containing 0.24% standardized ileal digestible (SID) Met was formulated. Six additional diets were formulated by adding 0.036%, 0.072%, or 0.108% d-Met or l-Met to the basal diet, and these diets, therefore, contained 77%, 87%, or 97% of the requirement for SID Met. Fifty-six barrows (10.53 ± 1.17 kg) were housed in metabolism crates and allotted to the seven diets with eight replicate pigs per diet. Feces and urine were collected quantitatively with 7-d adaptation and 5-d collection periods. Blood and tissue samples from pigs fed the basal diet and pigs fed diets containing 0.108% supplemental Met were collected on the last day. Results indicated that N retention (%) linearly increased (P < 0.01) as supplemental d-Met or l-Met increased in diets. Based on N retention (%) as a response, the linear slope-ratio regression estimated the bioavailability of d-Met relative to l-Met to be 101% (95% confidence interval: 57%–146%). The villus height and crypt depth in the jejunum were not affected by the Met level or Met source. Total antioxidant capacity or thiobarbituric acid reactive substance concentrations in plasma or tissue samples from pigs fed the control diet or diets containing 0.108% supplemental d-Met or l-Met were not different. Abundance of mRNA for some AA transporters analyzed in intestinal mucosa of pigs also did not differ. Therefore, it is concluded that d-Met and l-Met are equally bioavailable for weanling pigs.  相似文献   
992.
This study aimed to examine the bioavailability (BA) and pharmacokinetic (PK) characteristics of sulfadiazine (SDZ) in grass carp (Ctenopharyngodon idellus) after oral and intravenous administrations. Blood samples were collected at predetermined time points of 0.083, 0.17, 0.5, 1, 2, 4, 8, 16, 24, 48, 72, and 96 hr (n = 6). The samples were extracted and purified by organic reagents and determined by the ultra‐performance liquid chromatography. The software named 3P97 was used to calculate relevant PK parameters. The results demonstrated that the concentration–time profile of SDZ was best described by a one‐compartmental open model with first‐order absorption after a single oral dose. The main PK parameters of the absorption rate constant (Kα), the absorption half‐life (t1/2 Kα), the elimination rate constant (Ke), the elimination half‐life (t1/2Ke), and the area under concentration–time profile (AUC0‐∞) were 0.3 1/h, 2.29 hr, 0.039 1/h, 17.64 hr, and 855.78 mg.h/L, respectively. Following intravenous administration, the concentration–time curve fitted to a two‐compartmental open model without absorption. The primary PK parameters of the distribution rate constant (α), the elimination rate constant (β), the distribution half‐life (t1/2α), the elimination half‐life (t1/2β), the apparent distribution volume (VSS), the total clearance (CL), and AUC0‐∞ were 9.62 1/hr, 0.039 1/hr, 0.072 hr, 17.71 hr, 0.33 L/kg, 0.013 L h?1 kg?1, and 386.23 mg.h/L, respectively. Finally, the BA was calculated to be 22.16%. Overall, this study will provide some fundamental information on PK properties in the development of a new formulation SDZ in the future and is partially beneficial for the appropriate usage of SDZ in aquaculture.  相似文献   
993.
批次化生产是欧美等畜牧业发达国家开发的一种工厂化养猪模式,近年来我国也在逐渐推广应用,它显著提升了猪场生产效率与生物安全,尤其对当前我国非洲猪瘟防控和生猪产能恢复具有重要意义.文章简述了母猪批次化生产的研发历史,并综述了其技术优势、关键技术以及我国目前研发、应用情况,以期提高我国母猪批次化生产水平,促进养猪业转型升级.  相似文献   
994.
为探究雏鸭重组禽流感(H5+H7)三价灭活苗母源抗体消长规律,确定最佳首免日龄,将试验分为A组(种鸭免疫H5N1 Re-11+Re-12株、H7N9 H7-Re-2株、H5N2疫苗)和B组(种鸭免疫H5N2 rSD57株+rFJ56株、H7N9 rGD76株疫苗);选其孵化后的雏鸭各300羽,分别于1、7、14、21、...  相似文献   
995.
为提高畜牧兽医行政监管效能和信息化监管水平,河南省建立了智慧兽医云平台,实现了动物检疫全链条信息化闭环管理和畜产品质量安全全程可追溯.该平台首先将动物检疫电子出证监管向养殖场纵向延伸,强化产地管理,实行养殖档案电子化,通过编制不同颜色的二维码,实现养殖场的动态分类监管;然后实行畜禽屠宰从养殖场到屠宰场的"点对点"调运闭...  相似文献   
996.
刘涛 《猪业科学》2021,38(10):38-41
非洲猪瘟对家庭猪场的生产稳定性带来极大的挑战。文章分析了家庭猪场防控非洲猪瘟存在的问题及对关键点针对性的防控措施。  相似文献   
997.
近年来,"瘦肉精"、"苏丹红"、"三鹿奶粉"等食品安全事件接连发生,食品安全问题成为社会的焦点。食品安全直接关系人民群众身体健康与生命安全,已成为关系国民经济  相似文献   
998.
本文对罗氏沼虾蛋白质、脂类、碳水化合物、维生素及矿物质等营养成分的需要量的研究进行了综述.  相似文献   
999.
The parasite of genus Sarcocystis is one of the most commonly found parasite in domestic animals worldwide. Some species of Sarcocystis cause important economic loss when causing clinical and sub clinical disease. The aim of this study was to determine the prevalence of Sarcocystis in slaughtered Cattle in Kerman, Iran. The prevalence of Sarcocystis spp. infection was investigated in 480 cattle, slaughtered from May 2005 to February 2006 in the Kerman, Iran using naked eye examination for macroscopic Sarcocysts, and peptic digestion, muscle squash, squeezing methods for microscopic types. Muscles from heart, tongue, and esophagus, cervical and abdominal muscles of 480 slaughtered cattle were examined for Sarcocystis cysts. The prevalence of microscopic Sarcocystis cysts in cattle was detected in 100% and there was no macroscopic cyst in examined cattle.  相似文献   
1000.

Purpose  

To determine trends in calving ages and calving interval as measures of reproductive performance in Iranian Holsteins in Fars province, southern Iran during 2000–2005.  相似文献   
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