燕麦皮和甜菜粕对1～42 d肉鸡生长性能、消化道发育及营养物质消化率的影响

文章旨在对比日粮中添加纤维原料(燕麦皮或甜菜粕)对1～42 d肉鸡生长性能、消化道发育及营养物质消化率的影响。试验选择1日龄肉仔鸡336只,随机分为3组,每组4个重复,每个重复28只鸡。对照组饲喂玉米-豆粕型基础日粮,燕麦皮和甜菜粕组分别在基础日粮中添加0.2%燕麦皮或甜菜粕,试验共进行42 d。结果表明:与对照组相比,燕麦皮和甜菜粕组显著降低了1～10 d肉鸡料肉比(P 0.05);燕麦皮较对照组显著提高了1～10 d肉鸡日增重(P 0.05);燕麦皮组较对照组显著提高了1～42 d肉鸡的日采食量(P 0.05),较对照组和甜菜粕组显著提高了日增重(P 0.05),燕麦皮和甜菜粕组较对照组显著降低了试验全期的料肉比(P 0.05)。日粮添加纤维原料较对照组显著提高了肌胃的重量(P 0.05),其中甜菜粕组肌胃重量最高(P 0.05)。与对照组相比,燕麦皮和甜菜粕组显著提高了肌胃内容物含量和胃肠道相对重量(P 0.05)。日粮添加燕麦皮和甜菜粕颗粒显著提高了干物质、有机物、粗脂肪、灰分、氮和代谢能的表观消化率(P 0.05)。结论 :燕麦皮可以显著提高肉鸡生长性能和氮的表观消化率,而甜菜粕可以改善1～10 d肉鸡生长性能,但对25 d后肉鸡的生长性能有负面作用。     

日粮豌豆皮添加水平对肉仔鸡生长性能、养分消化率及胃肠道发育的影响

文章旨在研究日粮添加适宜水平的豌豆皮对肉鸡生长性能、养分消化率及胃肠道发育的影响。选择1日龄肉仔鸡500只,随机分为4组,每组5个重复,每个重复25只鸡,对照组饲喂基础日粮,试验组在基础日粮中添加1.5%、3.0%和6.0%的豌豆皮,试验分为1～7 d、8～14 d和15～21 d三个阶段,共21 d。结果显示:1.5%豌豆皮组较对照组和6.0%豌豆皮组显著降低了1～7 d肉鸡料重比(P 0.05);6%豌豆皮组较对照组和1.5%豌豆皮组显著提高了8～14 d肉鸡能量利用率(P 0.05)。3%豌豆皮组较对照组和6%豌豆皮组显著提高了15～21 d肉鸡日增重,而1.5%和3%豌豆皮组较6%水平组显著降低了15～21 d肉鸡料重比(P 0.05);对于试验全期,3%豌豆皮组日增重最高(P 0.05),1.5%和3%水平组料重比最低(P 0.05),对照组能量利用率最低(P 0.05)。6%豌豆皮组较对照组显著降低了空肠的隐窝深度(P 0.05),而1.5%豌豆皮组较对照组和6%水平组显著提高了绒毛高度/隐窝深度(P 0.05)。1.5%豌豆皮组较其他组显著提高了有机物和干物质的表观消化率(P 0.05),3%豌豆皮组较对照组和6%水平组显著提高了灰分的表观消化率(P 0.05),6%豌豆皮组能量消化率最低(P 0.05)。结论 :在本试验条件下,日粮中适宜的豌豆皮添加水平不宜超过3%,可以提高养分消化率和生长性能。     

亚麻籽对肉鸡生长、屠宰性能及肉品质的影响

文章旨在研究日粮添加不同水平亚麻籽对肉鸡生长、屠宰性能及肉品质的影响。试验选择1日龄AA肉鸡512只,随机分为4组,每组4个重复,每个重复32只鸡。试验以玉米-豆粕为基础日粮,各组日粮分别在基础日粮中添加0、5%、10%和15%亚麻籽,试验分为两个阶段,共进行42 d。15%亚麻籽组比对照组日增重显著降低10.27%(P <0.05),同时试验后3周体重显著降低7.28%(P <0.05)。随着日粮亚麻籽添加水平的升高,整个试验期肉鸡日增重显著降低(P <0.05)。对照组和5%亚麻籽组较10%和15%亚麻籽组显著降低了0~3周肉鸡料肉比(P <0.05),而对照组较5%和15%亚麻籽组显著降低了4~6周肉鸡料肉比(P <0.05),同时对照组较所有亚麻籽组显著降低了试验全期料肉比(P <0.05)。5%和15%亚麻籽组较对照组显著降低了肉鸡蛋白质和能量利用效率(P <0.05)。与其他各组相比,15%亚麻籽组显著降低了肉鸡胴体重(P <0.05);15%亚麻籽组较对照组和10%亚麻籽组显著降低了胸肌相对重量(P <0.05),而对照组较5%和15%亚麻籽组显著降低了腿肌相对重量(P <0.05)。随着日粮亚麻籽添加水平的升高,胸肌和腿肌亚麻酸含量显著升高(P <0.05),但对照组与5%亚麻籽组对腿肌亚麻酸含量无显著影响(P> 0.05),10%和15%亚麻籽组较对照组显著提高了胸肌和腿肌亚油酸含量(P <0.05)。在本试验条件下,日粮添加15%亚麻籽使肉鸡日增重降低8.2%,但日粮添加亚麻籽可以提高胸肌和腿肌亚油酸和亚麻酸含量,因此,日粮中适宜的亚麻籽添加水平为10%。     

甜菜粕替代玉米对肉牛生长性能及瘤胃发酵成分的影响

文章旨在研究日粮添加不同水平甜菜粕替代玉米对肉牛生长性能、瘤胃发酵能力及营养物质表观消化率的影响。试验选择初始体重为(237.2±24.5)kg的肉牛36头,随机分为4组,每组9头牛,每头牛作为1个重复,试验共进行20周。试验基础日粮以玉米和青贮高粱为主,处理组分别用33%、67%和100%甜菜粕等量替代玉米。结果:试验期间肉牛总增重和日增重随甜菜粕替代水平的升高表现为显著二次曲线效应(P<0.05),料比表现为显著二次曲线降低(P<0.05)。日粮添加甜菜粕显著提高肉牛瘤胃pH(P<0.05),33%甜菜粕替代玉米组瘤胃氨氮含量最高(P<0.05);随着日粮甜菜粕添加水平的升高,总脂肪酸、乙酸、丁酸含量及乙酸与丙酸比值表现为显著线性升高(P<0.05),而丙酸和异丁酸含量表现为显著线性降低(P<0.05)。有机物、粗蛋白质、中性洗涤纤维、酸性洗涤纤维和纤维素摄入量随日粮甜菜粕水平的升高表现为显著二次曲线增加效应(P<0.05),而粗脂肪摄入量表现为显著二次曲线降低效应(P<0.05)。有机物、中性洗涤纤维、纤维素和半纤维素表观消化率随甜菜粕水平的升高表现为显著线性升高(P<0.05)。血清肌酸酐、胆固醇水平随甜菜粕添加水平的升高表现为显著线性降低(P<0.05),而血清尿素氮、甘油三酯、IGF-1、皮质醇和T4含量表现为显著二次曲线升高效应(P<0.05)。结论:在本试验条件下,肉牛日粮用甜菜粕替代玉米可有效提高营养物质的消化率,改善肉牛瘤胃的发酵能力,在不损害动物健康的前提下提高日增重,降低料肉比,其适宜替代水平为67%。     

不同葵花粕用量对黄羽肉鸡生产性能和屠宰性能的影响

为研究饲粮中不同葵花粕用量对黄羽肉鸡生产性能和屠宰性能的影响，选择1日龄雌性黄羽肉鸡2240只，分为0%（对照组）、5%、10%、15%共四组，每组8个重复，每重复70只。保证各组的主要营养水平一致，试验共70 d。结果表明：与对照组相比，饲粮中使用15%的葵花粕对黄羽肉鸡前50 d的日增重、日采食量、料肉比均未产生显著影响（P> 0.05）；与对照组相比，15%葵花粕组51～70 d的日增重显著降低了8.8%(P <0.05),51～70 d和1～70 d的料肉比分别显著增加了11.5%、4.3%(P <0.05);5%、10%、15%葵花粕组的全净膛率分别显著降低了2.8%、2.3%、2.6%(P <0.05)，腹脂率分别显著提高了31.2%、28.1%、33%(P <0.05)；肌胃率分别显著增加了13.6%、14.8%、19.8%(P <0.05)。在本试验条件下，饲粮中前中期使用15%的葵花粕，后期使用10%的葵花粕不会显著影响黄羽肉鸡的生产性能，但使用葵花粕会降低黄羽肉鸡的屠宰性能。     

菜粕型日粮添加腐殖酸对肉鸡生长性能、肉品质及饲养成本的影响

文章旨在评估菜粕型日粮添加腐殖酸对肉鸡生长性能、胴体性状及肉品质的影响。试验将675只体重接近的1日龄商品肉仔鸡随机分为3组,每组5个重复,每个重复45只。各组肉鸡分别饲喂豆粕型日粮、菜粕型日粮、菜粕型日粮+5 g/kg腐殖酸,试验为期42 d。结果：菜粕组21 d体重、1～42 d日增重均显著低于豆粕组（P＜0.05）,同时豆粕组和腐殖酸组42 d肉鸡体重、22～42 d平均日采食量显著高于菜粕组（P＜0.05）,而1～21 d料重比显著低于菜粕组（P＜0.05）。豆粕组和腐殖酸组肉鸡胸肌重量、十二指肠、空肠和回肠长度显著高于菜粕组（P＜0.05）,但菜粕组心脏重量显著高于其他两组（P＜0.05）。腐殖酸组肌胃重量显著高于豆粕和菜粕组（P＜0.05）。腐殖酸组肌肉系水力、肉色a值、C18：0含量均显著高于其他两组（P＜0.05）。豆粕组肌肉C14：0和C16：0脂肪酸浓度显著高于其他两组（P＜0.05）,但C20：6脂肪酸浓度显著降低（P＜0.05）。结论：饲喂菜粕型日粮降低了1～42 d肉鸡的生长性能,补充5 g/kg腐殖酸可以改善生长性能,提高胸肌产量及肌肉中不饱和脂肪酸含量。 [关键词]菜粕|腐殖酸|肉鸡|生长性能|肉品质|脂肪酸|饲养成本     

糖化玉米秸秆对22～42日龄肉鸡生长性能、养分代谢率、屠宰性能及肉品质的影响

本试验旨在探讨糖化玉米秸秆(SCS)对22~42日龄肉鸡生长性能、养分代谢率、屠宰性能及肉品质的影响。选择22日龄健康的雌性爱拔益加(AA)肉鸡200只,随机分为4个组,每组5个重复,每个重复10只鸡。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加4%(Ⅰ组)、8%(Ⅱ组)和12%(Ⅲ组)的SCS。试验期21 d。结果表明:1)Ⅰ、Ⅱ和Ⅲ组肉鸡平均日采食量显著高于对照组(P<0.05),Ⅱ组肉鸡末重和平均日增重显著高于对照组(P<0.05)。各组之间料重比差异不显著(P>0.05)。2)各组之间能量、干物质、粗蛋白质、粗脂肪、钙、磷、中性洗涤纤维和半纤维素代谢率差异不显著(P>0.05)。Ⅱ和Ⅲ组酸性洗涤纤维、纤维素代谢率显著低于对照组(P<0.05)。3)各组之间屠宰率、腿肌率和腹脂率差异不显著(P>0.05)。Ⅰ、Ⅱ和Ⅲ组全净膛率显著高于对照组(P<0.05),Ⅰ组胸肌率显著高于对照组(P<0.05)。4)Ⅰ和Ⅲ组胸肌45 min pH显著低于对照组(P<0.05)。Ⅲ组胸肌滴水损失显著低于Ⅰ组(P<0.05),Ⅲ组腿肌滴水损失显著低于其他各组(P<0.05)。Ⅰ、Ⅱ和Ⅲ组腿肌熟肉率显著低于对照组(P<0.05)。Ⅲ组胸肌剪切力显著高于其他各组(P<0.05)。Ⅰ组胸肌红度(a*)值显著低于对照组(P<0.05),Ⅲ组腿肌a*值显著低于对照组(P<0.05)。由此可见,22~42日龄肉鸡饲粮中添加SCS能够促进肉鸡生长,提高全净膛率,但对肉品质有一定的影响,表明饲粮中添加4%~12%的SCS替代能量饲料是可行的。     

棕榈粕和复合酶对肉鸡生长性能、养分表观消化系数和表观留存率的影响

文章旨在研究肉鸡日粮中添加不同水平的棕榈粕和复合酶对肉鸡生长性能、养分表观消化系数和表观留存率的影响。试验选择健康、体重均一的1日龄肉仔鸡1152只,随机分为8组,每组4个重复,每个重复36只鸡。采用4×2因子设计试验日粮,即0、7%、14%和21%棕榈粕和0、150 mg/kg复合酶,试验共进行21 d。试验结果 :与对照组相比,7%、14%棕榈粕水平组显著提高肉鸡日增重(P 0.05);日粮添加150 mg/kg复合酶显著提高肉鸡日增重(P 0.05);日粮棕榈粕添加水平显著影响肉鸡日采食量,其中7%棕榈粕组肉鸡日采食量最高,21%棕榈粕组最低(P 0.05);对照组和7%棕榈粕组显著降低了肉鸡料重比(P 0.05)。对照组和14%棕榈粕组添加复合酶显著提高氮和总能的回肠表观消化系数(P 0.05);日粮棕榈粕添加水平显著提高淀粉和脂肪的回肠表观消化系数(P 0.05);对照组和14%棕榈粕组显著提高干物质和中性洗涤纤维表观存留率(P 0.05);对照组和7%棕榈粕组较14%和21%棕榈粕组显著提高氮和脂肪表观存留率(P 0.05);随着棕榈粕添加水平的升高,总能表观存留率显著降低(P 0.05),而添加复合酶可以提高总能存留率(P 0.05),21%棕榈粕组表观代谢能存留率最低(P 0.05)。结论 :在本试验条件下,氨基酸平衡日粮中棕榈粕适宜添加水平不超过14%,同时添加复合酶可以提高肉鸡生长性能。     

棕榈粕对肉兔生长性能及养分利用率的影响

文章旨在研究日粮添加棕榈粕对肉兔生长性能及养分利用率的影响。本研究开展了两个试验。试验1选择20只50 d的肉兔,平均体重为(1.55±0.18)kg,随机分为两组,每组10只用于代谢试验。试验2选择35 d断奶肉兔96只,随机分为两组,每组4个重复,每个重复12只,对照组饲喂基础日粮,试验组用20%的棕榈粕等量替代基础日粮,试验由断奶当天到63 d。结果显示:试验日粮较基础日粮显著提高了干物质、有机物和粗蛋白质的表观消化系数(P <0.05),显著提高了粗脂肪、中性洗涤纤维和酸性洗涤纤维的表观消化系数(P <0.05)。日粮添加棕榈粕显著提高了半纤维素和纤维素的表观消化系数(P <0.05),对酸不溶蛋白的表观消化系数无显著影响(P> 0.05)。与基础日粮组相比,棕榈粕组日增重显著降低了4.8%(P <0.05)。日粮添加20%棕榈粕对粪中产气荚膜杆菌的数量无显著影响(P> 0.05),但自由采食条件下,基础日粮组和棕榈粕组均显著提高了粪中产气荚膜杆菌的含量(P <0.05)。结论 :棕榈粕对肉兔是一种较好的纤维、蛋白质和脂肪来源,可以代替部分日粮中的部分苜蓿草粉。日粮添加20%棕榈粕可以提高肉兔的生长性能,对饲料消化率无负面影响。     

热带假丝酵母发酵棉籽粕对白羽肉鸡蛋白质代谢的影响

本试验旨在研究饲粮中添加不同水平热带假丝酵母发酵棉籽粕替代豆粕对白羽肉鸡蛋白质代谢的影响。选取1日龄科宝肉鸡公鸡480只,随机分成4个组,每组6个重复,每个重复20只鸡。对照组饲喂不添加发酵棉籽粕的基础饲粮,试验组分别饲喂在基础饲粮中添加3%、6%、9%发酵棉籽粕替代豆粕的试验饲粮。试验分生长前期(1～21日龄)和生长后期(22～42日龄)2个阶段进行。结果表明:1)第21天时,6%发酵棉籽粕添加组白羽肉鸡的胴体粗蛋白质沉积量、腿肌中的乳酸脱氢酶(LDH)和碱性磷酸酶(AKP)活性显著高于其他组(P0.05);与对照组相比,3%、6%、9%发酵棉籽粕添加组的胴体粗蛋白质和干物质含量、粗蛋白质和干物质表观消化率、表观代谢能、肝脏中的谷草转氨酶(GOT)和谷丙转氨酶(GPT)活性显著提高(P0.05),3%、6%发酵棉籽粕添加组的羽毛粗蛋白质含量和胸肌中的LDH、AKP活性显著提高(P0.05),6%发酵棉籽粕添加组肝脏中的LDH活性和胸肌、腿肌、肝脏中的甲状腺素(T_4)、生长激素(GH)含量显著提高(P0.05),9%发酵棉籽粕添加组胸肌和肝脏中的GH含量显著提高,6%、9%发酵棉籽粕添加组肝脏中的胰岛素(INS)含量显著提高(P0.05)。2)第42天时,与对照组相比,6%、9%发酵棉籽粕添加组的胴体粗蛋白质沉积量、肝脏中的LDH活性及胸肌、腿肌、肝脏中的GH含量显著提高(P0.05),3%、6%发酵棉籽粕添加组的粗蛋白质表观消化率显著提高(P0.05),3%、6%、9%发酵棉籽粕添加组肝脏中的AKP和GOT活性及胸肌、腿肌、肝脏中的T_4含量、肝脏中的INS含量显著提高(P0.05)。综上,在白羽肉鸡饲粮中添加发酵棉籽粕可通过提高饲粮的养分表观消化率、蛋白质代谢相关酶活性和激素含量,促进机体蛋白质沉积。     

Evaluation of the safety of daily administration of capromorelin in cats

Capromorelin is a ghrelin receptor agonist that is FDA approved for appetite stimulation in dogs. The objective of this study was to evaluate the safety of daily oral administration of capromorelin to cats over a range of doses and for an extended period. Two randomized, controlled studies were conducted: in Study 1, cats (n = 6 per group) received placebo or capromorelin at a dose of 9, 15, 30 or 60 mg/kg once daily for 14 days; and in Study 2, cats received capromorelin at 6 mg/kg (n = 8) or placebo (n = 4) once daily for 91 days. Cats were evaluated using clinical observations and clinical pathology test results for both studies, with the addition of postmortem examination in Study 1 and measurements of growth hormone and insulin‐like growth factor 1 in Study 2. Abnormal clinical observations were limited to emesis, hypersalivation, lethargy/depression, head shaking and lip smacking, which occurred more frequently in the capromorelin‐treated groups than in the placebo group. There were no clinically relevant differences in clinical pathology test results between the capromorelin and placebo groups in either study.     

不同青贮玉米品种抗病性评价

对10个青贮玉米品种自然发病情况进行调查,并采用病级分类方法对抗病性分类。结果表明:对锈病表现抗性和中抗的品种有3个和5个,分别占供试品种的30%和50%;对大斑病表现抗性和中抗的品种有4个和5个,分别占供试品种的40%和50%;对褐斑病表现抗性和中抗的品种有6个和3个,分别占供试品种的60%和30%;对小斑病表现抗性和中抗的品种有6个和3个,分别占供试品种的60%和30%。多数品种对青贮玉米4种病害抗性表现较好,可从青贮玉米供试材料中选用优良抗病材料用于四川地区种植。     

Evaluation of Oxygen-dependent Immunodefences of the Polymorphonuclear Cells of Some Tropical Ruminants

Activation of polymorphonuclear cells (PMNs) leads to the formation of superoxide, which is in turn dismutated to H₂O₂ by superoxide dismutase (SOD) and is partly responsible for oxygen-dependent microbicidal activity. However, no comparative information is available on the effect of SOD inhibition before PMN activation to allow simulation of the SOD defects that are known to occur in some ruminants. This paper attempts to examine the degranulative and phagocytic responses in buffalo, cattle and goat PMNs exposed to diethyldithiocarbamate, a known SOD inhibitor. The activity of glutathione peroxidase and reductase was increased in the presence of SOD inhibitor. On activation, H₂O₂ production increased significantly (p<0.01), while SOD inhibition before the activation of PMNs caused a significant decline in the production of H₂O₂ (p<0.05) in all the species studied. There was a significant increase (p<0.05) in the phagocytosis of Candida albicans spores by buffalo PMNs activated with opsonized zymosan. Activation of bovine PMNs after exposure to the SOD inhibitor resulted in a significant decline (p<0.05) in phagocytic activity; in the other species, the two values only approached significance. Among the activators, opsonized zymosan caused a significant increase in phagocytic activity as compared to lipopolysaccharide, particularly in the PMNs of buffaloes (p<0.05). Increased fungicidal activity (p<0.05) occurred with opsonized zymosan-activated PMNs of all the species studied. The fungicidal activity was found to decline in PMNs exposed to SOD inhibitor before activation (p<0.05). Interestingly, the phagocytic activity of caprine PMNs was found to be lower than that of PMNs from cattle (p<0.05).     

Effect of dietary stable isotopic ratios of carbon and nitrogen on the extent of their incorporation into tissues of rats

This study was conducted to investigate the effect of different dietary ratios of ¹³ C to ¹² C or ¹⁵ N to ¹⁴ N on their relative incorporation into tissues. Eighty male rats were used in two 21-day feeding trials in which they were fed diets with either high δ¹³C levels (δ¹³C = −13.89‰ and δ¹⁵N = 2.37‰ in experiment 1 and δ¹³C = −19.34‰ and δ¹⁵N = 4.73‰ in experiment 2) or low δ¹³C levels (δ¹³C = −17.90‰ and δ¹⁵N = 3.08‰ in experiment 1 and δ¹³C = −21.76‰ and δ¹⁵N = 0.53‰ in experiment 2), meanwhile, the dietary δ¹⁵N levels were designed to two ranks. Blood, liver, adipose and muscle tissues were collected on day 0, 3, 7, 14, and 21 for determination of ¹³ C, ¹² C, ¹⁵ N and ¹⁴ N isotopes. Rat growth rate, antioxidant capacity and metabolic parameters were also assessed. The results indicate that adipose tissue tend to deplete ¹³ C before the stable isotopic ratios achieved final equilibrium. Therefore, feeds with different isotopic signatures had different incorporation rates into tissues. Low dietary ¹³ C levels decreased tissue δ¹³C values whereas high dietary ¹³ C levels did not alter tissue δ¹³C values during the 21-d experiment. Blood δ¹⁵N values were a reliable parameter in assessing the relative contribution of dietary nitrogen to tissues. This study revealed a relationship between dietary isotopic signatures and their incorporation rates into rat tissues. However, more studies are needed to illustrate the mechanism through which dietary isotopic ratios influence the extent of isotopic incorporation into the tissues.     

Lack of postexposure analgesic efficacy of low concentrations of eugenol in zebrafish

Objective

To test the postexposure analgesic efficacy of low doses of eugenol in zebrafish.

氮对千日红试管苗生长和开花诱导的影响

本文以千日红组培苗为试验材料,研究培养基中氮形态及含量对千日红试管苗生长和开花诱导的影响。结果表明,1)相对于铵态氮(NH₄⁺),硝态氮(No₃^-)作为唯一氮源更有利于千日红试管苗生长和开花诱导,但千日红在NH₄⁺和NO₃^-同时存在的培养基中表现最佳。2)在20 mmol/LNH₄⁺(NO₃^-)和5 mg/L PP₃₃₃存在的条件下,试管苗生长基本随着培养基中NO₃^-(NH₄⁺)含量的增加而增加,并在含40 mmol/L NO₃^-+20 mmol/L NH₄⁺(即MS培养基中氮含量)的培养基中株高达到最大值5.91 cm;而叶片数和开花率则随着培养基中NH₄⁺和NO₃^-含量的增加呈现先增加后下降的趋势,并在20 mmol/L NO₃^-+5 mmol/LNH₄⁺培养基中达到最大值,分别为10.7片/株和38.89%。3)氮含量及形态配比结果表明,千日红试管苗开花率在培养基中氮总量为5 mmol/L、NO₃^-/NH₄⁺为4/1时达到最大值39.95%,而株高和叶片数在氮总量为35 mmol/L,NO₃^-/NH₄⁺为4/1时达到最大值8.52 cm和13.38片/株。千日红试管苗开花率与培养基中NO₃^-/NH₄⁺显著正相关,而与氮总量及株高之间显著负相关。此外,培养基中氮含量及形态配比还显著影响无菌苗根系生长。     

Pharmacokinetics of three formulations of vitacoxib in horses

The pharmacokinetic properties of three formulations of vitacoxib were investigated in horses. To describe plasma concentrations and characterize the pharmacokinetics, 6 healthy adult Chinese Mongolian horses were administered a single dose of 0.1 mg/kg bodyweight intravenous (i.v.), oral paste, or oral tablet vitacoxib in a 3-way, randomized, parallel design. Blood samples were collected prior to and at various times up to 72 hr postadministration. Plasma vitacoxib concentrations were quantified using UPLC-MS/MS, and pharmacokinetic parameters were calculated using noncompartmental analysis. No complications resulting from the vitacoxib administration were noted on subsequent administrations, and all procedures were tolerated well by the horses throughout the study. The elimination half-life (T_1/2λz) was 4.24 ± 1.98 hr (i.v.), 8.77 ± 0.91 hr (oral paste), and 8.12 ± 4.24 hr (oral tablet), respectively. Maximum plasma concentration (C_max) was 28.61 ± 9.29 ng/ml (oral paste) and 19.64 ± 9.26 ng/ml (oral tablet), respectively. Area under the concentration-versus-time curve (AUC_last) was 336 ± 229 ng hr/ml (i.v.), 221 ± 94 ng hr/ml (oral paste), and 203 ± 139 ng hr/ml, respectively. The results showed statistically significant differences between the 2 oral vitacoxib groups in T_max value. T_1/2λz (hr), AUC_last (ng hr/ml), and MRT (hr) were significantly different between i.v. and oral groups. The longer half-life observed following oral administration was consistent with the flip-flop phenomenon.     

Determination of optimal dietary selenium levels by full expression of selenoproteins in various tissues of broilers from 1 to 21 d of age

The current NRC dietary selenium (Se) requirement (0.15 mg/kg) of broilers is primarily based on growth performance data reported in 1986. Our study aimed to determine optimal dietary Se levels of broilers fed a practical corn-soybean meal diet for the full expression of selenoproteins in various tissues. A total of 384 one-d-old male broilers (n = 8 replicates/diet) were fed a basal corn-soybean meal diet or the basal diet supplemented with 0.1, 0.2, 0.3, 0.4 or 0.5 mg Se/kg in the form of Na₂SeO₃ for 21 d. Regression analysis was conducted to evaluate the optimal dietary Se levels using broken-line, quadratic or asymptotic models. The activity of glutathione peroxidase (GPX) in the plasma, liver, kidney and pancreas, iodothyronine deiodinase (DIO) in the plasma, liver and pancreas, and thioredoxin reductase (Txnrd) in the liver and pancreas, the mRNA levels of Gpx1, Gpx4, Dio1, selenoprotein (Seleno) h, Selenop and Selenou in the liver, Gpx4, Dio1, Txnrd1, Txnrd2, Selenoh, Selenop and Selenou in the kidney, and Gpx1, Gpx4, Selenoh and Selenou in the pancreas, and the protein levels of GPX4 in the liver and kidney of broilers were influenced (P < 0.05) by added Se levels, and increased quadratically (P < 0.05) with the increase of added Se levels. The estimates of optimal dietary Se levels were 0.07 to 0.36 mg/kg based on the fitted broken-line, quadratic or asymptotic models (P < 0.001) of the aforementioned selenoprotein expression in the plasma, liver and kidney, and 0.09 to 0.46 mg/kg based on the fitted broken-line models (P < 0.001) of the aforementioned selenoprotein expression in the pancreas. The results indicate that the optimal dietary Se levels would be 0.36 mg/kg to support the full expression of selenoproteins in the plasma, liver and kidney, and 0.46 mg/kg to support the full expression of selenoproteins in the pancreas of broilers fed a practical corn-soybean meal diet from 1 to 21 d of age.     

Influence of fibre and betaine on development of the gastrointestinal tract of broilers between hatch and 14 d of age

An experiment was designed to determine the influence of fibre and betaine on the development of the intestine, liver and pancreas of broilers from hatch to 14 d of age. A total of 250-day-old Cobb 500 male broilers were allocated to 16 cages with 15 broilers each. Treatments were arranged in a 2 × 4 factorial design, consisting of 2 feed formulations (low and high fibre diets) and 4 levels of betaine (0, 1, 3 or 5 kg/t). At hatch, 10 birds in total were euthanised, and samples of the liver, pancreas, yolk sac and intestine were collected for reference of the analysed parameters before the start of the trial. On d 4, 9 and 14, 5 birds per cage (10 birds per treatment) were selected, euthanised and treated as the same as the birds at hatch. Villus height and width and crypt depth were determined on the duodenum samples, and absorptive area was calculated. The number of enterocytes in mitosis at the villus was determined by a positive reaction to antibody for Ki67 protein, and fused villus was evaluated visually. The relative weight of the yolk sac reduced (P < 0.05) as birds aged while the intestine and liver reached a maximum (P < 0.05) at around d 4 and the pancreas at d 9. Birds fed the high fibre diet had greater feed intake, lower relative weight of the pancreas and higher villus (P < 0.05) than birds fed the low fibre diet. Villus width increased (P < 0.05) at 4 d of age, and this was associated with fused villus. Betaine inclusion reduced (P < 0.05) villus width, increased (P < 0.05) villus size and absorptive area, and reduced (P < 0.05) the number of enterocytes with positive reaction for the antibody Ki-67. Betaine inclusion reduced the width and increased the absorptive area and the villus height of the duodenum of birds up to 14 d of age. The higher fibre diet increased feed intake and villus height, yet reduced pancreas relative weight, while not affecting body weight gain. This response was possibly due to a dilution effect of the fibre, reducing nutrient absorption and consequently stimulating villus growth to improve absorption rates.     

Cryopreservation of immature oocytes of the indigeneous Vietnamese Ban Pig

We report the cryopreservation of oocytes from Ban miniature pigs which are endemic in Vietnam. Immature cumulus‐oocyte complexes were collected from antral follicles of 7–8 mo old female cyclic Ban pigs and vitrified in micro‐drops. Oocyte morphology, lipid content, post‐warming survival, nuclear maturation, and embryo development were compared to those of oocytes from commercially slaughtered Landrace × Large white hybrid pigs. The size of oocytes in the two breeds was similar. However, significantly lower amounts of intracellular lipid were detected in Ban oocytes. There was no difference (p > 0.05) between Ban and Landrace × Large white oocytes in percentages of post‐warming survival (93.1 ± 3.4% vs. 70.7 ± 16.7%, respectively) and nuclear maturation after in vitro maturation (80.4 ± 5.1% vs. 90.0 ± 1.3% respectively). Similarly, cleavage (30.8 ± 7.8% vs. 10.3 ± 6.1%, respectively) and blastocyst development rates (9.4 ± 5.0% vs. 0.79 ± 0.79, respectively) were not different (p > 0.05) between vitrified Ban and Landrace × Large white oocytes after in vitro fertilization and embryo culture. In conclusion, high survival and maturation rates were achieved after vitrification of immature Ban oocytes and their cryo‐tolerance was similar to that of Landrace × Large white oocytes, despite the difference in lipid content. We succeeded to generate reasonable rates of blastocysts from vitrified Ban oocytes by in vitro fertilization.