牛磺酸对早期断奶仔猪生长性能和肠道健康的影响

本试验旨在研究牛磺酸(Tau)对早期断奶仔猪生长性能、血清指标、肠道黏膜形态结构和相关基因表达的影响及其机制,并对比Tau和谷氨酰胺(Gln)的添加效果。选择(17±2)日龄断奶、平均体重为(5.17±0.04) kg的健康"(长×大)×荣昌"早期断奶仔猪30头,随机分为3个组,每组10个重复,每个重复1头猪。对照组(CON组)饲喂基础饲粮,试验组分别在基础饲粮中添加0.1%Tau(T组)和1.0%Gln(G组)。试验期17 d,其中预试期3 d。结果表明:1)与对照组相比,饲粮中添加Tau和Gln能显著提高早期断奶仔猪的平均日增重和平均日采食量(P0.05),降低腹泻率,Gln的效果优于Tau。2) T组早期断奶仔猪的血清白蛋白(ALB)含量显著高于对照组和G组(P0.05);与对照组相比,T和G组的血清碱性磷酸酶(AKP)活性显著提高(P0.05),血清天冬氨酸氨基转移酶(AST)活性显著降低(P0.05)。3)与对照组相比,T和G组早期断奶仔猪的血清甘油三酯(TG)含量显著降低(P0.05)。4) T组早期断奶仔猪的血清超氧化物歧化酶(SOD)活性显著高于对照组和G组(P 0.05); T和G组的血清过氧化氢酶(CAT)活性显著高于对照组(P0.05),G组效果较好。5)与对照组相比,除色氨酸(Try)、组氨酸(His)、异亮氨酸(Ile)、苯丙氨酸(Phe)、缬氨酸(Val)和谷氨酸(Glu)外,T和G组早期断奶仔猪的血清必需氨基酸(EAA)含量均呈升高趋势,血清非必需氨基酸(NEAA)含量均呈降低趋势;其中,饲粮中添加Tau对血清赖氨酸(Lys)、蛋氨酸(Met)和精氨酸(Arg)含量的提高效果显著优于Gln。6) T和G组早期断奶仔猪的空肠绒毛高度和绒毛高度/隐窝深度显著高于对照组(P0.05),隐窝深度显著低于对照组(P0.05)。7) T和G组早期断奶仔猪空肠和回肠黏膜的β-连环蛋白(β-catenin) mRNA相对表达量显著低于对照组(P0.05),G组最低。本试验结果表明,饲粮中添加0.1%Tau或1.0%Gln能提高早期断奶仔猪的生长性能,促进肠道发育,添加1.0%Gln的效果略优于0.1%Tau。     

酸汤对断奶仔猪生长性能、免疫性能、抗氧化性能及肠道微生物区系的影响

本试验旨在研究酸汤对断奶仔猪生长性能、免疫性能、抗氧化性能及肠道微生物区系的影响。试验选用31日龄、体重[(5.34±0.86)kg]相近、健康的断奶仔猪45头,随机分为5组,每组3个重复,每个重复3头。试验Ⅰ组为对照组,饲喂基础饲粮,试验Ⅱ、Ⅲ、Ⅳ、Ⅴ组分别在基础饲粮的基础上添加0.5%、1.0%、1.5%、2.0%的酸汤。预试期7 d,正试期40 d。结果表明:试验Ⅱ、Ⅲ、Ⅳ、Ⅴ组的平均日增重(ADG)显著高于试验Ⅰ组(P<0.05);试验Ⅴ组的腹泻率显著低于试验Ⅱ、Ⅲ、Ⅳ组(P<0.05);试验Ⅴ组血清免疫球蛋白G(IgG)的含量为2.86 g/L,显著高于试验Ⅰ、Ⅱ、Ⅲ组(P<0.05);试验Ⅴ组血清超氧化物歧化酶(SOD)活性显著高于试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组(P<0.05);试验Ⅳ组血清谷胱甘肽过氧化物酶(GSH-Px)活性显著高于其余各组(P<0.05);试验Ⅳ组血清丙二醛(MDA)含量显著低于试验Ⅰ、Ⅱ组(P<0.05)。试验Ⅴ组空肠绒隐比显著高于试验Ⅰ组(P<0.05);饲粮中添加酸汤有增加盲肠厚壁菌门相对丰度、降低拟杆菌门相对丰度的趋势,试验Ⅳ组盲肠乳杆菌属相对丰度显著高于试验Ⅰ组(P<0.05)。综上可知,饲粮中添加适量酸汤能提高断奶仔猪的生长性能、免疫性能以及抗氧化性能,一定程度上促进小肠形态发育以及改善盲肠菌群结构,可作为断奶仔猪饲料添加剂。     

谷氨酰胺对育成期水貂饲粮营养物质消化率和脏器重量的影响

试验旨在研究饲粮中添加不同水平谷氨酰胺(Gln)对育成期水貂营养物质消化率和脏器重量的影响。选取育成期水貂共160只,随机分为5组,每组32个重复(公、母各半),单笼饲养。对照组饲喂基础日粮(不添加Gln),试验组分别在基础日粮中添加0.2%、0.4%、0.6%和0.8%Gln,预试期1周,正试期7周。结果表明:0.4%Gln组公貂的粗蛋白质、钙、磷消化率均高于对照组(P<0.05),母貂的粗蛋白质、粗脂肪、钙消化率均高于0.2%Gln组和对照组(P<0.05);0.4%Gln组水貂赖氨酸消化率高于对照组(P<0.01),苏氨酸、丝氨酸、甘氨酸、异亮氨酸、苯丙氨酸、脯氨酸、蛋氨酸、胱氨酸、总氨基酸的消化率高于对照组(P<0.05);0.4%和0.6%Gln组公貂脾脏和肝脏重量高于对照组(P<0.05),0.4%组Gln母貂心脏和肝脏重量高于对照组(P<0.05)。综合各项指标,在夏季高温条件下,育成期水貂饲粮中Gln的适宜添加水平为0.4%。     

葫芦巴渣及提取物对断奶仔猪生长性能、抗氧化功能和血清生化指标的影响

本试验旨在研究饲粮中添加葫芦巴渣及提取物对断奶仔猪生长性能、抗氧化功能和血清生化指标的影响。试验选取21日龄体重相近的健康断奶仔猪160头,随机分为4组,每组5个重复,每个重复8头猪。对照组饲喂基础饲粮,试验组(Ⅰ组、Ⅱ组和Ⅲ组)分别在基础饲粮中添加5%葫芦巴渣、5%葫芦巴渣复合物(含0.05%葫芦巴提取物)、5%葫芦巴渣复合物(含0.10%葫芦巴提取物)。预试期3 d,正试期21 d。结果表明:1)Ⅱ组和Ⅲ组断奶仔猪的平均日增重(ADG)与对照组无显著差异(P0.05);Ⅱ组和Ⅲ组断奶仔猪的平均日采食量(ADFI)显著高于对照组(P0.05),分别升高了9.22%和9.19%;试验组断奶仔猪料重比(F/G)显著高于对照组(P0.05);各组之间断奶仔猪腹泻率差异不显著(P0.05)。2)Ⅱ组和Ⅲ组断奶仔猪血清总抗氧化能力(T-AOC)及总超氧化物歧化酶(T-SOD)、过氧化氢酶(CAT)显著高于对照组(P 0.05),Ⅰ组、Ⅱ组和Ⅲ组断奶仔猪血清丙二醛(MDA)含量显著低于对照组(P0.05)。各组之间断奶仔猪血清谷胱甘肽过氧化物酶(GSH-Px)活性差异不显著(P0.05)。3)Ⅱ组和Ⅲ组断奶仔猪血清肌酐(CREA)含量显著低于对照组(P0.05),Ⅲ组断奶仔猪血清葡萄糖(GLU)含量显著低于对照组(P0.05),Ⅱ组和Ⅲ组断奶仔猪血清尿素氮(UN)含量显著高于对照组(P0.05)。各组之间断奶仔猪血清谷草转氨酶(AST)、谷丙转氨酶(ALT)活性及总胆固醇(TC)、总蛋白(TP)、白蛋白(ALB)、球蛋白(GLO)和甘油三酯(TG)含量差异不显著(P0.05)。由此可见,饲粮中添加5%葫芦巴渣复合物(分别含0.05%和0.10%葫芦巴提取物)对断奶仔猪有诱食效果,能改善机体抗氧化功能,降低血糖水平和保护肾脏,并以添加0.10%葫芦巴提取物作用效果较好。     

母鸽血清中谷氨酰胺含量与生产性能关系的试验研究

本试验旨在研究母鸽饲粮中添加不同剂量谷氨酰胺(Gln)对母鸽月产蛋数、孵化率、乳鸽数的影响,并测定母鸽产蛋后不同时间段内血清中的Gln值。试验分为4组,每组100对种鸽,试验Ⅰ组、Ⅱ组、Ⅲ组每天分别饲喂0.1、0.2、0.3g/d的Gln,对照组饲喂基础饲粮。生产模式各组均为自然孵化。试验结果表明:在同一组不同产蛋时间段内,Ⅰ组母鸽血清Gln值产蛋后17d较产蛋后1d提高26.18%(P<0.01);Ⅱ组产蛋后17d较产蛋后8d降低18.01%(P<0.05);Ⅲ组和对照组产蛋后各时间段差异不显著(P>0.05)。其生产性能上,Ⅰ组母鸽月产蛋总数较对照组、Ⅱ组、Ⅲ组提高16.7%(P<0.01)、22.5%(P<0.01)、17.1%(P<0.01)。Ⅰ组母鸽月孵化率较对照组、Ⅱ组提高8.7%(P<0.01)、8.2%(P<0.01),Ⅲ组较对照组、Ⅱ组提高8.8%(P<0.01)、8.3%(P<0.01)。Ⅰ组母鸽月产乳鸽数较对照组、Ⅱ组、Ⅲ组提高25.9%(P<0.01)、32.7%(P<0.01)、17.3%(P<0.01),Ⅱ组较对照组、Ⅲ组降低4.9%(P<0.05)、11.4%(P<0.01);Ⅲ组较对照组提高了7.3%(P<0.01)。产双蛋、单蛋及间歇产蛋母鸽血清Gln值进行对比分析表明,母鸽只在产第1枚蛋后血清Gln与产蛋相关,产双蛋Gln值[(3.12±0.24)mmol/L]为正常生产值,Gln值高于2.89mmol/L(3.12-0.24=2.89mmol/L)的可以在48h内产第2枚蛋。综上,母鸽血清中Gln的含量与其生产性能有关,在饲料中添加一定量的Gln,可改善肉种鸽的生产性能,每只种鸽每日添加Gln0.1g最佳。     

谷氨酰胺在不同蛋白水平日粮下对断奶仔猪生产性能和血液指标的影响

试验研究了谷氨酰胺在不同蛋白水平日粮中对断奶仔猪的生产性能、腹泻率和血液指标的影响。试验选用120头28日龄的长×大二元杂交断奶仔猪,按体重、性别、窝别一致的原则随机分为6组,每组设2个重复,每个重复10头猪。第Ⅰ、Ⅲ、Ⅴ组为对照组,日粮蛋白水平分别为18%(低)、20%(中)、22%(高),第Ⅱ、Ⅳ、Ⅵ组在Ⅰ、Ⅲ、Ⅴ组基础上添加1.25%的谷氨酰胺(Gln),试验期为28 d。结果表明:高、中、低三种蛋白日粮中添加Gln与对照组相比分别可以提高断奶后0~2周日增重8.85%(P>0.05)、24.11%(P<0.05)、23.78%(P<0.05),全期来看,中蛋白组添加Gln与对照组相比可以有效提高日增重13.19%(P<0.05),降低料肉比3.73%(P>0.05);对腹泻率的影响,第Ⅱ、Ⅳ、Ⅵ组比对照组分别可以降低腹泻率35.12%(P<0.05)、60.47%(P<0.05)和60.76%(P<0.05),相互之间差异不显著(P>0.05);高蛋白、中蛋白和低蛋白的Gln组与对照组相比血清尿素氮的含量分别下降了23.32%(P<0.05)、34.52%(P<0.05)和37.79%(P<0.05),血清总蛋白含量分别提高了5.89%(P<0.05)、24.58%(P<0.05)和7.26%(P>0.05),白球比值分别下降了17.73%(P<0.05)、12.59%(P<0.05)和1.49%(P>0.05)。本试验条件下,在20%蛋白水平日粮中添加Gln对提高断奶后仔猪的日增重,降低腹泻率达到最优效果。     

葡萄糖氧化酶对仔猪胃肠道微生物区系及血液生化指标的影响

本文旨在研究葡萄糖氧化酶(GOD)对断奶仔猪胃肠道微生物区系和部分血液生化指标以及生产性能的影响,讨论其可能的作用机理。试验选用160头10 kg左右断奶仔猪,根据体重随机分为Ⅰ(对照)、Ⅱ、Ⅲ和Ⅳ4组,每组5个重复,每个重复8头猪。Ⅰ组饲喂基础日粮,试验Ⅱ、Ⅲ和Ⅳ组在饲喂基础日粮上分别添加0.1%、0.2%和0.3%的GOD。结果显示:与对照相比,日粮中添加0.3%GOD的仔猪日增重提高8.2%(P<0.05);饲料转化效率提高7.9%(P=0.09);血清胰岛素提高17.6%(P<0.05);日粮中添加0.2%和0.3%GOD的仔猪比对照组血清尿素氮水平分别降低16.37%和14.35%,差异均显著(P<0.05);与对照组相比,日粮中添加0.2%和0.3%GOD可以显著降低仔猪胃和回肠大肠杆菌数量(P<0.05),增加仔猪胃和回肠乳酸菌数量(P<0.05)。提示:日粮中添加0.2%～0.3%GOD可以提高仔猪饲料转化效率和对氮的利用效率,促进机体营养物质的合成,从而提高断奶仔猪的增重。     

不同水平血浆蛋白粉对断奶仔猪生产性能和免疫功能的影响

试验采用单因子随机分组设计,选取28日龄断奶、个体重相近、健康、遗传基础相似的杜×长×大仔猪120头,随机分为4组,分别饲喂含0、3.5%、5%和7.5%血浆蛋白粉的日粮。试验期14d。试验结果表明:①以对照组采食量为100%计,试验Ⅰ、Ⅱ、Ⅲ组平均日采食量分别为101.70%(P>0.05)、108.98%(P<0.05)、112.13%(P<0.05);②平均日增重对照组与各试验组间差异显著(P<0.05),试验Ⅰ组与试验Ⅱ、Ⅲ组间差异显著(P<0.05),试验Ⅱ组与试验Ⅲ组间差异不显著(P>0.05);③与对照组相比,试验Ⅰ、Ⅱ、Ⅲ组料重比分别下降了27.52%、34.40%、35.32%,差异极显著(P<0.01);④试验Ⅰ、Ⅱ、Ⅲ组IgG、IgM、IgA及补体C3、C4的浓度均显著高于对照组(P<0.05);⑤试验Ⅰ、Ⅱ、Ⅲ组与对照组相比,T淋巴细胞转化率分别提高了4.82%、8.15%、8.60%,差异显著(P<0.05)。说明仔猪日粮中添加血浆蛋白粉可提高仔猪的生产性能,并有增强仔猪免疫功能的作用。     

复合益生菌对早期断奶仔猪生长性能和免疫水平的影响

为研究酿酒酵母菌和枯草芽孢杆菌组成的复合益生菌对早期断奶仔猪免疫水平的影响,试验选取(杜×长×大)三元杂交断奶仔猪80头,分为试验Ⅰ、Ⅱ、Ⅲ组及对照组,每组20头,Ⅰ、Ⅱ、Ⅲ组在基础日粮中分别添加0.10%、0.20%、0.30%复合益生菌,对照组饲喂基础日粮,以期评价其生长性能、血液生化、血清细胞因子和肠道黏膜分泌性球蛋白A(SIgA)水平。结果表明,试验Ⅱ、Ⅲ组末重极显著高于试验Ⅰ组和对照组(P0.01);试验Ⅲ组平均日增重极显著高于试验Ⅰ、Ⅱ组及对照组(P0.01),试验Ⅲ组平均日采食量显著高于试验Ⅰ、Ⅱ组及对照组(P0.05),对照组、试验Ⅱ组腹泻率均极显著高于试验Ⅰ、Ⅲ组(P0.01);试验组中的乳酸脱氢酶(LDH)、谷丙转氨酶(ALT)和碱性磷酸酶(ALP)含量均高于对照组,总蛋白(TP)含量低于对照组,差异均不显著(P0.05);试验组中尿素氮(BUN)含量均显著高于对照组(P0.05),试验Ⅱ、Ⅲ组谷草转氨酶(AST)含量显著高于试验Ⅰ组和对照组(P0.05)。试验0d,试验组白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)水平与对照组相比差异不显著(P0.05);试验20d,试验Ⅱ、Ⅲ组中IL-6水平极显著高于试验Ⅰ组及对照组(P0.01),IL-1β和TNF-α水平与对照组相比差异不显著(P0.05);试验40d,试验组IL-1β水平均高于对照组(P0.05),IL-6和TNF-α水平均极显著高于对照组(P0.01)。试验组中空肠黏膜SIgA水平极显著高于对照组(P0.01);十二指肠和回肠黏膜SIgA水平均显著高于对照组(P0.05),盲肠黏膜SIgA水平低于对照组,差异不显著(P0.05)。说明不同含量酿酒酵母菌-枯草芽孢杆菌复合益生菌均可有效提高断奶仔猪的生长性能,缓解早期断奶仔猪应激反应,增强断奶仔猪的免疫功能。     

日粮中添加乳清粉和膨化豆粕对断奶仔猪生产性能影响

选择30日龄断奶三元杂交仔猪(杜×长×大)64头。随机分成对照组、Ⅰ、Ⅱ、Ⅲ组,对照组饲以基础日粮,试验Ⅰ组日粮以膨化豆粕替代普通豆粕,试验Ⅱ组由3%的乳清粉替代3%的豆粕。试验Ⅲ组中膨化豆粕替代普通豆粕同时由3%的乳清粉替代3%的膨化豆粕。试验结果:对照组培育仔猪需46d,试验Ⅰ组(膨化豆粕组)培育仔猪需40d,试验Ⅱ组(乳清粉组)培育仔猪需43d,试验Ⅲ组(膨化豆粕+乳清粉组)培育仔猪需39d;平均日增重试验Ⅱ组显著高于对照组(P<0.05),试验Ⅰ、Ⅲ组极显著高于对照组(P<0.01),试验Ⅲ组极显著高于Ⅱ组(P<0.01)、显著高于试验Ⅰ组(P<0.05);饲料利用率试验Ⅲ组最高,对照组饲料利用率最差;腹泻率试验Ⅰ组下降了38.13%,试验Ⅱ组下降了34.63%,试验Ⅲ组下降了47.08%。结果表明利用膨化大豆或乳清粉等优质蛋白。调整日粮结构,可显著降低TI等抗营养因子和抗原物质的含量,减少腹泻率,提高生长性能。     

Pharmacokinetics and bioavailability of carbetocin after intravenous and intramuscular administration in cows and gilts

The pharmacokinetics of carbetocin, which is used to control postpartum hemorrhage after giving birth, was studied in cows and gilts after a single intravenous (IV) or intramuscular (IM) injection. Blood samples from animals were assessed by oxytocin radioimmunoassay, and then the pharmacokinetic parameters were calculated using a noncompartmental model. For gilts, there was no significant difference between half-life (T_1/2λZ), mean residue time (MRT), and maximum concentration (C_max) between IM and IV administration. Conversely, the time to reach the C_max (T_max) and MRT were higher following administration of 350 μg/animal in cows via the IM administration compared with IV. The longest T_1/2λZ was 0.85 hr, indicating carbetocin was absorbed and eliminated rapidly in both animal species after administration. The T_max was similar between cows and gilts following IM administration. Moreover, the C_max after IM injection was about half that of IV administration in both animals. The bioavailability was more than 80% in cows, suggesting administration via the IM route is efficient. This is in agreement with the longer T_1/2λZ in cows after IM administration. However, the IV route is recommended for gilts due to a lower bioavailability (35%) and shorter T_1/2λZ after IM administration compared with IV.     

Genetic and phenotypic parameters and annual trends for growth and fertility traits of Charolais and Hereford beef cattle breeds in Kenya

This study estimated genetic and phenotypic parameters and annual trends for growth and fertility traits of Charolais and Hereford cattle in Kenya. Traits considered were birth weight (BW, kg), pre-weaning average daily gain (ADG, kg/day) and weaning weight (WW, kg); calving interval (CI, days) and age at first calving (AFC, days). Direct heritability estimates for growth traits were 0.36 and 0.21; 0.25 and 0.10; 0.23 and 0.13 for BW, ADG and WW in Charolais and Hereford, respectively. Maternal heritability estimates were 0.11 and 0.01; 0.18 and 0.00; 0.17 and 0.17 for BW, ADG and WW in Charolais and Hereford, respectively. Direct-maternal genetic correlations ranged between −0.46 and 1.00; −0.51 and −1.00; −0.47 and −0.39 for BW, ADG and WW in Charolais and Hereford, respectively. Genetic correlations ranged from −0.99 to unity and −1.00 to unity for growth and fertility traits respectively. Prospects for improvement of growth and fertility traits exist.     

中国伞形科当归属及相关类群毛状体和果实结构的系统学价值

深入研究了当归属及其相关7属,古当归属,高山芹属,柳叶芹属,独活属,欧当归属,山芹属及前胡属毛状体和果实结构。结果显示毛状体及果实结构(如:毛状体细胞,翅,油管,维管束,中果皮,内果皮,结合面及结晶)可以用于区分当归属及其相关类群。滇南当归及隆萼当归应从当归属移入独活属,其余当归属物种分为结合面宽及结合面窄两组,前者与前胡属较为相似,但与独活属差别较大,后者与古当归属,高山芹属,柳叶芹属,欧当归属有相似之处。支持分子系统学揭示的当归属不是个自然类群,当归属与前胡属共同位于当归分支,而独活属位于独活分支。山芹属果实结构与其他属不同,翅的中果皮无细胞,且伴生油管位于维管束内侧,为分子系统学显示此属与高山芹属,柳叶芹属,及欧当归属亲缘关系较远提供了形态学依据。     

Genetic diversity and antimicrobial resistance of Campylobacter and Salmonella strains isolated from decoys and raptors

Infections caused by thermotolerant Campylobacter spp. and Salmonella spp. are the leading causes of human gastroenteritis worldwide. Wild birds can act as reservoirs of both pathogens. A survey was carried out to determine the prevalence, genetic diversity and antimicrobial resistance of thermotolerant Campylobacter and Salmonella in waterfowl used as decoys and wild raptors in Andalusia (Southern Spain). The overall prevalence detected for Campylobacter was 5.9% (18/306; CI_95%: 3.25–8.52) in decoys and 2.3% (9/387; CI_95%: 0.82–3.83) in wild raptors. Isolates were identified as C. jejuni, C. coli and C. lari in both bird groups. Salmonella was isolated in 3.3% (10/306; CI_95%: 2.3–4.3) and 4.6% (18/394; CI_95%: 3.5–5.6) of the decoys and raptors, respectively. Salmonella Enteritidis and Typhimurium were the most frequently identified serovars, although Salmonella serovars Anatum, Bredeney, London and Mikawasima were also isolated. Pulsed-field gel electrophoresis analysis of isolates showed higher genetic diversity within Campylobacter species compared to Salmonella serovars. Campylobacter isolates showed resistance to gentamicin, ciprofloxacin and tetracycline, while resistance to erythromycin and tetracycline was found in Salmonella isolates. The results indicate that both decoys and raptors can act as natural carriers of Campylobacter and Salmonella in Spain, which may have important implications for public and animal health.     

Babesiosis in dogs and cats--expanding parasitological and clinical spectra

Canine babesiosis caused by different Babesia species is a protozoal tick-borne disease with worldwide distribution and global significance. Historically, Babesia infection in dogs was identified based on the morphologic appearance of the parasite in the erythrocyte. All large forms of Babesia were designated Babesia canis, whereas all small forms of Babesia were considered to be Babesia gibsoni. However, the development of molecular methods has demonstrated that other Babesia species such as Babesia conradae, Babesia microti like piroplasm, Theileria spp. and a yet unnamed large form Babesia spp. infect dogs and cause distinct diseases. Babesia rossi, B. canis and Babesia vogeli previously considered as subspecies are identical morphologically but differ in the severity of clinical manifestations which they induce, their tick vectors, genetic characteristics, and geographic distributions, and are therefore currently considered separate species. The geographic distribution of the causative agent and thus the occurrence of babesiosis are largely dependent on the habitat of relevant tick vector species, with the exception of B. gibsoni where evidence for dog to dog transmission indicates that infection can be transmitted among fighting dog breeds independently of the limitations of vector tick infestation. Knowledge of the prevalence and clinicopathological aspects of Babesia species infecting dogs around the world is of epidemiologic and medical interest. Babesiosis in domestic cats is less common and has mostly been reported from South Africa where infection is mainly due to Babesia felis, a small Babesia that causes anemia and icterus. In addition, Babesia cati was reported from India and sporadic cases of B. canis infection in domestic cats have been reported in Europe, B. canis presentii in Israel and B. vogeli in Thailand. Babesiosis caused by large Babesia spp. is commonly treated with imidocarb dipropionate with good clinical response while small Babesia spp. are more resistant to anti-babesial therapy. Clinical and parasitological cure are often not achieved in the treatment of small Babesia species infections and clinical relapses are frequent. The spectrum of Babesia pathogens that infect dogs and cats is gradually being elucidated with the aid of molecular techniques and meticulous clinical investigation. Accurate detection and species recognition are important for the selection of the correct therapy and prediction of the course of disease.     

Intake, live animal scores/measurements and carcass composition and value of late-maturing beef and dairy breeds

The objectives of this study were to compare the progeny of 1) late-maturing beef with dairy breeds and 2) Charolais (CH), Limousin (LM), Simmental (SM) and Belgian Blue (BB) sires bred to beef suckler dams, for feed intake, blood hormones and metabolites, live animal measurements, carcass traits and carcass value in bull and steer production systems. The bull system included 50 late-maturing beef breeds and 22 Holsteins (HO) slaughtered at approximately 15 months of age, whereas the steer system consisted of 56 late-maturing beef breeds and 23 British Friesians (FR) slaughtered at approximately 24 months of age. Beef breeds were suckled until approximately 8 months of age, while dairy breeds were artificially reared until weaning at approximately 3 months of age. All animals were finished on an ad libitum concentrate diet. Mean live weight, live weight gain, carcass gain and feed efficiency were greater (P < 0.05) in beef than dairy breeds in both systems during the finishing period when offered concentrates. Although there was no difference in feed intake between beef and dairy breeds, intake expressed relative to live weight was lower (P < 0.001) in beef breeds in both systems. At 10 months of age and pre-slaughter, beef breeds had higher (P < 0.001) muscularity scores and greater scanned muscle depth (P < 0.001) than their dairy contemporaries. Carcass weight, kill-out proportion, carcass conformation score, meat proportion and value were greater (P < 0.001) and carcass fat and bone proportions were lower (P < 0.05) in beef than dairy breeds in both systems. Insulin concentrations were lower (P < 0.001) in beef than dairy breeds, whereas there was no difference in blood metabolites or IGF-1 concentrations. Feed intake expressed relative to live weight or feed efficiency did not differ between CH, LM, SM or BB sired progeny. Muscularity scores were greater (P < 0.05) in BB than SM, whereas skeletal scores were lower (P < 0.05) in LM than SM. Limousin had lower (P < 0.05) carcass gain per day of age than CH and SM, whereas SM had a lower (P < 0.05) carcass conformation score than BB and CH and a higher (P < 0.05) carcass fat score than CH. Simmental had a lower (P < 0.05) carcass meat proportion and a higher (P < 0.05) carcass fat proportion than CH, LM and BB, which were similar (P > 0.05). The improvement obtained for beef over dairy breeds in live weight gain was 12%, while the improvements in carcass gain and meat produced was 24% and 33%, respectively. This demonstrates that the importance of carcass data contributing to breed comparison studies cannot be over-emphasised.     

Seedling Defoliation and Drought Stress: Variation in Intensity and Frequency Affect Performance and Survival

Our ability to restore rangelands is limited, and it is unknown if seedling herbivory on its own, or in interaction with other stressors, is a major contributor to restoration failure. To address this, we conducted two experiments: a No Defoliation (ND) experiment (n = 48), in which seedlings from three perennial grasses (crested wheatgrass [Agropyron cristatum {(L.} Gaertn.], bluebunch wheatgrass [Psuedoroegnaria spicata {Pursh} Á. Love], Sandberg bluegrass [Poa secunda J Presl]) were subjected to wet and dry water regimes for 4 mo, and a concurrent Defoliation (D) experiment (n = 95), in which seedlings were factorially assigned to two defoliation treatments—frequency (LOW, HIGH) and intensity (30% vegetation removal, 70% vegetation removal). Indicators of seedling performance were aboveground and belowground biomass (AGB and BGB), root:shoot ratio, tillering, and mortality. The effect size statistic, Hedge’s g, allowed for comparisons between performance measures. Water stress induced reductions in most performance measures: BGB (g = ND: –1.3; D: –1.6), root:shoot ratio (g = ND: n.s.; D: –0.2), and tillering (g = ND: –1.7; D: –1.2), though not significantly for all species. For ABG, water stress interacted with defoliation, reducing performance less at an intensity of 70% (g = –2.0) as opposed to 30% (g = –3.0), but not always significantly in the former. Water stress also caused less reduction in AGB when no defoliation occurred (ND: –0.8; g = D: –2.5). Intensity and frequency of defoliation interacted; seedlings were generally resistant to reductions in performance except at high frequency, 70% defoliation. Agropyron cristatum and P. spicata displayed similar sensitivity to treatments, mostly in terms of changes in AGB and BGB, while P. secunda also experienced increased mortality and reduced tillering. If these differences in sensitivity result in differential survival, herbivory could impact species postrestoration population demographics.     

Prebiotics and probiotics used alone or in combination and effects on pullet growth and intestinal microbiology

A study was conducted examining the effects of prebiotics and probiotics separately and in combination on growth parameters, fecal and cecal microbiota. Six dietary treatments consisted of: 1) control, 2) control + 0.2 lb/ton calculated to contain 1 × 10¹⁰Pediococcus acidilactici/kg, 3) control + 0.2 lb/ton calculated to contain 2 × 10¹⁰ live Saccharomyces cerevisiae boulardii/kg, 4) control + 2 lb/ton yeast cell wall extract (YCWE), 5) control + 0.2 lb/ton calculated to contain 1 × 10¹⁰ /kg Pediococcus acidilactici/kg and + 2 lb/ton YCWE, and 6) control + 0.2 lb/ton calculated to contain 2 × 10¹⁰/kg live Saccharomyces cerevisiae boulardii/kg + 2 lb/ton YCWE. Dietary treatments had 10 replicates during the brooder phase; 6 replicates from grower phase through conclusion of the study. Bovan white pullets were utilized for the study. There was not a significant difference between treatments for feed intake, body weight, body weight gain or feed conversion. There were no significant differences between treatments for Salmonella enteritidis presence or fecal counts of E. coli, coliform, and Salmonella spp. Cecal E. coli and coliform counts were not affected by treatment. There was a significant treatment by time effect for Enterobacteriaceae cecal counts. Enterobacteriaceae counts increased at 16 wk of age and decreased through the study for all treatments, except for YCWE. The addition of prebiotics and probiotics, individually or in combination, did not significantly improve growth or alter the potentially pathogenic bacteria microbiology of feces or ceca in pullet chicks.     

Pharmacokinetics and bioavailability of cefquinome and ceftriaxone in premature calves

The aim of this study was to evaluate the pharmacokinetics and bioavailability of cefquinome (CFQ) and ceftriaxone (CTX) following intravenous (IV) and intramuscular (IM) administrations in premature calves. Using a parallel design, 24 premature calves were randomly divided into the two antibiotic groups. Each of the six animals in the first group received CFQ (2 mg/kg) through IV or IM administration. The second group received CTX (20 mg/kg) via the same administration route. Plasma concentrations of the drugs were analyzed by high‐performance liquid chromatography and noncompartmental methods. Mean pharmacokinetic parameters of CFQ and CTX following IV administration were as follows: elimination half‐life (t_1/2λz) 1.85 and 3.31 hr, area under the plasma concentration–time curve (AUC_0–∞) 15.74 and 174 hr * μg/ml, volume of distribution at steady‐state 0.37 and 0.45 L/kg, and total body clearance 0.13 and 0.12 L hr^?1 kg^?1, respectively. Mean pharmacokinetic parameters of CFQ and CTX after IM injection were as follows: peak concentration 4.56 and 25.04 μg/ml, time to reach peak concentration 1 and 1.5 hr, t_1/2λz 4.74 and 3.62 hr, and AUC_0–∞ 22.75 and 147 hr * μg/ml, respectively. The bioavailability of CFQ and CTX after IM injection was 141% and 79%, respectively. IM administration of CFQ (2 mg/kg) and CTX (20 mg/kg) can be recommended at 12‐hr interval for treating infections caused by susceptible bacteria, with minimum inhibitory concentration values of ≤0.5 and ≤4 μg/ml, respectively, in premature calves. However, further research is indicated to assess the pharmacokinetic parameters following multiple doses of the drug in premature calves.