213份燕麦种质的白粉病抗性评价

为明确不同燕麦种质资源抗白粉病差异,于2012-2014年采用田间自然感病法对213份燕麦(Avena sativa)种质进行了由禾布氏白粉菌燕麦专化型(Blumeria graminis f.sp.avenae)引起的燕麦白粉病的田间抗性筛选和评价。结果表明,在供试材料中未监测到免疫材料;12份材料青永久420、青永久316、青永久9、青永久252、青永久98、青永久180、青永久479、青永久25、青永久87、永118、青永久304和五燕6号表现高抗(HR);199、青永久164、青永久237、青永久260、青永久83、青永久49、青永久016、青永久94、青321、青永久154、原45、永73-1、83-27、S20-36-6、保罗、330、原15和白苏鲁2055共18份材料表现中抗;其余183份表现中感、高感和极感,分别占供试材料的5.6%、8.5%和85.9%。获得的这些有效抗病种质,可为品种的合理布局及抗病育种提供核心抗源。     

291份燕麦种质资源对红叶病抗性的鉴定

为明确不同燕麦种质抗大麦黄矮病毒差异,于2011～2016年采用人工接种对291份燕麦种质进行了由大麦黄矮病毒(Barley yellow dwarf virus,BYDV)引起的燕麦红叶病的田间抗性鉴定。结果表明:在供试的204份皮燕麦(Hulled oats)材料中,未检测出免疫材料;其中DA92-2F4,DA92-3F4和Rigdon等3份材料表现高抗(HR),占供试材料的1.5%;Wallaroo、青永久96、青23、青永久709等11份材料表现为抗(R),占5.4%;青3115、131-10燕麦、S20-36-6、DA92-1F4、青永久304等42份材料表现中抗(MR),占20.6%;45份和103份材料分别表现感(S)和高感(HS),占22.1%和50.5%。在供试的87份裸燕麦(Naked oats)材料中,未检测到免疫材料,其中VAO-1,定莜2032和花早2号等3份材料表现高抗(HR),占3.4%;2002x2-2-5-1-5-16、200215-13-2-2、9641-6、9418和08行-171-22等5份材料表现抗(R),占5.7%;白燕2号、白燕11号、内燕4号、07-21-7、定西R-30-21燕麦等28份材料表现为中抗(MR),占32.2%;36份和15份材料分别表现感(S)和高感(HS),占41.4%和17.2%。6份燕麦品种(系)首次被鉴定为高抗BYDV材料,可为燕麦种质的合理布局和抗病育种提供核心抗源。     

33份燕麦种质田间抗蚜性和 抗大麦黄矮病毒评价

由大麦黄矮病毒(barley yellow dwarf virus, BYDV)导致的燕麦(Avena sativa)红叶病,是我国燕麦产区的主要病害之一。为明确不同燕麦种质材料对蚜虫和大麦黄矮病毒的抗性水平,本研究于2015–2017年,用模糊识别法和目测法调查了33份燕麦资源在灌浆期自然感染蚜虫和BYDV的情况。通过计算蚜量比值和病害平均严重度,对其进行了抗蚜性和抗病性评价。结果表明,铃铛麦、青永久420、青永久119、白燕1号、农大360、MN10253、宁莜1号和重穗莜麦8份材料在3年间均对蚜虫表现抗性,占供试材料的24.24%。而Jim、MN11213和花晚6号3年间均一致表现感蚜,占供试材料的9.09%;参试材料中有10份均对BYDV表现抗性,包括铃铛麦、堵吉、农大360、青永久119、青永久260、青永久420、科燕1号、青永久31、宁莜1号和青永久9,占供试材料的30.3%。而定莜4号和Jim在3年间均一致表现感病,占供试材料的6.06%。33份供试材料中在3年间既抗蚜虫又抗BYDV的有铃铛麦、青永久119、青永久420、农大360和宁莜1号5份,是优异的病虫兼抗燕麦种质;Jim既感蚜又感BYDV。田间蚜量比值与BYDV病害严重度呈显著正相关关系(P 0.05)。白燕15号作为离群材料,易被BYDV感染。本研究对燕麦种质资源抗蚜性和BYDV抗性进行了分析,筛选出了抗性较强的燕麦种质,对燕麦的抗病虫育种工作具有极其重要的指导意义。     

青藏高原高寒地区早熟燕麦资源筛选和适应性评价

为选育适应青藏高原高海拔地区高产优质的早熟燕麦品种，对西宁地区种植的595份燕麦资源进行熟性划分，筛选出22份产量优异的早熟燕麦资源，在海北和湟中2个试验点进行适应性评价，选择生产性能良好的早熟燕麦资源进行籽粒性状比较，为选育适宜青藏高原高寒地区种植推广的早熟燕麦提供了理论依据。结果表明：1)早熟燕麦主要是缩短了拔节期-孕穗期和开花期-完熟期的时间，从而缩短了整个生育期。中熟和晚熟燕麦资源干草产量表现较高，平均为4744.8和4999.9 kg·hm^-2；而中熟燕麦资源平均种子产量表现最高，为3186.9 kg·hm^-2。2)筛选的22份早熟燕麦资源中，平均饲草产量以海北试验点表现较高，为10209.5 kg·hm^-2，平均种子产量以湟中试验点表现较高，为2640.6 kg·hm^-2；海拔3100 m的海北试验点燕麦平均生育期较海拔2700 m的湟中试验点推迟15.3 d，生育期超过116 d不能在海北地区进行种子生产。3)湟中试验点燕麦种子萌发性能远高于海北试验点，其中青永久782、青永久797在...     

陇西南部山区不同燕麦种质适应性研究

在甘肃省陇西县南部山区引种了15份燕麦(Avena sativa)种质,通过测定株高,产草量和牧草品质等项目,评价了15份燕麦种质的表现。结果表明,供试燕麦株高在83.1~119.8cm,平均株高为100.9cm;青永久108燕麦的产草量最高,为12.9t/hm2,青永久205燕麦的产草量最低,为4.4t/hm2。青永久198、青永久416、青永久205和青永久415叶片产量较高,约占总产量的35%以上;青永久415燕麦干草的粗蛋白含量为8.2%,显著高于其他燕麦种质(P0.05),青永久83燕麦的粗蛋白含量最低,为3.1%;青永久286燕麦的酸性洗涤纤维(ADF)含量为44.5%,显著高于其他燕麦(P0.05);青永久198燕麦的ADF含量为21.5%,显著低于其余各燕麦种质(P0.05);青永久108燕麦的中性洗涤纤维(NDF)含量显著高于其他燕麦种质(P0.05);青永久18燕麦的NDF含量为39.9%,显著低于其余燕麦种质(P0.05)。综合干草产量和品质分析表明,青永久108和青永久415燕麦是甘肃陇西南部二阴山区建植燕麦栽培草地的首选品种。     

青藏高原燕麦品种生物抗性初探

研究26个燕麦(Avena sativa L.)品种的抗病性和抗蚜性,采用灰色系统理论对其进行综合评价。结果表明:黄矮病是天祝地区燕麦的主要病害,其中青永久18、青永久81、青永久15、青永久139、青永久136、丹麦444及青永久316抗性综合表现优异;表现良好的有青永久877、CNC、青引1号;表现一般的有青永久94、青永久118、青永久343、青永久440以及初岛燕麦,其余品种表现较差;用逐步回归法筛选出对燕麦品种生物抗性影响显著的指标,分别为黄矮病病情指数、植株矮化率、褐枯病发病率及蚜害指数,并以此为据建立了天祝高寒地区燕麦生物抗性综合评价的指标体系。     

鹅观草不同居群条锈病和白粉病抗性评价

鉴定不同居群鹅观草种质对条锈病和白粉病的抗性,为牧草及麦类作物抗病基因的选取和抗病品种选育提供遗传资源基础。本研究采用田间接种法对来自国内外的34份鹅观草种质资源(野生资源33份,品种1份)进行了成株期抗病性鉴定和评价。结果表明,种质资源抗病能力存在多样性。34份鹅观草条锈病的严重度、病叶率和病情指数的变异范围分别为11.49%~50.46%,19.85%~74.24%和2.63~37.60,变异系数分别为30.01%,26.54%和49.67%;反应型和发生程度的变异范围分别为1~4和轻发生(1级)至大发生(5级);各病害指标之间均为极显著正相关(P<0.01)。以上5个指标综合聚类分析表明:34份材料中,6份高抗(HR,占17.65%)、4份中抗(MR,占11.76%)、17份中感(MS,占50.00%)和7份高感(HS,占20.59%)。34份鹅观草白粉病的反应型、严重度和植株感病率的变异范围分别为0~4,0~60.00%和0~100%;34份材料聚类分析得知:12份高抗(HR,占35.29%)、5份中抗(MR,占14.71%)、11份中感(MS,占32.35%)和6份高感(HS,占17.65%)。对条锈病和白粉病均具有较好抗性的材料有ZY 1007和Pr 87-88 344,可作为育种材料进一步深入研究。     

豌豆种质资源白粉病抗性鉴定

为了充分利用抗病豌豆(Pisum sativum)种质资源,于2009～2011年连续3年对来自国内外的535份豌豆材料进行白粉病田间自然鉴定。结果表明,田间表现高抗的有1个材料,占鉴定总数的0.19%;抗病材料2个,占总数的0.37%;中抗材料17个,占总数的3.18%;中感材料60个,占总数的11.12%;感病材料434个,占总数的81.12%;高感材料21个,占总数的3.93%。通过对田间表现出抗性的20个材料进行室内苗期接种鉴定表明,除了4个中抗材料的抗性发生了变化外,其余均与田间抗性表现一致,具有较好的抗性稳定性。     

燕麦种质抗坚黑穗病鉴定与评价

为明确不同燕麦种质抗坚黑穗病（Ustilago segetum var. avenae）的差异和探讨形成燕麦抗坚黑穗病鉴定技术规范,于2013-2014年采用菌粉拌种和菌土覆盖的接种方法对135份燕麦种质进行坚黑穗病的田间抗性鉴定,结果表明,在菌粉拌种条件下,64份裸燕麦中,12份免疫,6份高抗,1份抗,19份中感,16份感,10份高感,分别占鉴定裸燕麦的18.8%,9.4%,1.6%,29.7%,25.0%,15.6%;71份皮燕麦中,45份免疫,22份高抗,2份抗,2份中感,分别占鉴定皮燕麦的63.4%,31.0%,2.8%,2.8%。在菌土覆盖条件下,64份裸燕麦中,17份免疫,8份高抗,13份抗,22份中感,3份感,1份高感,分别占鉴定裸燕麦的26.6%,12.5%,20.3%,34.4%,4.7%,1.6%;71份皮燕麦中,56份免疫,13份高抗,1份抗,1份中感,分别占鉴定皮燕麦的78.9%,18.3%,1.4%,1.4%;在2种接种方法下,62份材料抗性完全一致;10份材料在菌粉拌种接种方法的抗病性低于菌土覆盖的抗病性;菌粉拌种较菌土覆盖易使63个燕麦品种的发病率增加,使其抗病性下降,说明菌粉拌种接种方法明显优于菌土覆盖。试验中获得的这些有效抗病种质,可为品种的合理布局和更替提供科学依据,同时可为育种部门提供核心抗源。     

燕麦种质抗坚黑穗病鉴定与评价

为明确不同燕麦种质抗坚黑穗病(Ustilago segetum var.avenae)的差异和探讨形成燕麦抗坚黑穗病鉴定技术规范,于2013-2014年采用菌粉拌种和菌土覆盖的接种方法对135份燕麦种质进行坚黑穗病的田间抗性鉴定,结果表明,在菌粉拌种条件下,64份裸燕麦中,12份免疫,6份高抗,1份抗,19份中感,16份感,10份高感,分别占鉴定裸燕麦的18.8%,9.4%,1.6%,29.7%,25.0%,15.6%;71份皮燕麦中,45份免疫,22份高抗,2份抗,2份中感,分别占鉴定皮燕麦的63.4%,31.0%,2.8%,2.8%。在菌土覆盖条件下,64份裸燕麦中,17份免疫,8份高抗,13份抗,22份中感,3份感,1份高感,分别占鉴定裸燕麦的26.6%,12.5%,20.3%,34.4%,4.7%,1.6%;71份皮燕麦中,56份免疫,13份高抗,1份抗,1份中感,分别占鉴定皮燕麦的78.9%,18.3%,1.4%,1.4%;在2种接种方法下,62份材料抗性完全一致;10份材料在菌粉拌种接种方法的抗病性低于菌土覆盖的抗病性;菌粉拌种较菌土覆盖易使63个燕麦品种的发病率增加,使其抗病性下降,说明菌粉拌种接种方法明显优于菌土覆盖。试验中获得的这些有效抗病种质,可为品种的合理布局和更替提供科学依据,同时可为育种部门提供核心抗源。     

Characterization of d-Glucose Transport across Equine Jejunal Brush Border Membrane Using the Pig as an Efficient Model of Jejunal Glucose Uptake

To test the hypotheses that glucose transport capacity across the brush border membrane (BBM) of the large colon is lower than that of the small intestine in equids, and that small intestinal transport capacity in equids is lower than suids. d-glucose transport capacity (V_max) and affinity (K_M) across the BBM of the distal jejunum (DJ) and proximal large colon (PLC) of the pony and pig were measured. Mucosa was collected from the DJ and PLC of ponies (n = 4) and pigs (n = 3), flash-frozen in liquid nitrogen, and stored at −80°C. Jejunal and colonic BBM vesicles were manufactured, and d-glucose transport was determined. There was no detectable active uptake of glucose in the equine PLC. Compared with the pig DJ, d-glucose transport capacity was lower (2595 ± 331 vs. 655 ± 286 ρmol·mg protein⁻¹·s⁻¹, respectively, P < .01) and transport affinity tended to be lower (0.09 ± 0.07 vs. 0.27 ± 0.06 mM, respectively, P = .11) in the pony DJ. Compared with the pig DJ, d-glucose transport capacity (2,595 ± 331 vs. 571 ± 331 ρmol·mg protein⁻¹·s⁻¹, respectively, P < .001) and transport affinity (0.09 ± 0.07 vs. 0.54 ± 0.07 mM, respectively, P < .001) in the pig PLC were lower. Results show there is negligible d-glucose uptake across pony PLC, and capacity for d-glucose absorption across DJ BBM is fourfold lower in the pony compared with the pig. Results further exemplify, at a physiological level, the limited capacity of the equid small intestine to transport glucose relative to an omnivorous mammal, and the likely evolutionary adaptation of equids to low dietary levels of nonstructural carbohydrates.     

Morphological and morphometric characterization of domestic cat epididymal sperm

Sperm morphometry is the tool that confers objectivity to the morphological evaluation by accurately measuring the dimensions of the gamete and its structures. Thus, the aim of the study was to perform a morphometric characterization of the domestic cat sperm. Therefore, sperm samples were collected from twenty pairs of epididymis in a TRIS extender at 37ºC. An aliquot of the sample was used to make a smear with Rose Bengal solution, and afterwards, the morphology and morphometry were analysed. In the morphology, were quantified the percentage of normal sperm cells, morphological changes of head, midpiece and tail. In morphometry, each normal sperm cell was measured for length, width, area and perimeter of head and midpiece, tail length and total length. The parameters ellipticity, elongation, regularity and rugosity were also determined. The percentage of normal sperm was 67.21%. Of the abnormalities, the curled/folded tail, followed by the curved midpiece, abnormal shaped head and detached head were the most quantified. The sperm head presented 5.56 ± 0.01 μm and 3.10 ± 0.01 μm of length and width, respectively. The head area was 16.94 ± 0.05 μm², while the perimeter was 16.16 ± 0.03 μm. In the derived parameters, the values were as follows: ellipticity of 1.81 ± 0.00; elongation of 21.39 ± 0.12; regularity of 0.81 ± 0.00; and rugosity of 0.14 ± 0.00. The midpiece presented length and width of 7.96 ± 0.01 μm and 0.76 ± 0.01 μm, respectively. The mean length of the sperm tail was 45.12 ± 0.06 μm, and the total cell size was 58.67 ± 0.06 μm. Thus, it was concluded that the cat sperm is an elongated cell, with high rugosity and regularity. The spermatic tail represents more than ¾ of the total length of the cell and the midpiece exceeds the length of the head.     

Comparison of in vitro and in vivo fertilizing potential of buffalo bull semen frozen in egg yolk‐, soya bean lecithin‐ and liposome‐based extenders

The objective of this study was to compare different extenders for post‐thaw in vitro sperm function and in vivo fertility of buffalo semen. Accordingly, sperm of 30 ejaculates extended in egg yolk (TRIS with 20% egg yolk; EY), two soya lecithin‐based (SL‐1; AndroMed^® and SL‐2; Bioxcell^®) and a liposome‐based extender (LS; OptiXcell^®) were tested. The post‐thaw semen was evaluated for computer‐assisted sperm analysis (CASA), sperm viability, membrane and acrosome integrity, DNA integrity and acrosome reaction and first service pregnancy rate (FSPR) in a fixed‐time artificial insemination programme. Total motility and VCL were the only CASA‐based parameters that exhibited significantly higher (p < .05) percentage in LS among these extenders. Post‐thaw percentage of acrosome integrity (55.9 ± 1.4, 58.1 ± 2.0, 55.8 ± 2.0, 56.6 ± 2.3) and DNA integrity (68.8 ± 2.0, 69.2 ± 2.3, 71.3 ± 2.1, 69.1 ± 2.1) did not differ (p > .05) in EY, SL‐1, SL‐2 and LS extender, respectively. However, a variable response in terms of efficacy of different extenders for sperm viability and plasma membrane integrity was observed. Assessment of inducibility of acrosome reaction showed significant differences between extenders (51.9 ± 2.1, 44.3 ± 2.4, 46.1 ± 2.3 and 58.1 ± 3.1%, respectively, for EY, SL‐1, SL‐2 and LS). Furthermore, field trials revealed significantly higher (p < .05) FSPR of LS‐extended semen as compared to that for EY, SL‐1 and SL‐2 extender (46.3%, 41.2%, 31.2% and 29.7%, respectively). It is concluded that the liposome‐based extender is more effective than egg yolk‐ and soya lecithin‐based extenders and may be used for cryopreservation of buffalo semen in the future.     

Pharmacokinetics of tildipirosin in beagle dogs

The objective of this study was to investigate the pharmacokinetic profile of tildipirosin (TD) in 24 beagle dogs following intravenous (i.v.) and intramuscular (i.m.) administration, respectively, at 2, 4, and 6 mg/kg. Plasma samples at certain time points (0–14 days) were collected, and the concentrations of drug were quantified by UPLC‐MS/MS. Plasma concentration–time data and relevant parameters were described by noncompartmental through WinNonlin 6.4 software. After single i.m. injection at 2, 4, and 6 mg/kg body weight, mean maximum concentration (C_max) was 412.73 ± 76.01, 1,051 ± 323, and 1,061 ± 352 ng/ml, respectively. Mean time to reach C_max was 0.36 ± 0.2, 0.08 ± 0.00, and 0.13 ± 0.07 hr after i.m. injection at 2, 4, and 6 mg/kg, respectively. The mean value of T_1/2λz for i.m. administration at doses of 2, 4, and 6 mg/kg was 71.39 ± 28.42, 91 .33 ± 50.02, and 96.43 ± 45.02 hr, respectively. The mean residence times were 63.81 ± 10.96, 35.83 ± 15.13, and 38.18 ± 16.77 hr for doses of 2, 4, and 6 mg/kg, respectively. These pharmacokinetic characteristics after i.m. administration indicated that TD could be rapidly distributed into tissues on account of the high lipid solubility and then released into plasma. In addition, the absolute bioavailability of 2 mg/kg after i.m. injection was 112%. No adverse effects were observed after i.v. and i.m. administration.     

Analyses of parental and seasonal influences on the synchrony of dexamethasone-induced lambing and lamb characteristics

Synchronization of parturition in a commercial flock of sheep has many advantages including the maintenance of the efficiency of the operation as well as optimization of care for periparturient animals. In a research setting, using an ovine model for experiments involving the induction of parturition yields the results that can be applied to other mammalian species. In sheep, as well as in a variety of other farmed species, dexamethasone is the drug used to induce synchronized parturition at the end of gestation. However, considerable variations have been noticed in the time between induction and the onset of lambing. This study set out to determine the role that the breed of dam and sire, the age and reproductive history of ewes, the month of induction and the litter/lamb characteristics played in determining the time between dexamethasone treatment and parturition. The lambing was induced in 146 ewes (4 purebred Dorset, 19 purebred Rideau Arcott and 123 Rideau Arcott × Dorset ewes) using a single i.m. dose of 20 mg dexamethasone (Unidex^®, Univet Pharmaceuticals, Milton, ON, Canada) on day 140 of gestation. The ewe breed was weakly correlated (r = − 0.19, P < 0.05) whereas the sire breed was moderately correlated (r = − 0.37, P < 0.001) to the time between dexamethasone treatment and the onset of parturition (the breed in this study was defined as the % of the Rideau Arcott genotype). The time between induction and the onset of labour averaged 57.3 ± 5.3 h and 64.3 ± 8.2 h in February and April, respectively, and it was significantly longer (P < 0.05) compared with the times recorded in July, September and November (42.0 ± 2.0 h, 38.7 ± 2.8 h and 36.1 ± 5.0 h, respectively). There was a negative correlation (r = − 0.41, P < 0.001) between the proportion of ram lambs and the mean birth weight of ewe lambs. These results can be interpreted to suggest that the breed and time of the year may both affect the synchrony of dexamethasone-induced lambing. The reasons for the associations found between the month of induction and the time elapsed to the onset of parturition as well as between the proportion of ram lambs and birth weights of ewe lambs are not fully understood and warrant further studies.     

Factors influencing pre-ovulatory follicle diameter and weaning-to-ovulation interval in spontaneously ovulating sows in tropical environment

Follicle development and timing of ovulation are indicators of the reproductive performance of sows. The present study aimed to determine factors influencing pre-ovulatory follicle diameter and weaning-to-ovulation interval (WOI) in spontaneously ovulating sows in tropical climates with special emphasis on breed, parity and backfat thickness at weaning. In total, 80 sows were included in the study. Follicle development was determined by using transrectal real-time B-mode ultrasonography every 6 hr after standing oestrus. Weaning-to-oestrous interval (WEI), oestrous-to-ovulation interval (EOI), WOI and the diameter of graafian follicles were investigated in relation to breed, parity number (1, 2–3 and 4–7) and backfat thickness (low, moderate and high) of sows. Overall, WEI, EOI, WOI and the pre-ovulatory follicle diameter were 92.5 ± 21.6 hr, 64.3 ± 19.3 hr, 156.3 ± 29.1 hr and 10.3 ± 2.0 mm, respectively. Pre-ovulatory follicle size was smaller in primiparous sows compared with sows of greater parity, 4–7 (9.7 ± 0.51 and 11.7 ± 0.52 mm, respectively, p < .05). Weaning-to-ovulation interval was positively correlated with WEI (r = 0.75, p < .001) and EOI (r = 0.66, p < .001), but negatively correlated with size of the graafian follicle (r = –0.34, p < .01). Sows with a shorter WEI had a larger pre-ovulatory follicle diameter (at 64 hr after oestrus) (r = –0.37, p < .01). Sows with low backfat thickness had a WOI 23.4 hr longer than those with moderate backfat thickness (p < .05) and 17.6 hr longer than sows with a high backfat thickness (p = .140). The follicle diameter in primiparous sows with high backfat thickness (11.7 ± 1.1 mm) was higher than in those with low (8.9 ± 0.7 mm, p < .05) or moderate (8.6 ± 0.8, p < .05) backfat thickness. In conclusion, factors influencing follicle diameter and WOI in sows included parity number and backfat thickness at weaning. The impact of backfat thickness on follicle diameter, WEI and WOI was most pronounced in primiparous sows.     

Comparison of selected indices of internal environment and condition of laying hens kept in furnished cages and in aviaries

Biochemical and hematological examination of blood and individual assessment of the birds were performed in Lohman Brown laying hens at 45 weeks of age housed in different systems. The biochemical examination revealed higher (p < .01) corticosterone levels, creatine kinase, and aspartate aminotransferase activity and lower (p < .01) levels of lactate, triglycerides, albumin, calcium, and phosphorus in aviary hens compared to hens housed in furnished cages. Hematological examination of hens housed in aviaries revealed higher (p < .05) hematocrit, leukocytes, heterophils, eosinophils, basophils, monocytes, and H/L ratio. Furthermore, hens housed in aviaries had lower (p < .01) body weight than hens in furnished cages, they were worse feathered (p < .001), had more damaged combs (p < .05), and poorer physical condition (p < .01). In contrast, caged hens showed worse (p < .01) feather condition of the wings due to abrasion and claws due to overgrowth. The results have shown that the housing system has a significant impact on the internal environment and condition of birds and that housing in aviaries without taking into account the specifics of such housing may lead to significant stress and disturbance to the welfare of laying hens.     

Sanguinarine metabolism and pharmacokinetics study in vitro and in vivo

Sanguinarine (SA) is a benzo[c] phenanthridine alkaloid which has a variety of pharmacological properties. However, very little was known about the pharmacokinetics of SA and its metabolite dihydrosanguinarine (DHSA) in pigs. The purpose of this work was to study the intestinal metabolism of SA in vitro and in vivo. Reductive metabolite DHSA was detected during incubation of SA with intestinal mucosa microsomes, cytosol, and gut flora. After oral (p.o.) administration of SA, the result showed SA might be reduced to DHSA in pig intestine. After i.m. administration, SA and DHSA rapidly increased to reach their peak concentrations (C_max, 30.16 ± 5.85, 5.61 ± 0.73 ng/ml, respectively) at 0.25 hr. Both compounds were completely eliminated from the plasma after 24 hr. After single oral administration, SA and DHSA rapidly increased to reach their C_max (3.41 ± 0.36, 2.41 ± 0.24 ng/ml, respectively) at 2.75 ± 0.27 hr. The half-life (T_1/2) values were 2.33 ± 0.11 hr and 2.20 ± 0.12 hr for SA and DHSA, respectively. After multiple oral administration, the average steady-state concentrations (C_ss) of SA and DHSA were 3.03 ± 0.39 and 1.42 ± 0.20 ng/ml. The accumulation indexes for SA and DHSA were 1.21 and 1.11. The work reported here provides important information on the metabolism sites and pharmacokinetic character of SA. It explains the reasons for low toxicity of SA, which is useful for the evaluation of its performance.     

The effect of incremental replacement of wheat with soya hulls in diets for Jersey cows on lactational performance, diet digestibility and feeding behaviour

Eight Jersey cows were used in two balanced 4 × 4 Latin Squares to investigate the effects of replacement of dietary starch with non-forage fibre on productivity, diet digestibility and feeding behaviour. Total-mixed rations consisted of maize silage, grass silage and a soyabean meal-based concentrate mixture, each at 250 g/kg DM, with the remaining 250 g consisting of cracked wheat/soya hulls (SH) in the ratios of 250 : 0, 167 : 83; 83 : 167 and 0 : 250 g, respectively, for treatments SH0, SH83, SH167 and SH250. Starch concentrations were 302, 248, 193 and 140 g/kg DM, and NDF concentrations were 316, 355, 394 and 434 g/kg DM, for treatments SH0, SH83, SH167 and SH250, respectively.Total eating time increased (p < 0.05) as SH inclusion increased, but total rumination time was unaffected. Digestibility of DM, organic matter and starch declined (p < 0.01) as SH inclusion increased, whilst digestibility of NDF and ADF increased (p < 0.01). Dry-matter intake tended to decline with increasing SH, whilst bodyweight, milk yield and fat and lactose concentrations were unaffected by treatment. Milk protein concentration decreased (p < 0.01) as SH level increased. Feed conversion efficiency improved (p < 0.05) as SH inclusion rose, but it was not possible to determine whether this was due to the increased fibre levels alone, or the favourable effect on rumen fermentation of decreasing starch levels.     

Tannic acid extracted from gallnut prevents post-weaning diarrhea and improves intestinal health of weaned piglets

This experiment was conducted to evaluate the effects of different levels of tannic acid (TA) on growth performance, diarrhea rate, nutrient digestibility and intestinal health in weaned piglets. A total of 180 weaned piglets (Duroc × Landrace × Yorkshire, 24 d of age, initial average BW = 7.77 ± 0.17 kg) were allotted to 5 groups (6 pigs/pen and 6 replicates/group) in a randomized complete block design according to their gender and body weight. Piglets were fed a basal diet, or the basal diet supplemented with 0.05%, 0.1%, 0.2% or 0.4% TA for 28 d. The supplementary levels of TA in the diets were obtained by adding tannalbin containing 51% TA and 40.17% protein. The results showed that, compared with the CON group, dietary TA did not affect ADFI, ADG or F:G, and linearly reduced (P < 0.01) the diarrhea rate and diarrhea index of piglets. There were no significant effects on apparent total tract digestibility (ATTD) in the 0.05%, 0.1% and 0.2% TA groups, while negative effects (P < 0.05) on apparent digestibility of crude protein and gross energy were observed in the 0.4% TA group. In addition, the nutrient digestibility of dry matter, crude protein and gross energy linearly decreased (P < 0.01) with the increase of TA dosage. Supplementation of TA increased (P < 0.05) the villus height of the duodenum and jejunum, as well as increased (P < 0.05) catalase (CAT) activity in serum. Dietary TA improved (P < 0.05) the Bacillus counts in cecal digesta. Further, TA significantly improved (P < 0.05) Bacillus counts and reduced (P < 0.05) the Escherichia coli counts in colonic digesta. The concentration of acetic acid, propionic acid, butyric acid and isovaleric acid in cecal digesta were significantly increased (P < 0.05). The mRNA expression level of zonula occludens-1 (ZO-1), zonula occludens-2 (ZO-2), and claudin-2 (CLDN-2) in the jejunum were greater (P < 0.05) in TA supplemented groups. The study showed that, compared to the control, TA prevented post-weaning diarrhea and improved intestinal health of weaned piglets, and the appropriate level of TA supplementation would be from 0.1% to 0.2%.