高山美利奴羊主观评定性状与客观测量性状现状及两者相关性研究

本文通过对甘肃省绵羊繁育技术推广站高山美利奴羊核心群2015—2017年出生的1686只育成母羊基于5分制的质量性状主观评定和数量性状客观检测资料,统计分析了高山美利奴羊周岁母羊头型分、被毛密度分、羊毛弯曲分、羊毛油汗颜色分、毛丛污染分、羊毛细度匀度分、羊毛细度支数等7个主观评定性状以及毛长、体重、污毛量、净毛量、净毛率、毛纤维直径6个主要客观测量性状的现状,同时分析了主观评定性状对客观测量性状的影响,以及主观评定性状与主要测量性状的相关性。结果表明:高山美利奴羊育成母羊的毛长、体重、污毛量、净毛量、净毛率、毛纤维直径分别达(10.50±0.982)cm、(44.17±4.670)kg、(4.41±0.746)kg、(2.58±0.424)kg、(58.64±6.220)%和(18.21±1.520)μm,周岁母羊客观检测的羊毛细度支数80~90支占到53.7%,100~120支(纤维直径14~17μm)占比达到21.1%。每个主观评定性状都对一到多个客观测量性状存在显著影响,这种影响多数存在显著的相关性规律。     

甘肃高山细毛羊优质毛品系选育研究

以甘肃高山细毛羊为遗传基础,在同质选配、主要性状客观检验选种的基础上,采用导入中国美利奴血液的开放式育种的主导育种措施,从2001年开始通过5年选育,在地处祁连山高寒地区的甘肃省皇城绵羊育种试验场育成甘肃高山细毛羊优质毛品系。建立了以1066只理想型母羊和56只公羊组成的品系群体,母羊周岁育成时羊毛纤维直径、净毛量、体重、体侧毛长分别达到18.48μm、2.18kg、38.67kg和9.82cm,成年母羊上述4项指标分别达到21.017μm、2.56kg、49.46kg和9.02cm。用MTDFREML法进行了品系遗传参数的估计。育种工作开展5年间,品系理想型育成母羊羊毛纤维直径下降2.77μm,净毛量提高0.34kg。。     

细毛羊育成期年度性状研究分析

本文主要针对甘肃省绵羊繁育技术推广站2000至2020年育成期所有羊只展开论述。性状研究分析所用到的育种数据统计方法主要有vf、excel、 spss,三种方法相结合，根据需求灵活使用。将体侧毛长、体重、污毛量、净毛量、净毛率、纤维直径等主要性状数据变化开展具体研究分析。根据统计分析结果显示，总体趋势经历了一个起伏波动的改进过程，从先前的下降再到后来的回升，改进幅度较显明。结果表明：育成公羊的体侧毛长、体重、污毛量、净毛量虽有下降，但不难看出，总体趋势是逐步上长的趋势；羊毛纤维直径从2000开始全群检测以来稳步改进，总体改进4μm;净毛率从2000年的46.4%提高到2020年的50.29%,改进幅度较显明。育成母羊的体侧羊毛长度总体上有所降低，从总趋势看经历了先降后升的过程；羊毛细度支数从2000年的平均65.5支提高到2020年的71.69支；周岁体重从2000年的平均38.31kg提高到2020年的40.25 kg;羊毛纤维直径从2000年的平均19.96μm,下降到2020年的17.65μm,改进2.31μm;羊毛平均纤维直径变异系数从2000年的23.48%下降到2020年的...     

乾华肉用美利奴羊主要经济性状遗传参数的估计

利用吉林省乾安志华种羊繁育有限公司2011—2015年出生的15只乾华肉用美利奴羊公羊的1 230只女儿的测定数据,采用父系同胞相关法和单元内半同胞相关法分别估计了乾华肉用美利奴羊的初生重、断奶重、周岁羊毛纤维直径、周岁毛长、周岁剪毛量、周岁剪毛后体重、2周岁羊毛纤维直径、2周岁毛长、2周岁剪毛量、2周岁剪毛后体重等经济性状的遗传参数。结果表明:所有性状均在0.1~0.7的中高等遗传力;乾华肉用美利奴羊的大部分经济性状间呈正相关,周岁、2周岁时的羊毛纤维直径与羊毛长度间均呈中等负遗传相关;周岁羊毛纤维直径与2周岁羊毛纤维直径、2周岁毛长与2周岁剪毛量之间均呈强的正遗传相关;2周岁羊毛纤维直径与2周岁剪毛量间呈强的负遗传相关,而周岁羊毛纤维直径与剪毛量间则呈中等负遗传相关;初生重与断奶重、周岁体重、2周岁体重间,断奶重与周岁体重、2周岁体重间,周岁体重与2周岁体重间均呈中等正遗传相关。本研究表明乾华肉用美利奴羊主要经济性状均为中、高水平的遗传力,且大多数经济性状之间呈中等以上的遗传相关和表型相关。     

导入澳血公羊对甘肃高山细毛羊生产性能的影响研究

试验探讨了通过导入体大高产澳血公羊对甘肃高山细毛羊F1、F2代周岁母羊主要生产性能的影响。从体侧毛长、体重、剪毛量、纤维直径、净毛率等主要生产性能进行了分析比较,为培育甘肃高山细毛羊体大高产品系奠定基础。结果表明:(1)F1代周岁母羊与同龄甘肃高山细毛羊超细品系母羊相比,羊毛长度增长了0.398cm(P0.01),体重增加了3.7949kg(P0.01),剪毛量有所增加(P0.01),毛纤维变粗(P0.01),净毛率没有变化。(2)F2代周岁母羊羊毛细度变化不显明,与甘肃高山细毛羊超细品系母羊相比变粗了1.294μm(P0.01);毛长和剪毛量有所提高(P0.01);体重分别较甘肃高山细毛羊和甘肃高山细毛羊超细品系母羊增加了3.3051kg(P0.01)、1.0648kg(P0.05);净毛率没有变化(P0.05)。     

培育贵州半细毛羊试验(第三报)

威宁县是全省绵羊的主要产区,绵羊约占全省的一半。1973年明确培育贵州半细毛羊后,1974～1979年通过考察威宁县种羊场、社办雪山牧场、甘家院牧场和黑石公社水平大队羊群,引用考力代羊、罗姆尼羊同细毛杂种羊进行育成杂交的结果: 1.考细杂二岁母羊体重36.62公斤,比细杂稍小,差异不显著;剪毛量3.67公斤,净毛率58.27％,剪毛量低于细杂,差异显著;净毛量2.14公斤,不低于细杂;毛长9.24厘米,比细杂增长21.9％,差异显著;细度在58支以下的占62.5％,主体细度58～60支,比细杂增粗一个品级支数。在农村社队饲养条件下亦得到类似的结果。 2.考考细杂二岁母羊体重36.56公斤,毛量3.66公斤,净毛率62.65％,毛长9.69厘米,与考细杂无显著差异;细度在58支以下的个体占到83.33％,主体细度56～58支,比考细杂又增粗一个品级支数。但在农村社队上列各项指标均低于考细杂。 3.罗细杂二岁母羊体重40.31公斤,剪毛量2.96公斤,净毛率59.19％,毛长8.57厘米,细度在58支纱以下的占76.32％,主体细度56～60支,以58支为中心。与细杂比较体重增大,毛量减少,毛长增加,都有非常显著的差异,细度有明显的增粗。与考细杂比较体重亦大,毛量减少,毛长较短,其差异亦非常显著。细度分布较考细杂好,58支以下的个体所占的比例有一定程度的增加,并出现少数50支的个体。 4.罗罗细杂二岁母羊体重39.00公斤,剪毛量2.92公斤,净毛率58.64％,毛长8.67厘米,细度在58支以下的个体占88.89％,主体细度56～58支。与罗细杂比较,体重稍小,剪毛量略有增加,毛长亦稍有提高,但差异都不显著,细度分布有进一步改善,58支以下的个体又有增加。与考考细杂比较,体重大,毛量少,毛长稍短,但差异亦不够显著,细度分布有一定的改善,58支以下的个体较多。 5.考力代羊和罗姆尼羊与细毛杂种羊杂交的一代,毛长、细度都有明显的改变,从提高毛长,加粗纤维直径来讲效果显著。体重和毛量的变异,因父本不同而异。罗细杂体重大,差异显著,考细杂体重稍小差异不显著。净毛率有较大幅度提高,剪毛量低于细杂,差异显著。净毛量考细杂略高于细杂,罗细杂则低于细杂。两个品种的杂交二代,细度分布又得到进一步的改善。 6.从考细杂、考考细杂组合选理想羊横交的结果,一世代一岁母羊生产性能:体重30.75±0.85公斤,剪毛量3.07±0.18公斤,毛长10.59±0.35厘米,细度在58支以下的个体占50％,体侧羊毛纤维直径26.30±2.02微米。与同龄同期考考细杂比较,无明显差异,并达到贵州半细毛羊育种指标要求。但在社队当前饲养条件下,一世代一岁羊的生产性能与育种指标要求尚有相当的距离,乃饲养水平的差异所致。因此必须把改变生产的基本条件当着头等大事来抓,从合理利用草坡,贮备充足的冬草入手,大种优质牧草,块根饲料,努力提高羊群的饲养水平,切实地为培育贵州半细毛羊提供可靠的物质基础。     

青海细毛羊主要经济性状遗传参数估计

估测了三角城种羊场青海细毛羊１３个性状的遗传力，表型相关和遗传相关估测结果表明，初生重，断奶重，周岁剪毛量，羊毛细度，毛长，剪毛前体型，剪毛量都是高遗传力性状，通过个体选择可取得良好效果。断奶重，周岁剪毛量，剪毛前体重与剪毛量之间呈强正遗传相关，断奶重可作为早期性状对剪毛量进行早期选择；因断奶重与羊毛细度之间呈负遗传相关，因此要注意细度的变化。     

胚胎移植技术在优质细毛羊育种中的研究与应用

采用 FSH、L H、PMSG、氟孕酮阴道海绵栓等激素进行超数排卵 ,通过人工授精、手术采卵、同期发情、胚胎移植、B超妊娠检查等技术 ,共处理优秀美利奴母羊 4 5 6只 ,获得可用胚胎 (A、B、C级胚胎 ) 30 33枚 ,平均 6 .6 5枚 /只(30 33/ 4 5 6 ) ,移植受体母羊 2 333只 ,冻胚受孕率 4 7.0 2 % (10 97/ 2 333) ,产羔数 14 2 6只 ,产羔率 12 9.99% (14 2 6 /10 97)。其中 ,公羔 6 85只 ,母羔 74 1只。优质细毛羊初生重公羔平均 4 .4 5 kg,母羔平均 4 .6 1kg。断奶重公羔平均38.2 4 kg,母羔平均 33.6 8kg。 12月龄平均体重公羊 76 .15 kg,母羊平均 6 2 .15 kg。周岁毛长公羊平均 11.6 7cm,剪毛量平均 12 .0 4 kg;母羊毛长平均 11.12 cm ,剪毛量平均 7.6 5 kg;平均净毛率达到 6 8.5 %。 2岁公羊体重平均 10 6kg,毛长平均 11.5 cm,剪毛量平均 11.85 kg,净毛率 6 9.5 %。2岁母羊体重平均 72 kg,毛长平均 11.0 cm,剪毛量平均8.5 kg,净毛率 6 9.0 6 %。羊毛纤维平均细度 18.71μm。 3岁公羊最大体重 14 8kg,母羊最大体重 10 2 kg。优质细毛羊新类群同期上述各项指标均显著或极显著高于中国美利奴羊     

引进澳美公羊与高山美利奴羊杂交F1代生产性能对比分析

本文在引入澳洲美利奴公羊对高山美利奴羊进行选育提高的进程中，通过对生产出含澳血的F1代周岁母羊与纯种高山美利奴周岁母羊在体重、剪毛量、羊毛纤维直径、体侧毛长、净毛率等生产性能方面的数据进行测定采集后，经过对测定的数据进行统计分析对比，得出改良效果为含澳血F1代周岁母羊比纯种高山美利奴周岁母羊在体重、剪毛量、体侧毛长和净毛率等生产性状方面选育提高差异极显著，应进一步扩大选育提高改良规模，生产出优质种羊，通过国家绒毛用羊技术体系平台向社会推广，在助推乡村振兴，促进广大牧民和养殖户致富增收方面发挥积极作用。     

青海高原毛肉兼用半细毛羊经济性状遗传力估测

对青海省柴达木地区青海高原毛肉兼用半细毛羊9个主要经济性状进行了遗传力估测。结果表明,初生重、断奶重、周岁剪毛量、羊毛细度、毛长、剪毛前体重、剪毛量都是高遗传力性状,也是青海高原毛肉兼用半细毛羊育种过程中的主要选择依据;断奶重、周岁剪毛量、剪毛前体重与剪毛量之间呈强正遗传相关,断奶重可作为对剪毛量进行早期选择的参数;断奶重与羊毛细度之间呈负遗传相关。     

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.     

Salmonella in pork cuttings in supermarkets and butchers' shops in Denmark in 2002 and 2006

The prevalence of Salmonella in fresh pork cuttings in Denmark in the years 2002 and 2006 was investigated at retail and compared with the retail supply pattern. A total of 1025 and 3473 samples were taken in 2002 from butcher's shops and supermarkets, respectively. The corresponding numbers in 2006 were 259 from butchers' shops and 628 from supermarkets. In 2002, 1.2% of all samples were positive for Salmonella; butchers' shops and supermarkets had 1.8% and 1.0% positive samples, respectively. The overall prevalence in 2006 was 4.2%, with prevalence of 8.1% and 2.6% for butchers' shops and supermarkets, respectively. Hence, increases around 3- to 5-fold were found. There was neither observed any parallel increase in Salmonella positive carcasses in Danish slaughterhouses during the study period, nor were any changes in supply routes towards slaughterhouses with higher prevalence observed, which could explain the apparent increase. We hypothesize that hygiene levels and ability to avoid cross-contamination and prevent growth of the organism, in the meat processing chain after slaughter were the most likely responsible factors. Results from this study indicate that the hygiene performance, particularly at retail, has a significant impact on the occurrence of Salmonella. This implies that there is no direct link between slaughterhouse Salmonella surveillance data and the level of Salmonella contamination at retail. To improve risk assessment of Salmonella in fresh pork meat, this study underlines the need for comprehensive retail data.     

Bartonella and Babesia infections in cattle and their ticks in Taiwan

Bartonella and Babesia infections and the association with cattle breed and age as well as tick species infesting selected cattle herds in Taiwan were investigated. Blood samples were collected from 518 dairy cows and 59 beef cattle on 14 farms and 415 ticks were collected from these animals or in a field. Bartonella and Babesia species were isolated and/or detected in the cattle blood samples and from a selected subset (n = 254) of the ticks either by culture or DNA extraction, PCR testing and DNA sequence analysis. Bartonella bovis was isolated from a dairy cow and was detected in 25 (42.4%) beef cattle and 40 (15.7%) tick DNA samples. This is the first isolation of B. bovis from cattle in Asia and detection of a wide variety of Bartonella species in Rhipicephalus microplus. Babesia spp. were detected only on one farm from dairy cows either infected by Babesia bovis (n = 10, 1.9%) or B. bigemina (n = 3, 0.6%).     

Mycobiota and aflatoxins in raw materials and pet food in Brazil

Commercial feedstuffs are a basic element in modern pet husbandry in the world. In dogs, the effect of mycotoxins is severe and can lead to death. Few reports on the influence of dietary mycotoxins were found in the scientific literature. The aims of this work were to isolate and identify the mycoflora and to determine the aflatoxins (AFs) natural occurrence in raw materials and ready dry pet food. Therefore, the aflatoxigenic capacity of Aspergillus flavus species was investigated. Aspergillus was the prevalent genera (65-89%) followed by Penicillium and Fusarium spp. Aspergillus flavus was the most prevalent species, followed by Aspergillus sydowii, Aspergillus fumigatus and Aspergillus versicolor. Aspergillus flavus frequencies ranged from 58% to 86% except in sorghum meal. All samples assayed (except corn grains and ready pet food) showed Fusarium spp. contamination. Corn meal and corn meal and gluten samples had 100% Fusarium verticillioides. Fusarium graminearum was isolated from sorghum meal. Aspergillus flavus strains (75%) isolated from raw materials and 57% from pet food were able to produce AFs. All samples showed AFs contamination percentages over 70%; corn and sorghum meal obtained the highest AFs levels. Ready pet food did not show quantitative levels of the tested toxins. This is the first report of the aflatoxigenic capacity by A. flavus from Brazilian pet food.     

Salmonellae and Campylobacters in Household and Stray Dogs in Northern Taiwan

Rectal swabs were collected from 437 household and 491 stray dogs in northern Taiwan from May 2003 to June 2005 to investigate the prevalence and antimicrobial susceptibilities of salmonellae and campylobacters. The results revealed that 2.1% of household dogs and 6.3% of stray dogs were positive for salmonellae, with Salmonella Duesseldorf being the most dominant serotype in both. Additionally, 2.7% of the household dogs and 23.8% of the stray dogs were positive for campylobacters. Campylobacter jejuni was the most prevalent species (86.8%), followed by C. upsaliensis (9.3%) and C. coli (3.9%). Both salmonella and campylobacter isolation rates from the stray dogs were significantly higher than those from the household dogs (p < 0.01). The susceptibility of 33 C. jejuni isolates to eight antimicrobials was studied by the E-test. A high rate of resistance was observed to azithromycin (93.9%), clindamycin (87.9%), erythromycin (81.8%), tetracycline (78.8%), chloramphenicol (69.7%), nalidixic acid (51.5%), gentamicin (33.3%), and ciprofloxacin (18.2%). The susceptibility of 40 Salmonella isolates to 15 antimicrobials was also studied by the disc-diffusion method. All the Salmonella isolates were susceptible to ciprofloxacin and ceftriaxone. Resistance was observed most frequently to tetracycline (77.5%), chloramphenicol (52.5%), and ampicillin (50%).     

Helminth and protozoan parasites in dogs and cats in Belgium

This study investigates the level of helminthic and protozoal infestation over the last 10 years in strays, well-cared-for dogs and cats. Determination of the prevalence of infections was based either on faecal examination or on worm counts at necropsy. Of 2324 faecal flotations (NaCl sp.gr. 1.20) of stray dogs, 34.2% had eggs or proglottids of one or more worm species consisting of Toxocara canis (17.4%), Toxascaris leonina (10.1%), Uncinaria stenocephala (11.4%), Trichuris vulpis (7.0%) and cestodes (2.1%). Isospora oocysts were observed in 5.2% of the dogs. The data on the distribution of the various worm species in the positive dogs indicate that T. canis eggs were by far the most common (50.9%). Necropsy data from 212 infected dogs indicate that 38.9% were infected with T. canis and 33.7% with T. leonina. The overall prevalence of worm infestation of 246 well-cared-for kennel dogs, based on worm egg counts by the McMaster technique, was 36.1%. Of 30 feline faecal samples examined by flotation, 83.3% were positive for parasites, including Toxocara cati (60%), Ancylostoma tubaeformae (36.6%), Taenia (Hydatigera) taeniaeformis (20%) and coccidia (30%). Toxocara cati was the most frequently found worm species at the necropsy of 25 cats (52%). Toxoplasma was not observed.     

Chlortetracycline in swine-bioavailability and pharmacokinetics in fasted and fed pigs

Chlortetracycline hydrochloride was administered intra-arterially (11 mg/kg) and as an oral drench (33 mg/kg) to ten 21.0-31.5-kg pigs. Five of the pigs were fasted 18 h prior to dosing and five of the pigs were fed ad libitum prior to dosing. The mean volume of distribution determined by area-under-the-curve calculations for the fasted pigs (0.967 +/- 0.210 l/kg) was significantly less (P less than 0.05) than the mean volume of distribution for the fed pigs (1.39 +/- 0.31 l/kg). Mean total body clearance of the drug was also significantly less (P less than 0.05) in the fasted pigs (0.165 +/- 0.055 l/kg/h) as compared to the fed pigs (0.307 +/- 0.053 l/kg/h). The elimination constants (beta) were not found to be statistically different (P less than 0.05): 0.1811 +/- 0.0057 for the fasted pigs; 0.2260 +/- 0.0461 for the fed pigs. The bioavailability for both groups was similar; 19.12 +/- 8.3% for the fasted pigs and 17.88 +/- 5.3% for the fed pigs. In a second experiment three groups of six pigs which weighed 34.5-44.1 kg were fed a corn-soy diet ad libitum. The rations were fortified with chlortetracycline at 100, 400 or 1000 mg chlortetracycline hydrochloride/kg feed. Chlortetracycline concentrations were determined in plasma samples collected over a 6-day period. Plasma chlortetracycline concentrations reach a plateau within 24 h after initial access to the trial diets and were highly correlated with the dose of the drug consumed (r2 = 0.97).