不同杂交组合优质冷鲜鸡屠宰性能和肉品质比较

培育适合屠宰加工的早熟、青脚、优质肉鸡新品系,通过比较63日龄ABC、ABD和AEB杂交组合鸡群的屠宰性能和肉品质,初步筛选最优杂交组合。结果表明:3个杂交组合63日龄母鸡体重均超过1.8 kg,公鸡体重均超过2.2 kg;公母鸡的屠宰率均超过86%,全净膛率均超过68%;ABC母鸡的全净膛率、胸肌率均显著高于其他杂交组合(P0.05);ABC组合母鸡的腹脂率显著低于其他2个组合(P0.05);ABC和ABD组合公母鸡胸肌肌苷酸含量显著高于AEB母鸡肌苷酸含量(P0.05);ABC公母鸡肌内脂肪含量显著高于ABD母鸡、AEB公鸡(P0.05);3个杂交组合组合间、组合内及公母间屠宰性能(失水率、剪切力和p H)均差异不显著。ABC公母鸡胸肌肉色L值显著高于其他2个杂交组合(P0.05);ABC母鸡肉色a值显著低于AEB(P0.05)。通过对3个杂交组合屠宰性能和肉品质的比较,发现ABC组合的屠宰率、全净膛率、胸肌率、肌苷酸含量、肌内脂肪含量和肉色相对较好,初步确定ABC组合最佳,为下一步优质冷鲜鸡的新品系培育奠定基础。     

日粮中添加荷叶提取物对黄羽肉鸡生长性能和肉品质的影响

选择28日龄岭南黄慢速型黄羽肉鸡1200只随机分成3组,每组10个重复,公母各半,每个重复40只鸡。对照组为基础日粮,试验组分别为基础日粮添加0.1%和0.2%荷叶提取物,饲养至120日龄,研究日粮中添加荷叶提取物对黄羽肉鸡生长性能、屠宰性能及肉品质的影响。结果显示:日粮中添加荷叶提取物能显著提高公鸡试验后期(56～120d)的日增重(P=0.01);日粮中添加0.1%荷叶提取物能显著降低公鸡试验后期(56～120d)(P=0.01)和全期(28～120d)的料重比(P0.01)。与对照组相比,添加荷叶提取物的试验组公鸡的胸肌率均高于对照组,添加0.2%荷叶提取物组公鸡胸肌率与对照组的差异达到显著性水平(P0.05)。日粮中添加0.1%荷叶提取物还能极显著地提高公鸡胸肌的pH45min值(P0.01);日粮中添加荷叶提取物均显著提高了母鸡胸肌肉色b*值(P0.05)。由此可见,日粮中添加荷叶提取物可以提高黄羽肉鸡的生长性能和胸肌率,改善鸡肉品质。     

MYH10基因在大恒699肉鸡、白羽肉鸡以及藏鸡不同组织器官中的表达差异研究

为了研究MYH10基因在不同鸡种不同组织器官间的表达差异,试验利用定量PCR方法检测了MYH10基因在白羽肉鸡、大恒699肉鸡、藏鸡不同组织器官(胸肌、腿肌、下丘脑、垂体)、不同生长阶段(2周龄、6周龄、10周龄)的表达量。结果表明:在2周龄,白羽肉鸡公鸡胸肌中MYH10基因的表达量显著高于大恒699肉鸡(P0. 05),白羽肉鸡母鸡胸肌中MYH10基因的表达量极显著低于其他鸡种(P0. 01),藏鸡公母鸡腿肌中MYH10基因的表达量极显著高于其他鸡种(P0. 01);在6周龄,白羽肉鸡公鸡胸肌中MYH10基因的表达量显著高于大恒699肉鸡(P0. 05),藏鸡母鸡胸肌和腿肌中MYH10基因的表达量分别显著高于大恒699肉鸡和白羽肉鸡;在10周龄,藏鸡公母鸡胸肌中MYH10基因表达量极显著高于其他鸡种(P 0. 01)。说明MYH10基因参与了鸡肌肉组织的生长和发育过程的调控。     

凉山岩鹰鸡屠宰性能及肉质特性分析

选择在果园中散放饲养条件下饲养的154日龄的凉山岩鹰鸡20只,公母各10只进行屠宰性能测定和肉制品质分析。结果表明,活重公鸡极显著地高于母鸡(P<0.01);公母鸡屠宰率分别为86.64%和83.70%,半净膛率分别为81.30%和78.25%,全净膛率分别为68.45%和65.65%,公鸡都显著地大于母鸡(P<0.05);在胸肌率、腿肌率指标中,公鸡略大于母鸡,但差异不显著(P>0.05);公鸡的腹脂率极显著地小于母鸡(P<0.01);在肉色、pH值、失水率、嫩度等多数指标优于优质型崇仁麻鸡和大型白羽肉鸡(科宝)、粤禽快大黄鸡2003的物理性状。     

枯草芽孢杆菌发酵棉粕对黄羽肉鸡屠宰性能和肉品质的影响

为了研究添加不同比例枯草芽孢杆菌发酵棉粕对黄羽肉鸡屠宰性能及肉品质的影响,试验将42日龄黄羽肉鸡120只随机分成4组,1组为对照组,2,3,4组分别添加2%、5%和8%发酵棉粕,研究发酵棉粕不同添加量对黄羽肉鸡生长后期屠宰性能和肉品质的影响。结果表明:4组肉鸡屠宰率最高,2,3,4组肉鸡屠宰率、半净膛率、全净膛率、胸肌率、腿肌率和肌肉p H45 min值均显著高于1组(P0.05);2,3,4组失水率、滴水损失、剪切力均降低,其中4组这三项指标数值均显著低于1组(P0.05);与1组相比,2,3,4组胸肌脂肪含量提高,其中3,4组显著高于1组(P0.05);2,3,4组腿肌脂肪含量均显著高于1组(P0.05)。说明枯草芽孢杆菌发酵棉粕添加量为8%时对肉鸡屠宰性能和肉品质的影响效果最好。     

贵妃鸡与麒麟鸡杂交F1代体尺、屠宰性能和肉品质测定

为了研究贵妃鸡的肉用开发价值,本试验以贵妃鸡为父本,麒麟鸡(卷羽鸡)为母本进行杂交探索,同时对12周龄F1代杂交鸡进行体尺性状,屠宰性能和肉品质测定。结果表明:(1)12周龄F1代杂交公鸡体斜长、龙骨长、胫长均显著高于母鸡(P0.05)。(2)屠宰性能:12周龄公母鸡体重分别达到1 236.67 g和1 063.00 g,差异极显著(P0.01);屠宰率、半净膛率、全净膛率、胸肌率、腿肌率、腹脂率、肌间脂肪宽和皮脂厚,公鸡分别为91.09%、83.44%、61.58%、15.33%、22.95%、3.71%、7.95 mm、3.96 mm,母鸡分别为89.36%、81.10%、61.75%、13.15%、19.08%、3.94%、7.53 mm、5.66mm,活体重、屠体重、半净膛重、半净膛率、全净膛重、胸肌重、腿肌重和心脏重极显著高于母鸡(P0.01),腿肌率、翅膀重显著高于母鸡(P0.05),而皮脂厚却极显著低于母鸡(P0.01),其余指标公、母差异不显著(P0.05)。(3)肉品质:在胸肌方面,12周F1代杂交母鸡的失水率显著高于公鸡(P0.05),其他指标没有显著性差异(P0.05);在腿肌方面,12周F1代杂交母鸡的肉色L值和失水率极显著高于公鸡(P0.01),但是杂交母鸡的肉色a值极显著低于公鸡(P0.01),其他指标没有显著性差异(P0.05)。     

饲粮蛋氨酸水平对29～91日龄杂交鸡生长性能和屠宰性能的影响

为研究不同饲粮蛋氨酸水平对杂交鸡生长性能和屠宰性能的影响,将126只29日龄杂交鸡(罗斯308公鸡×大骨鸡母鸡,公母鸡各半),按2×3因子分别随机分成3组,每组3个重复,每个重复7只,分别饲喂低、中、高水平蛋氨酸饲粮,饲养期9周,测定生长性能及屠宰性能。结果表明:(1)不同蛋氨酸水平对29～49日龄杂交公母鸡的平均采食量影响显著,中水平组和低水平组极显著高于高水平组(P0.01),50～91日龄杂交公母鸡平均采食量低水平组高于高水平组(P0.01),中水平组显著高于高水平组(P0.05)。(2)屠宰性能结果显示:49、91日龄公鸡腿比率、胸肌率、腿肌率中水平组显著高于其他两组(P0.05);91日龄母鸡在中水平下腿比率显著低于其他两组(P0.05)。提示中水平组饲粮有利于提高29～49日龄杂交鸡生长性能,低水平组饲粮有利于提高50～91日龄杂交鸡生长性能,中水平组饲粮有利于提高杂交公鸡屠宰性能。     

不同分子质量甲壳低聚糖对0～4周黄羽肉鸡性能的影响

旨在研究不同分子质量甲壳低聚糖对0～4周龄黄羽肉鸡生长、血脂含量、抗氧化能力及屠宰性能的影响。选取400只1日龄健康体重相近的黄羽肉鸡母鸡,随机分为5组,每组8个重复,每个重复10只。对照组饲喂基础日粮,试验组分别在基础日粮中添加0.58%分子质量为600、1117、2374、3600Da的甲壳低聚糖。试验期为28d。结果表明:①各组间平均日增重、平均日采食量和料重比均无显著差异(P0.05);②添加不同分子质量甲壳低聚糖使血清甘油三酯含量趋于降低(P=0.069);与对照组相比,2374Da和3600Da甲壳低聚糖组显著降低血清游离脂肪酸含量(P0.05),其它血脂成分组间均有明显变化(P0.05);③添加2374Da和3600Da分子质量甲壳低聚糖显著提高血清SOD和GSH-PX活性(P0.05),而添加600Da和1117Da分子质量甲壳低聚糖对肉鸡抗氧化能力未显效应;④屠宰率、全净膛率、半净膛率、胸肌率和腿肌率等各项屠宰性能组间差异不显著(P0.05)。综上所述,0～4周龄黄羽肉鸡日粮中添加分子质量为600～3600Da的甲壳低聚糖对其生长和屠宰性能无显著影响,但对肉鸡血脂含量和抗氧化功能有明显的影响,添加2374Da和3600Da甲壳低聚糖可显著降低肉鸡血脂水平,改善了肉鸡的抗氧化能力,而添加600Da和1117Da的甲壳低聚糖对肉鸡血脂含量和抗氧化能力未显效应。     

仙居鸡早期肉用性状的测定与遗传力估计

通过测定仙居鸡体重、体尺、屠宰和肉品质性状,研究其肉用特性。试验用12个公鸡家系的720只健康雏鸡(公、母各半),进行为期12周的饲养。每周测定个体重,12周龄时每个家系取5只公鸡、5只母鸡测定其体尺、屠宰性能和肉品质。结果表明:2周龄后公鸡体重均极显著大于母鸡(P<0.01),12周龄公、母体重分别为858.9g和719.5g;12周龄公鸡的体斜长、龙骨长、胫长、胫围都显著大于母鸡(P<0.05);公鸡的屠体率、半净膛率、胸肌率、头率、爪率、心率、肝率等指标均极显著大于母鸡(P<0.01),而肌、腺胃率则是母鸡极显著大于公鸡(P<0.01);公鸡胸肌剪切力显著大于母鸡(P<0.05)。     

琅琊鸡肉品质的研究

为了给琅琊鸡遗传资源保护及开发提供理论依据,试验选取120日龄琅琊鸡180只,设6个重复组,每个重复组30只,公母各半,在相同饲养条件下饲养,于300日龄时分析不同性别琅琊鸡的屠宰性能,并屠宰取胸肌和腿肌分析不同部位间肉品质常规指标、化学指标及风味物质指标。结果表明:公鸡、母鸡屠体率均超过87.00%,全净膛率均大于65.00%,公鸡腿肌剪切力显著高于公鸡胸肌(P0.05),母鸡腿肌剪切力极显著高于母鸡胸肌(P0.01),公鸡、母鸡胸肌和腿肌pH值随着时间推移均呈下降趋势,公鸡腿肌红度值(a~*值)极显著高于公鸡胸肌和母鸡胸肌(P0.01);公鸡腿肌干物质、粗蛋白含量显著低于公鸡胸肌和母鸡胸肌、腿肌(P0.05),公鸡胸肌、腿肌粗脂肪含量低于母鸡且差异极显著(P0.01),公鸡、母鸡腿肌中胆固醇含量极显著高于胸肌(P0.01),公鸡胸肌、腿肌中肌苷酸含量低于母鸡且差异极显著(P0.01);公鸡胸肌、腿肌单不饱和脂肪酸含量显著高于母鸡(P0.05),而公鸡胸肌、腿肌中n-6多不饱和脂肪酸、n-3多不饱和脂肪酸含量极显著低于母鸡(P0.01);母鸡胸肌中必需氨基酸/总氨基酸(EAA/TAA)值和必需氨基酸/非必需氨基酸(EAA/NEAA)值最高,分别为39.97%和66.89%。说明琅琊鸡具有屠宰性能良好、肉质细嫩和味鲜、腿肌富含风味前体物质等优点。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein