不同品种肉牛杂交F1育肥效果对比试验

选择不同杂交品种肉牛和本地黄牛共40头,即西黄牛(西门塔尔牛×本地黄牛)、夏黄牛(夏洛来牛×本地黄牛)、皮黄牛(皮埃蒙特牛×本地黄牛)的F1和黄牛(本地黄牛)公牛各10头,进行了100 d育肥饲养比较试验.结果表明:夏黄牛(1 334 g)、西黄牛(1 309 g)和皮黄牛(1 121 g)育肥期平均日增重均显著高于黄牛(827 g,P<0.05),西黄牛和夏黄牛平均日增重也分别显著高于皮黄牛,而西黄牛和夏黄牛之间没有显著差异(P>0.05).夏黄牛(61.3%)、西黄牛(60.8%)和皮黄牛(58.2%)屠宰率均显著高于黄牛(51.2%,P<0.05),杂交组肉牛屠宰率间没有显著差异(P>0.05);3个杂交组肉牛净肉率均显著高于黄牛(P<0.05),虽然西黄牛和夏黄牛净肉率间较差异不显著(P>0.05),但却分别显著高于皮黄牛(P<0.05).3个杂交组牛肉眼肌面积均比黄牛大,而杂交组之间没有显著差异(P>0.05);西黄牛和皮黄牛牛肉大理石纹状度较好,夏黄牛肉嫩度不如西黄牛、皮黄牛和黄牛.4个组之间牛肉的pH和灰分没有差异(P>0.05),但是黄牛肉蛋白质含量显著高于3个杂交组牛(P<0.05),皮黄牛肉脂肪含量明显低于其他3组牛.     

不同品种肉牛杂交F_1育肥效果对比试验

选择不同杂交品种肉牛和本地黄牛共40头,即西黄牛(西门塔尔牛×本地黄牛)、夏黄牛(夏洛来牛×本地黄牛)、皮黄牛(皮埃蒙特牛×本地黄牛)的F1和黄牛(本地黄牛)公牛各10头,进行了100d育肥饲养比较试验。结果表明:夏黄牛(1334g)、西黄牛(1309g)和皮黄牛(1121g)育肥期平均日增重均显著高于黄牛(827g,P0.05),西黄牛和夏黄牛平均日增重也分别显著高于皮黄牛,而西黄牛和夏黄牛之间没有显著差异(P0.05)。夏黄牛(61.3%)、西黄牛(60.8%)和皮黄牛(58.2%)屠宰率均显著高于黄牛(51.2%,P0.05),杂交组肉牛屠宰率间没有显著差异(P0.05);3个杂交组肉牛净肉率均显著高于黄牛(P0.05),虽然西黄牛和夏黄牛净肉率间较差异不显著(P0.05),但却分别显著高于皮黄牛(P0.05)。3个杂交组牛肉眼肌面积均比黄牛大,而杂交组之间没有显著差异(P0.05);西黄牛和皮黄牛牛肉大理石纹状度较好,夏黄牛肉嫩度不如西黄牛、皮黄牛和黄牛。4个组之间牛肉的pH和灰分没有差异(P0.05),但是黄牛肉蛋白质含量显著高于3个杂交组牛(P0.05),皮黄牛肉脂肪含量明显低于其他3组牛。     

皮埃蒙特肉牛改良柴达木黄牛效果分析

利用皮埃蒙特肉牛冻精对柴达木黄牛进行杂交改良。结果表明:皮杂F1牛平均初生重、6月龄体重、12月龄体重和不同生长发育阶段的体高、体斜长、胸围等指标分别比同龄本地黄牛高13.75 kg、58.90 kg、112.31 kg和14.42%~27.08%,差异均极显著(P<0.01),改良效果十分显著。     

弗莱维赫牛在遵义的杂交改良效果

[目的]研究弗杂牛在当地的生长及肉用性能。[方法]随机选择弗莱维赫牛与遵义本地黄牛的杂交F1代（弗×本）、弗莱维赫牛与（西门塔尔×本地黄牛）三元杂交一代F1（弗×西本）牛,作试验组,本地纯种黄牛（对照组）各30头,进行饲养和育肥试验。[结果]表明：6月龄时试验组弗×本、弗×西本的体重分别为90.00 kg、118.18...     

利木赞牛与本地黄牛杂交一代性能测定

对利木赞牛×本地黄牛杂交一代和本地黄牛的外貌特征进行了观察,同时测定了它们的生长发育性能肉用性能和繁殖性能。结果表明：利木赞牛×本地黄牛杂交一代表现了较强的杂交优势,具有显著的社会、经济效益。     

肉牛二元、三元杂交组合增重对比试验报告

为了培育适应当地条件的育肥牛品种,选择黑白花、西门达、秦川(细管冻精)分别授配当地黄牛;选择利木辛、德国黄牛(细管冻精)分别授配西杂F_1,在相同饲养管理条件下,①测定黑杂F_1、西杂F_1、秦杂F_1在1月龄、2月龄、3月龄时的增重效果。结果表明,1月龄时,西杂牛增重比黑杂牛增重重5.8 kg,黑杂牛增重比秦杂牛增重重3.2kg;2月龄后,西杂牛增重比黑杂牛增重重15.8 kg,黑杂牛增重比秦杂牛增重重9.5 kg;3月龄后,西杂牛增重比黑杂牛增重重26 kg,黑杂牛增重比秦杂牛增重重17.2 kg;西杂F_1增重明显,经济效益显著。②测定德西黄、利西黄牛出生重、体高、日增重等主要生长发育指标。结果表明,德西F_1初生重比利西F_1重3.3kg,3月龄时德西F_1比利西F_1重13.4kg,6月龄时德西F_1比利西F_1重16.7 kg,按市场价计算德西牛可比利西牛头均可多创收367.4元,品种优势明显。     

黄牛良种化配套技术项目实施效果

本文总结了黄牛良种化配套技术实施效果。结果表明:采用人工授精技术,用荷斯坦牛、皮埃蒙特牛细管冻精,对当地黄牛进行改良,共计授配母牛2348头,受胎2091头,受胎率为89.91%。育肥试验结果表明:皮×黄组日增重达到985±126g;黑×黄组日增重达到925±100g;黄牛组日增重为752±37.50g。18月龄时的平均宰前活重,皮×黄F1:303.85kg,黑×黄F1302.75kg,黄牛215.98kg,屠宰率分别是54.36%、52.50%、48.90%,净肉率分别是47%、45.30%、40.50%。皮×黄、黑×黄产肉量比黄牛分别提高55.344、9.68kg。经方差分析,皮黄F1组与对照组增重差异极显著(P<0.01,黑黄F1组与对照组增重差异显著(P<0.05),皮黄F1组与黑黄F1组无显著差异(P>0.05)。皮黄F1组和黑黄F1组与对照组在体高和胸围方面差异显著(P<0.05),体斜长差异不显著(P>0.05),而皮黄F1组与黑黄F1组之间体高、胸围、体斜长三者都差异不显著(P>0.05)。另外通过对项目区内及周边地区初生及6月龄犊牛的体尺、体重进行不间断的测定可以看出,杂种牛的体尺、体重较大、生长发育快,杂种优势明显。     

云南黄牛杂交改良效果分析

[目的]为了提高云南黄牛的生产性能,优选主要的杂交改良父本,开展云南黄牛杂交改良。[方法]用西门塔尔牛、短角牛、安格斯牛、海福特牛等分别与云南黄牛母本杂交,测定不同杂交组合后代初生、6月龄、12月龄、24月龄的体重体尺。[结果]云南黄牛经过杂交改良后,改良效果良好,杂交后代对云南高原的气候条件适应性良好。在农村饲养条件下,西×云杂一代牛初生重平均为24.57kg,6月龄体重平均为135.83kg,12月龄体重平均为196.21kg,24月龄体重平均为344.24kg,分别比本地黄牛提高74.13%,59.20%,56.53%和78.10%。短×云杂交一代牛初生重平均为22.28kg,6月龄体重平均为117.20kg,12月龄体重平均为193.56kg,24月龄体重平均为314.86kg,分别比本地黄牛提高57.90%,38.10%,54.21%和62.90%;安×云杂交一代牛犊牛初生重平均为21.21kg,6月龄体重平均为134.34kg,12月龄体重平均为196.18kg,24月龄体重平均为268.45kg,分别比本地黄牛提高50.32%,57.45%,56.51%和38.89%;海×云杂交一代牛初生重平均为22.78kg,6月龄体重平均为124.97kg,12月龄体重平均为190.52kg,24月龄体重平均为289.50kg,分别比本地黄牛提高61.45%,46.47%,51.99%和49.78%。[结论]西×云杂一代牛、短×云杂交一代牛、安×云杂交一代牛和海×云杂交一代牛生产性能显著提高,效益明显。     

安格斯肉牛改良沿河本地黄牛效果研究

应用安格斯肉牛细管冻精改良沿河本地黄牛。经观测：安本F_1牛体型趋向父本、毛色呈显性遗传,多为黑色或黑褐色;平均初生重为20．80±2．63kg,6月龄体重为111．08±5．02kg,12月龄体重为172．91±12．47kg,18月龄体重为229．56±14．67kg,比同龄的沿河本地黄牛分别提高46．99%、43．55%、45．81%和47．79%,差异极显著(P＜0．01);各月龄阶段的体尺指标均显著高于本地黄牛(P＜0．05),增长幅度大多在10%～20%之间。结果表明：安格斯肉牛改良沿河本地黄牛、杂种优势明显,能显著改善本地黄牛体形不足的缺陷,安本F_1牛生长发育快,且抗病力强,耐粗饲,适应能力强,是改良山区黄牛的理想肉牛品种,值得推广。     

杂交牛的放牧补饲育肥及屠宰效果研究

选取14~17月龄湘西黄牛、西杂F1(西门塔尔牛×湘西黄牛)和安杂F1(安格斯牛×湘西黄牛)各6头,于南方放牧条件下补饲精料,进行90d的育肥试验。结果表明:杂交牛的增重水平和育肥效益明显优于湘西黄牛,其中西本杂交牛和安本杂交牛的日增重分别为0.71kg、0.63kg,比湘西黄牛分别提高44.90%(P<0.01)、28.57%(P<0.01);屠宰率以西本杂交牛最高(55.60%),净肉率以安本杂交牛较高(44.32%);肉质分析以西本杂交牛的脂肪含量极显著高于湘西黄牛(P<0.01);杂交牛放牧补饲育肥效益明显。     

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.     

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.     

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.     

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.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -