灵台县肉牛二元、三元杂交选配方案的研究

选用南德温、西门塔尔、利木辛的细管冻精分别授配本地黄牛母牛。用南德温冻精分别授配利黄F1、西黄F1母牛,用西门塔尔冻精分别授配利黄F1、南黄F1母牛,用利木辛冻精分别授配西黄F1、南黄F1母牛。母牛和犊牛在相同饲养管理条件下,测定二元杂交代在一定生长阶段的体尺、体重等主要生长发育指标。结果表明,南黄组合二元杂交犊牛初生、3月龄、6月龄的体尺、体重明显高于其他组合二元杂交代;南德温作为父本改良西黄牛、利黄牛效果非常显著,明显优于南德温二元杂交牛,同时,杂合了南德温与西门塔尔或利木辛的品种优势,且克服了西门塔尔和利木辛的缺点,可以作为灵台县及类似生态环境条件下肉牛三元杂交的终端父本品种在黄牛改良中推广应用。     

甘南州南德温肉牛杂交改良效果观察

用南德温牛(细管冻精)授配改良甘南州本地黄牛与西黄牛,测定其后代体尺、体重等主要生长发育指标。结果表明:南西黄犊牛初生、6月龄、12月龄、18月龄的体尺、体重明显高于南黄犊牛。南德温牛作为父本杂交改良西黄牛,效果非常明显,可以作为肉牛三元杂交的优选父本在高寒阴湿地区黄牛改良中广泛应用。     

临夏州肉牛二元、三元杂交选配的研究

用南德温牛和德国黄牛（细管冻精）授配本地西门塔尔母牛,进行二元和三元杂交组合选种选配研究,分别测定其后代体尺、体重等主要生长发育指标,并经过各杂交组合间的比较,结果表明南本、德本、南德本组合犊牛初生、2月龄、4月龄、6月龄、12月龄体尺体重均高于本地牛和德南本组合,南德温作为父本对本地牛进行改良效果非常明显,可作为类似生态环境条件下肉牛二元、三元杂交的优选父本品种,在今后的本地牛改良中推广应用。     

南德温肉牛杂交改良效果测定

用南德温牛（细管冻精）授配甘南州舟曲县当地黄牛，测定其后代体尺、体重等主要生长发育指标。结果表明：南德温×当地黄牛组犊牛初生、六月龄、12月龄的体尺、体重明显高于当地黄牛组。南德温作为父本改良当地黄牛，效果非常明显，可以作为舟曲县及类似生态环境的地区黄牛改良中推广应用。     

南德温肉牛与甘南高寒地区西杂牛三元杂交效果调查

[目的]为了提高甘南本地黄牛和西杂牛的生产性能,[方法]从2006年开始引进南德温肉牛细管冻精与当地西黄F1 代母牛进行杂交,测定其杂种后代体重、体尺等主要生长发育指标和进行适应性观察.[结果]表明:南×(西×黄)犊牛初生、6月龄、12月龄、18月龄体重、体尺显著高于西×黄F1 代(P<0.01),且能很好的适应甘南高寒牧区的生态环境和饲养管理条件.[结论]所以,南德温肉牛可作为肉牛三元杂交的终端父本在甘南高寒环境下黄牛产区大面积推广.     

南德温肉牛杂交改良效果测定

用南德温牛(细管冻精)授配改良甘肃省甘南藏族自治州舟曲县当地黄牛,测定其后代体尺、体重等主要生长发育指标.结果表明:南德温牛×当地黄牛组,其犊牛初生、6月龄、12月龄的体尺和体重明显高于当地黄牛组.南德温牛作为父本杂交改良当地黄牛,.效果非常明显,可以作为舟曲县及类似生态环境条件下肉牛杂交的优选父本品种而在黄牛改良中广泛应用.     

青海高原地区良种肉牛改良当地黄牛的效果

在青海高原环境下,用引进的良种肉牛蓝白花、利木赞、西门塔尔和皮尔蒙特改良当地黄牛。结果显示:四个杂交组合F1代不同年龄的生长速度和体尺指标均明显优于青海黄牛(P<0.01),说明用良种肉牛改良青海黄牛效果明显;在不同杂交后代的比较中,皮×黄F1代各年龄段体重均高于蓝×黄F1、利×黄F1和西×黄F1(P<0.01),皮×黄F1代还保留了青海黄牛抗逆性强,耐粗饲等优良特性,杂交组合较为理想;皮尔蒙特牛可作为当前高原环境下改良青海黄牛的理想父本品种使用。     

湘西黄牛与西本F1代母牛的生长发育与繁殖性能比较调查

在对湘西黄牛采取人工杂交改良的过程中,通过对湘西黄牛、湘西黄牛的杂交组合西本F1母牛进行了生长发育与繁殖性能的调查研究,并统计湘西黄牛与西本F1代初生重、12月龄、18月龄、24月龄及初配体重、初配月龄、发情季节、妊娠期、受胎率、成活率、所生犊牛的体重体尺及断奶后体重体尺(6月龄)。统计结果表明:西本F1代各年龄阶段的体重体尺数据明显高于湘西黄牛;西本F1与湘西黄牛的受胎率、成活率均无明显差异(P>0.05);发情季节大多集中春秋及夏秋两季,初配月龄在22~23月龄之间,初配体重比湘西黄牛重67.76kg,两者差异显著(P<0.05);西本F1代所生犊牛初生体重体尺与其断奶后体重体尺数据明显高于湘西黄牛,其泌乳性能也优于湘西黄牛。     

良种牛与本地黄牛杂交改良效果初探

用西门塔尔牛、利木赞牛与本地黄牛杂交,其效果:西×本、利×本杂交公、母犊牛初生重分别比本地黄牛公、母犊牛初生重增加3.9、4.7、3.6和4.3kg;分别提高了16.67%、24.61%、15.30%和22.51%。西×本、利×本6月龄杂交公、母牛体重分别比本地黄牛6月龄公、母牛体重增加61.3、50.6、58.2和47.2kg,分别提高48.69%、45.87%、46.23%和42.79%;西×本、利×本12月龄杂交公、母牛体重分别比本地黄牛12月龄公、母牛体重增加98.0、56.2、92.1和52.2kg,分别提高60.98%、43.57%、57.31%和40.47%。西×本、利×本杂交牛初生重、6月龄体高、体斜长、胸围、体重、12月龄体高、体斜长、胸围、体重分别与本×本后代相比差异均极显著;西×本与利×本杂交牛相比差异不显著。利用西门塔尔、利木赞良种牛作父本改良本地黄牛效果十分显著。     

南西黄与德西黄三元杂交组合犊牛生长发育情况

用南德温牛和德国黄牛(细管冻精)授配西黄F1母牛,母牛和犊牛在相同饲养管理条件下,研究了2个三元杂交组合所产犊牛在初生、3、6月龄阶段的体重、体斜长、体高、胸围、日增重等主要生长发育指标。结果表明:南×西黄杂种犊牛的初生重、3、6月龄体重比德×西黄分别高10.36、20.24、46.53kg(P<0.01);初生体斜长、体高、胸围高20.6、4.1cm和10.2cm(P<0.01);3月龄平均体斜长、体高、胸围分别高3.85、3.05cm和7.0cm(P<0.01);6月龄平均体斜长、体高、胸围分别高14.65、7.6cm和7.3cm(P<0.01);3、6月龄的日增重分别高94.2g和189.8g。     

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.     

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