鹅蛋蛋形指数对孵化效果影响的观测

<正> 前言影响鹅蛋孵化效果的因素很多,既有外因,又有内因。在每次外因条件基本相同,研究禽蛋品质对孵化效果的影响具有重要意义,可用蛋形指数评定种蛋品质。鸡蛋蛋形指数对孵化影响试验研究报道较多,水禽种蛋蛋形指数影响研究少见报道。为探讨鹅蛋蛋形指数对孵化效果的影响,对孵化、育种工作提供依据。作者于1986年3月和1987年2月,结合生产实际,用电孵机和自制孵化器分别进行小批量试验观测,现将试验结果资料整理报道于后。     

朝鲜鹌鹑种蛋重和蛋形指数对孵化效果的影响

选取288枚朝鲜鹌鹑种蛋,按蛋重、蛋形指数大小各分为3组,在相同条件下孵化,研究蛋重和蛋形指数对孵化效果的影响。试验结果表明:蛋重、蛋形指数对受精蛋孵化率的影响均极显著(P<0.01)。蛋形指数对健雏率的影响显著(P<0.05),蛋重对健雏率的影响不显著(P>0.05)。     

母鸡产蛋方位及其有关物理性状的探讨

收集4个品种鸡的2008枚蛋观察表明:鸡蛋以锐端先产出居多(70%以上),且产蛋方位与蛋形有关(P<0.05),钝端先产出的蛋比锐端先产出的蛋形指数要大。5537枚蛋孵化试验表明:蛋形、蛋重和产蛋方位都不影响孵化率、受精率和公母比例,在生产实际中没有必要对蛋形过分挑剔。蛋形与出壳时间有关(P<0.05),蛋形指数较大,出产时间就稍迟,而且出壳时间与公母比例有关(P<0.01),出壳时间较迟的,公雏居多。21.5天出雏的公雏数是20.5天的1.5倍。观察发现,蛋形和蛋重与产蛋时间有关,上午产的蛋比下午的蛋形指数小,而蛋重大(P<0.01)。但产蛋方位与产蛋时间无关(P>0.05)。随机测量40枚白洛克发现,蛋形指数和蛋重与蛋壳厚度没有相关(P>0.05)。100枚白来航蛋资料分析表明,蛋形指数与蛋重也没有相关(P>0.05))。     

利用蛋形指数对黔东南小香鸡种蛋进行性别鉴定初步研究

为研究黔东南小香鸡蛋形指数与性别的相关性,根据种蛋的不同蛋形和大小分成2个组：Ⅰ组种蛋231枚,平均蛋形指数R=1.36±0.045;Ⅱ组种蛋245枚,平均蛋形指数R=1.29±0.048。按组分别入孵,并对36日龄雏鸡用外貌观察法进行性别鉴定。结果表明：Ⅰ组种蛋雄性百分率为97.6%;Ⅱ组种蛋雌性百分率为93.5%,...     

蛋重、蛋形和蛋色对北京油鸡种蛋孵化性能的影响

研究测定了44~48周龄北京油鸡的蛋重、蛋形指数和蛋壳颜色,并分析其对种蛋孵化性能的影响。结果显示,北京油鸡蛋重、蛋形指数和蛋色均较一致;蛋重对孵化性能影响不显著(P0.05),但是随着蛋重的增加孵化性能有增加的趋势;蛋形指数对受精蛋孵化率的影响显著(P0.05),蛋形指数0.75~0.80的种蛋组显著高于其他组;蛋壳颜色对北京油鸡的受精率、受精蛋孵化率和健雏率均无影响(P0.05)。本研究结果为北京油鸡的选种提供了重要的参考依据。     

贮藏方式及时间对不同颜色鸡蛋品质的影响研究

为研究贮藏方式及时间对不同颜色鸡蛋品质的影响,选取大小适中、品质良好的鸡蛋150枚,其中白、褐、粉壳鸡蛋各50枚,同种颜色鸡蛋随机分成10组,5组置于室温保存,另5组置于低温的冰箱冷藏,分别于第0、7、14、21、28天测定鸡蛋的失重率、气室高度、蛋形指数、蛋壳厚度、哈夫单位、蛋黄指数、蛋清pH、蛋壳相对重、蛋黄相对重、蛋清相对重、卵磷脂含量、蛋黄水分比、蛋清水分比和蛋比重。结果表明:白、褐、粉壳鸡蛋贮存至第14天,因贮藏方式不同,鸡蛋品质出现显著差异(P 0.05),不同颜色鸡蛋置于低温贮藏,更能有效保持鸡蛋的良好品质。     

不同蛋形指数与鸡蛋性别关系的研究

为了研究玫瑰冠鸡蛋形指数与性别的相关性,根据种蛋的不同蛋形指数分成3组:A组平均蛋形指数R=1.29±0.03;B组平均蛋形指数R=1.36±0.03;C组平均蛋形指数R=1.40±0.03。每组取120枚玫瑰冠鸡种蛋,3个重复,即每个重复40枚。结果表明玫瑰冠鸡蛋形指数在1.36±0.03时孵化率最高;蛋形指数与性别比例无直接关系,符合遗传规律1∶1的性别比例关系。     

不同周龄和饲养方式对岭南黄鸡鸡蛋品质的影响研究

试验比较了20周龄笼养、30周龄笼养和30周龄放养三种饲养方式下的岭南黄鸡鸡蛋品质指标:蛋重、哈夫单位、全蛋胆固醇、蛋黄指数、蛋形指数、蛋壳相对重和蛋壳厚度。试验结果表明,三组蛋形指数无显著差异;笼养条件下岭南黄鸡随着产蛋周龄的增加,蛋重增加、其他指数下降;30周龄放养鸡鸡蛋的蛋重接近20周龄笼养鸡蛋,蛋壳显著增厚,全蛋胆固醇含量高于其他两组。     

闽南火鸡蛋形指数对孵化率的影响

对闽南火鸡4组蛋形指数范围的种蛋孵化试验表明，蛋形指数对火鸡蛋的受精率和孵化率的影响是明显的。蛋形指数在1．50～1．59之间受影响最小，而蛋形指数在1．60以上和1．39以下受影响最大。4种指标受影响程度最大值与最小值的差分别为：受精率7．0％，受精蛋孵化率15．0％，入孵蛋孵化率12．0％，健雏率21．5％。     

鸳鸯蛋部分蛋品质的测定

为了研究鸳鸯蛋品质,试验对19枚鸳鸯蛋的蛋重、蛋形指数、蛋壳厚度等部分蛋品质参数进行了测定。结果表明:鸳鸯蛋平均蛋重为45.48 g,平均蛋形指数为1.336,平均蛋壳厚度为0.30 cm。鸳鸯蛋的蛋品质参数与鸡蛋的蛋品质参数较接近。     

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.     

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     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.