菜籽粕对大恒肉种鸡生产性能和孵化性能的影响研究

本试验旨在研究不同水平菜籽粕对大恒肉种鸡生产性能和孵化性能的影响。选择大恒肉种鸡120只,随机分成4个处理(每个处理3个重复,每个重复10只鸡),对照组日粮为玉米-豆粕型日粮,试验组日粮为玉米-豆粕-菜籽粕型日粮,菜籽粕水平分别为4%、8%和12%,试验期6周。结果表明:在日粮中添加4%、8%和12%菜籽粕对大恒肉种鸡的产蛋率和蛋重均无显著影响;试验组的蛋壳厚度、蛋壳强度、蛋形指数和哈氏单位与对照组无显著差异(P0.05);试验组的种蛋合格率、受精蛋孵化率、入孵蛋孵化率与对照组相比差异均不显著(P0.05);添加4%和12%菜籽粕组的入孵蛋受精率显著高于对照组(P0.05)。由此可见,在大恒肉种鸡日粮中添加12%双低菜籽粕是可行的,且添加菜籽粕可提高大恒肉种鸡的种蛋受精率。     

蜂胶黄酮对黄羽肉种鸡生产性能的影响

为研究蜂胶黄酮对黄羽肉种鸡生产性能的影响,本研究选取2430只34周龄新广K96黄羽肉种鸡,随机分成3组,每组6个重复,每个重复135只,各重复间生产性能差异不显著。对照组饲喂基础日粮,试验Ⅰ和Ⅱ组分别在基础日粮的基础上添加300g/t和500g/t蜂胶黄酮预混剂,正试期为6周。结果表明:与对照组相比,日粮添加不同水平的蜂胶黄酮对黄羽肉种鸡的平均日采食量、产蛋率、平均蛋重、料蛋比和死亡率的影响均差异不显著(P0.05),但试验Ⅰ组在平均日采食量和平均蛋重上表现较好,而试验Ⅱ组的死亡率最低;试验第21天种蛋入孵,各组间受精率和入孵蛋出雏率差异不显著(P0.05),但添加蜂胶黄酮有提高受精率和入孵蛋出雏率的趋势;第42天种蛋入孵,试验Ⅰ组的受精率极显著高于对照组(P0.01)。以上结果提示,无论是添加300g/t还是500g/t蜂胶黄酮对黄羽肉种鸡的采食量、产蛋率、蛋重和料蛋比影响较小,但对种鸡死亡率、种蛋受精率和孵化率有比较明显的正面效果。     

外源肌苷酸对种鸡产蛋性能、蛋品质及种蛋孵化性能的影响

本试验通过在种鸡的基础饲粮中加入肌苷酸(IMP)来研究其对种鸡产蛋性能、蛋品质和种蛋孵化性能的影响。选择遗传背景相同、体重相近,产蛋率达到5%的20周龄健康AA种鸡864羽,随机分为2组(对照组饲喂基础饲粮;试验组饲喂基础饲粮+0.5%肌苷酸),每组6个重复,每个重复72羽,试验期30 d。测定试验期间所有种蛋的平均蛋重、产蛋率和合格蛋率;每组随机选取部分种蛋进行蛋品质测定;于孵化开始第17天,通过照蛋处理统计种蛋受精率,第21天出雏时,计算受精蛋孵化率、入孵蛋孵化率和健雏率。试验结果表明:与对照组相比,试验组种鸡的平均蛋重、产蛋率和合格蛋率均有升高的趋势,但差异不显著(P>0.05);蛋形指数显著升高(P<0.05),蛋壳强度、蛋壳厚度和蛋黄颜色显著降低(P<0.05);受精率、受精蛋孵化率和入孵蛋孵化率显著升高(P<0.05),健雏率和雏鸡体重有升高的趋势,但差异不显著(P>0.05)。综上,0.5%外源肌苷酸对种鸡的产蛋性能和种蛋孵化性能均有促进作用。     

外源肌苷酸对种鸡产蛋性能、蛋品质及种蛋孵化性能的影响

本试验通过在种鸡的基础饲粮中加入肌苷酸（IMP）来研究其对种鸡产蛋性能、蛋品质和种蛋孵化性能的影响。选择遗传背景相同、体重相近,产蛋率达到5%的20周龄健康AA种鸡864羽,随机分为2组（对照组饲喂基础饲粮;试验组饲喂基础饲粮＋0.5%肌苷酸）,每组6个重复,每个重复72羽,试验期30 d。测定试验期间所有种蛋的平均蛋重、产蛋率和合格蛋率;每组随机选取部分种蛋进行蛋品质测定;于孵化开始第17天,通过照蛋处理统计种蛋受精率,第21天出雏时,计算受精蛋孵化率、入孵蛋孵化率和健雏率。试验结果表明：与对照组相比,试验组种鸡的平均蛋重、产蛋率和合格蛋率均有升高的趋势,但差异不显著（P>0.05）;蛋形指数显著升高（P<0.05）,蛋壳强度、蛋壳厚度和蛋黄颜色显著降低（P<0.05）;受精率、受精蛋孵化率和入孵蛋孵化率显著升高（P<0.05）,健雏率和雏鸡体重有升高的趋势,但差异不显著（P>0.05）。综上,0.5%外源肌苷酸对种鸡的产蛋性能和种蛋孵化性能均有促进作用。     

酵母培养物“赛克灵”对蛋种鸡生产性能和粪便微生物的影响

为了研究酵母培养物"赛克灵"对蛋种鸡生产性能和粪便微生物的影响,试验选择55周龄罗曼粉父母代蛋种鸡810只,随机分为试验A组(添加0.1%"赛克灵")、试验B组(添加0.2%"赛克灵")和对照组,每组6个重复,每个重复45只,测定蛋种鸡的产蛋率、种蛋合格率、平均蛋重、料蛋比、成活率、种蛋受精率、受精蛋孵化率等生产性能指标和粪便中大肠杆菌、乳酸杆菌含量等。结果表明:1)日粮中添加0.1%、0.2%"赛克灵"可极显著提高蛋种鸡产蛋率、种蛋合格率、平均蛋重、存活率、种蛋受精率(P0.01),显著降低料蛋比(P0.05)。2)日粮中添加0.1%、0.2%"赛克灵"可降低蛋种鸡粪便中的大肠杆菌含量,试验A组与对照组无显著差异(P0.05),试验B组与对照组、试验A组差异显著(P0.05);日粮中添加0.1%、0.2%"赛克灵"可提高蛋种鸡粪便中的乳酸杆菌含量(P0.05)。说明酵母培养物"赛克灵"有提高蛋种鸡生产性能和改善粪便微生物数量的作用,0.2%添加量效果较好。     

饲粮精氨酸水平对黄羽肉种鸡产蛋高峰期繁殖性能的影响

本试验旨在研究不同饲粮精氨酸水平对黄羽肉种鸡繁殖性能的影响。试验选用780只36周龄的黄羽肉种鸡作为试验鸡,采用单因素随机分组试验设计分成5个组(饲粮精氨酸水平分别为0.65%、0.80%、0.95%、1.10%和1.25%),每组6个重复,每个重复26只鸡。试验预试验2周,饲喂精氨酸水平为0.65%的饲粮;正试期10周。结果表明:饲粮中添加不同水平精氨酸对试验全期种鸡产蛋率、平均蛋重和料蛋比均没有显著影响(P0.05)。1.10%精氨酸组的产蛋率最高,与0.65%和1.25%精氨酸组相比有提高的趋势(P0.10)。1.25%精氨酸组平均蛋重最低,与其他4组相比均有降低的趋势(P0.10)。饲粮中添加不同水平精氨酸对种蛋蛋壳强度、蛋壳厚度、蛋黄比例、蛋白质含量以及种鸡血浆中丙二醛含量和还原型谷胱甘肽/氧化型谷胱甘肽值均有显著影响(P0.05)。饲粮精氨酸水平对种蛋受精率、孵化率、健雏率和健雏平均出壳重均没有显著影响(P0.05)。由此可见,适度添加精氨酸一定程度上能提高黄羽肉种鸡产蛋率,增强种蛋蛋壳强度和种鸡抗氧化能力。综合分析本试验多项指标,推荐快大型黄羽肉种鸡产蛋高峰期饲粮中精氨酸水平为1.10%。     

紫苏籽提取物对蛋种鸡生产性能的影响

本试验研究了日粮中添加不同水平的紫苏籽提取物对蛋种鸡生产性能的影响。试验选取169日龄海兰父母代蛋种鸡1 440只,随机分成4个组,分别为对照组和试验Ⅰ组、试验Ⅱ组、试验Ⅲ组,试验期为16周,预试期1周。试验组Ⅰ组、试验Ⅱ组、试验Ⅲ组,在基础日粮的基础上分别添加紫苏籽提取物150、250、350 mg/kg。结果表明,在日粮中添加紫苏籽提取物,能提高蛋种鸡产蛋率、种蛋合格率、种蛋受精率和孵化率(P0.05),提高单枚蛋重和饲料转化率(P0.05),经济效益显著提高。综合分析,日粮添加250 mg/kg紫苏籽提取物效果较好。     

日粮添加大蒜素对岭南黄肉种种鸡产蛋及种蛋孵化性能的影响试验

试验选取300只28周龄的岭南黄父母代肉种鸡，随机分成5组，研究了四个水平的日粮大蒜素添加量对产蛋性能及种蛋孵化性能的影响。结果表明：日粮中添加适量的大蒜素能够显著的提高产蛋率、饲料报酬和经济效益，而对平均蛋重、种蛋的受精率和孵化率没有显著影响。     

日粮添加大蒜素对岭南黄肉种鸡产蛋及种蛋孵化性能的影响试验

试验选取３００只２８周龄的岭南黄父母代肉种鸡，随机分成５组，研究了四个水平的日粮大蒜素添加量对产蛋性能及种蛋孵化性能的影响。结果表明：日粮中添加适量的大蒜素能够显著地提高产蛋率、饲料报酬和经济效益，而对平均蛋重、种蛋的受精率和孵化率没有显著影响。     

腐植酸钠对尼克红父母代蛋种鸡生产性能的影响

为了研究腐植酸钠对种鸡生产性能的影响,选用1200羽48周龄尼克红父母代种鸡进行了为期45 d的饲养试验。将试验鸡群随机分为4组,一组为对照组,其它为试验组,在试验组基础日粮中分别添加0.5%、1.0%、2.0%的腐植酸钠。结果表明种鸡日粮中添加不同比例的腐植酸钠对蛋种鸡生产性能的影响有显著差异。1%的腐植酸钠对蛋种鸡的生产水平有显著的促进作用,可显著提高产蛋率、降低料蛋比,显著改善种蛋的受精率和孵化率。2%的添加量不但未提高其生产性能,反而降低了其生产水平,而0.5%的添加水平没有对种鸡生产产生显著影响。     

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.