奶牛日粮加锌对营养物质表观消化率的影响研究

选择8头泌乳前期的中国荷斯坦奶牛,采用4×4重复拉丁方设计,研究奶牛日粮加锌对营养物质全消化道表观消化率的影响。试验分为4组,每组2头,其中A为对照组(基础日粮);B组(基础日粮 20mg/kgZn);C组(基础日粮 40mg/kgZn);D组(基础日粮 60mg/kgZn,试验期分3个阶段,共3个月。结果表明:B组、C组和D组干物质、粗蛋白质、粗脂肪、酸性洗涤纤维和中性洗涤纤维的全消化道表现消化率均比A组有增强的趋势,但均差异不显著(P>0.05)。     

不同钾水平日粮对绵羊养分表观消化率的影响

选择4头新疆细毛羊羯羊,采用4×4拉丁方试验设计,研究了以碳酸钾为钾源的高钾日粮对绵羊养分表观消化率的影响。试验分为4组:A为对照组(基础日粮)、B组(基础日粮+538mg/kg)、C组(基础日粮+1084mg/kg)、D组(基础日粮+1631mg/kg)为试验组,使4组的钾水平分别达到1.4%、1.8%、2.2%和2.6%。试验结果表明:B组、C组和D组干物质、粗蛋白、粗脂肪、酸性洗涤纤维和中性洗涤纤维的全消化道表现消化率均比A组有增强的趋势,但均差异不显著(P>0.05);钾的表观消化率均比A组高,且在2.2%和2.6%时达到显著水平(P<0.05);钙表观消化率先升后降,但差异不显著(P>0.05);磷表观消化率随钾水平的升高也升高,但差异不显著(P>0.05)。     

不同水平葵花籽对奶牛日粮养分消化率和产奶量的影响

为了研究葵花籽对奶牛日粮养分消化率和产奶量的影响,选择4头处于泌乳中期的中国荷斯坦奶牛,采用4×4拉丁方试验设计,分为对照组(A组)、6%葵花籽添加组(B组)、10%葵花籽添加组(C组)和15%葵花籽添加组(D组)进行试验。结果表明:与A组相比,B、C、D组日粮干物质采食量分别减少了0.40,0.64,0.84 kg/d;D组中性洗涤纤维、酸性洗涤纤维、粗蛋白、粗脂肪和干物质的全消化道表观消化率显著低于其他3组(P<0.05),而A、B、C组间差异不显著(P>0.05);在产奶量方面,与A组相比,B、C、D组产奶量分别提高了0.50 kg/d(P>0.05)、0.90 kg/d(P<0.05)和0.30 kg/d(P>0.05);B、C、D组的乳脂率比对照组分别提高了3.26%、6.23%、7.12%,但差异不显著(P>0.05)。说明日粮中添加葵花籽可以降低奶牛干物质采食量,促进养分消化率的提高,对乳脂率也有一定改善作用,特别是添加10%的葵花籽可以显著提高产奶量。     

小肽对奶牛产奶量、血清生化指标和营养物质消化率的影响

本试验旨在研究小肽对奶牛产奶量、血清生化指标和营养物质消化率的影响。试验选用80头产奶量、泌乳天数和胎次相近的健康荷斯坦牛,随机分成4组,每组20头奶牛。对照组(A组)饲喂基础日粮,B、C和D组在基础日粮基础上分别添加小肽5、10和15g/(头·d),预饲期7d,正试期60d。结果表明,添加小肽提高了奶产量,C组与A组相比,提高了3.21kg/d(P0.05);小肽增强了奶牛机体免疫力,降低了乳体细胞数,B、C和D组血清中的IgA和IgM含量显著高于A组(P0.05);C组有机物和酸性洗涤纤维的表观消化率也显著高于A组(P0.05)。在本试验条件下,综合考虑奶产量、血清生化指标和表观消化率等指标,小肽添加量为10g/(头·d)效果最好。     

松针粉对散养柴鸡养分消化率和表观代谢能的影响

为了研究散养柴鸡日粮中添加松针粉对养分消化率和表观代谢能的影响,确定松针粉添加于日粮的最佳比例,试验将120只160日龄体重约1.0 kg健康柴鸡分为4组,每组3个重复,每个重复10只,在柴鸡基础日粮中分别添加0(A组)、3%(B组)、5%(C组)、7%(D组)松针粉,测定消化代谢相关指标。结果表明:与A组相比,B、C组干物质表观消化率显著提高(P0.05),B、D组蛋白质表观消化率显著提高(P0.05),B组饲料代谢能显著提高(P0.05),B组中性洗涤纤维表观消化率、酸性洗涤纤维表观消化率显著提高(P0.05),B、C、D组大部分氨基酸消化率显著提高(P0.05)。说明柴鸡日粮中添加松针粉可以提高养分消化率和代谢能,对氨基酸消化率也有提高作用,以3%的松针粉添加量较适宜。     

不同全混合日粮对2岁梅花鹿消化代谢影响的研究

在粗蛋白水平一致的前提下,研究不同精、粗比全混合日粮(TMR)对2岁雄性梅花鹿消化代谢的影响。采用4×4拉丁方设计,全混合日粮精粗比分别是A组65∶35;B组55∶45;C组45∶55;D组35∶65。结果表明,A、B组在干物质(DM)表观消化率、粗蛋白(CP)表观消化率、中性洗涤纤维(NDF)采食量、中性洗涤纤维(NDF)表观消化率、钙吸收率、磷吸收率等方面与C、D组存在显著差异(P<0.05);处理组A、B间除磷吸收率外其他指标差异均不显著(P>0.05),且处理组B磷吸收率显著高于处理组A(P<0.05);B处理组的钙吸收率高于A处理组(P=0.05);不同处理组在蛋白质日沉积量和蛋白质日均代谢率上均无显著差异(P>0.05)。     

全株发酵杂交构树替代豆粕对育肥猪生长性能、肉品质及养分表观消化率的影响

试验旨在研究日粮中添加不同比例的全株发酵杂交构树替代豆粕对育肥猪生长性能、胴体性状、肉品质和养分表观消化率的影响。选择48头初重（60.44±2.51） kg、健康的“杜×长×大”三元杂交育肥猪,随机分为4组,每组3个重复,每个重复4头猪。A组（对照组）育肥猪饲喂基础日粮,B组、C组、D组育肥猪分别饲喂使用3%、5%、7%全株发酵杂交构树替代豆粕的试验日粮。预试期10 d,正式试验期45 d。结果显示,与A组相比,B组育肥猪的平均日增重增加了2.78%(P>0.05);各试验组育肥猪的眼肌面积、肌内脂肪、蛋白质含量均显著升高（P<0.05）;C组、D组育肥猪对日粮酸性洗涤纤维、粗脂肪、中性洗涤纤维、钙、磷的表观消化率均显著升高（P<0.05）。研究表明,使用3%全株发酵杂交构树代替豆粕对育肥猪的生长性能、肉品质和表观消化率的影响作用较好。     

米曲霉对奶牛瘤胃降解率及日粮表观消化率的影响

[目的]本文旨在研究不同水平的米曲霉日粮对奶牛瘤胃降解率及日粮表观消化率的影响。[方法]试验选用三头安装永久性瘤胃瘘管的健康荷斯坦奶牛,采用3×3拉丁方试验设计,试验分为三组,A组为基础日粮,B组和C组分别为基础日粮添加米曲0.04%和0.08%DM。[结果]米曲霉显著提高了日粮干物质、粗蛋白、酸性洗涤纤维和中性洗涤纤维的瘤胃降解率,其中B组的瘤胃降解率影响效果优于A组和C组,且差异显著（P〈0.05）。三组日粮干物质和酸性洗涤纤维的表观消化率大小顺序为B〉C〉A,但各组间差异不显著（P〉0.05）;B组日粮CP和NDF消化率均显著高于A组和C组（P〈0.05）,但A组和C组差异均不显著（P〉0.05）。[结论]适量添加米曲霉（0.04%DM）有利于提高奶牛瘤胃DM、CP、ADF和NDF的降解率及日粮CP和NDF的表观消化率。     

牡丹籽饼对獭兔生产性能、消化性能及毛皮质量的影响

试验挑选64只2月龄的生长獭兔,随机分为A、B、C、D四组,每组16只,公母各半。A组饲喂基础日粮,B、C、D组在基础日粮中分别添加4%、8%、12%的牡丹籽饼替代部分豆粕。试验期35 d。结果表明:C组的试验末重、平均日增重最高,显著高于A组(P0.05);D组的采食量最高,显著高于A组(P0.05);C组的料重比最低,显著低于A组和D组(P0.05);D组的腹泻率最低,C组的死亡率最高;C组的干物质表观消化率、粗蛋白质表观消化率均显著高于A组和D组(P0.05);C组的中性洗涤纤维表观消化率极显著高于A组(P0.01),显著高于B组和D组(P0.05);C组的酸性洗涤纤维表观消化率显著高于A、B、D组(P0.05)。A组的毛长最长,但各组间无显著差异(P0.05);C组的被毛密度显著高于A组(P0.05);D组的皮张厚度和面积最大,但各组间无显著差异(P0.05)。综上所述,添加牡丹籽饼可以提高獭兔生产性能、营养物质的表观消化率和毛皮品质,其中以饲粮中添加8%的牡丹籽饼最好,但在降低獭兔的腹泻率方面以添加12%的牡丹籽饼为好。     

脂肪酸钙对中国荷斯坦牛营养物质全消化道消化率影响的研究

选择6头经产、胎次相同、产后10～20d的中国荷斯坦奶牛，采用3×3重复拉丁方设计，研究脂肪酸钙对中国荷斯坦奶牛泌乳早期营养物质全消化道消化率的影响。试验处理分别为处理A组为基础日粮；处理B组为基础日粮+200g脂肪酸钙；处理C组为基础日粮+400g脂肪酸钙。试验结果表明日粮中添加脂肪酸钙对干物质、粗蛋白、酸性洗涤纤雏、中性洗涤纤维的全消化道消化率没有影响(p＞0.05)；使脂肪消化率升高(p＜0.05)，且脂肪消化率与脂肪酸钙的添加量呈线性正相关，相关系数为0.87。     

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.