冬春季节补饲精料对BMY牛育肥性能的影响

[目的]冬春枯草季节,为研究在不同饲养水平下对6-9月龄BMY公牛增重性能的影响。[方法]以6-9月龄BMY公牛为育肥对象,5种育肥方式分别为：对照组全放牧不设补饲;试验1组采用放牧＋补饲1.0 kg精料;试验2组采用全舍饲（粗饲料自由采食,补饲1.0 kg/d精料）;试验3组采用全舍饲（粗饲料自由采食,补饲2.0 kg/d精料）;试验4组采用全舍饲（粗饲料自由采食,补饲3.0 kg/d精料）。[结果]表明：6-9月龄BMY公牛在冬季全放牧条件下育肥,体重不会增加反而会减少,平均日增重（ADG）为-178 g;在冬季放牧＋补饲1.0 kg精料的情况下,ADG为395 g;在舍饲＋1.0 kg精料、舍饲＋2.0 kg精料和舍饲＋3.0 kg精料的情况下,ADG分别达600 g7、28 g和1,023 g,补饲效果差异极显著（P〈0.01）,表明BMY牛在舍饲条件下生长更快,可获得更高的ADG。随着补饲日粮营养水平的提高,随着BMY牛日粮干物质采食量增加,说明补饲精料有利于粗饲料的摄入,从而增加ADG。[结论]冬春枯草季节补饲精料,无论放牧还是舍饲,6-9月龄BMY公牛均有较好的ADG,以舍饲加补饲精料的增重效果最为明显,可获得理想的经济收益。     

甘蔗稍青贮对不同性别云南黄牛产肉性能的影响

以探索甘蔗稍青贮育肥不同性别云南黄牛的产肉性能为目的,选择10头云南黄牛,其中公牛5头,平均月龄37.60±6.84,母牛5头,平均月龄39.80±6.00;采用甘蔗稍青贮进行9个月持续育肥试验。结果表明:公牛组和母牛组平均日增重分别为0.67 kg和0.79 kg,屠宰率分别为63.20%和61.70%,但公、母牛组间差异不显著(P0.05)。对牛肉的外观评定结果表明,两组牛的高档肉块等级都达到A2~A3级,肉色4级,脂肪色2级。说明在同一饲养条件下,甘蔗稍加精料育肥云南黄牛效果好,公、母牛生长速度一致。     

不同管理模式与日粮营养水平对热区肉牛育肥效果的影响

为了研究不同品种、不同管理模式与营养水平对热区肉牛育肥的影响,试验一采用安格斯牛、西门塔尔牛杂交后代和婆罗门牛、本地黄牛与1/2婆罗门牛×1/4莫累灰牛×1/4云南黄牛(BMY牛)5个品种各10头,通过90 d生长性能与平均日增重(ADG)测定,筛选出BMY牛为适宜热区推广品种;试验二选取体重约160 kg的BMY公牛40头,分成5组,每组8头,分别采用全放牧不补饲、自由放牧+补饲精料1.0 kg、舍饲牧草+补饲精料1.0 kg、2.0 kg、3.0 kg的方式,在热区进行相同品种不同管理模式与日粮营养水平育肥对比试验。结果表明:相同管理模式与日粮营养水平下,BMY牛对热区环境的适应性与生长性能表现最好;在相同品种同等营养水平下,舍饲育肥的效果明显优于放牧管理;在相同品种相同管理条件下,保持3.0 kg日粮营养水平可获最高育肥效益。说明在我国热区选择BMY牛并保持3.0 kg以上日粮营养水平舍饲育肥能获取最优经济效益。     

熟洋蓟花苞片饲喂肉用型西门塔尔种牛效果及效益分析

[目的]利用熟洋蓟花苞外层片饲喂肉用型西门塔尔种牛,测量体重增重效果,分析熟洋蓟与玉米青贮作为粗料在相同的饲养环境条件下牛只饲养的经济效益情况。[方法]选取40头8~10月龄的肉用型西门塔尔育成母牛及20头哺乳母牛(犊牛在1月龄内)分别随机分成两组,Ⅰ组、Ⅱ组为育成母牛分别饲喂熟洋蓟和玉米青贮,Ⅲ、Ⅳ组为哺乳母牛分别饲喂熟洋蓟和玉米青贮;粗料按采食量添加,精料和青干草投放量育成牛两组相同、哺乳牛两组相同,犊牛精料均为自由采食,60d后称重。[结果]饲喂熟洋蓟和玉米青贮的Ⅰ组、Ⅱ组育成母牛60d后平均体重及日增重分别为307.72±13.94kg、1154±206g和278.28±17.60kg、711.53±187.43g;Ⅲ组、Ⅳ组哺乳母牛饲喂熟洋蓟和玉米青贮后其犊牛60d后平均体重及日增重分别为119.74±8.87kg、1115.83±247.13g和106.48±11.63kg、960.33±276.65g;差异均显著(P0.05)。[结论]分析通过四个组饲喂熟洋蓟和玉米青贮后牛只增重效果,可以看出,Ⅰ组和Ⅲ组(犊牛)饲喂熟洋蓟增重效果分别优于饲喂玉米青贮的Ⅱ组和Ⅳ组(犊牛);随着牛只对熟洋蓟采食量的增加,青干草采食量也有所增加,但精料量同时逐渐减少,到第35d时可完全不喂精料,可大大降低饲料成本,提高经济效益。     

不同粗饲料对平凉红牛分段式育肥效果的影响北大核心

试验旨在研究相同精料水平下,不同粗饲料和育肥条件对平凉红牛产肉性能和肉品质的影响,探索适宜平凉红牛的分段式育肥模式及粗饲料种类。将27头平凉红牛按不同初重和育肥预期总增重100 kg分为3组,即A_(1)组(250~350 kg)、A_(2)组(300~400 kg)和A_(3)组(350~450 kg),每组9头牛;再分别将各组的9头牛随机分为3组,即B1组、B2组和B3组,每组3头牛。B1组牛饲喂青贮玉米秸秆,B2组牛饲喂苜蓿干草,B3组牛饲喂小麦秸秆。试验期90 d。结果显示:A3B1组牛的育肥期平均日增重最高,经济效益最好,胴体重、屠宰率和净肉率最高,背膘厚和眼肌面积均最大;A1B1组牛肉的剪切值最小,大理石纹等级评价最优。研究表明,综合考虑育肥期生长性能、屠宰性能、肉品质和经济效益分析结果,适宜当地平凉红牛的育肥模式为350~450 kg,且以青贮玉米秸秆作为平凉红牛的粗饲料能够获得更好的生产性能和经济效益。     

发酵酒糟饲喂水平对西杂牛生长性能、血液生化指标和肌肉氨基酸组成的影响

试验旨在探究发酵酒糟饲喂水平对西杂牛生长性能、生化指标、牛肉氨基酸组成及经济效益的影响。选取18头体重为（315±15）kg、2周岁左右的西杂牛（西门塔尔牛♂×关岭黄牛♀），随机分为3组，每组6头牛。对照组饲喂40%精料+60%皇竹草鲜草（DM）,15%发酵酒糟组饲喂25%精料+15%发酵酒糟+60%皇竹草鲜草（DM）,30%发酵酒糟组饲喂10%精料+30%发酵酒糟+60%皇竹草鲜草（DM）。试验预试期15 d，正试期60 d。结果表明：与对照组相比，30%发酵酒糟组的干物质采食量和平均日增重均增加（P<0.05），血清中β-羟基丁酸含量均减少（P<0.05）、免疫球蛋白A含量增加（P<0.05）；与对照组相比，15%发酵酒糟组牛肉中丝氨酸、苯丙氨酸、组氨酸均增加（P<0.05）,30%发酵酒糟组牛肉中天门冬氨酸、苏氨酸、丝氨酸、蛋氨酸、苯丙氨酸、组氨酸及氨基酸总量均增加（P<0.05）；与对照组相比，15%发酵酒糟组、30%发酵酒糟组每头牛每日利润分别提高11.43、15.54元。在本试验条件下，采用30%发酵酒糟替代常规精料可增加西杂牛（西门塔尔×关岭...     

杂交肉牛不同精料水平育肥效果研究

选择西杂牛(西门塔尔与本地牛的杂交后代)40头，分为4组，分别饲喂精粗比例为35：65，45：55，55：45。65：35的4种饲粮。经过90d的育肥，结果表明：以55％精料组的增重最快，平均日增重为1．05kg。育肥结束时进行屠宰试验，产肉性能以65％精料组最好，但饲粮精料水平的不同并没有显著影响肉牛的屠宰性能及牛肉品质。     

不同啤酒糟比例的全混日粮育肥BMY牛试验

为了指导冬春季BMY育肥牛日粮的制作和获得有关BMY牛育肥性能的数据资料,直接利用湿啤酒糟,在全混日粮中添加不同比例的啤酒糟代替精料补充料,对12月龄左右(平均11.8±0.30月龄)的BMY公牛进行了3个月的育肥试验。供试牛的日粮以风干物构成比例的形式,精粗比都设计为75:25,1组的日粮构成为25%青干草、55%精料补充料和20%啤酒糟,2组和3组则在1组的基础上增加了啤酒糟的比例,分别用35%和50%的啤酒糟代替等量的精料补充料。饲养试验结束后,从每组抽取4头进行屠宰和产肉性能测定。试验结果显示:①(日粮风干物)平均采食量,1组、2组和3组依次为7.19kg/h.d、6.94kg/h.d和6.36kg/h.d,随着日粮中啤酒糟比例的增加,BMY牛的采食量呈现下降的趋势,3组下降尤其明显;②平均日增重,1组(1.130kg)2组(1.107kg)3组(0.771kg),与采食量的测定结果相一致,1组和2组均极显著高于3组(P0.01),而1组、2组间差异不显著(P0.05);③单位增重的日粮(饲料风干物)消耗量,2组(6.27kg)1组(6.36kg)3组(8.25kg),增重料耗比(G:F)以啤酒糟在日粮中的添加比例为35%时最低;④除了肉骨比外的各项产肉性能指标,包括宰前体重和胴体重、眼肌面积、净肉重和骨重,屠宰率及净肉率,背膘厚度和胴体脂肪总重,以及各优质肉块的产量、优质肉块总重和优质切块比例都随着日粮中啤酒糟比例的提高而呈下降的趋势;肉骨比以2组最高,3组最低,但各组间差异不显著(P0.05)。组间比较的结果,1组、2组间所有指标差异都不显著(P0.05),3组则在除了肉骨比和优质切块比例而外的各项指标方面都与1组、2组有显著性差异(P0.05)。⑤饲料成本随日粮中啤酒糟比例的增加而降低。2组的增重料耗比最低,获得的增重收益最高,比1组提高了28.22%;3组总饲料成本虽然比1组降低了30.19%,获得的增重收益反而是最低的,它比1组降低了45.97%。养分分析和饲养试验的结果表明,啤酒糟是肉牛较好的精料来源,而且湿啤酒糟的饲用成本非常低,添加比例为35%替代精料补充料时增重较快而料耗比较低,经济效益也较高。但湿啤酒糟的适口性不好,提高其在日粮中的添加比例会降低日粮的适口性而影响采食效果。而屠宰试验结果表明,日粮采食量对BMY牛的产肉性能有一定的影响。因为采食量较大的试验组从日粮中摄入了更多的营养素,可以获得较高的体增重,因而具有较大的宰前体重和较多产肉量,肉牛胴体品质也呈提高趋势。因此,日粮添加适当比例的啤酒糟替代精料补充料育肥生长牛效果较佳。     

全混合日粮压块饲料育肥肉牛试验研究

分别采用玉米秸秆、稻草秸秆与精料设计全混合日粮,配制压缩块状饲料进行肉牛育肥及屠宰测定试验,研究秸秆与精料分开的传统饲养模式与压块饲料饲喂肉牛对肉牛育肥效果的影响。结果,分别饲喂玉米、稻草秸秆与精料全混合日粮压块饲料的两试验组(Ⅰ和Ⅱ)育肥牛平均日增重分别为1259．26±161．11 g和1259．26±82．82 g,而对照组分别采用传统的精粗料分开不补喂/补喂蛋白补充料育肥牛平均日增重分别为506．17±228．48 g和318．93±119．80 g,各试验组与对照组牛之间平均日增重差异均达到极显著水平(P＜0．01);试验组Ⅰ和Ⅱ、Ⅲ和Ⅳ(对照)间平均日增重均无明显差异(P＞0．05),表明以玉米秸秆或稻草秸秆与精料补充料等复合配制而成的全混日粮压块饲料,育肥肉牛效果较秸秆与精料分开的传统饲养模式饲喂内牛育肥效果更为好。     

乡雪黑牛繁殖及生产性能的测定研究(初报)

为研究报道乡雪黑牛的繁殖及生产性能测定效果,试验选用湘中黑牛(安本杂)为母本,用日本和牛或利木赞牛为父本进行三元杂交,构建和安本与利安本两个杂交组合;通过对母本繁殖性能、犊牛生长性状及12月龄牛的育肥试验,测定其两组杂交牛生产高档牛肉的生产潜力。结果显示:母本牛的繁殖性能良好,犊牛生长发育优良,12月龄牛育肥6个月,平均日增重分别达1000g和1090g,至18月龄高可达500kg(平均443kg～461.5kg),屠宰率58%以上,胴体净肉率80%多,且脂肪沉积好,尤其是和安本三元杂交牛大理石纹明显,等级达1.5,其结果超过已报道的安本杂F2的测定结果。两组杂交牛比较,和安本杂交牛的肉质性(大理石纹等)状略强于利安本杂交牛,而后者的初生重、生长发育、日增重及屠宰性能(屠宰率、净肉率等)略强于前者。经测定两组杂交牛均有开发生产高档牛肉的良好潜力。     

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.