不同叶质对二回育成绩的影响

以过老叶、适熟叶、过嫩叶三种叶质进行二回育与普通育比较，结果５龄经过过老叶区较适熟叶长，过嫩叶区较适熟叶区短。四回育５龄经过时间长于二回育，产茧量过老叶四回育较适熟叶低，二回育较适熟叶稍优。过嫩叶则明优于适熟叶，过老叶明显低于适熟叶。二回育与四回育比较，过嫩叶、适熟叶四回育较二回育优，过老叶二回育较四回育优。茧质方面，过老叶显著低于适熟叶，过嫩叶显著优于适熟叶，过老叶与过嫩叶二回育均比四回育优，适熟叶二回育较四回育稍差。     

家蚕新品种贵蚕9号少回育饲养试验

为探索少回育对贵蚕9号经济性状的影响,开展了不同饲育回数试验研究。结果表明,二回育区病弱蚕数要显著高于三回育区和四回育区,四龄蚕结茧率显著低于四回育区;二回育区饲养管理用工时间最少,分别比三回育和四回育节约用工15.8%和29.4%;二回育区用叶量较少,分别比三回育和四回育节约用叶10.0%和14.01%。二回育区公斤茧用叶量最少,产茧量、克蚁收茧量和蚕茧产值最低,但公斤桑叶经济产值最高。     

种茧饲养采用条桑育初报

近年,国内外都进行了家蚕少回育试验,并取得了一定的成绩,为经济养蚕法开创了一条新的途径。我场应用稚蚕炕房四回育,壮蚕五回育,已有两年的成绩。在安徽合肥蚕种场母、原、普三级蚕种种茧育三回育一班制,经过三年七次实践成绩的启发下,思想大为解放,党的十一届三中全会号召我们“实践是检验真理的唯一标准”。种茧育是否可以少回育,向省力化发展,必须亲自试一下,为我们自身推广应用提出确切的依据。七九年春期我场以苏五、苏六100克进行全区三回育,稚蚕炕房育,壮蚕条桑育试点,初步总结汇报如下:一、试验方法:1.以普部一蚕室全部改建炕房,并辟一小间为稚蚕炕房室,与普蚕二室组作对照。2.1—5龄全龄采取三回育,1—3龄在炕房内饲养,四五龄蚕箔。     

省力化饲养五龄蚕技术的探讨

<正>结合生产实际,本人从1996年开始在戴庄乡沥潮村姚长明家采用5龄蚕薄膜覆盖斜面立体条桑二回育初获成功,同时进行了地面条桑二回育试验,之后又在乡蚕桑重点村进行了应用,取得了较好的经济和社会效益.材料与方法:供试蚕品种苏5苏6,以普通育为对照进行斜面立体条桑二回育和地面条桑二回育试验,各称取4眠蚕2.5公斤,重复三区,条桑育早晚给2次桑,用薄膜覆盖;普通育每天给桑4次,不覆薄膜条桑育、普通育在相同环境条件下饲养、结茧,采茧后调查分析.     

桑蚕三回育的试验

为了提高桑叶利用率,节省劳动力,提高担桑产值,今年下半年,我场连续三批进行三回育的试验,现将试验情况介绍如下:一.试养的方法和技术处理1、供试品种:桂夏二号.2、试养方式:共分二个类型,全令五回育,全令三回育.3、饲育技术处理,     

给桑条件与家蚕饲料效率关系的研究

本试验调查了不同给桑次数、不同给桑量条件下家蚕的饲料效率。在给桑次数相同的条件下,50kg桑茧层量以85％给叶量区和75％给叶量区相同,均比饱食区高。在给桑量相同条件下,二回育茧层饲料效率低于四回育,但是差异不明显,二回育较四回育节省工效,养蚕综合效益高。     

夏秋蚕添食尿素的效果

<正> 为了提高秋蚕饲养效果,我们于一九八三年早秋蚕期进行了家蚕五令尿素添食试验。添食分0.3%、0.5%、1%和1.5%四种浓度,以添食质小作为对照,每种处理各重复三区。供试蚕品种是苏华×日东,1—4令大区饲养,五令饷食后分区试验,每区定300头蚕,以浙江湖桑饲养,每日四回育,实行定量给桑。从五令第二天开始每天上午10时给桑时添食,用喷雾器喷撒添食液至叶面湿润而不滴水为度,见熟后立即停止添食。     

五龄高低温二回育对蚕儿逐日食桑量及发育速度的影响

<正> 一日二回育是一项省力高效,适宜于目前农村养蚕劳力不足的实用新技术。目前已从多方面对二回育技术进行了研究报道。但从饲育温度与蚕儿生长发育关系方面尚未见报道。本试验是从高温27℃,常温24℃对桑蚕五龄施行一日二回育。称量调查蚕儿体重增长变化情况,食桑量,消化量,以比较蚕儿生长发育差异,结茧后调查茧质。旨在给不同温度条件的蚕区推广二回育时作为参考。     

小蚕塑料薄膜一日二回育试验

<正> 近年武胜县农村大量劳动力外出,养蚕与农作的矛盾日趋突出。能否找到适宜的小蚕饲养模式,达到增产增收的目的?为此在塑料薄膜覆盖育的基础上,借鉴外地一日二回育的成功经验,大胆改进常规一日三回育、四回育,探索出了小蚕塑料薄膜一日二回育饲养技术。于1997年夏秋季和1998年春季进行了室内养蚕试验和小蚕共育中试,现将结果报告如下。     

秋期大蚕期条桑一日二回育试验

进行秋期大蚕条桑一日二回育与当前蚕区片叶一日四回育的生产试验,结果成绩一致,表明秋期大蚕采用条桑一日二回育是可行的。     

Effect of feeding frequency on bacterial and fungal concentrations, pH, and other parameters in the rumen.

Three sheep were fed a pelleted high-roughage diet either once, 6, or 24 times per day in a 3 x 3 Latin square trial. During each 21-d period, 14 d were allowed for adaptation followed by a 7-d collection period, in which samples for microbial counts were taken on d 1 and 5 and several rumen parameters were measured on d 2 and 6. Bacterial concentrations were not different between feeding frequencies on the first sampling day but were higher (P < 0.05) on the second sampling day when the sheep were fed 24 times a day. Fungal concentrations were not different among feeding frequencies on either sampling day. No effects of feeding frequency were observed for the concentration of cellulolytic bacteria or fungi. On d 2, ruminal volume was larger (P < 0.05) with six feedings than with one feeding and fluid volume turnover was greater (P < 0.05) when sheep were fed 24 times per day. Rumen pH values were higher (P < 0.01) on both d 1 and 5 when the sheep were fed once a day and the percentage of rumen dry matter was highest (P < 0.02) with 24 feedings. These findings would suggest that if the same amount of a given diet is fed daily, the number of feedings does not markedly affect microbial concentrations, rumen volume, or liquid turnover time.     

A preliminary study of the tolerance of healthy foals to a low residue enteral feeding solution

After a three day acclimatization period, six healthy, young (aged 4 to 20 days) orphan foals of mixed breeding were fed 100 per cent of their caloric needs (estimated at 523 kjoules/kg bodyweight [bwt] or 125 kcal/kg bwt/day) as a low residue isotonic feeding solution (LRF) for seven days. The solution provided 4.18 kjoules (1 kcal/ml) and was fortified with minerals and protein to meet estimated foal requirements. The solution was fed through an indwelling 12 French feeding tube. Five of the six foals completed the study; the loss of the sixth foal apparently was unrelated to the feeding protocol. The foals tolerated LRF well. Signs of intolerance were noted in two foals and were limited to flatulence, mild bloat and very mild abdominal pain associated with a decreased interval between two feedings during the first 48 h on 100 per cent LRF. Complete recovery without therapy occurred within 6 h and feedings were resumed. Growth in height and weight were comparable to published data for healthy foals raised with their dams. Feeding tubes were easily maintained with no apparent dysphagia, regurgitation or discomfort to foals. This low residue, calorically dense, isotonic feeding solution may be useful for enteral feeding of selected foals aged at least seven days.     

Effects of restricted feed intake on finishing pigs weighing between 68 and 114 kilograms fed twice or 6 times daily

In a previous study with limit-fed gestating gilts, we observed that gilts fed 6 times/d had greater ADG than those fed the same amount over 2 feedings. To confirm these earlier responses, we used finishing pigs as a model in two 42-d trials and two 28-d trials to evaluate the effects of restricted feed intake and feeding frequency (2 vs. 6 times/d, floor fed) on pig performance between 68 and 114 kg. In all experiments, pigs (10/pen) were housed in 1.8 × 3.1 m pens with a half-solid, half-slatted concrete floor. Pigs were fed a corn- and soybean meal-based diet formulated to 1.15% standardized ileal digestible Lys and 3,294 kcal of ME/kg. In Exp. 1 to 3, energy and Lys were supplied to pigs according to NRC (1998) calculations to target an ADG of 0.80 kg. In Exp. 4, the diet was supplied to pigs to target an ADG of 0.80 kg (low feed intake) or 0.95 kg (high feed intake) to determine if the amount of energy above the maintenance requirement and feeding frequency affected pig performance. Pigs were fed by dropping similar amounts of feed onto the solid concrete floor either 2 (0700 or 1400 h) or 6 times (3 meals within 2 h at the morning and afternoon feedings) per day with an Accu-Drop Feed Dispenser (AP Systems, Assumption, IL). In Exp. 1 and 2, pigs fed 6 times daily had increased (P < 0.02) ADG and G:F compared with pigs fed 2 times per day. Greater feeding frequency increased (P < 0.05) the duration of time spent feeding and standing and reduced the lying time. In Exp. 3, a third treatment was included to determine whether the improvements in performance were due to decreased feed wastage. This treatment was designed to minimize feed wastage by dropping feed closer to the floor for pigs fed 2 times per day. Pigs fed 6 times daily had improved (P < 0.05) ADG and G:F compared with pigs in either treatment fed 2 times per day. No difference (P > 0.05) in performance was observed between pigs fed 2 times per day when feed was dropped from the feed drop or by the modified method. In Exp. 4, increasing the feeding frequency from 2 to 6 times per day improved (P < 0.01) ADG and G:F for pigs fed the low feed intake and tended to increase (P < 0.06) ADG and improved (P < 0.05) G:F for pigs fed the high feed intake. In limit-feeding situations, increasing the frequency of feeding from 2 to 6 times per day improved pig performance, which confirmed our earlier findings in gestating gilts.     

平行串叶法小蚕片叶立体一日一回育技术的研究

在小蚕片叶立体一日一回育的基础上，试验了平行串法小蚕片叶立体一日一回育，与立体一日二回育比，节约用桑３％，节约劳力３６％，张种产量提高８．５％，还阐明了该法的技术要点。     

Effects of oral cisapride administration in chinchillas (Chinchilla lanigera) with experimentally induced fecal output reduction

BackgroundCisapride, a prokinetic drug, has been anecdotally recommended in chinchillas at a dose of 0.5 mg/kg PO q8-12h to treat gastrointestinal hypomotility. However, studies in other rodent species suggest that higher doses are necessary to be effective.MethodsIn two randomized, placebo-controlled, blinded, crossover studies, the effects of cisapride (10 mg/kg PO q12h for four doses), administered with or without concurrent syringe feeding of a critical care formula (25 mL/kg PO q12h for two doses) were evaluated in chinchillas following recovery from sedation induced by alfaxalone-butorphanol. Food intake and fecal output were quantified to assess the effects of cisapride on these parameters.ResultsOver the first 24 hours after recovery from sedation, animals that received cisapride and syringe feeding had the least reduction in fecal output (-27 ± 23%) compared to the control treatment (-48 ± 22%, P = 0.008) or to animals which received syringe feedings alone (-40 ± 23%, P = 0.12). Cisapride administered without concurrent syringe feedings had no effect on fecal output. No adverse effects were recorded following the administration of cisapride.Conclusions and clinical relevanceThe oral administration of cisapride at 10 mg/kg q12h in conjunction with syringe feeding resulted in a slight, but not clinically relevant, attenuation of fecal output reduction by ~13% compared to syringe feedings alone and by ~20% compared to no treatment. Without the concurrent administration of syringe feedings, cisapride had no effect on fecal output in chinchillas.     

氯化铵对肉仔鸡热应激的影响

通过离子平衡途径,在肉仔鸡日粮中添加氯化铵,观察其对家禽热应激的影响。将270只1日龄艾维茵肉雏鸡随机分为5个处理,每处理设3个重复,试验持续到5周龄。试验模拟夏季高温环境,全期人工控温28～35℃。1～28日龄进行饲养试验;29～34日龄进行代谢试验。5组试验日粮为:Ⅰ为正对照组,21%CP;Ⅱ为Ⅰ组日粮+0 62%氯化铵;Ⅲ为负对照组,19%CP;Ⅳ为Ⅲ组日粮+0 62%氯化铵;Ⅴ为Ⅲ组日粮+1 00%氯化铵。试验结果表明:Ⅱ、Ⅲ、Ⅳ和Ⅴ组肉仔鸡期末体重、日增重、采食量和饲料转化率与对照组无显著差异,Ⅴ组21日龄体重显著降低(P<0 05);Ⅱ和Ⅴ组显著提高CP、Ca和P的表观代谢率(P<0 05),Ⅴ组P除外;Ⅴ组粪便含水率明显增加(P<0 01);Ⅲ、Ⅳ组与对照组代谢指标差异不显著。     

Capability of the nematode-trapping fungus Duddingtonia flagrans to reduce infective larvae of gastrointestinal nematodes in goat feces in the southeastern United States: dose titration and dose time interval studies

Infection with gastrointestinal nematodes, particularly Haemonchus contortus, is a major constraint to goat production in the southeastern United States. Non-anthelmintic control alternatives are needed due to increasing resistance of these nematodes to available anthelmintics. Two studies were completed in Central Georgia in August 1999, and April–May 2000, using Spanish does naturally infected with Haemonchus contortus, Trichostongylus colubriformis, and Cooperia spp. to evaluate effectiveness of nematode-trapping fungi as a biological control agent. In the first experiment, five levels of Duddingtonia flagrans spores were mixed with a complete diet and fed once daily to the does (three per treatment) in metabolism crates. The treatment concentrations were (1) 5×10⁵, (2) 2.5×10⁵, (3) 10⁵, and (4) 5×10⁴ spores per kilogram body weight (BW), and (5) no spores. Fungal spores were fed for the first 7 days of the 14-day trial, and fecal samples were collected daily from individual animals for analysis of fecal egg count and establishment of fecal cultures. Efficacy of the fungus at reducing development of infective larvae (L3) in the fecal cultures was evaluated. The mean reduction in L3 from day 2 of the treatment period until the day after treatment stopped (days 2–8) was 93.6, 80.2, 84.1, and 60.8% for animals given the highest to lowest spore doses, respectively. Within 3–6 days after termination of fungal spore feedings, reduction in L3 development was no longer apparent in any of the treated animals. In a second experiment, effectiveness of 2.5×10⁵ spores of D. flagrans per kilogram BW fed to does every day, every second day, and every third day was evaluated. Reduction in L3 development by daily feeding was less in the second experiment than in the first experiment. Daily fungal spore feeding provided more consistent larval reduction than intermittant feeding (every second or third day). When fed daily under controlled conditions, D. flagrans was effective in significantly reducing development of L3 and appears to be an effective tool for biocontrol of parasitic nematodes in goats.     

An artificial rearing method to produce optimum growth in orphaned foals

Eleven foals were fed a dilute (1 to 10) milk replacer diet (15% fat, 23% milk protein; dry matter) from 1 to 8 weeks of age. Two suckled foals served as controls. Maximum consumption of formula was limited to 25% of body weight per day divided into 5 feedings per day during week one, 4 per day during week 2 and 3 feedings per day from weeks 3 through 8. Supplemental grain was offered to all foals beginning at week 2. Body weight was measured twice weekly and increased linearly over time. Height at withers, croup, elbow and hock were measured once a week and increased at a rate best described by a second order polynomial equation. Increases in body length were linear. There were no statistical differences between suckled and formula-fed foals for any growth parameter. Scours (foal diarrhea) occurred during weeks 1 or 2 in both the control and experimental groups. Diarrhea was mild and of short duration. This regimen resulted in growth and weight gains that were comparable to those of normally suckled foals.     

Effect of flavomycin on the apparent digestibility of crude nutrients in wethers, parameters of rumen fermentation in cattle and feed intake and weight gain of heifers

Three experiments with five wether each were carried out in order to investigate the influence of various levels of flavomycin (0, 5 and 10 mg per animal and day) on apparent digestibility of artificially dried grass. A short time individual feeding experiment (42 days) with 9 bulls and a long term individual feeding experiment (225 days) with 52 heifers were conducted. Animals consumed 0 or 30 mg flavomycin per day. Parameters of rumen fermentation were investigated. Feed intake and weight gain were measured in the experiment with heifers. Flavomycin did not significantly influence the apparent digestibility of organic matter and crude nutrients as well as parameters of rumen fermentation. Flavomycin did not influence dry matter intake, but increased significantly weight gain (49 g per animal and day, 10.5%) and reduced feed and energy required per kg weight gain (10.6%) in heifers. The reasons of ergotropic effects of flavomycin are mostly unknown at present.     

Concentration of free amino acids in the blood plasma of sheep with different amounts of nitrogen in the feed

Trials were conducted with four adult sheep of the Merino breed, live weight 45 to 50 kg, fed two diets with different nitrogen levels (7.6 g nitrogen per day as protein or 24 g nitrogen per day with an addition of 17.4 g urea nitrogen to 7.6 g nitrogen as protein). The following findings were obtained: the concentration of free amino acids in blood plasma in the 9th, 12th, 15th, 18th and 22nd weeks from the beginning of feeding with both diets was lower, in most of the analyzed amino acids, three hours after feeding than before feeding. The results show that at an increased intake of urea nitrogen the concentration increases of the free amino acids lysine, serine, glutamic acid, glycine, valine and isoleucine before feeding. Three hours after feeding these differences are less pronounced. An increase is only recorded in the concentration of arginine, glutamic acid and glycine, whereas the concentration of alanine decreases.