Recovery and Germination of Dichrostachys cinerea Seeds Fed to Goats (Capra hircus)

Goats can act as dispersal agents by consuming seed pods of woody plants and dispersing the seeds in feces. Concerns that goats might thereby promote encroachment by woody plant species such as Dichrostachys cinerea (sickle bush) have not been addressed. The objective of this study was to determine the recovery rate and germination of D. cinerea seeds that pass through the digestive tract of goats. We hypothesized that 1) D. cinerea seeds will remain intact and viable after passage through the digestive tract of goats and that 2) D. cinerea seeds will be scarified by such passage, resulting in improved germination percentages. The first trial measured the recovery rate of 1 500 D. cinerea seeds that were consumed by indigenous goats, either voluntarily after mixing them with feed pellets (mixed) or by force-feeding (gavaged). Seed recovery for the gavaged treatment (32.7%) was significantly higher than for the mixed treatment (9.9%; P &spilt; 0.001). The second trial determined germination percentages of D. cinerea seeds recovered from the feces of animals in the two treatments of the first trial as well as scarified and control (untreated) seeds. The germination percentage of mechanically scarified seeds (53.0%) was significantly higher than that of seeds that passed through the digestive system in the mixed (35.5%) or gavaged (31.2%) treatments or were untreated (19.0%; P &spilt; 0.001). Seeds that passed through the digestive tract (mixed and gavaged treatments) had a significantly higher germination percentage than untreated seeds (P &spilt; 0.001). A nonnegligible proportion of D. cinerea seeds remained intact after ingestive chewing and passage through the digestive system, and their germination percentage was even elevated. This suggests that goats have a potential to facilitate woody plant encroachment through dispersal of viable and scarified seeds.     

Effects of Acacia nilotica and Acacia karoo diets on Haemonchus contortus infection in goats

This study was carried out to determine the effects of Acacia karoo and Acacia nilotica diets on Haemonchus contortus infections in goats. Twenty-four Boer goats of mixed sex (live weight 17-22 kg) were randomly assigned to four treatment groups, namely: A. nilotica (AN) group, A. karoo (AK) group, control infected with H. contortus (HC) group and the non-infected control (NHC) group. Animals in the AN, AK and HC groups were orally infected with a single dose of 3000 HC third stage larvae. The AN and AK groups had dried leaves of AN and AK, respectively, included in their basal diet at a rate of 40% dry matter (DM) while the HC and NHC groups had the basal diet throughout the experiment. All animals received a total feed allowance of 500 g DM per day and Katambora Rhodes grass hay ad libitum for roughage. Parameters measured included faecal egg counts and live weight. At the end of the experiment, three animals from each group were slaughtered and abomasal worm burdens were determined. A significant decrease in the faecal egg counts was recorded in animals in the AK group (P<0.05) relative to those in the AN and HC groups. The worm burdens were reduced by 34% in the AK group (P<0.05) and by 10% in the AN group (non-significant) relative to the infected control group. The study indicates that the difference in the effects of the two forages on HC infections may be related to type and concentration of tannins.     

Disturbance and the frequency of root suckering in an invasive savanna shrub,Dichrostachys cinerea

The ecology of clonal species has rarely been studied in savannas. Dichrostachys cinerea, a common invasive shrub in southern African savannas, forms root suckers. This paper examines the effect of disturbance type and frequency on this form of clonal spread. Small plants were excavated (n = 370) at 11 sites exposed to different fire frequencies and grazing intensities and classified were as either seedlings or root suckers. Most of the plants (55%) were found to be root suckers. There was no significant effect of disturbance type and frequency on 'seedling' establishment from seeds versus root suckers. Even when burnt annually, D. cinerea continued to form root suckers. The combination of establishment from seeds and spread by root suckers makes this species a formidable native invasive woody shrub.     

蛋鸡小麦型日粮中添加叶黄素对鸡蛋品质的影响

将360只48周龄"尼克红"蛋鸡随机分为5组,每组设3个重复,每个重复24只.试验1组为玉米基础日粮组,试验2组为小麦型基础日粮组(0.10%酶制剂组),试验3组为0.10%酶制剂组 0.5%叶黄素添加剂,试验4组为0.10%酶制剂组 1.0%叶黄素添加剂,试验5组为0.10%酶制剂组 1.5%叶黄素添加剂.预试期7天,试验期21天.结果表明,添加1.5%的叶黄素添加剂可以显著改善鸡蛋的蛋黄颜色.与小麦对照组相比,蛋黄颜色提高了188.33%(P＜0.05).与玉米基础日粮组相比,日粮添加1.5%叶黄素添加剂组鸡蛋蛋黄颜色提高了0.82%,但差异不显著(P＞0.05),添加叶黄素添加剂对鸡蛋的蛋重、蛋比重、蛋形指数影响不大.     

蛋鸡小麦型日粮中添加叶黄素对鸡蛋品质的影响

将360只48周龄“尼克红”蛋鸡随机分为5组,每组设3个重复,每个重复24只。试验1组为玉米基础日粮组,试验2组为小麦型基础日粮组（0．10％酶制剂组）,试验3组为0．10％酶制剂组＋0．5％叶黄素添加剂,试验4组为0．10％酶制剂组＋1．0％叶黄素添加剂,试验5组为0．10％酶制剂组＋1．5％叶黄素添加剂。预试期7天,试验期21天。结果表明,添加1．5％的叶黄素添加剂可以显著改善鸡蛋的蛋黄颜色。与小麦对照组相比,蛋黄颜色提高了188．33%（P〈0．05）。与玉米基础日粮组相比,日粮添加1．5%叶黄素添加剂组鸡蛋蛋黄颜色提高了0．82％,但差异不显著（P〉0．05）,添加叶黄素添加剂对鸡蛋的蛋重、蛋比重、蛋形指数影响不大。     

日粮因素对反刍动物瘤胃消化代谢影响的研究现状

本文对反刍动物的瘤胃发酵作了总结,其中重点阐述了通过日粮组成对瘤胃消化代谢产物的影响,以便最大限度地发挥瘤胃发酵的有益方面,提高饲料的利用效率和生产性能。     

日粮因素对反刍动物瘤胃消化代谢影响的研究现状

本文对反刍动物的瘤胃发酵作了总结,其中重点阐述了通过日粮组成对瘤胃消化代谢产物的影响,以便最大限度地发挥瘤胃发酵的有益方面,提高饲料的利用效率争生产性能。     

大麦-高粱型饲粮中添加酵母培养物对肥育猪生长性能及肉品质的影响

本试验旨在研究大麦-高粱型饲粮中添加酵母培养物对肥育猪生长性能及肉品质的影响。选择体重相近、日龄基本一致的健康"杜×长×大"杂交肥育猪120头,随机分为3组,每组4个重复,每个重复10头猪。各组分别饲喂玉米-豆粕型饲粮、大麦-高粱型饲粮和在大麦-高粱型饲粮的基础上添加0.8%酵母培养物的试验饲粮。试验期为60 d。结果显示:1)与玉米-豆粕组相比,大麦-高粱组肥育猪平均日增重减少了8.62%(P0.05),料重比增加了9.78%(P0.05),而大麦-高粱+酵母培养物组平均日增重和料重比无显著变化(P0.05)。2)与玉米-豆粕组相比,大麦-高粱组背最长肌亮度(L*)值显著降低(P0.05),红度(a*)值显著升高(P0.05),而大麦-高粱+酵母培养物组L*、a*值无显著差异(P0.05)。各组肥育猪背最长肌p H45m in、滴水损失、肌内脂肪、粗蛋白质和水分等指标均无显著差异(P0.05)。3)与玉米-豆粕组和大麦-高粱组相比,大麦-高粱+酵母培养物组背最长肌饱和脂肪酸含量显著升高(P0.05),而单不饱和脂肪酸(M UFA)含量显著降低(P0.05);皮下脂肪组织中M UFA含量显著降低(P0.05)。4)与玉米-豆粕组相比,大麦-高粱+酵母培养物组挥发性盐基氮的含量显著降低(P0.05)。本研究提示,在大麦-高粱型饲粮中添加0.8%的酵母培养物能有效提高肥育猪的生长性能,改善肉品质。     

Effect of feeding Acacia nilotica pods to sheep on nutrient digestibility,nitrogen balance,ruminal protozoa and rumen enzymes activity

This study was conducted to evaluate the effect of supplying two levels of Acacia nilotica (A. nilotica) pods to rations of sheep on nutrient digestibility, nitrogen balance and rumen liquor parameters (pH, total protozoa count, protein concentration and enzymes activity). Twelve mature rams (50 ± 1.25 kg B.W.) were distributed into three groups, each with four rams. Animals in group one were considered as a control which fed a basal diet, consisting of concentrate mixture and Egyptian clover. The second group and the third one received the same basal diet with supplying the concentrate mixture by 1.5% and 3.0% of A. nilotica pods meal respectively. The experiment lasted for 3 weeks. It was found that supplementation of A. nilotica pods to the concentrate mixture at a rate of 1.5% and 3.0% significantly improved the total feed intake compared to the control. The digestibility of dry matter and crude fibre was significantly reduced with A. nilotica supplements, whereas the digestibility of crude protein was significantly improved. All of nitrogen intake and N‐retained were significantly increased in rams fed on concentrates with 1.5% and 3.0% A.  nilotica pods when compared to the control. The pH of ruminal fluid was not affected by the dietary treatments. Nevertheless, the total rumen protozoa count was significantly decreased in A. nilotica pods supplemented groups. Also, the rumen protein concentration and the ruminal enzymes activity, especially α‐amylase, cellulase and protease, were lower in A. nilotica pods supplemented treatments. In conclusions, inclusion of low levels of A. nilotica pods (1.5% and 3.0%) in the concentrates can be used as a natural protein protectant in ruminants by forming tannin protein complexes in the rumen to maximize the amino acids available in the lower digestive tract. Also, these levels can increase the protein digestibility as well as the N‐retained in the body .     

不同浓度冠菌素对桑种子萌发和幼苗生长的影响

为了探讨冠菌素(COR)对桑种子萌发及幼苗生长的影响,本文用不同浓度的冠菌素溶液浸泡桑种子,萌发后测定幼苗的生长情况以及根芽含糖量、蛋白含量、叶绿体色素含量等指标变化。结果表明:冠菌素可以提高桑树种子的发芽率和发芽势,缩短发芽时间,且COR浓度为10^-4μmol/L时效果最好;不同浓度的冠菌素都能提高种子的根长和芽长,其中对根长的作用效果显著,最适浓度在10^-3μmol/L左右;冠菌素还能显著提高幼苗根中可溶性糖和可溶性蛋白含量,对芽的糖和蛋白含量影响不大;对幼叶的叶绿体色素含量变化具有双重性效果,即高浓度(>10^-1μmol/L)时降低色素含量,低浓度(≤10^-4μmol/L)时提高色素含量。     

十二种柱花草种子萌发期耐盐性的测定

以热带地区常见的12种柱花草种子为试验材料，观测了它们在不同盐浓度处理下的萌发率。结果表明，低盐浓度对部分柱花草种子萌发有促进作用；随着盐处理浓度增高，发芽率一般呈下降趋势，但也有例外；不同浓度的盐胁迫下柱花草种子的适应情况不同，同一柱花草种子在萌发时对不同盐的适应情况也不同。     

十二种柱花草种子萌发期耐盐性的测定

以热带地区常见的12种柱花草种子为试验材料,观测了它们在不同盐浓度处理下的萌发率.结果表明,低盐浓度对部分柱花草种子萌发有促进作用;随着盐处理浓度增高,发芽率一般呈下降趋势,但也有例外;不同浓度的盐胁迫下柱花草种子的适应情况不同,同一柱花草种子在萌发时对不同盐的适应情况也不同.     

网上与地面平养四川白鹅肉质性状的比较研究

为探讨饲养方式对四川白鹅肉质性状的影响,本试验选用1日龄的四川白鹅100只,随机分为两个组,每组5个重复,每个重复10只(公母各半),分别采用地面平养和网上平养方式饲养。饲养至70日龄时从每个重复随机抽取4只、每个组共20只鹅进行屠宰、取肉样,测定并比较其屠宰及肉质指标。结果显示:网上平养四川白鹅的活重、屠体重、半净膛重、全净膛重显著高于地面平养(P<0.05);地面平养与网上平养四川白鹅肌肉物理性状差异不显著(P>0.05);网上平养四川白鹅肌肉的粗脂肪含量显著高于地面平养(P<0.05),而干物质含量、钙含量显著低于地面平养(P<0.05)。     

野大麦种子萌发条件及抗逆性研究

对野大麦种子在不同温度和预处理萌发条件以及在盐（ＮａＣｌ和Ｎａ２ＳＯ４）和干旱（聚乙二醇,分子量６０００）胁迫下萌发能力的研究表明,野大麦种子的最适发芽温度是１５／２５℃变温,破除休眠的最佳方法是预先冷冻,野大麦种具有较高的耐盐性,对２种盐的耐盐顺序为ＮａＣｌ〉Ｎａ２ＳＯ４;种子萌发期耐盐临界值为－１．３４ＭＰａ（ＮａＣｌ）和－１．１３ＭＰａ（Ｎａ２ＳＯ４）高渗透性盐胁迫（≥－０．５ＭＰａ）下,胚     

松嫩草地不同成熟度羊草种子对盐胁迫的发芽响应

羊草(Leymus chinensis)是多年生根茎型优质禾本科饲草,也是东北松嫩盐碱化草地的建群植物,针对不同成熟度羊草种子对盐胁迫发芽响应在国内外未被涉及的现状,本研究以NaCl为盐胁迫处理液,设置4个胁迫浓度(50, 100, 200和400 mM)研究不同成熟度(盛花期后24, 29, 34和39 d)羊草种子对盐胁迫的发芽响应。结果表明:不同成熟度的羊草种子同样表现出不同的耐盐性,盛花期后39 d的羊草种子活力最大,发芽率、发芽势、复萌率以及总发芽率均优于其余3个发育时期的种子。另外,盐胁迫下未萌发的羊草种子复萌率随着胁迫强度的增加而增加,这是羊草种子对高盐胁迫的生理适应策略,以休眠形式躲避不良环境,待土壤盐浓度降低时萌发出土。本研究可为羊草种子的发育与抗逆生理学等研究提供一定的科学依据。     

溶血卵磷脂对降能饲粮饲喂良凤花鸡生长发育的影响

旨在研究在两种能量水平饲粮中添加不同水平溶血卵磷脂(lysolecithin, LPL)对良凤花鸡生长性能、屠宰性能、肉品质、消化道酶活性以及养分消化率的影响。试验选用健康、体重相近的1日龄良凤花鸡1 080只,随机分为6个处理：1)对照组：饲喂基础饲粮;2)对照+500LPL组：在基础饲粮基础上添加500 mg·kg^-1的LPL;3)降能组：饲喂降能饲粮(在基础饲粮水平上降低251 kJ·kg^-1的代谢能);4)降能+500LPL组：在降能饲粮基础上添加500 mg·kg^-1的LPL;5)降能+750LPL组：在降能饲粮基础上添加750 mg·kg^-1的LPL;6)降能+1000LPL组：在降能饲粮基础上添加1 000 mg·kg^-1的LPL,每组6个重复,每个重复30只鸡。试验期52 d,分为前期(1～21日龄)和后期(22～52日龄)。试验结束后,屠宰取样测定相关指标。结果表明,降能饲粮组良凤花鸡料重比高于对照组,在添加750 mg·kg^-1 LPL...     

壳聚糖对桑树种子萌发及幼苗生理生化特性影响的研究

用不同浓度的壳聚糖柠檬酸溶液处理桑树种子 ,探讨壳聚糖对桑树种子萌发及幼苗生理生化特性的影响。实验结果表明 :0 5 %～ 2 .0 %的壳聚糖溶液能提高桑树种子活力 ,促进幼苗生长 ;萌动种子的呼吸速率、幼苗叶绿素及可溶性蛋白含量、过氧化物酶、硝酸还原酶及淀粉酶活性随壳聚糖处理浓度的增大而明显提高。     

两对家蚕杂交组合稚蚕人工饲料育饲养鉴定

本试验以1～2龄颗粒人工饲料育、3～5龄桑叶育饲养形式,调查了人工饲料适应性杂交组合ZHG×春54正反交和广食×春54正反交的饲养成绩。结果表明,2对杂交组合对人工饲料的摄食性良好,24h疏毛率均达到或高于98%,3龄起蚕率广食×春54正反交显著高于ZHG×春54正反交,但1龄和2龄眠蚕体重广食×春54低于ZHG×春54,发育经过以广食×春54短于其他3个杂交组合;茧层量和茧层率正反交平均值ZHG组合高于广食组合,但全茧量和小区产茧量则是广食组合略高于ZHG组合;4个杂交组合1～2龄存活率均为100%,虫蛹生命率均达到97%以上,但广食组合的死笼率略低于ZHG组合。试验结果初步证明,2对杂交组合具有很高的配合力,在摄食性、产茧量、生命率等方面能够达到小蚕人工饲料育实用化要求。     

麦秸日粮营养补添对绵羊全消化道养分消化率的影响

选择体重为1942±183kg的9月龄甘肃高山细毛羊36只，按体重、性别等区组设计分为4组，每组9只。试羊单圈单饲，自由采食粉碎麦秸，定量饲喂各组补添料150g（补添料量占日粮总采食量的30％以下）。在饲养试验的第32d，进行6d全收粪法消化试验。组别与补添料型为麦麸组、亚麻饼组，亚麻饼＋鸡粪组，鸡粪＋酒糟组。试羊每天结果表明冬季饲喂小麦秸的绵羊，经补添亚麻饼型和亚麻饼＋鸡粪型补添料后，6种主要营养素的消化率显著提高到50％以上，其中亚麻饼组粗蛋白（CP）、中性洗涤纤维（NDF）的消化率提高幅度较大，分别比麦麸组提高1176和1195个百分点（P<001），相对提高236％和255％；亚麻饼＋鸡粪组CP、NDF消化率分别比麦麸组提高101％、131％（P<005）；2组干物质（DM）、有机物（OM）、粗纤维（CF）、酸性洗涤纤维（ADF）的消化率分别比麦麸组提高677～958个百分点（P<001或005）和384～616个百分点（P<005除DM；P>005），2组6种养分消化量均分别比麦麸组显著提高（P<001或005）。鸡粪＋酒糟型6种养分的消化率均低于麦麸型44％～84％（P>005）。证明，在黄土高原冬季严酷生境和较低经济条件下，采用亚麻饼等当地廉价、低质氮源作补添，通过提高全消化道主要养分消化率来提高绵羊对麦秸日粮的利用是可行和实用的。经适宜营养平衡补添后，采食麦秸绵羊出现CP和NDF消化率同步提高效应，说明在低量补添条件下，氮源补添，尤其是瘤胃易降解和富含脂肪的氮源补添，更有利于平衡麦秸的营养缺乏，从而刺激纤维物质的消化和提高NDF的消化率。     

Comparison of Bite-Count and Rumen Evacuation Techniques to Estimate Cattle Diet Quality

We conducted a study to compare the bite-count technique (BC) of estimating forage intake and synthesized diet quality to direct estimates of diet quantity and quality with the use of the rumen evacuation technique (RE). We used four rumen-fistulated steers to evaluate both techniques. Four enclosures in a mixed-conifer rangeland were used. Each enclosure contained two 0.25-ha paddocks that were either nonstocked or stocked by cattle to remove 32 ± 4% of standing crop. We recorded bite-count data during foraging bouts for each steer in each paddock, and then evacuated each rumen following each foraging bout during summer (August). Paddocks stocked prior to each 20-min trial had a reduced (P < 0.05) quantity of forage consumed regardless of technique. BC and RE gave similar (P > 0.10) results on diet quantity and digestibility. However, BC-derived estimates were lower (P < 0.05) for crude protein (CP), acid detergent fiber (ADF), ash, and neutral detergent fiber (NDF). In summary, although BC has the advantage of not requiring rumen-fistulated animals, it did not yield comparable results to RE under range conditions with dense and diverse vegetation. Therefore, investigators should calibrate bite-count technique against fistula technique to solve any accuracy problem in their specific experimental conditions whenever possible.