Effect of surfactants on weight gain in mice

A study was conducted to determine if four surfactants can induce increased weight gain in the mouse. Basic-H, Triton X-100, Amway All Purpose Adjuvant and X-77 were put in water and fed to various groups of ICR 21 day old female mice for a period of 43 days. All the mice were clinically normal throughout the study period. Pathological examination of a random sample of the mice revealed no gross pathological changes. Similarly, histopathological examination of the lungs, livers and intestines did not reveal any visible lesions. Basic-H and Amway surfactants induced weight gain, though not significantly, better at 0.1% (V/V) concentration while X-77 and Triton X-100 induced weight gain better at 0.4% (V/V) concentration. Overall results show that none of the surfactants tested induced significant weight gain.     

醋酸铅对雌性小鼠生长发育及主要内脏器官的影响

将420只体质量为(20.23±1.88)g的雌性昆明系小鼠随机分成5个处理组和1个对照组,每组设7个重复,每个重复10只。各处理组分别腹腔按体质量注射10、15、20、25、30mg/kg的醋酸铅溶液,对照组注射等体积的灭菌生理盐水,每隔2d注射并称重1次,共注射10次,期间记录小鼠体质量及临床表现。染毒结束后,脱颈椎处死小鼠,取出心脏、肝脏、脾脏、肺脏、肾脏组织,称湿重;观察形,制作石蜡切片,观察其病理组织学变化。结果显示,(1)铅可明显影响小鼠体质量增长,且体质量随着染毒剂量的增加和时间的延长而明显降低,与对照组相比,差异显著或极显著(P0.05或P0.01);(2)与对照组相比,各染毒组小鼠脏器系数变化依次为肾、脾肝、肺心,且呈明显的剂量-时间效应关系;(3)铅暴露可引起小鼠心、肝、脾、肺、肾各脏器发生不同程度的损伤,小鼠肾脏、脾脏受损最为严重,其次为肝脏,再次为心脏,肺脏影响最轻,且损害的程度与铅染毒剂量和时间呈剂量-时间效应关系。结果表明,当醋酸铅暴露剂量≥20mg/kg时,对小鼠生长发育具有明显抑制作用;长期低铅染毒即可导致机体各组织器官发生广泛性病理损伤,且损伤的程度与染毒剂量呈现明显的剂量-时间效应关系。     

Correlated responses in growth hormone to selection for weight gain in mice

SUMMARY: Correlated responses in pituitary gland weight and growth hormone (GH) concentration in the serum and pituitary were studied in lines of mice selected for growth rate, and in controls. The selection criteria were weight gain between 28 and 38 days on an ad libitum feed intake (EPA line), or on intake restricted to 80% of the control mice (EPR line), and weight gain between 48 and 58 days under the above two feeding regimes (LPA and LPR lines). The control line was maintained by random breeding. In generation 13, pituitary weight and growth hormone levels were determined at 38 days in lines EPA, EPR and the control and at 58 days in lines LPA, LPR and the control. Pituitary weight, corrected for body weight gain, was smaller in the EPA line than in the control line at 38 days and was greater in the LPR line than in the control line at 58 days. There were large differences in serum GH concentrations between the selected lines and the control; the differences were statistically significant at 38 days, with the EPA and EPR lines having lower levels than the controls. ZUSAMMENFASSUNG: Ver?nderung von Wachstumshormonspiegel bei Selektion für Zuwachs bei M?usen Ver?nderungen im Hypophysengewicht und Wachstumshormon-(GH)-Konzentrationen im Serum und in der Hypophyse wurden bei Wachstumsselektionslinien und bei Kontrollm?usen untersucht. Selektionskriterien waren Zuwachs zwischen 28 und 38 Tagen bei ad libitum Futteraufnahme (EPA Linie) oder bei Linien, wo Futteraufnahme auf 80% derjenigen der Kontrollm?use (EPR Linie) begrenzt wurde und Zuwachs zwischen 48 und 58 Tagen unter beiden Futterweisen (LPA und LPR Linie). Die Kontrollinie wurde durch Zufallspaarung fortgepflanzt. In Generation 13 wurden Hypophysengewicht und Wachstumshormonspiegel im Alter von 38 Tagen in Linien EPA, EPR und in Kontrollen und bei 58 Tagen in Linien LPA und LPR und Kontrollen bestimmt. Hypophysengewicht, korrigiert für Zuwachs, war geringer in der LPA Linie als in der Kontrolle bei 38 Tagen Alter und gr??er in der LPR Linie als in der Kontrolle bei 58 Tagen. Zwischen GH Konzentrationen selektierter und Kontrollinien waren erhebliche Differenzen, die bei 38 Tagen signifikant waren, wobei EPA und EPR Linien geringere Werte als die Kontrollen aufwiesen.     

半胱胺对羔羊增重及羊毛生长的影响

选择 4～ 5月龄断奶雌性杂种羔羊 2 2 0只 ,随机分成对照组和添加半胱胺组 ,半胱胺组按 5 0mg/kg体重包膜保护半胱胺 ,连续添加 12 0d ,试验结束。结果显示 ,半胱胺组从试验第 4 6天体重、毛长显著高于对照组 (P <0 .0 5 ) ,整个试验期半胱胺组比对照组增重提高 17.9% (P <0 .0 5 ) ,毛长增长提高 6 .2 % (P <0 .0 5 ) ,说明半胱胺能够显著地促进断奶母羔体重增加和羊毛生长。     

香味剂及采食位置对仔猪采食量的影响

试验旨在研究日粮中添加香味剂及采食位置对断奶仔猪采食量的影响。试验共使用6栏53头30日龄左右的杜洛克、长白或大白断奶仔猪,其中两栏体重较轻(6 kg多),使用容积相对较小的圆型料槽,另外4栏体重超过10 kg,使用容积较大的矩形料槽。试验日粮为商业性断奶仔猪过渡料,一种添加了香味剂(味美佳),另外一种没有添加香味剂。每栏中有两个料槽分别放置于局限型位置或开敞型位置,并且在两个位置间逐日交替轮换两种饲料。试验持续期为6 d。按照重复测定试验设计,利用SAS的相关程序对仔猪的采食量进行分析。试验结果表明,与不添加香味剂的日粮相比,仔猪断奶后短期内采食添加香味剂的日粮没有提高仔猪的采食量,从数量上看,体重较小的仔猪采食香味剂日粮略多。仔猪采食对位置有明显的偏好,不管什么饲料,同栏仔猪在开敞位置消耗饲料的数量极显著高于在局限位置消耗饲料的数量(P0.01)。本研究不仅验证了日粮中添加香味剂及采食位置对仔猪采食量的影响,还为进行此类试验的设计提供了一种参考方法。     

虫草饲料添加剂对土杂肉鸡增重效果研究

3株虫草无性型菌株P2、P5、P6分别进行固体和液体发酵培养,将得到的6种虫草菌丝体饲料添加剂进行饲喂试验,固体培养物按0.5%和0.25%、液体培养物按0.2%和0.1%的浓度投放到试验组饲料中,分别饲喂1日龄土杂肉鸡,试验56 d.结果表明虫草添加剂对鸡体增重和饲料转化率有明显提高,其中用液体培养的P2和P5菌株浓度为0.2%时效果最佳,与对照组相比增重分别提高11.04%、11.56%,差异显著.     

日粮中添加不同剂量葡萄渣对成年羊增重效果的影响

选择28只健康无病、体重相近(P>0.05)的小尾寒羊成年母羊,分为试验Ⅰ组(对照组)、Ⅱ组、Ⅲ组和试验Ⅳ组,在相同的饲养管理条件下进行饲养试验,研究在日粮中添加不同剂量(8%、16%、24%)的葡萄渣对成年羊体增重的影响。结果表明:在日粮中添加不同剂量的葡萄渣对成年羊的体增重、平均日增重、饲料转化效率等均有显著影响(P<0.05)。     

半胱胺颗粒料促进羔羊增重的试验

为观察半胱胺颗粒料对羔羊增重的影响，用３日龄羔羊３０只，随机分成试验组和对照组各１５只，试验组每周喂１次ＣＳ颗粒料，观察８周，结果试验组比对照组增重提高１３．０％（Ｐ〈０．０１），表明半胱胺颗粒料具有促生长作用。     

Effect of sow parity and weight at service on target maternal weight and energy for gain in gestation

The objective of this study was to evaluate targeted maternal weight gains in sows by parity group during gestation. Weight and backfat gains during gestation by parity, weight, and backfat groups also were analyzed. The data evaluated were a subset (374 sows) of a larger experiment that compared three methods of feeding sows during gestation on weight and backfat gains and subsequent reproductive performance. Feed allowances were based on modeled calculations of energy and nutrient requirements to achieve target sow maternal weight and backfat gains. Actual backfat gain for gilts and sows was regressed on maternal weight gain and estimated energy available for gain. The regression equations were then used to predict maternal weight gains for target backfat gains for three parity groups (gilts, Parity 1 and 2 sows, and Parity 3 and older sows). For gilts and Parity 1 and 2 sows, much greater target maternal weight gains are required to achieve 6 and 9 mm of backfat gain, whereas Parity 3 and older sows require maternal weight gains similar to those targeted to achieve the desired backfat gain. Given similar energy intake levels above maintenance, gilts gained more weight than multiparous sows, as gain was based more on protein and less on fat and thus was more efficient. Gilts required more maternal weight gain than sows to achieve similar backfat gains due to the higher protein and low fat contents of gain in younger, lighter sows compared with older parity sows. Low-backfat sows that needed to gain large amounts of backfat failed to achieve these large gains. We speculate this failure may be due to lower tissue insulation levels with the low backfat levels and higher activity levels of these sows compared with high-backfat sows. It seems that both parity and weight are individually important factors that influence energy and nutrient requirements for gestation in the modern sow.     

Effect of the Y chromosome on testis weight in mice

We investigated the effect of the Y chromosome on testis weight in (B6.Cg-A^y × Y-consomic mouse strain) F₁ male mice. We obtained the following results: (1) Mice with the Mus musculus domesticus-type Y chromosome had significantly heavier testis than those with the M. m. musculus-type Y chromosome. (2) Variations in Usp9y and the number of CAG repeats in Sry were significantly associated with testes weight. The A^y allele was correlated with a reduced testis weight, and the extent of this reduction was significantly associated with a CAG repeat number polymorphism in Sry. These results suggest that Y chromosome genes not only influence testis weight but also modify the effect of the A^y allele in mediating this phenomenon.     

Effect of air velocity on deep body temperature and weight gain in the broiler chicken

Tunnel ventilation has been adopted as an effective approach to combatting heat stress in poultry. Setting tunnel air velocity to levels that ensure bird comfort, while optimizing performance is an important goal. In recent years, biotelemetry has provided a way to effectively evaluate the impact of management practices on poultry physiology. In this study, we present an approach for evaluating the effects of heat stress and tunnel ventilation on poultry deep body temperature (DBT) using biotelemetry. Three consecutive experiments were conducted using 6 broilers, each at the ages of 8.6, 9.0, and 9.4 wk. Experiments spanned approximately 12 h each and led to 18 data sets. DBT responses of birds under no ventilation rose by as much as 3°C as a result of step increases in ambient temperature. Birds exposed to tunnel ventilation maintained a lower DBT by as much as 0.9°C. During experiment days, birds exposed to tunnel ventilation consistently gained weight with a percentage weight gain ranging from 1% to 11%. Birds not exposed to tunnel ventilation behaved less consistently with some gaining as much as 14% while others lost as much as 9%. Although further studies are required to derive more comprehensive and more statistically significant results, this study provided preliminary data that is needed to warrant such studies, and a stepping stone for making optimal management and risk assessment decisions that are based on physiological needs of the birds.     

补饲控释尿素对放牧牦牛和藏羊日增重的影响

以藏羊和牦牛为研究对象,采用单因素分期分组设计,分两期进行。分别在海北同保牧场暖季、冷季做补饲控释尿素对藏羊和牦牛增重试验。结果表明：在冷季补饲时,试验期藏羊对照组、试验组只均增重分别为0.79 kg&#177;0.32 kg、1.85kg&#177;0.50 kg;试验期牦牛对照组、试验组只均增重分别为4.59 kg&#177;1.63 kg、7.52 kg&#177;1.30 kg,两组间增重差异均极显著（P〈0.01）。而在暖季补饲控释尿素,效果不显著。     

Effect of selection for growth on normal and reduced protein diets on weight gain, feed intake, feed efficiency and body composition in mice

Mice selected for weight gain from 3 to 9 weeks of age on a normal (N) protein diet containing 19.3% protein and a reduced (R) protein diet with 5.1% protein were reared on both diets in generations 7 and 9. The lines NH, NC, NL, RH, RC and RL (H, high; C, control; L, low) were tested for weight gain on diet N and R and for feed intake and feed efficiency on diet N in generation 7. In generation 9, the lines were tested for body composition traits (fat, protein and water percentage) at 3, 6, 9 and 12 weeks of age on both diets. A significant (p < 0.0001) genotype × environment interaction for growth rate was observed in generation 7. Weight gain at both the protein levels was best improved by selection at the protein level itself. Furthermore, the ranking of the lines on diet N was similar for weight gain, feed intake and feed efficiency. In generation 9 at 9 weeks of age, the ranking of the lines for fat percentage was equal to the ranking for weight gain in generation 7 on both test‐diets. The association between weight gain and protein or water percentage was less pronounced, particularly on diet R. These results suggest that the largest genetic improvement in growth rate is obtained when the protein content of the feed is the same in selection and production. However, when selection is carried out in one environment while the animals have to perform under conditions with varying nutrient protein contents, selection in an inferior environment may be advantageous.     

皮下埋植“左旋多巴胺、甲氧氯普胺”对藏系公绵羊体质量增速的影响

为研究左旋多巴胺和甲氧氯普胺联合使用对于藏系公绵羊生产性能的影响,选择西藏林芝当地藏公羊4只,在左季肋部埋植左旋多巴胺和甲氧氯普胺。利用胃肠电图仪检测瘤胃肌电的变化;利用血细胞分析仪分析血常规的变化,并观察其生长增质量情况。结果发现,瘤胃肌电各导联位点试验后平均频率(12.86±2.04,12.86±1.70,15.00±0.83,12.86±0.51)比试验前(4.86±0.52,5.45±1.28,5.45±0.42,5.81±0.12)的平均频率显著增加(P0.05);红细胞总数从试验前的(1.94±0.14)×10~(12)/L升高到试验后的(4.13±0.28)×10~(12)/L,差异极显著(P0.01);血红蛋白从846g/L升到1 118g/L,差异显著(P0.05);假手术对照组体质量增速为(0.059±0.012)kg/d,试验组为(0.080±0.010)kg/d,埋植试验促使体质量增加效果明显(P0.05)。证明埋植左旋多巴胺和甲氧氯普胺可使藏系绵羊出现适应高原的生理变化,并使消化能力增强,从而提高生产性能。