谷氨酰胺对创伤后大鼠恢复的效果

本研究观察了谷氨酰胺（ＧＬＮ）对创伤大鼠恢复的影响,１７只ｗｉｓｔａｒ大鼠随机分成ＧＬＮ组（９只）和对照组（８只）,大鼠行创伤手术后,分别饲喂含或不含１．２％ＧＬＮ的合成饲料。实验中观察了动物体重恢复、血浆蛋白变化,实验第１４天,处死动物,测定伤口皮肤抗张力强度和胶原蛋白含量、淋巴细胞转化率、小肠粘膜核酸及蛋白质含量。用Ｓｔｕｄｅｎｔ＇ｓＴ检验分析结果差异的显著性。实验结果显示：两组动物的饲料摄入量、体重增长、血浆蛋白水平、氮平衡均无明显差别,但在实验结束时,ＧＬＮ组大鼠的小肠粘膜ＤＮＡ、ＲＮＡ及蛋白质含量显著高于对照组（Ｐ＜０．０５）,同时其伤口皮肤抗张力强度、伤口胶原蛋白合成以及反映机体免疫功能的淋巴细胞转化率,亦有高于对照组的趋势,但无统计学差别（Ｐ＞０．０５）,揭示了ＧＬＮ具有保护肠道粘膜的作用,有益于大鼠创伤后的恢复。     

南方鲇的营养学研究:饲料的最适蛋白质含量

设计了6个不同蛋白质水平(39.9%,43.7%,46.8%,51.6%,55.7%,59.1%)的等能饲料,采用室内循环水养殖系统,在水温为27.5±0.2℃的条件下对南方鲇幼鱼进行了43d的生长实验.结果显示:随饲料蛋白质含量的升高,特殊体重生长率(SGR)、饲料干物质转化率(FCEdm)、蛋白质转化率(FCEp)、能量转化率(FCEe)和蛋白质效率(PER)均产生了显著的差异(P＜0.05);干物质摄食率(RLdm)与饲料蛋白质含量负相关(r=-0.62,P＜0.01);蛋白质摄食率(RLp)与饲料蛋白质含量正相关(r=0.96,P＜0.01);能量摄食率(RLe)不受饲料蛋白质含量的影响(P＞0.05).通过讨论提出南方鲇饲料的最适蛋白质含量为47%～51%.     

人工条件下不同饲料饲养金钱龟效果的研究

为提高作为家庭观赏动物金钱龟的养殖效果,进行了鲜活饲料、水龟配合饲料及二者混合饲料养殖效果的比较研究.经过320 d实验,利用粗蛋白含量35.2%的水龟配合饲料喂养,饲料成本最低,效率显著高于鲜活饲料组和混合饲料组(P<0.05),但体重增长率显著低于其他两组(P<0.05);从养殖成本、饲料转化率及日常管理考虑,配合饲料优于鲜活饲料.     

恒河猴日需蛋白质量的研究

本文报道了恒河猴(Macaca mulatta)日需蛋白质量的实验研宄。四组未成年恒河猴(共36只)分别饲喂蛋白质含量为15％、20％、24％的配合饲料和玉米加蚕豆,为时90天。四组动物的平均增重依次为0.3、0.6、0.6和0.2公斤。猴子日食蛋白质含量力20％的饲料,氮在体内的平均沉积率是57±13.5％。实验期间,各组动物血红蛋白,血清总蛋白和血总脂的含量无显著变化。以上结果和在本所试用的饲养效果表明,在我们的饲养条件下,配合饲料中蛋白质含量以20％较有利于恒河猴的生长发育和节约费用。     

黄鳝饲料蛋白质需求量的研究

为确定黄鳝(Monopterus albus)对饲料蛋白质的需求量, 试验分7组, 每组4个重复。每个重复放养初始体重为(17.1±0.2) g的幼鳝25尾, 分别以鱼粉和酪蛋白为主要蛋白源, 配制蛋白质含量为32.74%(T1)、38.50%(T2)、42.26%(T3)、48.35%(T4)、52.65%(T5)、57.87%(T6)和62.31%(T7)的7种等能不等氮饲料, 养殖期为60d。以生产性能、蛋白质保留率和生理生化指标等综合评价确定蛋白质的需求量。结果: (1)随饲料蛋白质含量升高, 饲料系数呈先降低后升高; 增重率(WGR)、特定生长率(SGR)、蛋白保留率(PRR)与蛋白质效率(PER)先升高后降低; 饲料蛋白质含量57.87%组获得最好的生长性能, 52.65%组蛋白质保留率最高。(2)随饲料蛋白质含量升高, 黄鳝血清中尿素氮(BUN)含量升高, 谷丙转氨酶(ALT)和谷草转氨酶(AST)的活性先降低后保持稳定, 总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)及血糖(GLU)含量降低; 丙二醛(MDA)含量呈现先降低后升高的趋势, 在52.65%时最低。(3)随饲料蛋白质含量升高, 黄鳝肝胰脏、胃和肠蛋白酶活性先显著上升后呈缓慢上升趋势; 肝胰脏脂肪酶活性先显著下降后呈缓慢下降趋势, 胃和肠脂肪酶活性各试验组之间无显著性差异; 胃淀粉酶活性无显著差异, 肝胰脏和肠呈先显著下降后缓慢降低的趋势。综上: 当饲料蛋白质含量低时, 黄鳝会加大摄食量满足蛋白质需求, 在饲料蛋白质含量过高时, 氧化应激增加, 黄鳝通过降低摄食量减少蛋白质摄入。以WGR、PER、SGR及饲料系数(FCR)为评价指标确定幼鳝对饲料蛋白质的适宜需求量为48.51%—52.60%。     

不同配方益生菌在高脂饮食诱导小鼠肥胖发生中的差异化作用

【目的】基于肠道微生物与宿主代谢的相互关系,研究不同配方的益生菌对小鼠肥胖的影响。【方法】50只C57BL/6J雄性小鼠随机平均分成10组,分别给予正常饲料、高脂饲料以及高脂饲料加8种不同配方的益生菌产品(50亿CFU/只),所有动物连续喂养9周,每周测量小鼠体重1次。最后一周测定空腹血糖、葡萄糖耐量试验(glucose tolerance test,GTT)、血脂相关指标,称取内脏重量,并留取小鼠盲肠内容物,提取小鼠肠道菌群总DNA,利用16S rDNA测序检测相关细菌含量。【结果】部分益生菌可引起小鼠体重增速加快,而部分益生菌可减缓小鼠肥胖和降低内脏脂肪重量,同时缓解高血脂症。丹尼斯克品牌益生菌配方组小鼠肠道中厚壁菌/拟杆菌比例(F/B)是正常饮食组的22.8倍,Akkermansia muciniphila(Akkermansia)细菌含量几乎为0;而菌拉丁品牌益生菌配方组小鼠F/B比例与正常饲料饮食组类似,Akkermansia含量为0.5%,为正常饮食对照组小鼠的一半左右。【结论】益生菌可影响小鼠体重和代谢,但不同配方的益生菌效果截然相反。特定的益生菌配方对肥胖和高血脂的改善可能是由于其选用的菌株本身的特性以及菌株之间的相互配比能够降低小鼠肠道中F/B比例以及升高Akkermansia的含量所带来的。此研究为进一步开发可改善代谢的益生菌产品提供了参考。     

促菌生活菌制剂对小白鼠促生长作用的初步探讨

促菌生用一种蜡状芽孢杆菌(Bacillus cereus)制成的无毒活菌制剂,其用途主要用于婴幼儿腹泻、慢性腹泻、肠功能紊乱、肠炎、痢疾等,对禽,畜腹泻病也有明显疗效。本制剂在四川应用于禽畜腹泻病的治疗过程中曾发现用促菌生菌片治疗后的仔猪较未用促菌生治疗的仔猪,其体重增长较快。为证实这一现象,我们在实验室用小白鼠进行了比较实验,以求为开发促菌生新用途提供实验资料。本实验是一次初步探讨,实验将继续进行。动物:用体重12～14克的健康小白鼠。含菌饲料:用本所喂养小白鼠的饲料配方与菌     

南方鲇的营养学研究：Ⅲ．饲料脂肪对蛋白质的节约效应

于１９９７年１０月至１２月对南方鲇（Silurus meridionalis)(初始体重：３０－４４g)进行人工配合饲料的喂养实验。实验以白鱼粉和 玉米油作蛋白质和脂肪源,共配制６种不同蛋白质／脂肪比的饲料,其蛋白质（Ｐ）和脂肪（Ｌ）的含是分别为４３％Ｐ／１５％Ｌ,４７％Ｐ／１５％Ｌ,５１％Ｐ／１６％Ｌ,５０％Ｐ／８％Ｌ,５４％Ｐ／８％Ｌ,５８％Ｐ／８％Ｌ。实验每饲料水平设４个重复,采用室内循环水养殖系统,在２７．５℃下以饱足日粮水平喂养６周。实验结果表明：供以高脂肪低蛋白质饲料组鱼体的特殊生长率（ＳＧＲ）和饲料转化率（ＦＣＥ）与低脂肪高蛋白饲料的无显著差异,而前者喂养的实验鱼的蛋白质效率（ＰＥＲ）显著大于后者,因此,南方鲇饲料脂肪对蛋白质有明显的节约效应。     

鲩鱼Ctenopharyngodon idellus鱼种生长阶段蛋白质最适需要量的研究

采用蛋白质梯度饲养法,进行了三期试验。试验饲料分别以酪蛋白和鱼肉蛋白为蛋白源,饲料蛋白质含量范围为0.44-50.16%,在水温26-30.5℃条件下,研究了鲩鱼鱼种生长阶段(平均体重2.4-8.0克)在日投喂量占体重5-9%情况下,饲料蛋白质最适需要量,经采用直线回归和抛物线回归计算确定为22.77-27.66%。鲩鱼对饲料蛋白质利用率,随饲料蛋白质含量增高而下降,成负的直线相关关系:Y=29.2786-0.5296X。在蛋白质最适需要量范围,鲩鱼对蛋白质利用率波动于14.72-17.11%。       

山魈初生幼仔人工育幼

圈养山魈有10％-20％因为初产或者母性不强,或者因母体奶汁分泌少等原因,不能顺利哺育自己的后代,因此必须对被弃幼仔施行人工哺育。成都动物园分别以纯牛奶和鲜羊奶为主、配以全价奶粉和米粉饲喂被弃山魈幼仔,在育幼中注意温度、湿度的控制,1个月后,适当给予苹果、蔬菜等,3月龄后可逐渐减少奶的投喂量,增加常规饲料的投喂量,6月龄后可以停奶。本育幼过程中,在同一育幼方法的基础上,采用了两种不同的饲料配方。通过比较分析,两种饲料配方日均供给能量与体重的比例相当,山魈幼仔体重增长和体尺增长没有明显的差异,其生长发育和健康状况均良好。由此说明,该育幼方法及两种饲料配方是可行的。     

Techniques for hand-rearing tree-shrews (Tupaia belangeri) from birth

In captivity, Tupaia belangeri (Thailand tree-shrew) frequently show aberrant patterns of maternal care which result in the death of offspring. In order to maximize the potential of the tree-shrew as an animal resource for experimental studies we have developed a program for hand-rearing tupaiidae from birth. Newborn tree-shrews were removed from mothers with a history of poor parental care to a nursery maintained under conditions of controlled relative humidity (70 ± 10%) and temperature (25 ± 1°C) on a 12 h dark: 12 h light cycle. The young tree-shrews were fed on a liquid formula until the eyes opened (Day 18–23) and for the subsequent 10 days on a transitional diet until they could feed themselves on solid food. Our hand-rearing protocol appears to conform to the natural weaning pattern of tupaiids. Food consumption during the liquid diet phase was linearly related to age and the increase in body weight in both sexes. The initial growth rate of male and female hand-reared tree-shrews was slower than that of maternally reared animals during the liquid diet phase. The growth rate accelerated subsequently and the body weight of hand-reared tree-shrews eventually reached that of maternally reared animals of the same sex. Various developmental changes occurred during the same period in artificially and naturally reared animals. In both hand-reared and maternally reared groups, the growth rate of male tree-shrews exceeded that of females from about Day 40 onward. The accelerated growth rate of male tree-shrews was in apparent association with an increase in androgen secretion at the onset of puberty. The high fecundity of tree-shrews in captivity reinforced with a program for hand-rearing the young make T belangeri a potential alternative to more conventional laboratory species in specific areas of biomedical research.     

Genetic variation in PLAG1 associates with early life body weight and peripubertal weight and growth in Bos taurus

Variation at the pleiomorphic adenoma gene 1 (PLAG1) locus has recently been implicated in the regulation of stature and weight in Bos taurus. Using a population of 942 outbred Holstein-Friesian dairy calves, we report confirmation of this effect, demonstrating strong association of early life body weight with PLAG1 genotype. Peripubertal body weight and growth rate were also significantly associated with PLAG1 genotype. Growth rate per kilogram of body weight, daily feed intake, gross feed efficiency and residual feed intake were not significantly associated with PLAG1 genotype. This study supports the status of PLAG1 as a key regulator of mammalian growth. Further, the data indicate the utility of PLAG1 polymorphisms for the selection of animals to achieve enhanced weight gain or conversely to aid the selection of animals with lower mature body weight and thus lower maintenance energy requirements.     

Importance of the water regimen for animal growth in increased motor activity

Growth rate of male rats exposed to intensive physical exercise and the impact of exercise on the muscle system have been studied. To increase the locomotor activity the animals were kept in higher, as compared to the control, cages with the feeding rack attached to the ceiling. A tendency to an increase in body weight and specifically in gastrocnemius was noted. A reduction in water consumption was shown to slow the growth rate of rats in increased locomotor activity, while in low physical activity water shortage exerted but a negligible effect on the animal growth.     

Effects of feed restriction during organogenesis on embryo-fetal development in rabbit

BACKGROUND: Appropriate maternal nutrition and body weight gain during pregnancy is well established as a major factor in healthy prenatal development in humans. Given the role of nutrition and body weight gain in normal development, pharmaceuticals intended to reduce appetite and promote weight loss will generate developmental toxicity data that may be challenging to interpret. To aid with this, the effects of feed restriction, and subsequent reduction in maternal body weight gain, on embryo-fetal development was investigated in the rabbit. METHODS: Groups of 15 pregnant New Zealand White rabbits were offered 150 (control), 110, 75, 55, 35, and 15 g feed/day from gestation day (GD) 7-19. Cesarean sections were carried out on GD 29 and fetuses were examined for external, visceral, and skeletal development. RESULTS: Maternal body weights at the end of the feed restriction period (GD 20) were 0.97, 0.98, 0.93, 0.94, and 0.86 x control for the 110, 75, 55, 35, and 15 g feed/day groups, respectively. Only at 15 g feed/day was there a net maternal body weight loss (the GD 20 body weight was 0.93 x the GD 6 body weight) at the end of the feed restriction period. Six does aborted in the 15 g feed/day group; there were no other abortions associated with feed restriction. Fetal body weight was significantly reduced at 75, 55, 35, and 15 g feed/day (0.95, 0.90, 0.86, and 0.84 x control, respectively). There were no external or visceral malformations or variations, and no skeletal malformations associated with feed restriction. The incidence of fetuses with sternebrae 5 or 6 unossified was increased at feed levels < or = 75 g/day. At a feed level of 35 g/day there was an increase in unossified metatarsals and metacarpals, and an increase in the number of fetuses with a reduced number of caudal vertebrae ossified. Although these findings were not increased at a feed level of 15 g/day, the lack of dose response was likely due to increased abortion and subsequent decrease in fetuses available for evaluation at 15 g feed/day. CONCLUSION: These data demonstrate that feed restriction to feed levels that produce substantial reductions in maternal body weight gain can result in developmental toxicity expressed by abortion, reduced fetal weight, and alterations in ossification. Abortion only occurred when feed was restricted to an amount that produced maternal body weight loss (15 g feed/day) whereas reduced fetal weight and increased incidence of fetuses with unossified sternebrae, metatarsals, metacarpals, or caudal vertebrae were noted at feed levels of < or = 75 g/day. There were no fetal malformations associated with feed restriction.     

Short communication: Variability of response to feed restriction in lactating Charolais cows

Involuntary temporary feed restriction on commercial cattle is likely to become more frequent with forage shortages in the context of climate change. If general consequences of feed restriction have been the subject of an abundant scientific literature, focus on the inter-individual variability of response is scarce. Here, we explore the response profile in terms of BW, body condition score, milk production, calf weight and cyclicity resumption of 293 lactations from 169 Charolais cows during a winter feed restriction in early lactation and its subsequent recovery at grazing using a principal component analysis followed by a hierarchical clustering on principal component. Results show a very continuous range of response profiles that was divided into three clusters: one with light animals having an intermediate response in terms of milk production and body maintenance, one with animals prioritising body maintenance and cyclicity resumption over milk production and calf weight, and the last one with animals prioritising milk production and calf weight over the rest. Among the animals performing more than one lactation, 57% remain in the same cluster on two successive lactations. This work highlights that an average group response to feed restriction may hide various resilience individual profiles. Further studies are required to determine the existence of a genetic component as well as the consequences of not taking this phenomenon into consideration with the regular use of feed restriction in commercial farms.     

Relationship between seasonal energy economy and thyroid activity in farm-raised raccoon dogs

1. The levels of thyroid hormones (T3, T4), total lipids and urea in blood serum of adult farmed raccoon dogs (Nyctereutes procyonoides Gray 1834) were monitored year-round, and compared with seasonal changes in body weight and feed consumption during intense, maintenance and restricted fasting feeding. 2. Thyroid hormone levels tended to be low during winter whereas during the rest of the year no marked seasonal differences were observed. That thyroid hormone levels were influenced by altering feed intake suggests the hypothesis that the winter hypothyroidism observed was a result of a decreased level of voluntary feed intake. 3. The colder the temperature was during winter, the less the animals consumed the feed supplied. 4. Neither season nor feed intake level affected serum levels of total lipids or urea. 5. Marked seasonal changes in body weight of the animals were found. From maximum values occurring in early winter their body weight generally dropped about 30% reaching the minimum values in mid-summer. This marked seasonal change was mainly the result of changes in subcutaneous fat reserves.     

Changes in body weight and intake of food by Octopus vulgaris

The changes in body weight of 12 octopuses, fed on fish or crabs, were followed under laboratory conditions for periods of 1 to 7 1/2 months. The food intake was estimated and compared with the changes in body weight of the octopuses; 25 to 55% of the total intake of food appeared to be incorporated. The range of the average increase in weight over the whole observation period of each of the animals was 1.9 to 7.7g per day (1 to 7 1/2 months); the mean value was 4.8g per day. The effect of changing the diet of small octopuses (fish or crab)was followed for four weeks but there was no evidence that alteration of the diet affected the rate of changes in body weight of animals of more than 47g initial body weight.     

The influence of clenbuterol on growth in rats.

1. The influence was studied of a beta 2-agonist, clenbuterol, on mean gain of body weight, feed efficiency and growth of muscle tissue in female Wistar rats of three different weights (70, 150 and 200 g). 2. Clenbuterol significantly increases mean gain of body weight and feed efficiency in all the studies realised, but much more effectively in animals of greater age/weight (200 g). 3. In addition, it favours protein deposition in muscle, given that it increases significantly (P less than 0.001) the muscle/body weight ratio in all of the experiments.     

Influence of dietary protein level on growth: effect of clenbuterol.

1. The influence has been studied of a beta-agonist, clenbuterol, on body weight increase, feed efficiency and muscular tissue growth in Wistar rats of two different weights (70 and 200 g) fed with a diet of differing protein levels (4, 10 and 15%). 2. Treatment with clenbuterol had a negative influence on body growth and feed efficiency when the animals were fed with low protein diets (4%). 3. With a higher protein content (10 and 15%), the situation changed completely, and these indices increased, with a relationship appearing between these changes, the agonist dose and the animal's age. 4. In all the experiments clenbuterol improved muscle/body ratio significantly (P less than 0.001). The favourable effect of clenbuterol on muscle growth is due to a specific increase in protein deposition and not to changes in the water content of muscular tissue, even though these changes may be produced.     

Accurate measurement of body weight and food intake in environmentally enriched male Wistar rats

Laboratory animals are crucial in the study of energy homeostasis. In particular, rats are used to study alterations in food intake and body weight. To accurately record food intake or energy expenditure it is necessary to house rats individually, which can be stressful for social animals. Environmental enrichment may reduce stress and improve welfare in laboratory rodents. However, the effect of environmental enrichment on food intake and thus experimental outcome is unknown. We aimed to determine the effect of environmental enrichment on food intake, body weight, behavior and fecal and plasma stress hormones in male Wistar rats. Singly housed 5–7‐week‐old male rats were given either no environmental enrichment, chew sticks, a plastic tube of 67 mm internal diameter, or both chew sticks and a tube. No differences in body weight or food intake were seen over a 7‐day period. Importantly, the refeeding response following a 24‐h fast was unaffected by environmental enrichment. Rearing, a behavior often associated with stress, was significantly reduced in all enriched groups compared to controls. There was a significant increase in fecal immunoglobulin A (IgA) in animals housed with both forms of enrichment compared to controls at the termination of the study, suggesting enrichment reduces hypothalamo‐pituitary‐adrenal (HPA) axis activity in singly housed rats. In summary, environmental enrichment does not influence body weight and food intake in singly housed male Wistar rats and may therefore be used to refine the living conditions of animals used in the study of energy homeostasis without compromising experimental outcome.