Possibility of fat addition in the rabbit diets

Baladi rabbits were fed on five-similar-experimental diets, except the replacement for starch in the 1st diet, cattle tallow in the 2nd, cotton seed oil in the 3rd, and hydrogenated palm oil in the 4th instead of 2% more wheat bran in the 5th (control) diet. All other husbandry conditions were the same for all groups of animals during the experimental period of 7 weeks. The cattle tallow in the second diet caused significant increase of feed intake, growth rate, relative weights of kidneys, lungs and heart and calcium of the tibia bone. This diet had tendency to diminish significantly blood contents of total nitrogen and cholesterol as well as vitamin A in the liver and tibia contents of silica, phosphorus and magnesium. Diet number 3 included cottonseed oil lowered blood contents of glucose, phosphorus, cholesterol and enzyme activity of glutamate oxaloacetate transaminase in the serum and specific gravity of tibia bone. On the other hand, it elevated significantly (P less than or equal to 0.01) stored vitamin A in the liver than on all other experimental diets. Feeding rabbits on diet including hydrogenated palm oil subsided liver contents of dry matter, ash and vitamin A and raised ether extract of the liver significantly. It reduced also dry matter content of the femoral muscle. Substitution for starch (instead of 2% of the diet fats or bran) increased blood content of haemoglobin and haematocrit (insignificant) but values of glucose and phosphorus as well as liver content of dry matter, content of femoral muscle of dry matter and ether extract and content of tibia bone of silica and phosphorus were significantly higher than the other experimental diets. It decreased relative weights of different organs (significantly) and liver contents of ether extract and vitamin A (insignificantly) than on control diet. It could be said that the addition of cattle tallow and cottonseed oil would be recommended to be included in rabbit diets after more studies to determine the effects of the different animal-vegetable mixtures of fats, the best ratio between the two sources of fats, the interrelationships between that mixtures and the energy of the diet, the dietary protein level, the rabbit breed and their weights and aim of the production under the seasonal variation of the weather.     

Low concentrations of zearalenone in diets of boars for a prolonged period of time

Thirty-two boars were fed diets containing 0, 3, 6 or 9 ppm zearalenone from 32 d of age up to 145 or 312 d of age. Rate of gain, feed intake and gain:feed were not significantly different among treatments. Feeding of diets containing 9 ppm zearalenone did not affect the libido in seven boars. There was a tendency for boars fed 9 ppm dietary zearalenone to produce lower total and gel free volumes of semen, with lower total motile sperm; however, only the percent motility of the sperm was reduced (P less than .05).     

热应激条件下日粮消化能水平对肉兔生产性能和养分消化率的影响

试验旨在研究热应激条件下日粮消化能水平对肉兔生产性能和饲粮养分消化率的影响。选择30日龄断奶新西兰兔150只,随机分成5个处理组,每个处理5个重复,每个重复6只兔,分别饲喂8.79、9.62、10.46、11.30MJ/kg和12.13 MJ/kg消化能的饲粮。结果显示,热应激条件下,随着日粮消化能的增加,肉兔采食量和料重比均一定程度下降(P>0.05或P<0.05),日增重呈先升高后降低的趋势;干物质、粗蛋白质和粗灰分消化率随着消化能水平的提高,呈现先上升后下降的趋势,粗脂肪和粗纤维的消化率随着消化能水平的提高,呈现逐渐升高的趋势。综合来看,在热应激条件下肉兔饲粮的消化能水平以10.46～11.30 MJ/kg为宜。     

Dietary cholecalciferol and phosphorus influence intestinal mucosa phytase activity in broiler chicks

1. The role of cholecalciferol and phosphorus in the regulation of intestinal mucosa phytase was investigated in broiler chicks. 2. A total of 144 7-d-old male broiler chicks were grouped by weight into 6 blocks of 4 cages with 6 broiler chicks per cage. Four maize-soybean meal-based mash diets were randomly assigned to cages within each block. The 4 diets consisted of cholecalciferol at 0 or 75 microg/kg and total phosphorus at 3.6 or 7.0 g/kg in a 2 x 2 factorial arrangement. The birds were given the experimental diets for 12 d under conditions which excluded ultraviolet light. 3. Broiler chicks fed on diets with the higher concentration of cholecalciferol had higher Vmax and Km of the mucosa phytase, weight gain, feed intake, feed efficiency and percentage tibia ash, higher ileal digestibility of dry matter, energy, phosphorus (P) and calcium (Ca), and increased retention of dry matter, nitrogen, P, Ca and energy. 4. Broiler chicks receiving diets with the higher P concentration showed lower Vmax and Km of the intestinal mucosa phytase but greater weight gain, feed intake, feed efficiency and percentage tibia ash, higher ileal digestibility of dry matter, energy, P and nitrogen, and increased retention of dry matter, energy, nitrogen and Ca. 5. In conclusion, both dietary P and cholecalciferol influenced the activity of intestinal mucosa phytase.     

Effect of salinomycin level on nutrient digestibility and ruminal characteristics of sheep and feedlot performance of cattle

A sheep digestion trial and two feedlot trials with cattle were conducted to study effects of an ionophore, salinomycin, on nutrient digestibility, ruminal metabolism and cattle performance. In trial 1, addition of salinomycin at 5.5, 11 or 22 ppm to 60% concentrate diets fed to ruminal-cannulated rams had no effect (P greater than .05) on apparent digestibility of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF) or starch in comparison with control diets. Apparent nitrogen (N) digestibility was increased (P less than .05) in animals fed salinomycin. Salinomycin did not affect total volatile fatty acid (VFA) concentrations in the rumen, but resulted in a linear (P less than .05) increase in molar proportion of propionate and a linear (P less than .05) decrease in molar proportions of acetate and butyrate and in acetate:propionate ratios. Shifts in VFA proportions were fully expressed within 4 d after salinomycin was added to the diet. In trial 2, salinomycin was added at 5.5, 11, 22 or 33 ppm to 85% concentrate diets fed to finishing steers. Salinomycin level had a quadratic effect (P less than .05) on daily weight gain and resulted in a quadratic (P less than .05) decrease in feed intake with a resultant average improvement of 10.3% in feed efficiency. Salinomycin (5.5, 11, 16.5 or 22 ppm) and monensin (22 ppm) were added to 90% concentrate diets in trial 3 and produced increased rates of gain without affecting feed intake.(ABSTRACT TRUNCATED AT 250 WORDS)     

不同料水比的湿拌料对育成期银狐采食量、营养物质消化率、氮代谢及体重的影响

本试验旨在探讨不同料水比的湿拌料对育成期银狐采食量、营养物质消化率、氮代谢及体重的影响。试验选用平均体重为(3.44±0.19)kg的12周龄左右的健康银狐30只,随机分为3个组,每组10只,公母各占1/2。3组银狐分别饲喂料水比为1.0∶2.5(Ⅰ组)、1.0∶3.5(Ⅱ组)和1.0∶4.5(Ⅲ组)的湿拌料,试验期48 d。结果表明:1)随着湿拌料添加水分比例的升高,各周龄银狐的干物质平均日采食量均有不同程度的增加,其中Ⅲ组银狐干物质平均日采食量在14、15、17、18、19周龄时极显著高于Ⅰ组和Ⅱ组(P0.01),在16周龄时显著高于Ⅰ组(P0.05);Ⅲ组干物质总采食量极显著高于Ⅰ组和Ⅱ组(P0.01),且Ⅱ组也有高于Ⅰ组的趋势,但差异不显著(P0.05)。2)Ⅰ组干物质消化率显著高于Ⅲ组(P0.05);蛋白质消化率各组间差异不显著(P0.05),但Ⅰ组较Ⅱ组升高4.62%,Ⅱ组较Ⅲ组升高5.42%;脂肪消化率各组间差异不显著(P0.05),但Ⅰ组较Ⅲ组升高4.03%,Ⅱ组较Ⅲ组升高4.46%。3)食入氮表现为Ⅲ组极显著高于Ⅰ组和Ⅱ组(P0.01),Ⅱ组也有高于Ⅰ组的趋势,但差异不显著(P0.05);尿液量随着湿拌料添加水分比例的升高显著或极显著升高(P0.05或P0.01);氮沉积各组间差异不显著(P0.05);粪氮排出量表现为Ⅲ组显著高于Ⅰ组和Ⅱ组(P0.05),Ⅱ组高于Ⅰ组,但差异不显著(P0.05);随着湿拌料添加水分比例的升高,尿氮排出量有升高的趋势,而净蛋白质利用率有降低的趋势,但各组间差异不显著(P0.05);Ⅰ组蛋白质生物学价值显著高于Ⅱ组和Ⅲ组(P0.05)。4)不同料水比的湿拌料对银狐不同周龄平均体重、各阶段平均日增重、总增重均无显著影响(P0.05);对于料重比,Ⅱ组较Ⅲ组降低4.30%,Ⅰ组较Ⅱ组降低1.21%,但各组间差异不显著(P0.05)。综合各项指标,从降低环境污染和饲料成本以及保证银狐体增重的角度出发,育成期银狐湿拌料中料水比以1.0∶2.5为宜。     

益生素对梅花鹿仔鹿和羔羊日粮营养物质消化率的影响

4只5月龄梅花鹿仔鹿和3只7月龄安装永久瘤胃瘿管的小尾寒羊,先后饲喂基础日粮(定量颗粒饲料和自由采食玉米秸秆;对照组)和基础日粮添加4 g益生素(BioLac;试验组),观察添加益生素不同动物干物质采食量,日粮营养物质的消化率和秸秆在小尾寒羊瘤胃中的降解情况。结果表明,添加益生素可显著提高仔鹿和羔羊干物质的采食量,仔鹿干物质采食量由未添加益生素的441.4 g/d提高到506.0 g/d;羔羊的干物质采食量由未添加益生素的598.8 g/d提高到719.6 g/d。但试验组干物质、有机物、粗蛋白和中性洗涤纤维的消化率(仔鹿分别为:49.3％、52.1％、57.4％和49.3％;羊分别为:53.6％、56.7％、47.9％和53.0％)显著低于对照组(仔鹿分别为:56.4％、58.7％、65.0％和56.4％;羊分别为:61.0％、64.0％、58.8％和61.0％)。结果仔鹿可消化干物质的采食量在对照组(248.9 g/d)和试验组(249.1 g/d)间无显著差异,试验组羔羊可消化干物质采食量(384.9 g/d)略高于对照组(365.7 g/d)。瘤胃降解试验结果表明,秸秆干物质,有机物质和中性洗涤纤维2-48 h,在饲喂益生素的羔羊瘤胃内的降解率均略高于未添加益生素的羔羊瘤胃内的降解率,粗蛋白在饲喂试验日粮的羔羊瘤胃内的降解率在2 h时高于在饲喂对照日粮的羔羊瘤胃内的降解率,其他时间低于在饲?     

Comparison of fattening performance in Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis) fed on high roughage diet

The objective of this study was to compare the fattening performance in Brahman grade cattle (crossbred cattle) and crossbred water buffalo at the same young age and fed with high roughage based fattening rations in the Philippines. Ten crossbred cattle and 10 crossbred water buffalo, aged between 18 and 24 months old were used in this experiment. The animals were fed diets consisting of 85% Napier or Para grass and 15% concentrate mixture (CM) on a dry matter (DM) basis. The grass, total DM intake and bodyweight gain were significantly (P < 0.01) higher for the crossbred water buffalo than for the cattle. There was no species significant difference in the digestion coefficient and feed conversion rate between the crossbred cattle and water buffalo. The return over feed cost for fattening was significantly (P < 0.05) higher in the crossbred water buffalo than in the cattle. These results clearly indicate that under high roughage‐based fattening rations, young crossbred water buffalo are better able to utilize the roughage and they perform better in terms of feed intake and live weight gains than the crossbred cattle in the Philippines.     

Effect of dietary contamination with mercury on the performance of rabbits

This work was designed to study effects of HgSO4 on rabbits performance when added in the mash diet for 7 weeks with concentrations of 0, 150, and 300 ppm as Hg (6 animals/group). The Hg application caused mortality associated with diarrhoea, haemorrhage, oedema and liver and stomach necrosis. The contaminated diets caused significantly increased feed intake, drinking water consumption and live body gain. Mercury did not affect organ percentages significantly (P greater than or equal to 0.05). Serum analyses reflected a significant (P less than or equal to 0.05) rise in the glucose content (for the animals fed the 300 ppm Hg-diet) with a slight decrease in Ca level and activity of both transaminases GPT and GOT. The most affected organ by the application of Hg was the liver which reflected a slight increase in its dry matter substance, significant increase (P less than or equal to 0.01) in the ether extract percentage on the 300 ppm Hg-diet and severe reduction (P less than or equal to 0.01) in its vitamin A as well as in the iron content (P less than or equal to 0.05) on the 300 ppm Hg-diet. The highest level of Hg added caused an increase (P less than or equal to 0.01) in bone magnesium.     

热应激条件下脂肪来源对肉兔生产性能、养分消化率及血清脂质代谢和抗氧化指标的影响

本试验旨在研究热应激条件下脂肪来源对肉兔生产性能、养分消化率及血清脂质代谢和抗氧化指标的影响。试验选择30日龄的断奶新西兰兔600只,随机分成5个组,每个组6个重复,每个重复20只。对照组饲喂基础饲粮,各脂肪添加组分别饲喂含2%牛油、猪油、玉米油、豆油的饲粮。试验兔均饲养在热应激兔舍(温湿指数为29.5±0.5)中。试验期7周。结果表明:与对照组相比,热应激条件下饲粮中添加不同来源的脂肪均可以显著提高肉兔的平均日增重(P0.05),显著降低料重比(P0.05),其中以玉米油的效果最佳。与对照组相比,热应激条件下饲粮中添加不同来源的脂肪均可以显著提高肉兔的干物质和粗蛋白质消化率(P0.05),显著降低粗脂肪消化率(P0.05),但对粗灰分和粗纤维消化率无显著影响(P0.05),其中玉米油组的干物质消化率最高,豆油组的粗蛋白质消化率最高。与对照组相比,热应激条件下饲粮添加牛油或猪油可以显著提高肉兔血清甘油三酯和总胆固醇含量(P0.05);玉米油组和豆油组肉兔血清甘油三酯和总胆固醇含量则与对照组差异不显著(P0.05)。与对照组相比,热应激条件下饲粮添加豆油和玉米油可以显著提高肉兔血清超氧化物歧化酶活性和总抗氧化能力(P0.05),显著降低血清丙二醛含量(P0.05);牛油组和猪油组血清超氧化物歧化酶活性、总抗氧化能力和丙二醛含量则与对照组差异不显著(P0.05)。由此可见,热应激条件下,饲粮添加不同来源的脂肪均可提高肉兔生产性能及干物质和粗蛋白质消化率,从整体效果来看,玉米油豆油猪油牛油;饲粮添加牛油或猪油可提高肉兔血清甘油三酯和总胆固醇含量,对机体抗氧化能力的影响不显著;饲粮添加豆油或玉米油对肉兔血清甘油三酯和总胆固醇含量无显著影响,但可显著提高机体的抗氧化能力。     

Influences of wet feeding and supplementation with ascorbic acid on performance and carcass composition of broiler chicks exposed to a high ambient temperature.

In two experiments was investigated whether feeding with an air-dry feed mixed with different amounts of water and/or supplemental ascorbic acid affect performance and carcass compositions of broilers exposed to a high ambient temperature (35 to 37 degrees C for 8 h/d and thermoneutral for 16 h/d). In the first trial, 64 one-week-old male broiler chicks were fed ad libitum in four dietary treatment groups for a 6-week period. Experimental mash diets were prepared by mixing a maize-soybean based standard broiler starter or finisher with tap water in the ratios of 0.0:1.0, 0.5:1.0, 1.0:1.0 and 1.5:1.0 (water:air-dry feed, w/w). More water in the diet increased BWG, DMI, abdominal fat and carcass weight, carcass CP, crude fat, but it deteriorated DM conversion efficiency. In the second experiment, 64 one-week-old male broiler chicks were given air-dry or wet (water:feed, 1.5:1) starter or finisher diets without or with ascorbic acid supplementation (0 and 250 mg/kg air-dry feed, resp.) ad libitum for a 6-week period. Ascorbic acid supplementation increased BWG, carcass weight and carcass CP significantly, while reducing carcass crude fat content. However, feeding broilers with a diet mixed with water in a ratio of 1.5:1.0 increased BWG, DMI, carcass weight and carcass lipid markedly, but deteriorated DM conversion efficiency. There was also a significant interaction between ascorbic acid and wet feeding, whereby ascorbic acid supplementation induced a significant reduction in carcass lipid contents of broilers fed on air-dry diets but not on wet diets. It is concluded that wet feeding, especially an addition of 150% water to produce a porridge like consistency, improved growth performance by increasing fat, ash and protein deposition in the body, while reducing DM conversion efficiency. It is also concluded that under heat stress supplemental ascorbic acid in air-dry diets stimulates broiler performance but not in wet diets.     

獭兔玉米赤霉烯酮中毒的诊断

山东某獭兔场饲养的3 000只母兔发生了一种以流产及青年兔死亡为特征的疾病,通过对发病兔进行细菌培养及兔病毒性出血症病毒的RT-PCR以及饲料中的玉米赤霉烯酮、呕吐毒素及黄曲霉毒素进行鉴别检测,首先排除细菌病及兔病毒性出血症发病的可能,并从饲料中检测3种毒素的含量分别为1 196.1、130.8、6μg/kg,经过对照饲料标准发现玉米赤霉烯酮严重超出标准(标准为300μg/kg)。通过饲喂试验发现这次发病与所饲喂的饲料有关,诊断为玉米赤霉烯酮中毒。     

Low concentrations of zearalenone in diets of mature gilts

Four groups of sixteen gilts were each individually fed diets containing 0, 3, 6 or 9 ppm pure zearalenone starting the day after they exhibited puberal estrus. They were artificially inseminated twice at subsequent heat periods. Fifteen of the 30 gilts not exhibiting estrus within 80 d of the start of the experiment were slaughtered and their reproductive tracts examined. The remaining 15 gilts that did not return to estrus were fed the control diet after 80 d to determine the effect on return to estrus. Eighty-eight percent of the gilts fed 6 or 9 ppm zearalenone became pseudopregnant as confirmed by plasma progesterone levels and(or) examination of their reproductive tracts. However, three animals fed the two higher levels of zearalenone conceived and farrowed. No conclusions can be made regarding the effect of zearalenone on litter size due to the relatively few numbers of gilts fed the higher levels of zearalenone that farrowed. Gilts fed diets containing 6 or 9 ppm zearalenone returned to estrus spontaneously (n = 7) or following injection of cloprostenol (n = 8) approximately 45 d after the removal of zearalenone from their diet.     

Feed intake of young double-muscled bulls fed on grass and supplemented with sugar-beet pulp.

Daily dry matter intake in young growing double-muscled bulls, fed indoors on grass, was estimated based on forty-four intake data from 28 animals, ageing at least five months and weighing up to 400 kg live weight. Intake was measured during five consecutive days using one of eighteen cuts of grass. Fresh meadow grass (mainly Lolium perenne) was fed ad libitum and two kg dried sugar-beet pulp was offered per animal and per day. Animal live weight averaged 278 +/- 82 kg and mean total daily dry matter intake amounted to 5.05 +/- 1.59 kg or 73.6 +/- 13.7 g per kg metabolic weight, while pulp dry matter intake amounted to 1.49 +/- 0.50 kg per day. Regression analysis showed that animal as well as feed characteristics could explain up to approximately 90% of the variation in daily dry matter intake. The supplementation resulted in an extra daily dry matter intake of 0.68 g per g pulp dry matter. Intake of double-muscled animals was considerably lower than previously reported for non-double-muscled cattle. An extra supplementation of young grazing double-muscled animals could be advised from these findings, while extra protein should also be considered.     

Effects of Fasciola gigantica infection on growth and nutrient utilisation of buffalo calves

The effects of Fasciola gigantica infection on bodyweight gain, dry matter intake, digestibility of nutrients and feed conversion efficiency in buffalo calves were investigated. Nine male buffalo calves of the Murrah breed, aged 12 to 15 months with a mean (se) bodyweight of 166 (12.5) kg, were randomly assigned to groups of five (group 1) and four (group 2). The animals in group 1 were given 1000 viable, mature metacercariae of F gigantica orally, while the animals in group 2 served as uninfected controls. They were stall fed on diets containing a concentrate mixture and ad libitum wheat straw and were maintained by standard management practices for a period of 165 days after infection. The average daily liveweight gain of the infected animals was 110.6 g, compared with 439.4 g in the uninfected controls, and was associated with the appearance and establishment of immature flukes in hepatic bile ducts. The feed conversion efficiency declined significantly (P<0.01) from 41 days after infection and was lowest at the end of the experiment. F gigantica infection did not influence the digestibility of the nutrients. The impaired feed conversion efficiency was mainly due to a reduction in dry matter intake due to inappetence.     

A review of okara (soybean curd residue) utilization as animal feed: Nutritive value and animal performance aspects

Year by year, huge quantities of by-products are generated during the manufacturing process of soybean-based products. Okara is one of the by-products, and it is an insoluble portion of the soybean. It consists of high moisture (8.4–22.9%); on dry matter basis, it contains high metabolizable energy (9.0–14.2 MJ/kg) and other components that include crude protein (20.9–39.1%), crude fiber (12.2–61.3%), crude fat (4.9–21.5%), and ash (3.4–5.3%). Fermentation of okara improves its nutritional quality and reduces its anti-nutrient contents. Due to animals' palatability, okara can be used to replace the soybean meal/concentrate feed partially or completely in ruminant's diet and partially in nonruminant's diet. Okara feeding does not depress the intake, digestibility, growth, milk production, blood metabolic profiles, and meat quality of animals. However, this by-product decays quickly due to its high moisture content, and its heavy weight and sticky nature make it difficult to process and expensive to dry using conventional methods. This paper thoroughly summarizes the utilization of okara as animal feed in the cause of developing a general guideline with favorable levels of inclusion in the diets of animals for its exploitation and valorization. This review will encourage further research to develop eco-friendly and value added feed for animals.     

中草药制剂对獭兔免疫功能及血清生化指标的影响

本试验旨在研究中草药制剂对獭兔免疫功能及血清生化指标的影响。采用单因素分组设计,选用120只30日龄健康、体重相近的獭兔(公、母各半),随机分为6组,每组4个重复,每个重复5只。对照组饲喂基础日粮;抗生素组(Ⅰ组)在基础日粮中添加4 mg/kg地克珠利;中草药组(Ⅱ、Ⅲ、Ⅳ、Ⅴ组)分别在基础日粮中添加0.5%、1.0%、1.5%和2.0%的中草药制剂。预试期7 d,正试期50 d。结果表明:①与对照组相比,日粮中添加中草药制剂提高了獭兔胸腺指数、脾脏指数及血清中免疫球蛋白G(IgG)含量,但各组间脾脏指数差异不显著(P>0.05)。②与对照组相比,日粮中添加中草药制剂提高了獭兔血清中总蛋白(TP)、白蛋白(ALB)、生长激素(GH)、胰岛素样生长因子(IGF-Ⅰ)、甲状腺素(T4)含量,其中1.5%中草药制剂组中各指标分别显著提高了4.40%、7.46%、12.76%、23.53%和6.24%(P<0.05),但对血清球蛋白(GLB)、三碘甲状腺原氨酸(T3)含量影响均不显著(P>0.05)。综上所述,中草药制剂对獭兔具有血液免疫调节作用,改善了免疫器官的发育及机体的免疫机能,建议獭兔日粮中中草药制剂的添加量以1.5%为宜。     

The occurrence of Fusarium varieties and their mycotoxins in silo corn. 2. The formation of zearalenone in the field by artificial infection of silo corn with Fusarium culmorum (W. G. Smith) Sacc

The formation of zearalenone in a maize plot artificially infected with Fusarium culmorum was studied. The zearalenone concentration steeply increased only in the 8th week after inoculation and reached a maximum value of ca. 7 ppm, whereas zearalenone could not be detected in the control variants. The crude nutrient and dry matter content was not significantly influenced by the fungal infection. The infected crop showed average ear dry weights distinctly lower than that of the control variants (P less than or equal to 0.001). Apart from zearalenone, the mycotoxin deoxynivalenol was qualitatively detected in the infected maize. The toxicological relevance of the ascertained zearalenone content with regard to the health of dairy cattle and pigs was discussed.     

Effect of indigestible sugars on nitrogen utilization in adult rabbits

To determine the effects of indigestible sugars on the digestibilities of nutrients and utilization of nitrogen (N) in adult male rabbits, 12 rabbits with or without a collar that prevented cecotrophy were fed experimental diets for 8 days, comprising 3 days for adaptation and 5 days for collection of feces and urine. The experimental diets were formulated by adding D‐mannitol or citrus pectin to a commercial diet at 60 g/kg. In the rabbits allowed cecotrophy, mannitol increased the absorption of crude ash but did not significantly alter the digestibilities of crude protein (CP), dry matter and acid‐detergent fiber. By contrast, the digestibility of CP was decreased by pectin. The ratios of retained N to consumed N and absorbed N were elevated by mannitol. In the rabbits prevented from cecotrophy, mannitol had no effect on N retention, but increased the N content of cecotrophs (soft feces) and the ratio of the N content of cecotrophs to consumed N. Pectin did not have any significant influences on N retention and the N content of cecotrophs. These results suggest that D‐mannitol stimulates cecal microbial proliferation, thereby improving N utilization in rabbits.     

Effect of growth hormone-secreting tumors on body composition and feed intake in young female Wistar-Furth rats

Growth hormone (GH) was elevated in young growing, intact female Wistar-Furth rats bearing growth hormone (GH1) or growth hormone and prolactin (GH3) secreting tumors. Animals were injected with GH1 or GH3 cells at 1 wk of age. Total feed intake was measured for the 8-wk period from weaning until killed at 11 wk of age. Animals were fed a commercial chow diet throughout the trial. Body composition and composition of the liver and tibialis anterior muscle were determined. Tumor-bearing rats were about 65% heavier than control rats at 11 wk of age: most of the difference in body weight gain was obtained during the last 4 wk of the trial. Total feed intake during the 8 wk after weaning was increased in both GH1 and GH3 tumor-bearing rats when compared with controls. Overall feed efficiency (grams feed consumed/gram body weight gain) was improved in tumor-bearing animals when compared with controls. The GH1 tumor-bearing rats were slightly hyperphagic during wk 8, 9 and 10 (grams feed consumed/gram body weight) when compared with controls. The total amount of body dry matter, protein and ash was increased in tumor-bearing rats when compared with controls. There was no effect on total body fat. Tumor-bearing rats had increased liver weight and increased fat, protein, RNA, DNA and dry matter content when compared with controls. Tumor induction increased the weight, total RNA and total fat content of the tibialis anterior muscle when compared with controls. There was no effect on muscle protein content.(ABSTRACT TRUNCATED AT 250 WORDS)