A comparison of the effect of forage type and level of feeding on the digestibility and gastrointestinal mean retention time of dry forages given to cattle, sheep, ponies and donkeys

Four cattle, sheep, ponies and donkeys were fed dehydrated lucerne, early-cut hay, later-cut hay or barley straw in a Latin square-based design for four periods of 35 d. In the first sub-period animals were fed the diets ad libitum (1-21 d) and in the second sub-period they were fed the same diet restricted to 0.75 of ad libitum intake (days 22-35). Measurements of forage intake, apparent digestibilities and gastrointestinal mean retention times (MRT) were made in the last 7 d of each sub-period. Differences between species in voluntary DM intake (VDMI; g/kg live weight (LW)(0.75) and g/LW) were greatest on the lucerne and least on barley straw. Cattle VDMI (g/kg LW(0.75)) compared with intake of the other species was > ponies > sheep > donkeys on lucerne. On barley straw VDMI (g/kg LW(0.75)) of cattle compared with intake of the other species was = donkey = ponies > sheep. VDMI of hays were intermediate between the lucerne and straw forages. Apparent digestibilities of DM, organic matter (OM), neutral-detergent fibre (NDF) and acid-detergent fibre (ADF) of the lucerne and hays were higher in the ruminants than in the equids. Effect of feeding level was not significant. Gastrointestinal MRT was shorter in the equids than in the ruminants. On straw diets donkeys showed similar apparent digestibilities of feed components to those of the cattle, whilst apparent digestibility of the straw diet by the ponies was lowest. Results are discussed in relation to evolutionary differences in feeding and digestion strategy associated with fore- or hind-gut fermentation in ruminants and equids.     

内毒素对胃肠通过时间及肠通透性的作用

应用6周龄的白鼠注射内毒素（E．coli0111：B4）的方法以评价胃肠通过时间，肌酐清除率，双糖（乳果糖、甘露醇）的肠道通透性。给予~（51）铬－依地酸动态监测通过消化道时间表明，内毒素组胃排空时间比生理盐水对照组明显延长（t1／2＝26±2vs162±20minP＜0．01），小肠运行时间无明显改变（81±17vs93±29min）。通过尿中乳果糖／甘露醇排泄比来评定肠通透性，内毒素组通透性比对照组高（1．01±0．08vs0．60±0．04P＜0．01）。在测试期测定小肠有效吸收标记物数量以校正个别糖排泄后，结果是内毒素可使乳果糖吸收增加，但甘露醇吸收无改变。本研究也提示内毒素血症（通过药物或其它治疗后无并发症）能使胃排空时间明显延长，于是影响到口服或鼻胃管喂养的耐受性。     

The effect of red and black pepper on orocecal transit time.

The effects of spices on intestinal peristalsis have not been studied in humans. In this pilot study we evaluated the effects of red pepper and black pepper on small intestinal peristalsis measuring orocecal transit time (OCTT) utilizing a lactulose hydrogen breath test. Subjects included 16 healthy volunteers. The lactulose hydrogen breath test was done on different days with or without the powdered red pepper (2 g) or black pepper (1.5 g) given in gelatin capsules. The baseline orocecal transit time was increased significantly after red pepper consumption (88 +/- 37.2 to 128 +/- 63.2 min, p less than 0.01). Although the change in OCTT was not statistically significant, a similar trend was observed after black pepper consumption (90 +/- 51 min to 122 +/- 88 min., p = 0.09). The pathogenesis of increased OCTT after red pepper may be attributed to the known effects of capsaicin, a constituent noted to be a potent stimulator of many biologically active peptides. Although the effect of spices on OCTT is likely to vary depending upon the dose and nature of the product, it is of clinical importance in the management of various gastrointestinal tract disorders.     

The effect of provision of the first-limiting amino acid, gastrointestinal microbial activity and the level of nitrogen intake on protein utilization and energy digestibility in rats

1. The present work with growing rats was undertaken to study the effect of protein quality, gastrointestinal microbial activity and the level of nitrogen intake on protein utilization and energy digestibility. The experiment involved a total of thirty-six dietary treatments in a 9 x 4 factorial design, with five rats per treatment. The thirty-six diets resulted from nine protein sources. Each diet was composed of a basal N-free mixture plus minerals and vitamins, with N sources added at the expense of the N-free mixture to provide 15.0 gN/kg dry matter (DM) in the first three protein-addition treatments and 30.0 gN/kg DM in the fourth protein-addition treatment. The nine protein sources were soya-bean meal, casein, wheat gluten, skim-milk powder, meat-and-bone meal, wheat bran, barley, wheat and cooked brown beans (Phaseolus vulgaris). The four formulations for each protein source incorporated the protein unsupplemented at 15.0 gN/kg DM, unsupplemented at 30.0 gN/kg DM, or supplemented at 15.0 gN/kg DM with the estimated first-limiting amino acid or the antibiotic Nebacitin. 2. With all protein sources, the inclusion of the first-limiting amino acid had no effect on either protein or energy digestibility. 3. The microbial activity in the digestive tract affected protein utilization and energy digestibility to a different degree depending primarily on the level and type of dietary fibre. True protein digestibility (TD) of skim-milk powder and brown beans, both rich in easily-fermentable energy, increased from 0.959 to 1.000 and from 0.680 to 0.777 respectively by the addition of Nebacitin. TD of the other protein sources was only marginally affected by the antibiotic treatment. Only with brown beans was the biological value (BV) markedly affected by Nebacitin with an increase from 0.482 to 0.557 by the treatment. Energy digestibility was significantly lower in rats given antibiotic with soya-bean meal, wheat bran, barley, wheat and brown beans. 4. The effect of level of N intake on protein utilization was dependent on both protein quality and the fibre concentration of the diet. Protein sources with high BV were more affected than proteins of lower BV. It was concluded that TD is not always independent of dietary protein concentration.     

The effect of indigestible particles on digestive transit time and colonic motility in dogs and pigs

The myoelectric activity of the colon was examined in three dogs and three pigs when they were given a basal diet or a basal diet plus indigestible particles (IP), 2 mm in diameter, at 100 g/kg dry matter. The mean retention time was determined using coloured discs as a marker added to the daily meal. Colonic electromyograms of dogs and pigs given IP revealed a 30% reduction in the number of long spike bursts (LSB) when compared with controls. The other components, propulsive migrating spike bursts (MSB) or non-propulsive short spike bursts (SSB), were unchanged. Mean retention time was decreased from 28.6 h to 17.6 h in dogs and from 129 h to 94.2 h in pigs. These changes developed progressively during 3-4 d in both species, suggesting that the reduction in motor activity was an adaptation to the changes in bulk contents. From the decreased motility of the colon linked to the reduction of LSB and paralleled by an increased transit time, it was concluded that one of the functions of the LSB is to impede the passage of digesta.     

The effect of digestibility and forage species on the removal of digesta from the rumen and the voluntary intake of hay by sheep

1. The characteristics of digestion, passage and rumen fill of three hays: early- and late-cut perennial ryegrass (Lolium perenne cv. Endura) and white clover hay (Trifolium repens cv. Blanca and Pronitro) were studied using six rumen-cannulated sheep fed at a restricted level of intake (18 g dry matter (DM)/kg live weight (LW) per d), in a two 3 x 3 Latin square design. 2. Voluntary intake of the same diets was measured using a further six non-cannulated sheep in a similar design. 3. Rate of digestion of the three hays was measured using dacron bags and the rates of digestion of DM and neutral-detergent fibre (NDF) for clover hay were significantly (P less than 0.05 and P less than 0.001 respectively) faster than those for the two grass hays whose rates did not differ. Rates of passage, determined using chromium-mordanted hay, did not differ between treatments. 4. Rumen pool sizes of DM, organic matter and fibre were generally greatest for the late-cut grass hay and lowest for the clover hay, while voluntary intake was highest (P less than 0.001) for the clover hay (36.6 g DM/kg LW per d) and lowest for the late-cut grass hay (24.7 g/kg LW per d). 5. The net rate of removal of indigestible fibre from the rumen appeared to vary within the day, with maximal disappearance occurring during eating, followed by a lag phase between 5 and 10 h after feeding, with a second increase in rate between 10 and 24 h post-feeding.     

The effect of protein quality and fibre level in the diet and microbial activity in the digestive tract on protein utilization and energy digestibility in rats

Two nitrogen-balance experiments were performed with growing rats to test the effect of dietary fibre level, protein quality and antibiotic inclusion on microbial activity, N excretion patterns and energy digestibility. Each experiments involved eight dietary treatments in a 2 X 2 X 2 factorial design, with five rats per treatment. The eight treatments resulted from a combination of two protein treatments, two fibre treatments and two antibiotic treatments. In Expt 1 the protein was provided as barley, or barley plus 2 g L-lysine hydrochloride/kg dry matter (DM) (at 15 g N/kg DM) and in Expt 2 as soya-bean meal or soya-bean meal plus 2 g DL-methionine/kg DM (at 15 g N/kg DM). In both experiments the basal diet was provided with or without additional fibre as 100 g barley husk/kg DM and with or without antibiotic as 7 g Nebacitin/kg DM. With both barley and soya-bean meal, true protein digestibility (TD) was improved with the addition of amino acids. Only with the soya-bean meal diets was TD increased with Nebacitin treatment, with the effect of Nebacitin and methionine being additive. Barley husk slightly reduced the TD of soya-bean meal. The effect of treatments on biological value (BV) was considerable. Lysine increased BV of the barley diet from 0.741 to 0.815 whereas Nebacitin reduced BV from 0.799 to 0.757. Methionine increased the BV of soya-bean meal from 0.754 to 0.911 while BV was reduced by Nebacitin from 0.843 to 0.821 and by barley husk from 0.845 to 0.820.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fecal output, gastrointestinal transit time, frequency of evacuation and apparent excretion rate of dietary fiber in young men given diets containing different levels of dietary fiber.

Five healthy young male subjects were given meals containing different levels of dietary fiber (DF) for one week each, and the effects on the fecal output, gastrointestinal transit time, frequency of evacuation, and apparent excretion rate of dietary fiber in feces were studied. The experiments were conducted twice by varying the subjects and the DF levels. The following results were obtained. 1) With an increase in the intake of DF, feces increased significantly in both wet weight and volume. The fecal specific gravity did not show any clear-cut relation with the intake level of DF. 2) The gastrointestinal transit time tended to shorten in each DF period compared to the DF-free period. However, it did not shorten with an increase in the intake level of DF. 3) Frequency of evacuation tended to be high in any of the DF periods compared to the DF-free period. However, the differences in the intake level of DF produced no changes in the frequency. 4) The DF content in feces increased significantly with an increase in the intake of DF, indicating that the larger the fecal output, the larger the fecal DF content. The apparent mean excretion rate of DF in feces remained in the range of 60-75% throughout the two experimental phases. Residues in feces other than DF increased with an increase in the DF intake. 5) The results obtained here indicate that the DF intake of at least 20 g per day produces 140-150 g of fecal output which can be easily excreted daily by a normal adult person.     

非营养性吸吮对早产儿营养、胃肠道转运时间及喂养相关并发症的影响

目的 分析非营养性吸吮对早产儿营养、胃肠道情况的影响.方法 选取广西壮族自治区妇幼保健院经鼻胃管喂养健康早产儿72例为研究对象,随机分为观察组和对照组各36例,对照组早产儿常规喂养,观察组早产儿在常规喂养基础上给予非营养性吮吸,分析两组早产儿胃肠道运转时间、营养变化以及并发症情况.结果 两组新生儿生长发育指标无明显差异(t=0.254,P＞0.05),两组早产儿开始喂养时间无明显差异(t=0.252,P＞0.05),观察组鼻饲管留置时间(16.0±1.5)d、恢复出生体重时间(8.6±2.7)d、胃肠道营养达标时间(18.4 ±2.6)d、排尽胎粪时间(5.6±1.3)d均显著短于对照组鼻饲管留置时间(17.8±1.5)d、恢复出生体重时间(11.1±2.6)d、胃肠道营养达标时间(21.9±2.3)d、排尽胎粪时间(7.8±1.8)d,(t值分别为5.091、4.002、6.050、5.945,均P＜0.05);观察组患者胃残留(16.7％)、喂养不耐受发生率(27.8％)均显著低于对照组胃残留(38.9％)、喂养不耐受发生率(61.1％),(x2值分别为0.035、0.004,均P＜0.05).结论 早产儿在常规喂养基础上采用非营养性吸吮能够缩短胃肠道运转时间,降低喂养相关并发症发生率,具有推广价值.     

The effect of pesticide exposure on time to pregnancy

The Ontario Farm Family Health Study provided data for examination of the effects of pesticide exposure on time to pregnancy. In this retrospective cohort study of farm couples in Ontario, Canada, the farm operator, husband, and wife completed questionnaires during 1991-1992. We asked about pesticides used on the farm and pesticide activities of the husband and wife for each month of trying to conceive. After exclusions, 2,012 planned pregnancies remained for analysis. We used an analog of the Cox proportional hazards model to calculate conditional fecundability ratios (conditional on pregnancy). There was no strong or consistent pattern of associations of pesticide exposure with time to pregnancy. During exposure intervals in which women participated in pesticide activities (during most of which the men also participated), however, 6 of 13 pesticide exposure categories were associated with a decrease in fecundability (conditional fecundability ratio range = 0.51-0.80). For exposure intervals in which only the men participated in pesticide activities or in which neither men nor women participated in pesticide activities but pesticides had been used on the farm, conditional fecundability ratios ranged from 0.75 to 1.50, with no apparent consistency among pesticide classes, chemical families, or active ingredients.     

The effect of size and density on mean retention time of particles in the gastrointestinal tract of sheep

The selective retention of particles in the reticulo-rumen and in the gastrointestinal tract distal to the reticulo-rumen was studied in fistulated sheep maintained on a roughage diet. Polyethylene glycol and plastic particles of different lengths (1 and 10 mm) and densities (0.92, 1.03, 1.22 and 1.44 g/ml) were either fed or were introduced into the omasum. The mean retention time in the reticulo-rumen (MRTRR) of 1 mm long particles with a density of approximately 1.0 g/ml was about 67 h, that is eight times longer than the MRTRR of fluid; the heavier particles were retained only three times longer than fluid. Particles with a length of 10 mm were retained in the reticulo-rumen 19-28 h longer than 1 mm long particles of the same density. Particles with a length of 10 mm were reduced to smaller particles (0.5-4 mm) due to rumination. Multiple regression analysis indicated that particle density and particle size accounted for 59 and 28% of the total variation of MRTRR respectively. The mean retention time distal to the reticulo-rumen (MRTGut) of 1 and 10 mm long particles with a density near 1.0 g/ml was 18-19 h, similar to that of fluid (16 h). The heavier particles were retained about 3-8 h longer.     

Influences of cold exposure on digestion of organic matter, rates of passage of digesta in the gastrointestinal tract, and feeding and rumination behaviour in sheep given four forage diets in the chopped, or ground and pelleted form

Sixteen sheep, each fitted with cannulas in the rumen and proximal duodenum, were given four diets in the chopped or ground and pelleted form, at fixed intakes at intervals of 2 h. The sheep were closely shorn and exposed to temperatures of 22-25 degrees or 1-4 degrees for four periods of 45 d. Flow of duodenal digesta by reference to the markers CoEDTA and 103Ru-phenanthroline, chewing behaviour and particle size of rumen and duodenal digesta were measured. Apparent digestibility of organic matter (OM) in the gastrointestinal tract was depressed (P less than 0.05) by grinding and pelleting the diet, and by exposure of sheep to cold ambient temperatures. This was attributable to depression (P less than 0.01) by 0.1 of OM digestion in the reticulo-rumen. No effects on intestinal digestion of OM were observed. Cold ambient temperatures did not affect the content, but increased the rate of digestion for pelleted diets but not for chopped diets, of potentially-degradable cell-wall constituents of ground dietary material incubated in nylon-bags in the rumen. Retention times of markers of the particulate and liquid phases of rumen digesta were not significantly (P less than 0.05) affected by ambient temperature, despite significant (P less than 0.001) increases in the rate of contraction of the reticulum. Retention time of 103Ru-phenanthroline in the intestines was not affected by cold exposure. Cold exposure was associated with depression (P less than 0.05) of volatile fatty acids concentration in the rumen and elevated (P less than 0.05)pH. Molar proportions of acetic and isovaleric acid were reduced (P less than 0.01), accompanied by increased (P less than 0.001) proportions of propionic acid during cold exposure. Cold exposure and pelleting of the diets were both associated with reduction in digesta particle size in the rumen. Duodenal particle size was not affected by cold exposure. Pelleting of the diet markedly reduced (P less than 0.001) duration of chewing and number of chews/d during eating and rumination. Cold exposure of sheep resulted in a faster (P less than 0.01) rate of eating of the diets. When allowed to express their voluntary feed consumption during a 10 d period, intakes of chopped diets were increased by 0.13 (P less than 0.01) by cold exposure, in contrast to lack of significant change in sheep given pellets.(ABSTRACT TRUNCATED AT 400 WORDS)     

不同孕期碘营养水平对甲状腺功能激素的影响

目的:探讨孕早、中、晚期妇女不同碘营养水平对甲状腺功能激素水平影响。方法:选取2018年5月-2019年2月本院产科门诊孕妇210例为研究对象,孕早、中、晚期分别为72例、70例、68例,检测所有孕妇的尿碘、血清促甲状腺激素(TSH)、游离三碘甲状腺原氨酸(FT3)和游离甲状腺素(FT4)并比较分析。结果:孕早期组碘缺乏率(38.9%)高于孕中期和孕晚期组(P<0.05);孕早、中期妇女甲状腺功能异常主要表现为低FT4血症和亚临床甲状腺功能减退症,极少数孕晚期孕妇存在甲亢;孕早期碘缺乏妇女甲状腺功能异常率(66.7%)高于孕中和孕晚期妇女(P<0.05);孕晚期碘过量妇女甲状腺功能异常率(30.0%)高于孕早期和孕中期组(P<0.05)。结论:妊娠中、晚孕妇碘营养基本处于适宜水平,但孕早期妇女普遍存在碘缺乏。应密切监测妊娠期妇女,特别是孕早期妇女的碘营养水平,对尿碘<150μg/L或>250μg/L的孕妇均应给与甲状腺功能筛查。