Regional differences in the effects of various doses of cerulein upon the small-intestinal migrating motor complex in fasted and non-fasted sheep

There are no precise data concerning the effect of cerulein on the small-intestinal migrating motor complex (MMC) in sheep. Thus, the effort was directed towards the elucidation of the role of cerulein, a cholecystokinin (CCK) amphibian analogue, in the regulation of MMC cycle in conscious fasted and non-fasted sheep in various regions of the small intestine. In six sheep, equipped with bipolar electrodes in the entire small intestine and with one duodenal strain gauge force transducer in four of these animals, the continuous myoelectric and motor activity recordings were performed. During control period, two normal consecutive MMC cycles were recorded in fasted and non-fasted animals and then cerulein was slowly injected at the dose 1 (during 30 s), 10 (during 30 s or 60 s) or 100 ng/kg (during 30 s, 60 s or 120 s) or infused at the dose 0.5 or 1.5 ng/kg/min during 60 min. After cerulein administration at least two consecutive MMC cycles were also recorded. It was found that cerulein in moderate and higher doses injected in both fasted and non-fasted animals, especially during phase 2a or 2b MMC, inhibited phase 3 in the duodenum in at least one-third of the experiments and significantly increased the MMC cycle duration. The application of 100 ng/kg of cerulein during 120 s in the course of phase 2b MMC prolonged cycle duration from 70 +/- 21 to 113 +/- 19 min (p < 0.05) or from 51 +/- 18 to 113 +/- 19 min (p < 0.01) in fasted and non-fasted sheep respectively. The first phase 3 MMC arriving after cerulein administration at the highest dose was usually abnormal in approximately 60% of the experiments. The second phase 3 observed following the hormone injection was abnormal much less frequently and to the lesser extent. Furthermore, both cerulein doses significantly shortened the duration of phase 3 MMC either in fasted (from approximately 5.5-6.5 cpm to 4-5 cpm) or in non-fasted sheep (from approximately 4.5-5.5 to 3-4.5 cpm). The effects of cerulein exhibited the dose-response character. They were more pronounced when cerulein was injected during phase 2b or 2a MMC when compared with phase 1 MMC. The effects of cerulein on the ileal MMC were less evident, although the inhibition of the ileal phase 3 in response to both higher injected doses was observed occasionally. Infusions of cerulein in non-fasted sheep exerted similar effects as cerulein injections. It was stated that cerulein exerts marked regulatory effect upon the small-intestinal MMC in sheep. Although it remains uncertain whether the efficient doses of cerulein used in the present study correspond to physiological or pharmacological doses of CCK it seems likely that most of these doses were physiological. Thus, it is concluded that cerulein participates in the control of MMC cycles in the digestive and interdigestive states in sheep. It is possible that CCK is a physiological regulator of the ovine small-intestinal MMC.     

Plasma secretin fluctuates in phase with periodic pancreatic secretion and the duodenal migrating myoelectric complex in calves

Plasma secretin and cholecystokinin (CCK) levels and the periodic secretions of the exocrine pancreas were studied simultaneously with the duodenal migrating myoelectric complexes (mmc) in six milk-fed calves which had been starved overnight. The experiments were performed first when the calves were 10 to 16 days old and subsequently when they were 36 to 45 days old. Plasma secretin and the secretion of pancreatic juice fluctuated periodically in phase with the duodenal MMC: plasma secretin, and the pancreatic secretion of water and protein were significantly higher during the phase of irregular spiking activity than during the phase of no spiking activity in both investigations. Plasma CCK did not change throughout the MMC. The intravenous infusion of secretin at 120 pmol kg⁻¹ bodyweight for one hour markedly stimulated pancreatic secretion and prolonged the duodenal MMC cycle, but it did not abolish pancreatic and duodenal periodic activity.     

Toxoplasmosis in sheep. Influence of various factors on the antibody contents.

The contents of toxoplasma antibodies were estimated by a micro-modification of the dye test for up to 3 years after the initial stage of infection both in ewes which had aborted and in ewes with normal pregnancies. During the first 2 years the titres in ewes which had aborted were significantly higher than in ewes with normal pregnancies. The investigation indicated that dye test titres ≥ 1/512 usually occur during the first stage of infection, and are mainly found in ewes with clinical toxoplasmosis.The dye test titres in lambs due to antibodies transferred with the colostrum were up to 4 twofold dilutions higher than in their dams during the first 2 days after birth. Later the titres declined, and at the age of about 2 months only 3 of 29 lambs had higher titres than their dams. After the age of about 3 months maternally derived antibodies were not detected.The contents of toxoplasma antibodies in sheep with listeric encephalitis were nearly the same as found by a serological survey of the local sheep population. The examination indicated that the dye test titres in sheep are little influenced by conditions that may affect the defence mechanism.Sheep with haemoglobin type B had significantly higher dye test titres than sheep with the haemoglobin types A and AB when examined less than about 6 months after they had acquired the infection. No association was found between the susceptibility to toxoplasma infection and the haemoglobin type. kw|Keywords|k]toxoplasma infection; k]antibody formation; k]sheep {fn1|This work was supported by grants from The Norwegian Research Council for Science and for the Humanities.}     

饲养模式对绵羊冷季生产效益的影响

在肃南裕固族自治县选择草场类型一致,绵羊(Ovisaries sp.)体况相近的3个牧户分别采取暖棚全舍饲(试验组Ⅰ),放牧+补饲(试验组Ⅱ)以及全放牧(对照组)3种饲养方式,通过测定整个繁殖周期绵羊体质量变化、母羊繁殖率和羔羊成活率指标,比较不同饲养模式对绵羊生产效益的影响.结果表明,3种饲养模式下越冬母羊体质量损失...     

Metabolism and hematology studies of intensively raised fattened lambs under various feeding and management conditions. 1. The effect of various feeding methods on the blood picture, serum mineral and bilirubin concentration, and vitamin A concentration in the liver]

Calcium, phosphorus, magnesium and bilirubin content, blood picture and liver vitamin A were determined in six groups of lambs fattened on different rations, in comparison with a control group. The results are presented in graphs and tables. There was no clear difference between the various groups, in the criteria examined.     

The influence of feeding conditions on urine pH and plasma bicarbonate levels in healthy sheep

In healthy sheep the reaction of the urine has generally been accepted to be on the alkaline side (Bentinck-Smith 1963). Thus Healy et al. (1928) only found 2 of 40 healthy sheep with an acid urine. Bentinck-Smith reported that nursing animals in contrast to adults will produce an acid urine. However, the influence of feeding on urine pH and plasma bicarbonate levels in sheep does not seem to have been systematically investigated. During recent years it has often been observed in this laboratory that healthy animals, examined as a matter of routine, may produce an acid urine. Based on these observations healthy sheep under different feeding conditions were examined in order to elucidate the influence of the diet on the pH of the urine and the plasma bicarbonate content. Since an excessive lactic acid production and increased fat metabolism may also influence the acid-base balance, the lactic acid concentration of rumen fluid was determined, and the urine was tested for ketone bodies.     

Influence of the embryo on intrauterine migration in sheep.

Mechanisms of intrauterine migration were examined in 55 ewes. In the first experiment, corpora lutea were removed from unilaterally ovariectomized ewes on d 4 (d 0 = estrus) and pregnancy was maintained by giving exogenous progesterone. In Exp. 2, the reproductive tract was altered surgically such that embryos initially entered the uterine horn contralateral to the site of ovulation. In Exp. 3, ewes received beads of silastic polydimethylsiloxane that released either cholesterol or estradiol-17 beta in an attempt to mimic embryonic synthesis of estradiol. In the fourth experiment, unilaterally ovariectomized ewes were superovulated and spacing of embryos within the uterus was then examined. In all experiments, ewes were slaughtered on d 15 and recovery of embryos or beads from each uterine horn indicated that migration had occurred. All ewes in Exp. 1 and 2 that had two conceptuses experienced embryonic migration. Beads impregnated with estradiol migrated farther (P less than .01) than cholesterol-containing beads (27.6 +/- 4.3 vs 12.5 +/- 1.6 cm, respectively). In Exp. 4, only one conceptus had migrated into the contralateral horn in all ewes. These results demonstrated that 1) embryonic migration was not affected by local vs systemic exposure to progesterone, 2) embryos migrated into the unoccupied horn, regardless of the initial horn of entry, 3) estradiol may stimulate embryonic migration, and 4) conceptuses were not equally distributed between horns.     

Metabolism and hematology studies of intensively raised fattened lambs under various feeding and management conditions. 3. The effect of weaning age under various management conditions on the blood picture, serum mineral and bilirubin concentration and vitamin A concentration in the liver]

Calcium, phosphorus, magnesium and bilirubin, blood picture and liver vitamin A were studied in six groups of lambs weaned at various ages and fattened under four types of management, in comparison with a control group. Results are shown in graphs and tables, with a comparison with conventionally fattened lambs. Age at weaning had no demonstrable effect on the parameters investigated.     

Involvement of neuronal nitric oxide synthase (nNOS) in the regulation of migrating motor complex (MMC) in sheep

The objectives of this study were to evaluate the role of nitric oxide (NO) synthase isoforms (nNOS, eNOS, and iNOS) in the regulation of the migrating motor complex (MMC) in sheep using electromyography and their expression in the gastrointestinal (GI) tract by Western blot (WB) and immunohistochemistry. Intravenous administration of L-NAME or the nNOS inhibitor 7-nitroindazole (7-NI) decreased the MMC interval. Myoelectric activity of intestinal phase II was increased, whereas antral activity was reduced. These effects were blocked by L-arginine. Inhibitors of either iNOS (aminoguanidine and S-methylisothiourea) or eNOS (L-NIO) were ineffective. The NO donor sodium nitroprusside decreased GI myoelectric activity, inhibited the MMC pattern, and prevented the effects induced by L-NAME and 7-NI in the intestine. Intracerebroventricular administration of these agents did not modify GI motility. In the rumen, abomasal antrum, duodenum, and jejunum, WB showed three bands at about 155, 145, and 135kDa corresponding to nNOS, and a 140-kDa band (eNOS); however iNOS was not detected. Positive nNOS immunostaining was observed in neurons of the myenteric and submucous plexus of all GI tissues, while eNOS was found in the endothelial cells, ruminal and intestinal epithelium, as well as in some enteric neurons and in endocrine-like cells of the duodenal Brunner's glands. In contrast, only weak iNOS immunoreactivity was found in ruminal epithelium. Taken together, our results suggest that NO, synthesized at a peripheral level by nNOS, is tonically inhibiting the MMC pattern and intestinal motility in sheep.     

六脉穴埋线对藏系绵羊心肌电位、瘤胃肌电位及瘤胃张力的影响

为调整西藏反刍动物的生理功能,干预高原环境对动物的不利影响,提高牛羊对饲草的高效利用。试验通过六脉穴位埋线,对试验羊只埋线前后进行心电图、胃肠电及胃内张力等进行描记,结果发现六脉穴埋线具有促进藏系绵羊血液循环和缓解心肌过载负荷,调节心电轴右偏达40°的作用;通过对瘤胃肌电图分析,埋线后VPP和RA明显降低,瘤胃内张力降低1/3。结果表明,六脉穴埋线具有缓解右心室肥大,降低瘤胃张力,改善藏系绵羊的胃肠和心血管功能,保障饲草在瘤胃中充分的消化时间。     

Correlations among antral follicular echotexture,apoptosis and expression of key steroidogenic enzymes in sheep

Nineteen cycling ewes underwent transrectal ultrasonography of ovaries followed by ovariectomies during the growth phase of the first follicular wave of the interovulatory interval or the proestrus/estrus phase of the cycle. Quantitative ultrasonographic characteristics of the antrum and follicular wall in a total of forty-three ovine antral follicles were examined for correlations with the protein expression of three steroidogenic enzymes (cytochrome P450 17α-hydroxylase, CYP17; cytochrome P450 aromatase, CYP19; and 3β-hydroxysteroid dehydrogenase, 3β-HSD) determined by densitometric analysis of immunohistochemical slides, follicular dimensions, granulosa layer thickness and the percentage of apoptotic granulosa cells. Significant correlations were found between echotextural attributes of ovine antral follicles and the percentage of apoptotic granulosa cells, CYP17 expression (theca), CYP19 expression (granulosa) and 3β-HSD expression (theca cells). Computer-aided analyses of ultrasonographic images can be beneficial to the development of assisted reproductive technologies and diagnosis of hormonal imbalances without the need for ovarian biopsies or hormone assays.     

Studies on the effect of nutritional factors on the rumen mucosa. 2. Report. Morphological conditions after feeding with fattening rations in various physical forms]

3 groups of fattening cattle (DSR breed) were fed rations of nearly identical composition for a period of 395-455 days. The rations consisted of either crushed (group I), finely ground (group II) or finely ground and pelleted material (group III). Samples of the ruminal mucosa from 26 animals were investigated macroscopically, microscopically and histologically. All samples from animals of group I were found to be normal whereas clumping of the villi, hyperkeratosis, atrophy and loss of villi over 40%-50% of the surface of the ruminal mucosa were observed in the animals from group II, and, to a larger extent in animals of group III. The main reason for the mentioned changes of that kind are the very fine foodstuff particles, less than 0.05 to 0.5 mm in length, which form extraneous deposits in the mucosa or act as cement substances between neighbouring villi. This leads to hyperkeratosis because these particles prevent desquamation of the corneal cells and at the same time produce conditions of compression; these, in turn, result in a hardening of the newly formed stratum corneum. Hypertrophy of the undamaged villi was observed in animals of group III receiving the pelleted ration (thickness of villi group III: 243 mum as compared with group I:196 mum). The unfavourable morphological state of the ruminal mucosa in animals of group III was associated with a reduced rate of daily weight gains and increased food consumption.     

Noradrenergic and cholinergic innervation of the accessory sexual glands in male sheep

Immunohistochemistry was applied to determine the distribution patterns of nerve fibres containing tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP) and vesicular acetylcholine transporter (VAChT) in the prostate, seminal vesicle (SV) and bulbourethral glands (BU) of male sheep. In all organs studied, cholinergic innervation was more developed than noradrenergic innervation. Numerous VAChT-immunoreactive (IR) nerve fibres were found in the muscular layer and mucosa of the SV and BU as well as in the prostate. A similar abundance of noradrenergic nerve fibres (showing immunoreactivity both to TH and DbetaH) was also found in both layers of the SV and BU (but not in the prostate). In the prostate a moderate density of VIP-IR nerve fibres was present but only very scarce NPY-IR nerve fibres were shown. All the studied accessory sexual glands (ASG) of male sheep contained VIP-IR nerve fibres in a similar frequency. Double immunohistochemistry revealed that the vast majority of noradrenergic nerve fibres also contained NPY. None of the noradrenergic nerve fibres showed the presence of VAChT or VIP. The possible functional significance of these findings is discussed.     

湖羊精料补充料饲用价值的研究

通过饲养试验和消化试验评定精料补充料在湖羊中的饲用价值。选取健康的、体重约22 kg的生长育肥湖羊120只(60♂+60♀),将其分成对照组和试验组,每组60只(30♂+30♀),每组4个重复,每个重复15只。对照组羊日粮为羊场现行的日粮,由大体积性饲料与羊场精料补充料组成;试验组羊日粮由大体积性饲料(和对照组相同)与本试验研制的精料补充料组成;饲养试验周期60 d,消化试验期7 d。结果如下:①与对照组比较,试验组羊平均日增重提高37.95%(P<0.01);对无氮浸出物、粗纤维、粗蛋白质和粗脂肪的消化率分别提高5.10%(P<0.01)、5.38%(P<0.05)、5.83%(P<0.05)和3.07%(P<0.05)。②试验组羊血糖显著高于对照组(P<0.05);血清谷草转氨酶活性极显著低于对照组(P<0.01);其余多数血清生化参数不同程度地优于对照组羊,但差异不显著(P>0.05)。③试验组羊每千克增重所需饲料成本(10.49元/kg)较对照组(13.04元/kg)降低19.56%,净节约饲料成本2.55元。结果表明:自制的精料补充料饲用价值优于羊场精料补充料,为湖羊精补料的开发提供依据。     

Influence of management system on litter size, lamb growth, and carcass characteristics in sheep.

Three management systems (winter, spring, and late summer) distinguished by season of lambing and management practices were compared for litter size born and weaned and growth and carcass characteristics of lambs. Three sire breeds (Cheviot, Rambouillet, and Suffolk) and three dam breeds (Florida Native, Native-X, and Synthetic-X) were used in 698 matings over a 3-yr period. System affected (P < .01) litter size born. Spring lambing yielded more lambs (1.62) than winter (1.49) and late summer (1.12). The winter-born lambs were lighter but fatter (P < .05), and spring-born lambs were leaner with higher leg conformation and carcass quality scores. The late summer-born lambs were not different from spring-born lambs. Wethers had higher (P < .01) weights off test than ewe lambs (43.9 vs 42 kg) but had lower (P < .01) leg conformation scores, percentage kidney and pelvic fat, yield grade, and dressing percentages. Dam breed effects were significant (P < .05) for average preweaning daily gains with 249+/-5, 201+/-9, and 191+/-9 g for progeny of Native-X, Florida Native, and Synthetic-X, respectively. Single-born lambs had higher daily gains (P < .05) than twins in a preweaning period in all management systems and higher postweaning and lifetime daily gains for winter and spring management systems.     

A comparative study of feeding behavior and digestive function in dairy goats, wool sheep and hair sheep

An intake and digestibility study was conducted with three groups (six animals per group) of yearling wether dairy goats (four Toggenburg, two Alpine), wool sheep (Targhee X Dorset) and hair sheep (St. Croix). Body weight (BW) ranged from 42 to 52 kg, averaging 47 kg. All animals were penned individually and given ad libitum access to a mixture of alfalfa-smooth bromegrass hay in pelleted, chopped or long form. Each group contained three ruminally cannulated animals. There were no apparent differences in the composition of feed consumed among goats, wool sheep and hair sheep, and no significant animal type X forage form interactions for any of the variables evaluated. Significant differences were observed in dry matter intake (DMI) between wool sheep, hair sheep and goats: 3.17%, 2.66% and 2.23% of BW, respectively (P less than .05). Daily water intake (WI) was greatest for wool sheep (P less than .05), but not different between hair sheep and goats. Total digestibility of dry matter (DM) and all fiber fractions were similar among animal types. For the cannulated animals, ruminal content weight and total ruminal volume were greatest for wool sheep (P less than .05). Ruminal acid detergent lignin (ADL) turnover was greater in wool and hair sheep than goats (P less than .05), but no differences were apparent for dry matter or neutral detergent fiber (NDF) turnover. For all animals, DMI, DMI/BW, digestible DMI and WI were greater for pelleted than chopped and long hay (P less than .05). Total ruminal volume, contents weight (on an absolute or BW basis) and fluid volume were lower in the cannulated animals consuming pelleted hay (P less than .05). Ruminal DM turnover rate was faster on pelleted than long hay, while DM turnover rate on chopped hay was intermediate. Turnover of ADL was faster on pelleted than chopped or long hay (P less than .05), but there were no differences among forage forms in NDF turnover rate. Fluid turnover rate was faster on pelleted and chopped than on long hay (P less than .05). Under the conditions of this study, no apparent differences were observed among animal types in the nutrient composition of feed consumed, ruminal or total tract digestibilities or rate of passage for dry matter. However, feeding behavior or selectivity differences under natural grazing conditions may deviate from what has been observed in confinement.     

Metabolism and hematology studies of intensively raised fattened lambs under various feeding and management conditions. 2. The effect of various management methods on the blood picture, serum mineral and bilirubin concentration and vitamin A concentration in the liver]

Calcium, phosphorus, magnesium and bilirubin content, blood picture and liver vitamin A were studied in four groups of intensively fattened lambs kept under different conditions of management, in comparison with a control group. Results are shown in graphs and tables, Group-specific differences were found in some of the parameters examined: - Ca, P, erythrocytes, leucocytes, vitamin A.     

饲养水平对阿勒泰羊胃肠道发育、瘤胃发酵参数及瘤胃微生物区系的影响

为研究饲养水平对阿勒泰羊胃肠道发育、瘤胃发酵参数、消化酶活性及瘤胃微生物区系的影响,选取月龄相近(3～3.5月龄)、体重均一(19.16±0.54)kg、臀型一致、健康状况良好的阿勒泰母羔羊30只,随机分为3组,每组10只,自由采食60 d后,参照NRC(2007)饲养标准中维持能量(Em)需要,3个组分别按1.5Em...