The influence of ketamine and other intravenous anaesthetic agents on cerebral blood flow in the sheep

Cerebral blood flow (CBF) was measured in sheep by measuring clearance of directly injected ¹³³ Xenon from the cerebral cortex. The influence of ketamine at various dose levels on the CBF was measured and compared to the effects produced by pentobarbitone and CT1341. It was found that ketamine caused an initial depression of CBF followed by a rise, pentobarbitone produced a profound long lasting depression whilst CT1341 caused an initial depression which was rapidly followed by a return to control values.     

The effect of gastrointestinal parasitism on blood copper and hemoglobin levels in sheep

Endoparasitism is a problem in Trinidad, as it is in most tropical countries. Parasite infection has been suspected to contribute to the pathogenesis of swayback disease (which is also prevalent in Trinidad), but the mode of action has not been clearly defined, although it has been suggested that parasites interfere with the absorption of copper from the gastrointestinal tract. The objectives of the study were to assess the effect of endoparasitism on blood copper levels and hemoglobin (Hb) concentration in sheep in Trinidad. Copper was administered intramuscularly to parasite infected and noninfected animals. The results showed that parasitism has a depressing effect on blood copper and Hb levels, even when administered parenterally. It is concluded that parasitism can aggravate existing hypocupremia and possibly influence the expression of swayback disease.     

Effects of physical stress on serum enzymes and other blood constituents in sheep

In connection with transfer of sheep from the lowland near Oslo to mountain pastures at an altitude of 1,200 m above sea level, investigations were carried out in 37 animals to study the effect of physical stress on serum enzymes and other blood constituents. The sheep were adult ewes and lambs. About half of the animals had been accustomed to outdoor life on pasture for more than one month, while the others were moved directly from indoor feeding. Blood was collected before departure, after six hrs. of long-distance transportation by lorry, and after three hrs. of subsequent continuous herding on foot. The following blood components were determined: Aspartate aminotransferase (AspAT = GOT), alanine aminotransferase (A1AT = GPT), α-hydroxybutyrate dehydrogenase (HBD), total lactate dehydrogenase (LDH), LDH isoenzymes, alkaline phosphatase, calcium, inorganic phosphorus, magnesium, blood sugar, total serum proteins, and haemoglobin.In summary, it may be said that the lambs reacted with greater changes of the blood components than adult animals, and that untrained, indoor fed lambs were distinctly more sensitive than those taken from pasture. The “indoor” lambs showed a statistical significant increase from the initial values in AspAT, HBD, total LDH, the isoenzymes LDH₃ and LDH₄, and blood sugar. Significantly decreased values were recorded in Ga, P, Mg, and total serum protein. Some of these changes, as in Mg and P, were most pronounced after transportation, while elevations of serum enzyme levels continued to increase during the subsequent herding.Based upon the shift in LDH isoenzyme distribution towards a more cathodically dominated pattern it is supposed that the main origin of increased serum enzyme activity was skeletal muscle.     

锗硒对绵羊血液中某些微量元素含量的影响

为探讨绵羊补充锗硒的有效性以及对血液中其他微量元素含量的影响,选取20只羯滩羊随机分成4组,每组5只.Ⅰ组为对照组,Ⅱ组每只绵羊每20d肌肉注射0.2%亚硒酸钠溶液2mL,Ⅲ组每只绵羊每天口服Ge-132溶液(1g/L)50mL;Ⅳ组同时补充亚硒酸钠和Ge-132,试验期为2个月.在试验前和试验第10、20、30、40、50天采取血样,测定全血中锗、硒、锌、铜含量.结果显示,单独补充硒或锗后,绵羊全血硒、锗含量都显著升高(P＜0.05或P＜0.01),与锗硒联合应用组全血锗、硒含量没有显著差异;各试验组绵羊全血铜、锌含量与对照组差异不显著.结果表明,绵羊补充锗硒后,全血锗、硒含量显著升高,与锌、铜没有拮抗作用.     

The influence of manganese in association with other dietary components on certain shell characteristics

Four groups of pullets were given, from 17 weeks of age, a high‐Mn diet, or one of three low‐Mn diets. Hens given low‐Mn diets laid eggs with poor shells, judged by appearance, strength and thickness at the start of lay, but only one low‐Mn diet (diet 4), was associated with poor shells throughout 12 months of egg production. Supplementary Mn (100 mg/kg) added to low‐Mn diets after 12 months had no significant effect during the next 2 months on shell appearance score, strength or thickness.

In a second experiment, four groups of pullets aged 16 weeks were given diets of low or high Mn content and high or moderate P content. At the start of the laying period there was a significant interaction between Mn and P, a high level of P increasing shell defects caused by low Mn. At a later stage, 4 months after the start of egg laying, high P significantly reduced shell strength and thickness but had no effect on appearance score: low Mn had only a small non‐significant effect on any shell characteristic at this stage.

In a third experiment pullets of five White Leghorn type hybrids aged 16 weeks were given diets of low or high Mn and high or low Ca until the point of lay, when all birds received the high‐Ca diet but continued receiving the level of Mn given from 16 weeks of age. Only shells produced at the start of lay were studied. Type of hybrid influenced the number of soft shells produced but had no significant effect on other characteristics. Manganese significantly influenced all shell measurements and a high level of Ca increased the number of soft shells, decreased strength and thickness but had no effect on appearance score. There were no significant interactions.     

Effect of different fat sources on in vitro degradation of nutrients and certain blood parameters in sheep

This study was designed to determine the effects of calcium salt of palm oil fatty acids (CS), hydroxyethylsoyamide (HESA), butylsoyamide (BSA) and soybean oil (SO) on degradation of crude protein and fibre in vitro, and on the blood plasma lipid parameters in vivo. Five mature wethers (body weight 75 kg) were fed five diets in a 5 x 5 Latin square experiment. The control diet consisted of 50% meadow hay and 50% concentrate with no added fat. The control diet was supplemented with CS, HESA, BSA, or SO. Fat was added at 3.5% of dietary dry matter (DM). The final ether extract content of the ration was near 6%. Each period lasted 20 days. Fat supplements, except HESA, consistently decreased the in vitro DM disappearance of soybean meal as compared to control. In contrast to the effect of other treatments, crude protein degradation was greatest in the test tubes with inocula obtained from sheep fed diet with HESA. Fat supplements equally inhibited the DM and fibre breakdown of alfalfa pellet. CS and HESA seemed to be less detrimental to in vitro fermentation of neutral detergent fibre (NDF) than BSA and SO. All fat supplements increased blood plasma triglyceride, cholesterol and total lipid content. Plasma concentration of cholesterol and total lipid was highest with SO. The inclusion of CS in the diet increased 16:0, while all fat supplements increased plasma 18:0 and decreased 16:1 and 18:1 fatty acid content. Plasma 18:2n-6 was not changed by feeding CS and SO. However, compared to the control diet, 18:2n-6 increased with 12 and 41% in plasma fatty acids when sheep were fed HESA and BSA, respectively. The results showed that plasma concentration of linoleic acid was enhanced more when the amide was synthesised from butylamine than when from ethanolamine.     

策勒黑羊、和田羊和卡拉库尔羊血液蛋白多态性研究

血液蛋白多态性可以作为一个遗传标记因子来反映动物的遗传变异情况。不同品种间的不同位点血液蛋白具有一定差异,所以由多种血液蛋白多态性所标记的多基因型,可用来标记品种特征（张细权,1997）。本研究利用血液蛋白多态性,对塔里木盆地周边的策勒黑羊、和田羊、卡拉库尔羊3个绵羊品种进行遗传多样性分析,对种质资源保护和科学开发利用以及品种的起源、进化研究提供科学依据。     

蛋氨酸铜对绵羊增重及体内代谢的影响

26只晋中绵羊随机分为试验组(添加蛋氨酸铜)和对照组(添加硫酸铜),供试日粮及营养水平完全相同,试验时间60d。结果表明,试验组比对照组绵羊平均日增重提高34.22%(P<0.05);平均日粮干物质采食量、肝脏铜和血浆铜含量明显提高(P<0.05)。     

Interactive relations between copper, iron, zinc, arsenic, cadmium and lead in the liver in sheep after experimental poisoning with copper oxide

The interactions between copper, iron, zinc, arsenic, cadmium and lead were studied in the livers of 12 ewes of the Improved Wallachian breed after experimentally induced intoxication with cuprous oxide from industrial emission. The highest correlation coefficient was recorded between the concentrations of copper and zinc in the livers of the experimental ewes (r = 0.916) and its value was at a significance level of p less than 0.05. The interaction between copper and arsenic in the liver of the experimental animals corresponded to a correlation coefficient of r = 0.359 and that between copper and cadmium corresponded to r = 0.129. The lowest correlation coefficient in the livers of the experimental animals was recorded between copper and lead (r = 0.073). As to the relationships between the remaining elements, the highest correlation coefficient (r = 0.667) was obtained between the contents of zinc and cadmium in the livers of the experimental ewes. The interaction of copper with the other risky metals after experimental intoxication was limited by the concentration of the studied elements in the industrial emission as well as by the course of the disease itself.     

Control of sheep scab and other sheep ectoparasites with propetamphos

Propetamphos is a new organophosphorous compound with broad spectrum acaricidal and insecticidal activity. Dip wash concentrations of 100 to 200 ppm protect sheep against field challenge for approximately 10 weeks for blowflies, 16 weeks for lice and keds and six weeks for ticks. During laboratory and field trial studies a wash concentration of 125 ppm propetamphos eradicated sheep scab and protected from reinfestation for over four weeks.     

Production of N2 and N2O from nitrate ingested by sheep

Supplementing ruminants with nitrate reduces their enteric methane (CH₄) emissions; however, the greenhouse gas (GHG) mitigation achieved can be partially offset by small emissions of nitrous oxide (N₂O), a more potent GHG. Sheep were dosed intraruminally with ¹⁵ to investigate whether dietary is a precursor of N₂O and/or di‐nitrogen gas (N₂), and to quantify the amounts of recovered as N₂O and N₂ in gas emissions from sheep adapted or not adapted to dietary . Ruminally cannulated sheep were adapted to a hay diet supplemented with (n = 3; 10 g /kg DM) or urea (n = 3; 5.3 g urea/kg DM). On the day of the experiment all sheep were dosed intraruminally with ¹⁵ and quickly moved into gas‐tight chambers to enable recovery of ¹⁵N in N₂O and N₂ to be measured. Measurements of gases accumulating in the chambers were made over 10 successive 50 min periods; this enabled the amount of N₂O produced, and the recovery of ¹⁵‐N in N₂O and N₂ to be determined over a total of 10 hr. Only 0.04% of labelled ‐N was recovered as N₂O, and this was not dependent (p > .05) on whether or not the animals had been adapted to dietary . Approximatively 3% of ¹⁵‐N was recovered as ¹⁵N₂, which was also not dependent (p > .05) on whether sheep had been adapted to . Because the kinetics of rumen ammonia (NH₃) were uncertain, the recovery of ¹⁵N from in rumen NH₃ could not accurately be quantified, but our results suggest that approximately 76% of dietary was converted to NH₃ in the rumen. We conclude that the small amount of recovered in N₂ was evidence of denitrification, previously thought not to occur in the rumen.