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.     

Lactate dehydrogenase isoenzymes in the lungs of sheep with acute and chronic pneumonia

Total lactate dehydrogenase and the absolute and percentage levels of its isoenzymes were measured in lung lesions and macroscopically normal areas of lung from lambs with chronic proliferative exudative pneumonia and acute pasteurella pneumonia. Lung lesions had a higher total enzyme activity which was associated mainly with increases in the activity of the LDH₄ and LDH₅ isoenzymes, particularly in chronic pneumonia, and gave lung lesions a considerable potential for altering the serum isoenzyme distribution. Thus, the nature of any changes in the serum isoenzyme distribution will depend on whether the isoenzymes are released from abnormal or normal areas of lung. This appears to be the first report on lactate dehydrogenase isoenzymes in ovine pneumonia.     

Serum enzyme changes in lambs with experimentally induced acute muscular dystrophy

An experiment was performed to study some serum enzyme changes taking place in artificially fed lambs made dystrophic on a skim milk ration supplemented with α-tocopherolextracted cod liver oil. In the course of two to three weeks the lambs showed highly increased serum values of aspartate- and alanine aminotransferase (AspAT = GOT and A1AT = GPT), total lactate dehydrogenase (LDH), and creatine phosphokinase (GPK). The latter enzyme proved to be the most sensitive test of myopathies, with serum values above 1000 times the normal level. A high-grade hyaline skeletal muscle degeneration was confirmed by histology. Myocardial changes were also present.Contrary to expectations, electrophoretic separation of LDH isoenzymes in the serum of the dystrophic lambs did not reflect any increase of the prevalent muscular cathodic thermolabile fraction LDH₅. The use of a so-called LDH heat stability test as an aid in clinical diagnostic work, as previously suggested, therefore does not seem to be valid in this disease. The results are discussed.     

Isoenzymes of lactate dehydrogenase in swine. Stability during storage at different temperatures and by heat treatment

The isoenzymes of lactate dehydrogenase (LDH) in serum from normal pigs were studied after separation by agar gel electrophoresis with subsequent staining with a tetrazolium salt.Experiment 1. The stability of isoenzymes was investigated for 5 successive days after storage at room temperature (22°C), in the refrigerator (4°G), and once after storage for 32 days in the deep-freezer (—20°C). Greatest loss of activity was seen after storage in the refrigerator, where LDH₂ and LDH₃ lost most of its activity after 5 days. In LDH₄ and LDH₅ no loss had occurred at this time. Also at room temperature great losses were seen in LDH₂ and LDH₃. After storage in the deep-freezer an increase in LDH₃ activity was recorded.Experiment 2. Serum samples were kept in water baths for 30 min. at 50, 53, and 56°C. A simultaneous and increasing loss in activity of LDH₃, LDH₄, and LDH₅ was seen from 50° to 56°C. At 56° no activity was left in LDH₃, LDH₄, or LDH₅, and only about 15 % of the original activity was present in LDH₂. LDH₁ showed no loss at 56°, but all activity was lost at 65°.A close correlation was found between total lactate dehydrogenase and α-hydroxybutyrate dehydrogenase activity in both experiments.     

Heat stability of serum lactate dehydrogenase and its isoenzymes in young and adult cattle and sheep. Evaluation of a relative heat stability test and serum determination of alpha-hydroxybutyrate dehydrogenase in diagnostic work

The heat stability of lactate dehydrogenase (LDH) has been investigated in serum from young and adult cattle and sheep. The thermoresistance of the isoenzymes was determined by electrophoresis of serum samples preincubated at different temperatures. Marked differences were found in the percentage distribution of isoenzymes in serum from the two species as well as in the heat stability. LDH in serum from sheep was inactivated at a lower temperature than that in serum from cattle, and inactivation occurred at a lower temperature in young than in adult animals. The enzyme was in both species less tolerant to elevated temperatures than what is reported for human serum. Procedures worked out for a so-called relative heat stability test of LDH in human clinical diagnosis may therefore give misleading results if they were applied uncritically to sera from these animals.The LDH isoenzyme pattern of some main organs in calves and sheep indicates that a serum heat stability test may be useful in the diagnosis of skeletal muscle injuries in sheep. In cattle the tissue isoenzyme distribution is assumed to be too uniform to give information about specific organ lesions either by serum electrophoresis or by a heating technique.In contrast to what has been reported in man, serum levels of α-hydroxybutyrate dehydrogenase (HBD) in cattle and sheep, as earlier reported in swine, are found to be far better correlated to total LDH than to the most thermostable isoenzyme, LDH₁.     

A serum enzyme increasing effect of non-toxic herring meal fed to sheep

In a series of experiments it was demonstrated that highly increased activities of aspartate aminotransferase (= GOT), total lactate dehydrogenase (LDH), and α-hydroxybutyrate dehydrogenase (HBD) occurred in serum of sheep on herring meal feeding. The alanine aminotransferase (A1AT = GPT) level remained unchanged. The enzyme increase was apparently not related to the liver toxic agent dimethylnitrosamine (DMNA) occasionally occurring in lethal doses in meals produced from raw materials preserved with excesses- of nitrite. Histological changes of the liver or other tissues were never detected in experimental animals killed at a stage with very high serum enzyme values. Diets equivalent in digestible crude protein consisting of vegetable as well as of animal protein sources other than fish meal, did not give rise to elevated serum enzyme values.Electrophoretic separation of the LDH isoenzymes in serum of herring meal-fed sheep showed an increased percentage of the LDH₁ fraction, which is predominant in liver, heart, and kidney. Determination of enzyme activities in various tissues resulted in a markedly higher concentration in livers from herring meal-fed animals than in sheep fed casein at an equal protein level. It is suggested that herring meal may have a special promoting effect on the de novo synthesis of the enzymes concerned.As a practical consequence of the experiments it must be emphasized that serum determinations of these enzymes for diagnostic purposes will give a false picture of the clinical condition of sheep fed even moderate amounts of herring meal.     

Lactate dehydrogenase isoenzymes in the lungs of sheep with acute and chronic pneumonia

Total lactate dehydrogenase and the absolute and percentage levels of its isoenzymes were measured in lung lesions and macroscopically normal areas of lung from lambs with chronic proliferative exudative pneumonia and acute pasteurella pneumonia. Lung lesions had a higher total enzyme activity which was associated mainly with increases in the activity of the LDH4 and LDH5 isoenzymes, particularly in chronic pneumonia, and gave lung lesions a considerable potential for altering the serum isoenzyme distribution. Thus, the nature of any changes in the serum isoenzyme distribution will depend on whether the isoenzymes are released from abnormal or normal areas of lung. This appears to be the first report on lactate dehydrogenase isoenzymes in ovine pneumonia.     

Enzymes Sériques pour le Diagnostic de la Nécrose Hépatique Aigüe Expérimentale

The activity of certain serum enzymes ornithine carbamyl transferase (OCT), serum isocitric dehydrogenase (SIC-D), total serum lactic dehydrogenase (LDH) and its isoenzymes (LD₁ and LD₅) was evaluated as a mean of assessing experimental hepatic necrosis on dogs treated with CCl₄. Measurement of activity levels of these enzymes, seldom carried out in veterinary clinical pathology, was made together with tests commonly used in our laboratories: serum glutamic pyruvic transaminase (SGPT), serum glutamic oxalacetic transaminase (SGOT) and serum alkaline phosphatase (SAP), cholesterol, bilirubin and prothrombin time. Measurement of the level of OCT was useful in the diagnosis of liver necrosis. The SIC-D level was important during the first four days of the experiment, but on subsequent days, the enzymatic activity was practically normal. Because of the wide variations of LDH serum levels in normal animals and since many factors influence its activity, the measurement of this enzyme and its isoenzymes was not a good index in the diagnosis of canine liver necrosis. The evaluation of cholesterol and bilirubin was judged of secondary importance because these metabolites are not specific to hepatic problems.     

Effect of yeast supplementation on the growth performance of Malpura lambs

Thirty-six Malpura lambs (age?=?58 days; 8.9 kg BW) were equally divided into three groups (N?=?12; six males and six females) to assess the effect of probiotics supplementation on growth, digestibility, rumen fermentation and carcass attributes. The lambs of the control group (CON) were not supplemented with probiotics, while test groups received either Saccharomyces cerevisiae (SC) or combination of S. cerevisiae and Lactobacillus sporogenes (SCLS) at 1.5 % of concentrate mixture. The lambs were fed ad libitum concentrate mixture and bajra (Pennisetum typhoides) straw in a cafeteria system until 180 days of age. Daily feed intake and weekly live weight changes were recorded. A metabolism trial was conducted on six lambs at 90 days. Rumen fermentation study was conducted at 105 days. At 6 months, all male lambs were slaughtered and carcass characteristics were recorded. Body weight and average daily gain (ADG) were similar among the three groups. The digestibilities of all the nutrients were also similar among the groups, except acid detergent fiber (ADF) digestibility, which was higher (P?=?0.032) in SC and SCLS than the CON. The rumen fluid pH was higher (P?=?0.04) in CON and SC group than SCLS at 0 h while NH₃-N at 8 h sample was higher (P?=?0.031) in SC and SCLS group than the control. Pre-slaughter weight, hot carcass weight and dressing yields were similar. ADF digestibility and rumen fermentation was improved in lambs by probiotic supplementation. However, carcass traits remained unchanged due to probiotics supplementation.     

妊娠后期母羊饲粮精料比例对羔羊生长性能、消化性能及血清抗氧化指标的影响

本试验旨在研究妊娠后期母羊饲粮精料比例对羔羊生长性能、消化性能和血清抗氧化指标的影响。试验选用66只妊娠90 d、平均体重为(44.45±2.20)kg的初产湖羊,按照体重相近原则随机分为3组,每组11个重复,每个重复2只。各组母羊妊娠期饲粮精料比例分别为50%、40%和30%,分娩后母羊饲喂相同的全混合日粮(TM R)。羔羊10日龄,每只母羊取1只羔羊断母乳,饲喂代乳粉;15日龄补饲开食料;20日龄补饲苜蓿干草,自由采食至60日龄。每10 d测定1次羔羊体重,51~60日龄进行羔羊消化代谢试验,20和60日龄采集羔羊血液测定血清抗氧化指标。结果表明:妊娠后期母羊饲粮精料比例对羔羊1、10、20、30、40、50、60日龄体重,20、60日龄体尺指标及营养物质表观消化率均无显著影响(P0.05)。随母羊饲粮精料比例降低,20日龄羔羊血清总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)活性极显著升高(P0.01),60日龄50%组显著或极显著低于其他2组(P0.05或P0.01);30%组20和60日龄羔羊血清谷胱甘肽过氧化物酶(GSH-Px)活性极显著高于其他2组(P0.01);血清中MDA的含量在20日龄时随母羊饲粮精料比例的降低而极显著降低(P0.01),60日龄时50%组显著高于30%组(P0.05)。结果提示,妊娠后期母羊饲粮的精料比例对产后早期断奶羔羊的体重、体尺、营养物质表观消化率无显著影响,但随母羊饲粮精料比例的降低,羔羊血清的抗氧化能力提高。     

Performance of the Santa Ines breed raised on pasture in semiarid tropical regions and factors that explain trait variation

This study aimed to evaluate sex, the number of lambs per birth, and the family effects on production traits in the Santa Ines breed of sheep by estimating the least square means and coefficient of variance for those traits. A total of 484 lambs were evaluated for the following traits: weight at birth, at weaning, and at 240 days of age; weight gain during the pre-weaning and post-weaning periods; height, width, and length of different body regions; and rib eye area and fat thickness between the 12th and 13th ribs. We observed coefficients of variation higher than 10 % for several traits. Generally, males were larger than females (P?P?P?ANOVA.     

Serum enzyme activity of newborn calves, pigs and lambs

Serum activities of aspartate aminotransferase (AspAT = GOT), alanine aminotransferase (AlAT = GPT), and total lactate dehydrogenase (LDH) have been investigated in newborn calves, pigs, and lambs. In the two latter species the LDH isoenzyme distribution in serum was also studied. Blood samples were taken at frequent intervals from birth to 48–72 hrs. post partum.Calves and pigs were born with very low serum enzyme values, whereas lambs showed a picture more similar to what has been reported in human infants. In all species a marked temporary enzyme increase occurred during the first 24–48 hrs. This elevation was found not to be due to colostrum feeding, since a parallel increase was found in starved animals. Possible regulating mechanisms are discussed.The LDH isoenzyme pattern proved to be more stable than total LDH in the early post-natal period.The percentage isoenzyme distribution, however, showed characteristic differences from that found in adult animals of the same species.     

Growth response to increasing doses of microencapsulated vitamin B12 and related changes in tissue vitamin B12 concentrations in cobalt-de cient lambs

AIM: To investigate growth responses of cobalt-deficient lambs to increasing doses of microencapsulated vitamin B₁₂, and to measure associated changes in serum and liver vitamin B₁₂ concentrations over 243 days.

METHODS: From a flock grazing pastures that had low cobalt (Co) levels (about 0.06 mg Co/kg dry matter), 4-6-week-old lambs (n=137) were assigned to four groups and received either no treatment or a subcutaneous injection of 3.0, 4.5 or 6.0 mg of microencapsulated vitamin B₁₂ on Day 1. At approximately monthly intervals, all lambs were weighed and blood samples were collected from a selection (n=10) of monitor animals, up to Day 243. Liver biopsies were also carried out on the monitor lambs (n=8) on Days 1, 124 and 215.

RESULTS: The vitamin B₁₂-treated lambs grew significantly faster (p<0.001) than untreated animals. Liveweights after 243 days were 28, 45, 45 and 47 kg for the untreated, 3.0, 4.5 and 6.0 mg vitamin B₁₂-treated lambs, respectively. Of the initial group of untreated lambs, 68% had to be removed before the end of the trial because of substantial weight loss, but none of the treated animals were similarly afflicted. Serum vitamin B₁₂ concentrations increased in all vitamin B₁₂-treated lambs, reaching a peak at Day 25, and those of the 4.5 and 6.0 mg vitamin B₁₂-treated lambs remained significantly higher (except at Day 124) than the untreated lambs to Day 187. However, at Day 124, but not Day 215, the liver vitamin B₁₂ concentrations of treated lambs were two to three times higher than those of controls.

CONCLUSIONS: The growth rates of Co-deficient lambs were markedly improved by injection of 3.0, 4.5 or 6.0 mg of microencapsulated vitamin B₁₂, and liveweights were maintained for at least 243 days. Serum vitamin B₁₂ concentrations were related to this growth response; concentrations of <220 pmol vitamin B₁₂/l were associated with a 95% probability that lambs were Co-deficient and would thus respond to Co/vitamin B₁₂ supplementation. Based on these data, the current New Zealand reference criteria for Co deficiency should be reviewed.

CLINICAL SIGNIFICANCE: An injection of 3 mg microencapsulated vitamin B₁₂2 given to lambs at tailing will treat Co deficiency and will increase and maintain liveweights in a flock for up to 8 months.     

Effects of Weaning Age on Growth Performance,Digestion and Metabolism of Hu Sheep Lambs and Serum Hormone Contents of Ewes北大核心CSCD

本试验旨在研究断奶日龄对湖羊羔羊的生长性能、消化代谢及母羊血清激素含量的影响,以期为补饲代乳料条件下,湖羊羔羊早期断奶的可行性提供依据,并确定最佳断奶时间。选取出生日期相差不超过3 d、体况良好、健康无疾病的羔羊90只,将羔羊随机分为3组,每组3个重复,每个重复10只。7日龄开始饲喂代乳料的情况下,分别于25日龄(试验Ⅰ组)、35日龄(试验Ⅱ组)、45日龄(对照组)断奶,试验期90 d。结果表明:1)在16~45日龄,试验Ⅰ组羔羊由于断奶应激,导致羔羊采食量减少,平均日增重低于试验Ⅱ组,且在31~45日龄,平均日增重显著低于对照组(P<0.05)。试验Ⅰ组平均日采食量分别比试验Ⅱ组高出5.09%(P<0.05),比对照组高出7.50%(P<0.05)。2)试验Ⅰ组的粗蛋白质(CP)表观消化率显著低于试验Ⅱ组与对照组(P<0.05),试验组湖羊羔羊的氮摄入量、净蛋白质利用率和蛋白质生物学价值指标与对照组相比差异显著(P<0.05)。3)断奶当天,试验Ⅰ组血清高密度脂蛋白胆固醇(HDL-C)的含量极显著高于试验Ⅱ组和对照组(P<0.01),且试验Ⅱ组显著高于对照组(P<0.05),试验Ⅰ组血清低密度脂蛋白胆固醇(LDL-C)含量极显著高于对照组(P<0.01),显著高于试验Ⅱ组(P<0.05),试验Ⅰ组血清总胆固醇(TC)含量显著高于试验Ⅱ组和对照组(P<0.05),试验Ⅱ组血清甘油三酯(TG)含量极显著高于试验Ⅰ组和对照组(P<0.01);90日龄,试验Ⅱ组血清葡萄糖(GLU)含量显著高于对照组(P<0.05);断奶当天,试验Ⅱ组血清碱性磷酸酶(ALP)活性显著高于对照组(P<0.05)。4)60日龄,试验Ⅱ组血清雌二醇(E2)含量显著高于对照组(P<0.05),而30日龄,试验Ⅰ组血清促乳素(PRL)含量极显著高于试验Ⅱ组和对照组(P<0.01)。5)试验Ⅰ组、试验Ⅱ组与对照组的羔羊成活率分别为76.67%、86.67%、90.00%。经综合评定,湖羊羔羊35日龄断奶是可行的。     

热应激条件下藿朴蒲苓散对育肥羔羊生长性能、消化性能和血清生化指标的影响

针对夏季绵羊遭受严重热应激现状,研究日粮中添加中草药组方(藿朴蒲苓散)对夏季育肥羔羊生长性能、消化性能、瘤胃发酵参数及血清生化指标的影响。选择200只体重相近、年龄一致的健康育肥公羔羊,随机分为4组,分别饲喂0%(对照组)、0.5%、1.0%和1.5%藿朴蒲苓散,试验期30 d,试验期间舍内温湿指数平均达79.11。试验末检测育肥羔羊生长性能、养分表观消化率、瘤胃发酵参数和血清生化指标。结果表明：1)饲喂0.5%藿朴蒲苓散的羊日增重显著高于对照组(P < 0.01);日饮水量和日采食量在不同组间未表现出显著性差异(P>0.05)。从生理指标分析,饲喂中草药的羊直肠温度和呼吸频率与对照组比较均未表现出显著性差异(P>0.05)。2)0.5%组的干物质(DM)、中性洗涤纤维、酸性洗涤纤维、粗蛋白、钙和磷等养分表观消化率均显著高于对照组(P < 0.05),DM消化率较对照组提高7.20%(P < 0.01),而1.0%和1.5%组的消化率较对照组未表现出显著性差异(P>0.05)。3) 从血清生化指标上,3个给药组的生长激素均显著高于对照组(P < 0.05),0.5%组含量最高,较对照组提高16.90%;且0.5%组的甲状腺素含量显著高于其他组(P < 0.05)。4)从瘤胃发酵参数分析,3个给药组总挥发性脂肪酸含量、乙酸和丁酸含量均显著高于对照组(P < 0.05),分别是对照组的1.19~1.30倍、1.18~1.24倍和1.28~1.43倍。综上,本试验条件下,日粮中添加藿朴蒲苓散有助于缓解育肥羔羊的热应激,添加量以0.5%效果更佳。     

Haemolytic Complement Activity of Sera of Foetal and New-Born Lambs

Determination of the haemolytic complement titres of serum from 24 foetal lambs bled at 77 to 149 days gestation failed to reveal this activity earlier than 123 days. Titres near the end of the gestation period of 150 days were still very low. Among serum specimens collected from 17 newborn lambs before suckling, three were still without demonstrable complement activity. During the first week titres rose considerably in all of these lambs, were higher at three weeks but at ten weeks were still below the adult level.

A number of foeti had been injected with antigen mixtures at 50 to 111 days' gestation and had responded with antibody development to one or more of these antigens. The rate of development of complement in these treated foetal lambs appeared similar to that in their untreated twin controls.

     

Effects of age on the electroencephalographic response to castration in lambs anaesthetized with halothane in oxygen from birth to 6 weeks old

ObjectivesTo characterize changes in the cerebro‐cortical response of lambs to rubber‐ring castration during the first 6 weeks of postnatal life.AnimalsCoopworth‐Texel cross ram lambs between 3 hours and 44 days of age.MethodsThe electroencephalogram (EEG) and heart rate responses to rubber ring castration were compared. Anaesthesia was induced via a face mask and maintained with halothane in oxygen (e′_Hal = 1.2%). Once a stable plane of anaesthesia had been achieved, data collection of EEG and electrocardiogram (ECG) commenced, and the lambs were castrated 15 minutes later, using rubber rings. Heart rate was derived from the ECG and the median frequency (F₅₀), spectral edge frequency (F₉₅) and total power (p_tot) were derived from the EEG.ResultsCastration‐induced changes in F₅₀ increased from 2 ± 1.8% in the youngest lambs to a maximum of 33 ± 8.9% in the 36 ± 0.5 day‐old lambs. Changes in F₉₅ increased from ?7 ± 3% in the youngest lambs to a maximum of 16 ± 11% in the 36 ± 0.5 day‐old lambs. Linear regression analysis in lambs up to 10 days of age demonstrated a change in the response with age that was significantly different from zero for F₅₀ (r² = 0.28, p = 0.007) and F₉₅ (r² = 0.38, p = 0.001), but not for p_tot or heart rate.ConclusionThis study identified significant changes in the responsiveness of the lambs’ cerebral cortex to the noxious stimulation of castration over the first 7–10 days of postnatal life. The results suggest that mechanisms that suppress responses of the fetus to noxious stimulation may still be active in the first few days after birth.Clinical relevanceThis study documents changes in central nociceptive processing which may reflect the ability of neonatal animals to perceive pain.     

Fattening ability and carcass value of Dhamari and Tehami ram lambs,F1 crossbreds of Dhamari × Tehami in Yemen

A fattening experiment was carried out to analyze and evaluate the effect of ram lamb genotype on the growth, feed conversion (FC), and carcass value of Dhamari ram lambs, F1 crossbreds of Dhamari?×?Tehami (F₁ DhT), and Tehami ram lambs. Genotype of the ram lambs including the experiment (n?=?30) had high significant effect on total weight gain (TWG), average daily gain (ADG), and FC (P?P?P?P?P?P?P?1 DhT was better than Tehami ram lambs in ADG, TWG, and FC. Additionally, the results show that the feed conversion was in F₁ DhT crossbreds ram lambs better than pure Dhamari and Tehami ram lambs, mainly in the carcass indicators.     

Effects of concentrate feeding systems,genotype and sex on productive performance and meat quality of Norwegian lambs

Abstract

Two factorial experiments, I and II, were carried out in this study using 84 lambs (140±1.24 days old, 40.00±0.75 kg live weight) divided into six groups. Two levels of concentrate supplementation; restricted (0.4 kg concentrate/lamb/day) or ad libitum, two breed types; Norwegian White lamb or Nor-X and two sex types; ram or ewe lambs, were investigated. In experiment I, a 2×2×2 factorial arrangement of treatments (level of supplementation, sex, and breed) was imposed whereas a 2×2 arrangement of treatments (level of supplementation and breeds) was studied in Experiment II. Each of the two experiments lasted for four weeks. Lambs on ad libitum access to concentrate grew at 231 g d^–1 and 125 g d^–1 faster than those on restricted access in Experiment I and II, respectively. Moreover, ram lambs grew at 64 g d^–1 faster than ewe lambs. Lambs on ad libitum access to concentrate had about 5 kg heavier carcasses than that on restricted access. Ewe and ram lambs on ad libitum allowance to concentrate had 4.2 kg and 5.6 kg, respectively, higher carcass weight than those on restricted allowance. The two levels of concentrate supplementation had limited effects on the meat sensory qualities. Meat taste intensity increased with level of concentrate supplementation. Difference in meat tenderness between ram and ewe lambs was only evidenced on ad libitum concentrate feeding. Irrespective of stage of growth (Experiment I vs. II) and concentrate supplementation level, Nor-X lambs were superior to Norwegian White lambs with respect to carcass conformation scores. Based on results from sensory assessments of meat, ram lambs should be slaughtered before October to avoid off-flavour on meat.     

Lactate dehydrogenase and its isoenzymes in the tissues and sera of clinically normal dogs

The total activity of lactate dehydrogenase (LDH) and the percentage distribution of its isoenzymes in the tissues and sera of clinically normal adult dogs are presented. Total LDH activity was greatest in skeletal muscle followed by heart muscle, kidney, small intestinal mucosa, liver, lung, pancreas and bone. Each tissue had a unique isoenzyme pattern and the proportions of the isoenzymes in serum suggested that liver is the source of normal serum LDH. The tissue isoenzyme patterns were similar to those obtained by other authors in human beings, horses, cattle, sheep and cats although in liver, differences between ruminants and monogastric animals including dogs were evident. The data presented provide a basis for the interpretation of serum LDH isoenzyme patterns in canine disease.