Complement activity and conglutinin activity in stored bovine sera.

Complement activity and conglutinin activity were measured in bovine sera stored under four conditions: phenolized (3 C), lyophilized (3 C), frozen (-23 C), and frozen (-57 C). The complement activity was lost after 12 weeks in phenol (3 C). The other three conditions, ranked in order of increasing effectiveness, are lyophilized (3 C) and frozen (-23 and -57 C). Conglutinin activity was lost after 23 weeks in phenol (3 C). The other three conditions, ranked in order of increasing effectiveness, are frozen (-23 C), lyophilized (3 C) and frozen (-57 C). Thus, the most effective condition to preserve complement and conglutinin simultaneously is freezing at -57 C.     

叶下珠提取物体外抗氧化和保肝作用

采用叶下珠水提取物、75%乙醇提取物、95%乙醇提取物体外对羟自由基(·OH)、超氧阴离子(O2-)的清除和抑制H2O2诱导小鼠红细胞氧化溶血性等方法来研究叶下珠的抗氧化活性。以体外培养法获取罗非鱼的原代肝细胞,用CCl4对肝细胞建立体外损伤模型,研究叶下珠水提取物、75%乙醇提取物、95%乙醇提取物对丙氨酸转氨酶(Alanine aminitransperase,ALT)、天冬氨酸转氨酶(Aspartate aminotransferase,AST)活力的影响。叶下珠水提取物对羟自由基(·OH)、超氧阴离子(O2-)的清除和抑制H2O2诱导小鼠红细胞氧化溶血性最强。加药组丙氨酸转氨酶、天冬氨酸转氨酶活性显著低于损伤组,差异极显著(P<0.01)。叶下珠提取物具有明显的体外抗氧化和保肝作用。     

Peripartal changes in serum alkaline phosphatase activity and lactate dehydrogenase activity in dairy cows.

Peripartal serum alkaline phosphatase activity and lactate dehydrogenase activity were measured in 30 dairy cows in order to examine the association between retained fetal membranes and enzyme activity. Daily blood samples were obtained from pregnant cows, starting 15 days before the expected day of calving until eight days after parturition. Sera from 15 cows which retained fetal membranes longer than 24 hours and 15 cows which shed fetal membranes within six hours after parturition were analyzed for alkaline phosphatase and lactate dehydrogenase enzyme activities. Mean alkaline phosphatase enzyme activities ranged from 15.93 to 32.6 U/L in retained and nonretained placenta cows. There was a trend towards higher serum alkaline phosphatase activities in retained placenta cows but the differences were not significant among the groups (P greater than 0.05). Mean lactate dehydrogenase activities ranged from 307.2 to 438.86 U/L in nonretained and retained placenta cows. Lactate dehydrogenase enzyme activities in nonretained and retained placenta cows were similar (P greater than 0.05). The alkaline phosphatase and lactate dehydrogenase enzyme activities peaked at the time of parturition in both groups. However, the differences in alkaline phosphatase and lactate dehydrogenase activities on different days within non-retained and retained placenta cows were significant (P less than 0.05). Results indicate that prepartal changes in alkaline phosphatase and lactate dehydrogenase enzyme activities are not predictive of placental retention postpartum.     

Sleep and activity of piglets weaned into cages.

The duration and type of sleep and activity were monitored in a group of 9 Duroc piglets weaned at 7 weeks of age and placed into a cage of 1.2 x 1.2 m. Average air temperature in the cage ranged between 20 and 23 degrees C and relative humidity was around 70%. The piglets were fed and watered ad libitum. The measurements were performed one week after the pigs had been transferred to the cages, in the period between 8 a.m. and 1 p.m. Approximately half of the 5-hour period of observation was occupied by sleep. There were, however, marked individual differences (ranges: 66 and 24%). Non-REM sleep occupied 79% while REM sleep 21% of the whole sleep time. REM episodes lasted, on the average, 3.8 + 0.58 min. The other half of the period studied was occupied by wakefulness which was devoted to movement, lying and, also, massaging and sucking each other. In some animals this activity was high and was the cause of unrest in the whole group. Differences in respiratory rate between non-REM and REM sleep recorded in heavier animals were the result of their heat load.     

DAP-decarboxylase activity and lysine production by rumen bacteria.

The last step of pathway of lysine biosynthesis by rumen bacteria was tested. The first measurements of DAP-decarboxylase activity and of lysine production by Megasphera elsdenii, Selenomonas ruminantium, Clostridium spp., Butyrivibrio fibrisolvens and Bacteroides succinogenes as well as the first attempts to increase the lysine production by ruminal streptococci by mutation are described. The highest values were measured in Selenomonas ruminantium (DAP-decarboxylase activity = 146 micrograms DAP.min-1.mg-1 protein and lysine production was 390 micrograms.mg-1 protein) and the lowest values were ascertained in Butyrivibrio fibrisolvens (DAP-decarboxylase activity = 27 micrograms DAP.min-1.mg-1 protein and lysine production was 32 micrograms.mg-1 protein). DAP-decarboxylase activity was increased by mutation especially in Streptococcus bovis, the lysine production in both of tested ruminal streptococci. The potential use of lysine-excreting mutants in calves in future is suggested.     

Phosphatase activity in avian mycoplasmas.

Fifty-four strains of avian mycoplasma representing 11 species or serotypes were examined for their phosphatase activity using two different methods. Both methods gave similar results. All of four strains of Mycoplasma anatis and six of M meleagridis and the type strain of serotype L were phosphatase positive. The other species gave variable reactions between strains and on different occasions of testing.     

Sexual activity patterns in rams.

Behaviour was measured in reproductively experienced rams from three crossbred strains and two pure breeds (Suffolk and Finnish Landrace) in an attempt to develop a method for rapid screening of sexually aggressive rams and to measure breed differences in sexual activity. A set sequential pattern of activity need not occur in sexually experienced rams, and components of their sexual behaviour may be influenced by the estrual status of the ewe. The data indicate that the number of attempted mounts is an acceptable selection tool, with a mount following a short period of investigation most likely to be followed by coitus. Two sequential ten minute periods are sufficient for rapid screening of rams for short-term sexual activity levels.     

Phosphatase activity of placental extracts and pregnant mare's plasma.

Equine placental extracts show phosphatase activity with a pH optimum between 4.5 and 6. The enzyme shows heat stability to 45 degrees C and electrophoresis on cellulose acetate demonstrates the presence of two bands of activity. Histochemistry confirms the presence of phosphatase activity in the placental villi. Assay of plasma samples from pregnant mares showed no increase in phosphatase activity through pregnancy under conditions of test.     

Turkey macrophage and heterophil bactericidal activity against Pasteurella multocida.

Bactericidal activity of turkey macrophages and heterophils was demonstrated in an in vitro colorimetric bactericidal assay. Two vaccine strains and one field isolate of Pasteurella multocida A:3,4 and a single isolate each of Escherichia coli and Staphylococcus aureus were compared for susceptibility to the bactericidal activity of turkey macrophages and heterophils. Only P. multocida A:3,4-strain M-9 (the least virulent strain) was susceptible to macrophage bactericidal activity in the absence of specific immune serum, whereas all three P. multocida A:3,4 organisms were killed when opsonized with specific immune serum. E. coli was susceptible to the bactericidal activity of macrophages, and S. aureus was resistant. All bacteria tested were highly sensitive to the bactericidal activity of intact turkey heterophils, regardless of the opsonin treatment. Electron microscopic findings suggested that heterophils may kill extracellular P. multocida. Only S. aureus and E. coli were killed by lysed heterophils.     

Anthelmintic activity of paraherquamide in calves.

Paraherquamide, an oxindole alkaloid metabolite of Penicillium paraherquei and Penicillium charlesii, was tested against the adult stages of nine common gastrointestinal and lung nematodes of calves at single, oral dosages of 0.5, 1.0, 2.0 or 4.0 mg kg-1. At dosages 1.0-4.0 mg kg-1 there was 95% or more removal of Haemonchus placei, Ostertagia ostertagi, Trichostrongylus axei, Trichostrongylus colubriformis, Cooperia oncophora, Nematodirus helvetianus, Oesophagostomum radiatum, and Dictyocaulus viviparus. Cooperia punctata, the dosage-limiting species, was virtually unaffected by any dosage except the highest, which produced an efficacy of 89%. The 0.5 mg kg-1 dosage was 95% or more efficacious against H. placei, O. ostertagi, C. oncophora, and D. viviparus, but weaknesses were evident against the other five species. No adverse reaction was observe in any calf.     

Selenium and gamma-glutamyl transferase activity in the serum of thoroughbreds.

Selenium and gamma-glutamyl transferase activity has been measured in the serum of clinically health thoroughbreds. The thoroughbreds, whose performance was reported to be unsatisfactory, had consistently low concentrations of selenium and high activity of gamma-glutamyl transferase in the serum when compared with those whose performance was as expected. Vitamin E levels in the serum showed no such difference. The only other biochemical and haematological abnormality was lower serum phosphate concentrations in the unsatisfactory group. These results suggest that low concentrations of selenium in the serum may be associated with subclinical hepatic insufficiency in the thoroughbred.