Effect of soft x-ray irradiation on immunological functions in mice.

Effect of soft x-ray irradiation on immunological functions in mice was investigated. Soft x-ray irradiation with 100R or more induced a significant reduction in the number of plaque-forming cells (PFC). The reduction in the number of PFC depended on the irradiation doses. Irradiation with 600R or more showed a significant reduction in the delayed reaction of footpad swelling. However, soft x-ray irradiation with doses ranging from 100R to 1000R did not exert significant influence on the K values of carbon clearance test. Irradiation with 100R or more of soft x-ray showed a remarkable reduction of response to concanavalinA (ConA) or lipopolysaccharide (LPS) in spleen cells, and the response to ConA was lower than that to LPS. These results suggest that in the soft x-ray-irradiated mice, antibody-producing ability, delayed type hypersensitivity reaction and mitogenic activity are sensitive to soft x-ray irradiation and furthermore, T cell is more sensitive than B cell, but phagocytic activity of reticulo-endothelial system (RES) is resistant to soft x-ray irradiation.     

Agarose gel electrophoretic separation of blood serum proteins in cattle.

The agarose gel electrophoresis described by Johansson (1972) was modified so that a buffer of pH 7.9 was used in the gel, whereas the buffer in the electrode vessels had a pH of 8.6.The cattle blood serum protein picture is described in detail. The β₁-globulin zone shows a very distinct picture of the genetically polymorphic bovine transferrins. The region between the α- and β-globulins shows a number of faint and often very distinct bands. A faint background staining over the whole electrophoretogram may partly be caused by a rather strong lipoprotein in the α₁-region, lipids thus having migrated all over the electrophoretogram.The modified method described is well suited as a “screen electrophoresis” for cattle serum and is also useful e.g. in studying bovine transferrin polymorphism.     

增加光照时间对锦江牛生产性能和行为的影响

为了探讨增加光照时间对锦江牛生产性能和行为的影响,选用锦江公牛16头、锦江母牛10头随机分为2组,即:自然光照组(10.2～13.8 h)和16 h光照组,每组公牛8头、母牛5头。试验期117 d,期间记录牛的始重、末重、采食行为、休息行为和活动量。结果:与自然光照组相比,16 h光照组末重和平均日增重显著增加(P0.01),且干物质采食量增加16.18%,料重比降低9.88%;16 h光照组采食时间、每次采食时间显著降低(P0.01),反刍时间和趴卧休息时间显著增加(P0.01),且反刍次数显著增加(P0.05);16 h光照组趴卧休息率增加(P0.05),公牛活动量降低39.21%。由此可知,增加光照至16 h可以增加锦江牛采食量、反刍时间和趴卧休息时间,减少其活动量,从而提高了其生产性能。     

Bovine respiratory syncytial virus-specific immune responses in cattle following immunization with modified-live and inactivated vaccines. Analysis of the specificity and activity of serum antibodies.

Cattle were immunized with vaccines containing modified-live or inactivated bovine respiratory syncytial virus (BRSV) and serum antibody responses were analyzed. Compared with preinculation values, at Day 14 after two biweekly immunizations with modified-live or inactivated vaccines there were significant increases in BRSV-specific titers in the sera of cattle that received both types of vaccines, as determined by a whole cell ELISA. Using a blocking ELISA and radioimmune precipitation it was determined that there was recognition of the fusion (F) protein by antibodies from cattle that received both types of BRSV antigens: however, virus neutralization assays revealed that only cattle that received modified live virus, either in monovalent or polyvalent vaccines, developed neutralizing antibodies to BRSV after two immunizations. These results indicate that inactivation of BRSV can lead to a dissociation between serological recognition of the F protein and virus neutralization in vaccinated cattle.     

Influence of varying levels of blood progesterone upon estrous behavior in cattle

The effect of four levels of progesterone on the occurrence and intensity of estrous behavior was determined in ovariectomized cows. Twelve Holsteins were bilaterally ovariectomized at least 2 mo before treatment. Progesterone (P4) was administered im two times/day for 5 d followed 72 h later with 2 mg estradiol (E2) im to induce estrous behavior. Treatments were control = oil, 100 mg P4/d, 300 mg P4/d and 500 mg P4/d. Each animal received all P4 treatments in a 4 X 4 Latin-square design. From d 2 through 6, with d 1 being the first day of P4 treatment, serum P4 concentrations averaged .3, 2.5, 6.1 and 12.3 ng/ml in treatments I to IV, respectively. Progesterone levels at the time of peak E2 (d9) were less than 1 ng/ml for treatments I, II and III and 1.8 ng/ml for treatment IV. Peak E2 levels for all groups averaged 23.9 pg/ml (12 h after E2 injection). Cows were observed continuously for 48 h after E2 injection to quantitate estrous behavior. Behavioral traits measured were: mounts initiated, mounts received, standing when mounted, chin rests initiated and chin rests received. Progesterone treatment caused a decrease in frequency of all five traits measured. As P4 levels increased, there was a linear (P less than .01) decrease in frequency of a behavioral trait. The percentage of the cows that showed each behavioral trait and mean time to first occurrence of each trait were not different after progesterone treatment, with the exception of standing behavior.(ABSTRACT TRUNCATED AT 250 WORDS)     

Isolation, characterization, and quantitative measurement of serum alpha 1-acid glycoprotein in cattle

Bovine alpha 1-acid glycoprotein (alpha 1AG) was purified from pooled normal bovine sera by successive ammonium sulfate precipitation, ion-exchange chromatographies and gel filtration. Bovine alpha 1AG had a molecular weight of 42,000 +/- 2,000 and a sedimentation coefficient of 3.4S. It contained 26.6% carbohydrate. Gel isoelectric focusing revealed a microheterogeneity with 7 to 8 bands in a pI range of 3.2 to 3.7. It migrated to the alpha 1-globulin region upon immunoelectrophoresis. Single radial immunodiffusion was developed for the quantitative measurement of bovine alpha 1AG in serum. The mean serum value of alpha 1AG in 152 healthy Holstein cattle (1-12 years old) was 283.2 +/- 82.3 micrograms/ml. Elevated values (cut-off value = 450 micrograms/ml) were observed in cattle with traumatic pericarditis (100%), arthritis (100%), mastitis (91%), pneumonia (70%), and mesenteric liponecrosis (43%).     

Effect of pre-slaughter handling on the behaviour and blood composition of beef cattle

The pre-slaughter handling, behaviour and blood composition of beef cattle at slaughter was studied in a commercial slaughterhouse. The main problems identified were the routine use of driving instruments and delays caused by stoppages in the slaughter line. The plasma concentration of cortisol at the time of slaughter was positively correlated with the time spent standing still and with the time spent in the pre-stun pen. The plasma activity of creatine kinase was positively correlated with the time spent in the race, but no correlations between creatine kinase and physical activity in the race were found. The plasma concentration of glucose was positively correlated with the time spent trotting and the number of times that struggling occurred. The proportions of cattle struggling, vocalizing and defaecating were greatest when they were confined in the race and pre-stun pen. Cattle kept overnight in the lairage had a greater concentration of free fatty acids at the time of slaughter than those slaughtered on the day of arrival. There were no other significant differences in either the blood composition or the handling and behaviour of cattle kept overnight in the lairage, compared with those slaughtered on the day of arrival. Some of the handling problems observed were caused by incorrect design of the handling facilities. There should be some means of removing cattle from a race if delays are encountered and some means of handling the cattle in the race other than by using an electrical goad. The optimal dimensions of races and passageways to prevent crowding and turning around should be assessed at the design stage. Non-slip floors are essential.