棉籽粕营养成分最新调查

本介绍了对棉籽粕养分含量的最新调查结果，数据包括了平均值和变异范围。本应该对考虑在日粮中应用棉籽粕的营养师具有价值。     

The Effect of Exogenous Hormone Treatment on Spermiation in Rhynchocypris oxycephalus (Sauvage and Dabry)

For the evaluation of hormonal control of spermiation in fish, a method to quanify the spermiation response of mature Rhynchocypris oxycephalus (Sauvage and Dabry) to hormonal therapy is described. Spermatocrit was determined after 7 min centrifugation at 18,000 ± g and sperm density was estimated by a standard hemocytomer method. Sperm density can be predicted from spermatocrit since their relationship is linear as described by the regression equation, Y = 3.68X - 27.18 ( R ² = 0.82, N = 50). where Y is spermatocrit and × is sperm density. Milt production by mature R. oxycephalus was highest at 24 h after injection of 1,000 IU human chorionic gonadotropin (HCG) and 50 μg luteinizing hormone-releasing hormone analogue (LHRHa) per kg body weight. Increased milt production coincided with low spermatocrit and sperm density levels. These results demonstrate that spermiation in mature R. oxycephalus can be reliably evaluated by a spermatocrit method and that HCG and LHRHa are effective in stimulating of spermiation in this species.     

Radiographic interpretation of normal skeletal variations and pseudolesions in the equine foot.

Effective radiographic interpretation requires a veterinarian who is knowledgeable of equine limb anatomy and the various principles that affect the resulting image. The normal and its variations must be recognized and understood before the abnormal can be confidently identified as pathologic. Proper patient positioning and sound radiographic technique are mandatory if reliable diagnostic radiographs are to be produced. This review emphasizes equine foot radiographic variations of normal and pseudolesions that occur with commonly used radiographic views performed in equine practice.     

Radiographic examination of the equine foot

A complete radiographic examination of the equine foot consists of properly exposed, processed, and positioned radiographs. For radiographic interpretation, in addition to knowing radiographic signs of disease, a knowledge of normal radiographic anatomy and possible insignificant anatomic variations is necessary.     

Microscopic detection of reactive oxygen species generation in the compatible and incompatible interactions of Alternaria alternata Japanese pear pathotype and host plants

 Reactive oxygen species (ROS) generation was examined in the interaction of Alternaria alternata Japanese pear pathotype and host plants using three methods: nitro blue tetrazolium (NBT) method for microscopic detection of O₂ ⁻, diaminobenzidine (DAB) methods for microscopic detection of H₂O₂, and cerium chloride methods for ultrastructural detection of H₂O₂. ROS generation was detected by NBT and DAB methods at appressoria on leaves of susceptible cultivars and heat-shocked leaves of resistant cultivars but not in leaves of resistant cultivars. Ultrastructural detection by the cerium chloride method identified ROS generation at cell walls of appressoria and penetration pegs in susceptible, resistant leaves and heat-shocked leaves. These differences in the ultrastructural and microscopic data in resistant areas were due to the restriction of ROS generation in limited areas, the side facing the plant surface, of appressoria and penetration pegs. Therefore, ROS generation was apparently induced regardless of the resistance or susceptibility of the cultivar with the difference being in the volumes generated. After evaluating the pathological role of ROS generation in fungal structures, such generation was found to be associated with early penetration of cell walls in pear plants. Additionally, ROS generation in plants was also found in degrading pectin layers near infected hyphae and in plasma membrane modification sites in susceptible leaves but not in resistant leaves. ROS generation in susceptible leaves might be accompanied with plasma membrane damage, although the role of ROS generation in the pectin layers is not clear. ROS generation in both fungal and plant cells during their interaction was likely associated with the expression of susceptibility. Received: June 3, 2002 / Accepted: July 31, 2002     

Peripartal Endocrinology in the Mare and Foetus

The endocrine profiles in the periparturient mares are dominated by increasing concentrations of progestagens and decreasing oestrogens. These hormones are produced by precursors from the foetus, metabolized by the placenta and act primarily on the maternal uterus. The circulating concentrations of hormones in maternal plasma, generally, represent a small proportion of those metabolized by the foetus and utero-placental tissues. There is clear evidence that the foetal hypothalamo-pituitary-adrenal (HPA) axis initiates the process of foetal maturation and the hormonal cascade which culminates in parturition at term. The endocrine changes associated with abnormal pregnancy and abortion in late pregnancy are less well understood, as are the hormonal treatments needed to avert these problems. Further work is needed to establish the biological role of the various hormones present in pregnant mares and, in particular, those hormones which control myometrial quiescence.