Effects of a breeding scheme combined by genomic pre‐selection and progeny testing on annual genetic gain in a dairy cattle population

The effectiveness of the incorporation of genomic pre‐selection into dairy cattle progeny testing (GS‐PT) was compared with that of progeny testing (PT) where the fraction of dam to breed bull (DB) selected was 0.01. When the fraction of sires to breed bulls (SB) selected without being progeny tested to produce young bulls (YB) in the next generation was 0.2, the annual genetic gain from GS‐PT was 13% to 43% greater when h² = 0.3 and 16% to 53% greater when h² = 0.1 compared with that from PT. Given h² = 0.3, a selection accuracy of 0.8 for both YB and DB, and selected fractions of 0.117 for YB and 0.04 for DB, GS‐PT produced 40% to 43% greater annual genetic gain than PT. Given h² = 0.1, a selection accuracy of 0.6 for both YB and DB, and selected fractions of 0.117 for YB and 0.04 for DB, annual genetic gain from GS‐PT was 48% to 53% greater than that from PT. When h² = 0.3, progeny testing capacity had little effect on annual genetic gain from GS‐PT. However, when h² = 0.1, annual genetic gain from GS‐PT increased with increasing progeny testing capacity.     

Distinct alpha (α)-subunits of salmon glycoprotein hormones: production sites in the pituitary with sexual maturity

Salmon pituitary glands contain two structurally distinct -subunit proteins (1 and 2) of glycoprotein hormones: the 2-subunit is common to all salmon gonadotropins (GTH I and GTH II), whereas the 1-subunit is present in only some GTH I molecules. GTH I is predominant in the pituitary gland and plasma during gametogenesis of salmon, but the roles of the 2 GTHs in gametogenesis remain unclear. To understand the roles of GTH I, it is important to clarify patterns of 1- and 2-subunit production with sexual maturity. Thus, we produced antisera that recognized the 1- or 2-subunit, and then immunohistochemically examined the production sites of these subunits in the trout pituitary gland during ovarian development. In all pituitary glands examined, the immunoreactivity of both the 1- and 2-subunits was strong in the GTH II-producing cells, although salmon GTH II, both 1- and II-subunits, has not been detected. However, GTH I-producing cells showed a less dense immunoreactivity for 1- and 2-subunits, whereas the I-subunit was abundant. On the other hand, TSH cells, reacted with 2 but not with 1.     

Systemic Effect of a Brassinosteroid on Root Nodule Formation in Soybean as Revealed by the Application of Brassinolide and Brassinazole

Leguminous plants form nitrogen-fixing root nodules and the number of nodules is controlled by a self-regulating mechanism called autoregulation. However, signaling substances involved in nodule regulation have not been identified. In the present study, we used brassinolide, a most effective molecular species of plant hormone brassinosteroids, and brassinazole, an effective inhibitor of brassinosteroid biosynthesis to determine whether brassinolide played a role in systemic regulation of noduel formation in wild type soybean and its super-nodulating mutant. Foliar application or direct injection of brassinolide into the root base inhibited nodule formation and root development in the super-nodulating mutant (En6500), but not in the parent line (cv. Enrei). The internodes in the plants subjected to foliar application were significantly longer than those in the untreated plants. In contrast, the application of brassinazole on mature leaves or into the culture media resulted in the increase of the nodule number in Enrei. These treatments also inhibited internodal growth in Enrei. The results indicate that brassinosteroids may regulate the nodule number in soybean plants. The function of brassinosteroids for the systemic regulation of nodule formation was examined.     

Recent irrigation practices in the Upper East Bank of the Chao Phraya Delta

This study aims to investigate recent practices on water allocation and cultivation in the Upper East Bank of the Chao Phraya Delta in Thailand, by using data collected by RID local offices, questionnaires, and analyses of satellite images. As a result, we have identified the advantage that upstream areas of irrigation canals have enjoyed, namely the preferential water allocation over the downstream areas. This advantage was strongly associated with the intensive cropping patterns of rice: the upstream areas were estimated to conduct almost continuous rice cultivation throughout a year. In addition, the intensive rice cultivation would partly be supported by water from private shallow wells, which were mostly concentrated in the upstream areas of main canals. Those shallow wells would be used at the beginning of the dry season and in drought years, when farmers could not expect water supply from irrigation canals. The result indicated that the conjunctive use of surface and ground water would be practiced in this region.     

Isoflurane anaesthesia in four sea lions (Otaria byronia and Zalophus californianus)

OBJECTIVE: To (1) evaluate a purpose-built chamber for inducing isoflurane anaesthesia in sea lions and (2) assess isoflurane as an anaesthetic for dental surgery in these species. STUDY DESIGN: Prospective case study. ANIMALS: Four sea lions, aged between 5 and 12 years and weighing 74-110 kg, with dental disease. METHODS: Sea lions were restrained in a custom-built acrylic chamber into which 5% isoflurane (vapourizer setting) was delivered in O(2) (30 L minute(-1)) from three anaesthetic machines. When the animals were recumbent, the chamber was opened and induction completed using a face mask. Anaesthesia was maintained with 1.5-3.0% isoflurane (vapourizer setting) for 10-15 minutes and after tracheal intubation, was maintained with 1.0-3.0% isoflurane (end-tidal) for 41-255 minutes, using a partial rebreathing system with CO(2) absorption. RESULTS: During induction, the sea lions attempted to support their weight on their thoracic limbs before slipping into sternal or lateral recumbency. Sea lions underwent either root canal surgery, 'crowning' or canine tooth extraction. The animals were completely unresponsive during these operations and apnoea was never encountered at any point during anaesthesia. After surgery, the sea lions were placed into transport cages and their tracheae extubated once they began to move their heads. Thereafter, recovery from anaesthesia was smooth and no signs of distress were observed. Animals were able to raise their forequarters using their flippers within 1 hour of the operation and were returned to the aquarium about 2 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: The purpose-built induction chamber is safe for inducing isoflurane anaesthesia in spontaneously breathing sea lions and isoflurane is an effective anaesthetic in this species.     

Comparison of field and laboratory microcosm methods on the mass loss ofQuercus serrata andPinus densiflora leaf litter

The decay rates of Japanese Konara Oak (Quercus serrata Murray) and Japanese Red Pine (Pinus densiflora Sieb. et Zucc.) leaf litter were monitored for one year. It aimed to compare the decomposition of leaf litter using microcosms set up in the field (FM) and in the greenhouse (GM), with the litterbag (LB) method as control. Results showed that incubation setting affected the decay rate (k), respiration rates and the changes in the concentrations of nitrogen (N). Thek value ofQuercus in FM was higher than LB, while thek value ofPinus was higher in the LB than in FM. The decay ratesk for both species, however, were significantly lower in GM than FM and LB, clearly suggesting that decay rate was inhibited in the greenhouse. Significant differences in microclimatic variables and soil biological activities (soil respiration) existed between greenhouse and field microcosms, hence, the decay rates were affected. The N concentrations for both litter types increased as decomposition proceeded. Decomposition studies using laboratory microcosm approach alone may lead to erroneous conclusions especially if no appropriate field studies are conducted along with it. Part of this paper was presented at the XXth International Union of Forestry Research Organization (IUFRO) World Congress, August 6–12, 1995, Tampere, Finland.     

Morphological variations in brachial plexus of beagle dogs: evaluation of utility as sources of allogeneic nerve grafts

Basic studies were carried out to apply frozen allogeneic nerve grafts in dogs after wide-ranging defects of the brachial plexus due to surgical resection of tumor. In this study, morphological variations in branching patterns of the brachial plexus were examined in ten beagle dogs, to evaluate whether the brachial plexus might represent a useful source of allogeneic nerve grafts. Spatial relationships between the axillary lymph node, which had the possibility of carcinomatous metastasis, and the musculocutaneous (MC) nerve, which was important for the function of the forelimbs, were also investigated. In all ten cases examined, the brachial plexus received ventral roots from the fifth cervical nerve to the first thoracic nerve. No significant variation in the branching pattern was found in any nerve except the phrenic, MC and dorsal thoracic nerves. Four communicating branches were observed and had some morphological variations which might be negligible for nerve grafting. Considering previous physiological and anatomical reports, the most important nerve to be reunited in graft operations for functional recovery is the radial nerve. The MC nerve and median or ulnar nerve should also be considered as possibilities for reuniting. Distances between the axillary lymph nodes and the MC nerve ranged from 11.2 mm to 21 mm (mean +/- SD: 16.1 +/- 2.3 mm). In conclusion, it was suggested that morphological variations in the brachial plexus were technically acceptable to apply allogeneic nerve grafts at least in beagle dogs.     

New multilocus genotypes of <Emphasis Type="Italic">Phytophthora infestans</Emphasis> in Japan

Twelve isolates of Japanese Phytophthora infestans, which differed from the major genotypes US-1, JP-1, JP-2, and JP-3, were analyzed for RG57 fingerprints, mtDNA haplotypes, two allozyme genotypes, and mating types. Genotypes JP-1.1, JP-2.1, JP-2.2, JP-3.1, and JP-4 were newly defined. JP-1.1 and JP-2.1 were isolated discontinuously from potato fields in several years, and JP-1.1 was found in Hokkaido and Kagoshima. These results show that some minor genotypes can overwinter and disperse from their original site.     

Changes in peripheral leukocyte subsets in dairy cows with inflammatory diseases after calving

To clarify the cellular immune system in dairy cows with inflammatory diseases after calving, the leukocyte subsets were examined in Holstein dairy cows. Twenty Holstein cows reared in one herd, were used in this study. Nine cows (Group 1) experienced onset of mastitis or puerperal fever within 2 weeks after calving, and the other eleven cows remained healthy (Group 2) after calving. The numbers of CD3(+), CD4(+) and CD8(+) cells tended to be lower in Group 1 than in Group 2 from the day of calving through week 1. These results suggested that the cows with inflammatory diseases might have experienced a decline in T cells by the day of calving, before the onset of disease.