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An experiment to determine the effect of temperature and photoperiod on Lupinus albus under controlled environmental conditions was carried out, using the three Lupinus albus genotypes 'Tifwhite', 'Esta' and 'Kiev', and three temperature (10/20, 18/28 and 20 °C continuously) and two photoperiod (8 and 16 h daylength) regimes, in all combinations. Half of the seeds were vernalized for 21 days at 4 °C to alleviate the obligate vernalization requirement of Tifwhite. Although Esta and Kiev do not have obligate vernalization requirements, they were influenced by this vernalization period. Observations included the duration of the period from planting to seedling emergence, the duration of the period from planting to the beginning of flowering and the duration of flowering. The vernalization treatment accelerated plant development in all genotypes. The period from planting to emergence was shorter under the higher temperature regime. For all genotypes, the period from planting to flowering was shorter under the longer photoperiod, the same trend as would be expected for long-day plants. Duration of flowering periods were, in contrast to pre-flowering periods, shorter for all genotypes at cooler temperatures. The results of this study confirm that photoperiod does contribute to the growth period from planting to flowering in L. albus and that this species does behave as a long-day plant.  相似文献   
2.
Long term follow-up of avascular necrosis of the femoral head in the dog   总被引:1,自引:0,他引:1  
In a clinical study of 35 dogs with avascular necrosis of the femoral head, 60 per cent were Yorkshire terriers; the mean age of 33 of the dogs at onset of clinical signs was seven months. The dogs had the following signs: muscle atrophy (n = 25), shortening of the affected leg (n = 14), pain on passive movement of the hip joint (n = 28), and crepitation of the hip joint (n = 8). Radiographic findings were irregular density and flattening of the femoral head in combination with degenerative joint disease. Conservative treatment consisted of exercise therapy, and surgical treatment of a standard femoral head and neck excision. In 17 of the dogs the results of therapy were evaluated with the help of a questionnaire. It is concluded that femoral head and neck excision is indicated when conservative treatment fails to lead to clinical improvement within four weeks. Femoral head and neck excision has a good long term prognosis; however, slight intermittent lameness may remain.  相似文献   
3.
A breeding experiment was carried out in a group of Shetland ponies in order to investigate the heredity of congenital lateral patellar (sub)luxation. A breeding herd was established and consisted of stallions and mares acquired at different times. Some were free from, and others were affected by lateral patellar (sub)luxation in either one or both femoropatellar joints. Over a period of 20 years, 49 foals were born from different mating combinations. Some offspring were free from the defect and others showed the abnormality. Though the number of foals bred during the experiment is rather small, there is sufficient evidence to suggest a monogenic autosomal recessive hereditary transmission of the defect.  相似文献   
4.
Economic values (EVs) of traits, accounting for environmental impacts and risk preferences of farmers, are required to design breeding goals that contribute to both economic and environmental sustainability. The objective of this study was to assess the effects of incorporating environmental costs and the risk preferences of farmers on the EVs of pig breeding goal traits. A breeding goal consisting of both sow efficiency and production traits was defined for a typical Brazilian farrow‐to‐finish pig farm with 1,500 productive sows. A mean‐variance utility function was employed for deriving the EVs at finishing pig level assuming fixed slaughter weight. The inclusion of risk and risk aversion reduces the economic weights of sow efficiency traits (17%) while increasing the importance of production traits (7%). For a risk‐neutral producer, inclusion of environmental cost reduces the economic importance of sow efficiency traits (3%) while increasing the importance of production traits (1%). Genetic changes of breeding goal traits by their genetic standard deviations reduce emissions of greenhouse gases, and excretions of nitrogen and phosphorus per finished pig by up to 6% while increasing farm profit. The estimated EVs could be used to improve selection criteria and thereby contribute to the sustainability of pig production systems.  相似文献   
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6.
The mean gestation periods of mares belonging to different horse and pony breeds common in The Netherlands have been calculated using data from the birth registers of five stud-book societies. The following mean values have been determined: Fjord pony: 342.2; Haflinger pony: 341.3; Draught horse: 343.3; Shetland pony: 337.2; and Frisian horse: 337.7 days. The variation in the mean gestation period is greater in horses than in cows, sheep or pigs. Colts are carried a little longer than fillies. Differences between years are not significant, but differences between the various breeds have been determined. Shetland foals born before 1 June are carried longer than those born after 1 June. The gestation period for mares of this breed mated at 2 years, is significantly longer than for those mated at more than 2 years.The length of the gestation period in horses is possibly affected by physiological factors other than those influencing the gestation period in some other farm animals.  相似文献   
7.
Hereditary paraganglioma (PGL) is characterized by the development of benign, vascularized tumors in the head and neck. The most common tumor site is the carotid body (CB), a chemoreceptive organ that senses oxygen levels in the blood. Analysis of families carrying the PGL1 gene, described here, revealed germ line mutations in the SDHD gene on chromosome 11q23. SDHD encodes a mitochondrial respiratory chain protein-the small subunit of cytochrome b in succinate-ubiquinone oxidoreductase (cybS). In contrast to expectations based on the inheritance pattern of PGL, the SDHD gene showed no evidence of imprinting. These findings indicate that mitochondria play an important role in the pathogenesis of certain tumors and that cybS plays a role in normal CB physiology.  相似文献   
8.
This study describes a radiographic survey of the anatomical development of the distal extremity of the manus in the donkey from 0 to 2 years of age. The right distal limb of 10 donkey foals, born in the spring of 2012, underwent radiographs every month for the first 6 months of age and every 3 months during the following 18 months. Latero‐medial radiographs with and without barium marker at the coronary band and dorso‐palmar radiographs with both front feet in weight bearing were obtained. The distal physis of the third metacarpal bone and the proximal physis of the proximal phalanx (phalanx proximalis) were closed at the mean age of 18.6 months. The distal physis of the proximal phalanx appeared as a clear radiolucent line at 2 weeks of age and was still subtly visible in some donkeys at 24 months. The proximal physis of the middle phalanx (phalanx media) was closed at the mean age of 16.7 months. The distal physis of this phalanx was visible at birth, but closed at 4 days. The distal phalanx (phalanx distalis) was triangular at birth. At the age of 20–21 months, the palmar processes (processus palmares) were both developed. The navicular bone (os sesamoideum distalis) was developed at the mean age of 9 months. The proximal sesamoid bones (ossa sesamoidea proximalia) were seen in continuously development during the 24 months. It seems that the physes in the distal extremity of the manus in the donkey close at an older age than the physes in the horse.  相似文献   
9.
European Journal of Forest Research - Climate-adaptive forest management aims to sustain the provision of multiple forest ecosystem services and biodiversity (ESB). However, it remains largely...  相似文献   
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