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Maize (Zea mays L.) is the most important cereal crop produced in Ghana. However, yield of the crop is generally low, producing just about 1.7 t/ha. The low yield is attributed to continuous use of local/unimproved varieties. Generally, hybrid varieties have proven to out-yield the local/unimproved varieties due to improved vigour. Development of hybrid varieties depend on good understanding of combining ability and inheritance of important quantitative traits such as grain yield (GY). 45 half-diallel crosses generated from 10 extra-early maturing yellow inbred lines were evaluated in 2015 under rain-fed conditions. The objectives were to determine the genetic control, breeding value and estimate heritability for GY and agronomic traits of the inbred lines under contrasting growing environments in Ghana. General combining ability (GCA) and specific combining ability (SCA) were important in the inheritance of GY and agronomic traits of the inbred lines. However, GCA was more important than SCA across environments to suggest that additive gene action was more important than non-additive gene action in the inheritance of GY and agronomic traits in the inbred lines. High broad-sense heritability, for GY and other agronomic traits indicated preponderance of additive gene action in trait expression, thus, selection based on phenotypic expression could be feasible. Inbred lines P1, P4 and P8 were good combiners for high GY. The genotype, P4 × P8, was identified as the ideal and most yielding single-cross hybrid across research environments and should be further tested on-farm before commercialization.  相似文献   
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Glucose or starch labelled with 14C was mixed thoroughly into slurried soils. Aggregates of different sizes were obtained from the soils as they dried. The labelled substrates were considered to be distributed in both micro- and macropores in the aggregates. Control samples (labelled substrates in macropores only) were prepared by adding the labelled carbohydrates after the formation of the aggregates. The various samples were sterilized by γ-irradiation and stored at ?15°C.Samples were wetted to about ?20kPa, inoculated with soil organisms, and incubated for 4 weeks at 28°C in closed systems, which enabled regular measurement of 14CO2 released.Based on the 14CO2 released, it was concluded that starch was protected from microbial attack when present in micropores in aggregates made from fine sandy loam.After incubation samples were dried and rewetted. The flush of 14CO2 released was twice as big for samples containing labelled starch compared with glucose, showing that disruption of aggregates, containing residual starch, and rearrangements of soil components are as important as chemical and biological factors in causing the flush of CO2 resulting from wetting a soil. Mechanical disruption of the aggregates resulted in a similar flush of 14CO2.  相似文献   
4.
Progressive loss of virulence for goat kids was noticed when peste des petits ruminants (PPR) virus was passaged in Vero cells. While goats inoculated with the 60th passage suffered from the clinical PPR disease and mortality, goats inoculated with the 80th passage did not show any sign of the disease. If the progressive loss of virulence of the virus with passage continues, it will not be long before a homologous PPR vaccine will be obtained at the National Veterinary Institute, Vom.  相似文献   
5.
In a pilot survey to compare the relative prevalence of three diseases in apparently healthy White Fulani Zebu (WFZ) cattle slaughtered in Nigeria, sera from 80 randomly selected animals with no significant gross lesions on ante mortem and post mortem inspection were examined for antibodies to Brucella abortus, Dermatophilus congolensis and bovine leukaemia virus. Of the samples screened, 5.0, 8.8 and 2.0% showed serological evidence for brucellosis, cutaneous streptothricosis and bovine leukosis respectively.  相似文献   
6.
Reports on the nutritional composition of cowpea leaves have been limited to a small number of lines and the palatability characteristics of leaves apparently have not been studied. This study was therefore undertaken on cowpea leaves to determine the nutrient composition of fifteen varieties and the sensory attributes of ten varieties grown in Ghana. Nutritional components studied were moisture, protein, phosphorus and ascorbic acid. The sensory attributes included leaf size, taste and overall acceptability. There were significant (p > 0.05) differences among varieties in all nutrient components (fresh and dry weight basis), leaf size and overall acceptability. The nutrient composition values, on a dry weight basis, ranged from 9.4 to 13.0% for moisture, 303.8 to 468.9 mg/100 g for phosphorus, 33.5 to 148.0 mg/100 g for ascorbic acid, and 27.1 to 34.7% for protein. Differences in the sensory scores of leaves for taste were not significant (p < 0.05). Overall acceptability positively correlated with leaf size. Moisture content was negatively correlated with overall acceptability, phosphorus and ascorbic acid. Results can be exploited in a breeding program to develop nutritionally superior and acceptable cowpea varieties which can be used for harvesting of both leaves and seeds.  相似文献   
7.
Three different batches of Thaumatococcus danielli (Benth) fruits were collected at different fruiting seasons. The proximate compositions of the pericarp and seeds were determined on a dry weight basis. Partial characterization of the lipid extract was carried out and tannin content determined. The average moisture, ash and lipid contents of the pericarp were higher (89.2 ± 4.17%, 20.7 ± 1.10% and 11.6 ± 1.23%, respectively) than those of the seed (31.2 ± 4.66% 9.1 ± 0.71% and 8.2 ± 1.64%, respectively). Crude protein and total carbohydrate were, however, higher in the seed (9.5 ± 4.38% and 69.4 ± 11.52%, respectively) than in the pericarp (4.5 ± 2.21% and 6.3 ± 3.94%, respectively). The dietary fiber contents of both pericarp and seed were high. Starch content was very low in the pericarp (0.4 ± 0.0%) compared to the seed (66.28 ± 9.21%). Tannin content in the pericarp and seeds was 12.1 ± 1.52 mg/g and 21.9 ± 2.28 mg/g, respectively. The oil extracted from both pericarp and seeds was light-yellow in color and slightly solid at room temperature. Unsaturation level of T. danielli oil was low, while free fatty acids were high. The results obtained suggested that T. danielli waste could potentially be a raw material in livestock feed formulation.  相似文献   
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The study evaluated the feeding behavior of growing male grasscutters (Thryonomys swinderianus) fed freshly cut Panicum maximum, supplemented with pelletized concentrates containing varying levels of dietary fiber. In a two-stage 4?×?4 Latin square arrangement, the relationships between water and dry matter intakes as influenced by dietary characteristics were investigated by offering supplements either at 09:00 h (morning) during the first stage or at 17:00 h (evening) during the second. Each test period lasted for 14 days with a 1-week rest period between changeovers. Time of feeding significantly (P?< 0.05) affected total dry matter intake (DMI) and intake of the supplements, with the total DMI increasing by 21% when the diets were offered in the evening relative to when offered in the morning. Regression analyses showed significant (P?<?0.05) correlations between dry matter (DM) and water intakes against some dietary characteristics. The current study has shown that crude fiber (CF) inclusion of up to 14% in pelletized supplements for growing grasscutters consuming a basal diet with CF up to 31% may not affect feed and water intake, as well as acceptability of the feed. However, feeding such supplements in the evening could stimulate higher feed intake. Also, dietary DM better predicted DMI compared to the other dietary characteristics.

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10.
The efficacy of the two most common techniques used for determining the sex of the greater cane rat, Thryonomys swinderianus, Temminck, was tested using 10 young and 8 adult animals with two technicians at the Animal Research Institute's Grasscutter Domestication Centre, Pokoase, Ghana. The techniques compared were the use of the head shape and/or head size and the use of the ano-genital distance. The use of the ano-genital distance for sex determination was validated in a colony of greater cane rats at various stages of development, i.e. from the day of birth to three or more years of age. The ano-genital distance was then used as the standard against which the use of the head shape and/or head size technique was tested. The results indicated that the use of the ano-genital distance for sex determination in the greater cane rat was error-free, even with little experience on the part of the practitioner. The ano-genital distance was more than twice as long in the males than in the females at all ages (p<0.001). However, the use of the head shape and/or head size for sex determination was found to be associated with some degree of error in both sexes. The use of the ano-genital distance can therefore be recommended as an efficacious technique for sex determination in the greater cane rat.  相似文献   
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