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2. The organism persisted for at least one year in an empty trial house at the laboratory in which naturally‐infected broiler breeder birds had previously been housed. A similar survival period was seen in a building which had housed an infected layer breeder flock, although infection was not detected in a subsequent pullet flock.
3. Salmonella enteritidis was also frequently found surviving outside poultry houses in small pockets of litter and fan dust which had been left after cleansing and disinfection of the site. On some poultry units S. enteritidis was also found in wild bird droppings.
4. Salmonella contamination appeared to persist preferentially in association with dust particles swept from the floor and in food troughs and S. enteritidis survived at least 26 months in artificially contaminated poultry food. 相似文献
2. NKC was treated with sodium hydroxide at 10 (ANKC 1) or 20 g (ANKC 2)/kg and incorporated into the test diets at 135 or 300 g/kg to replace 50 (low—L) or 100 (High—H) % of the PNM protein of the reference diet.
3. Despite comparable retentions of dry matter and total carbohydrate on L‐ANKC 1 and 2, fibre on L‐and H‐ANKC 2 and nitrogen, calcium and acid detergent fibre on all experimental diets compared to the retentions of chicks on the reference diet, only the chicks fed L‐ANKG 2 were found to grow and utilise food as well as those on the reference diet.
4. The activities of serum alkaline phosphatase on H‐ANKC 1 and alanine amino transferase on all test diets were depressed (P < 0.05), but the activity of serum aspartate amino transferase, total erythrocyte count and concentration of blood haemoglobin and urea were similar in all chicks.
5. No significant differences were noticed in the qualitative and quantitative characteristics of the meat of chicks fed on the reference diet and on diets incorporating ANKC at the lower concentrations. Feeding ANKC protein did not impart any untoward taste as evaluated in pressure cooked meat by a semitrained panel on a 7 point Hedonic scale.
6. Except for duodenal and jejunal inflammation in chicks on both reference and test diets, all the vital organs were normal, ruling out any adverse affects caused by residual neem bitters.
7. Comparable performance and cost of chicks fed on the reference and L‐ANKC 2 diets, warrants the utilisation of hitherto wasted protein‐rich NKC after alkali treatment in broiler chick diets to spare peanut meal for human consumption in developing countries. 相似文献
2. Chicks from the two genotypes were reared in wire‐floored cages and divided at random into 3 groups. Birds were fed on high protein (HP, 12.99 MJ ME, 238 g crude protein/kg and 12.94 MJ ME, 216 g crude protein/kg from 0 to 3 and 3 to 7 weeks, respectively), medium protein (MP, 12.99 MJ ME, 219 g crude protein/kg and 12.87 MJ ME, 201 g crude protein/kg from 0 to 3 and 3 to 7 weeks), and low protein (LP, 12.94 MJ ME, 205 g crude protein/kg and 12.75 MJ ME, 184 g protein/kg from 0 to 3 and 3 to 7 weeks) diets.
3. The LP diets resulted in a significantly lower daily body weight gain of males from 0 to 3 weeks. Dietary protein content had no effect on body weight gain from 3 to 7 weeks, body weight at 7 weeks, and the food intake of birds. Carcase composition of birds from both genotypes was unaffected by dietary protein.
4. Naked neck birds had significandy higher body weights at 7 weeks. Yields of carcase and breast of Na/na males were significantly higher than those of na/na males. There were no significant differences between females from the two genotypes as regards carcase yield.
5. It was concluded that the dietary protein requirements of naked neck birds were similar to those for normally feathered birds. 相似文献
2. We carried out post‐mortem examinations on 111 embryos that died within this period to assess the causes of this mortality.
3. Malpositioning and severe oedema were the predominant symptoms of dead‐in‐shell embryos with 55% being malpositioned and 41% showing severe oedema. Of these, 22 embryos (24%) showed both symptoms. Malpositioning generally results from incorrect setting of the eggs or inadequate turning and oedema was significantly correlated with the amount of water lost from the eggs which in turn was correlated with egg size.
4. Myopathy, gross lesions of internal organs, haemorrhage, bacterial infections and congenital deformities were found in less than 10% of chicks examined for these symptoms. 相似文献
Avian Hematology and Cytology. Terry W. Campbell. 1995. 104 pp. Illustrated. £48.00. Ames, Iowa State University Press. ISBN 0 8138 2970 4. 相似文献
2. We investigated the relationships between a hen's prelaying behaviour and its tendency to lay on the floor by recording the behaviour of 20 hens housed individually in wire cages with single littered nest boxes.
3. Most floor eggs (80%) were laid by the same 6 hens. These 6 “floor‐layers” performed more nest seeking behaviour, less nest‐building behaviour and less sitting prior to oviposition than the 14 hens that consistently laid in nest boxes.
4. The incidence of floor eggs declined with age. Both nest and floor laying hens performed less nest seeking behaviour with age. Floor layers, however, increased their performance of nesting behaviour, whilst nest layers performed less nesting behaviour with age.
5. Floor laying hens behaved as if they found the nest box less attractive than nest‐laying hens; perhaps because they had lower nesting motivation, or perhaps because their nesting motivation was as high, but they less readily perceived the nest box as an appropriate nest site. 相似文献
2. In the first experiment, colostomy had no significant effect on mineral balance. However, broilers exposed to high cycling ambient temperature reduced their retention of phosphorus, potassium, sodium, magnesium, sulphur, manganese, copper and zinc compared with birds housed at 24°C.
3. Despite the minimal effect of high ambient temperature on urine production, minerals excreted disproportionately excreted in urine included potassium, magnesium, phosphorus and sulphur while copper and magnesium were lost primarily via the faeces.
4. In the second experiment, exposure to 35°C increased urine output from 50.7 ml/12 h per kg of body weight at 24°C to 101.3 ml/12 h per kg of body weight and was associated with an increased urine:water ratio and reduced urine osmolal‐ity.
5. Reduced urinary chloride and higher potassium, phosphorus, sulphur, sodium, magnesium, calcium and manganese excretion was observed for broilers housed in under high ambient temperatures compared to 24°C.
6. These studies suggest that high ambient temperatures adversely influence mineral metabolism and, furthermore, that the route of excretion varies with the specific mineral and the environmental temperature exposure. 相似文献
2. Birds kept at the cool temperatures throughout life ate most food and gave the best production during lay. Minimum food intake and poorest performance were obtained with birds kept at the hot temperatures throughout life.
3. Performance in the hot environment during lay was improved by rearing birds in the cool environment, the response being related to an increased food intake. Food intake in the cool environment during lay was reduced, with only minor effects on performance, in birds which had been reared in the hot environment.
4. The results of the present study show that production responses during lay are affected by the temperatures experienced by hens during both growth and lay. 相似文献