全文获取类型
收费全文 | 92篇 |
免费 | 2篇 |
专业分类
林业 | 3篇 |
农学 | 14篇 |
基础科学 | 1篇 |
9篇 | |
综合类 | 17篇 |
农作物 | 2篇 |
水产渔业 | 1篇 |
畜牧兽医 | 41篇 |
植物保护 | 6篇 |
出版年
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 7篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 4篇 |
2009年 | 3篇 |
2008年 | 7篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有94条查询结果,搜索用时 15 毫秒
1.
SUMMARY Twenty-five Thoroughbred (TB) and 25 Standardbred (SB) stables were visited to determine their feeding practices. The ingredients of the main feed of the day for a mature gelding of average size in full training were weighed at each stable. Nutrient content of diets was calculated using published data for the individual ingredients. Results are expressed as mean±sd. The estimated body weight of TB horses was 493±34 kg and 437±32 kg for SB horses. There was considerable variation in diet composition and nutrient intake between stables. The TB trainers fed 11.0±2.4 kg and SB trainers 11.8±2.5 kg per day. The concentrate component of the diet weighed 7.8±1.6 and 7.7±2.3 kg for TB and SB stables, respectively, and the roughage component for TB horses 3.3±1.4 and SB horses 4.1±1.4 kg per day. The digestible energy intake of horses at TB stables was 129±29 MJ per day and at SB stables 132±31 MJ per day. Crude protein intake of TB horses was 1452±363 g and SB horses 1442±338 g per day. There were differences in some feeding practices at TB and SB stables. Standardbred trainers fed more roughage than TB trainers. Standardbred trainers fed chaffed lucerne (alfalfa) and cereal hays as the major roughage, whereas TB trainers fed more hay. The major hay type fed by TB trainers was lucerne, whereas many SB trainers preferred clover hay. Both trainers fed oats as the major grain, but TB trainers fed slightly more maize (corn) than SB trainers. The SB trainers fed barley as part of the concentrate component of the diet, whereas TB trainers usually fed boiled barley and linseed oil in winter only. Although many trainers used vitamin and mineral supplements, this appeared unnecessary in many Instances, especially with respect to Iron. Calcium and NaCI supplementation was necessary for some diets. We concluded that while there was a wide range in feed intake and diet composition for both TB and SB horses, average nutrient intakes were similar to National Research Council (1989) recommendations for horses performing intense work. 相似文献
2.
3.
Saeid Mobini Hamid Khazaei Thomas D. Warkentin Albert Vandenberg 《Plant Breeding》2020,139(6):1181-1189
The aim of this study was to reduce the length of the breeding cycle for faba bean by accelerating seed setting. We examined the mode and time of exogenous 6-benzylaminopurine (BAP) (cytokinin) application, and cold treatments and their combinations in two faba bean genotypes. Acropetal node number of pod and seed set and pollen viability were recorded during the experiments. Application of BAP improved pollen germination. The application of 10–5 M BAP 4 days after flowering increased seed set at the lower nodes. Cold treatment (8/4°C day/night for 2 days) after the onset of flowering induced the formation of more pods and faster pod set compared to the non-cold treatment. The time to first seed was significantly reduced, and pollen viability was increased in plants exposed to cold treatment. Increased pollen viability also showed a significant positive correlation with seed setting. The combinations of 10–5 BAP and cold treatment together had similar and independent effects. These results will accelerate plant breeding in faba bean by providing additional tools for reducing generation time. 相似文献
4.
Aly KAREN árpád Csaba BAJCSY Rosa MINOIA Rezs? KOVáCS Noelita Melo DE SOUSA Jean-Fran?ois BECKERS János TIBOLD István MáDL Ottó SZENCI 《The Journal of reproduction and development》2014,60(2):162-167
The aim of the present study was to determine the relationship of progesterone (P4),
bovine pregnancy-associated glycoprotein-1 (bPAG-1) and nitric oxide (NO) levels with late
embryonic (LEM; day 28 to day 42) and early fetal mortalities (EFM; > day 42 to day 56)
in dairy cows. Transrectal ultrasonography (6–8 MHz) was performed in 100
Holstein-Friesian cows at days 28, 42 and 56 after artificial insemination (AI; day 0) to
diagnose pregnancy and to monitor the fate of the embryo. After ultrasound scanning of
each cow, a milk sample was collected for assessment of P4 by an ELISA test and a blood
sample was collected for assessment of bPAG-1, by using a double-antibody
radioimmunoassay, and serum NO metabolites (nitrate + nitrite). Based on ultrasonographic
examinations and bPAG-1-RIA, 41 of 100 inseminated cows were confirmed pregnant at day 28
after AI. Nine cows suffered of LEM, and 6 cows suffered of EFM and the overall pregnancy
loss rate was 36.6% (15/41) between days 28 and 56 of pregnancy. By logistic regression
analysis, there were no significant relationships between the level of P4 and bPAG-1 at
day 28 after AI and the occurrence of LEM and EFM. Also, there were no significant
relationships between the levels of P4 and bPAG-1 at day 42 and the occurrence of EFM. On
the other hand, a significant relationship (P<0.05) was found between NO level at day
28 and the occurrence of LEM. In conclusion, measurement of the serum NO concentration at
day 28 of pregnancy might help to predict the outcome of pregnancy by day 42 in dairy cows
but further studies are needed to confirm this. 相似文献
5.
PE Sbardella RR Ulguim DL Fontana CV Ferrari ML Bernardi I Wentz FP Bortolozzo 《Reproduction in domestic animals》2014,49(1):59-64
The study evaluated the reproductive performance of primiparous sows submitted to post‐cervical insemination (PCAI) compared with cervical artificial insemination (CAI). Difficulty with catheter introduction, the occurrence of bleeding or semen backflow during insemination, and volume and sperm cell backflow up to 60 min after insemination were also evaluated. Sows were homogenously distributed, according to body weight loss in lactation, lactation length, weaned piglets, weaning‐to‐oestrus interval and total born in previous farrowing, in two treatments: PCAI (n = 165) with 1.5 × 109 sperm cells in 45 ml (2.4 ± 0.04 doses per sow) and CAI (n = 165) with 3 × 109 sperm cells in 90 ml (2.5 ± 0.04 doses per sow). During PCAI, sows were inseminated in the absence of boars. Transabdominal real‐time ultrasonography was performed at oestrus onset, immediately before the first insemination and at 24 h after last insemination. There was no difference (P > 0.05) between treatments in farrowing rate (91.5% × 89.1%) and litter size (12.5 × 11.9 piglets born, respectively for PCAI and CAI sows). Successful passage of the intrauterine catheter in all the inseminations was possible in 86.8% (165/190) of sows initially allocated to PCAI treatment. Difficulty of introducing the catheter in at least one insemination did not affect the reproductive performance of PCAI sows (P > 0.05). Bleeding during insemination did not affect (P > 0.05) the farrowing rate in both treatments, but litter size was reduced in CAI and PCAI sows (P ≤ 0.06). Percentage of spermatozoa present in backflow within 1 h after insemination was greater in CAI than PCAI sows (P < 0.01). More than 85% of primiparous sows can be successfully post‐cervical inseminated with doses containing 1.5 × 109 sperm cells in the absence of the boar during insemination without impairing the reproductive performance. 相似文献
6.
Field trial of a staphylococcal mastitis vaccine in dairy herds: clinical, subclinical and microbiological assessments 总被引:4,自引:0,他引:4
Objective To assess the efficacy of a new staphylococcal mastitis vaccine under commercial dairying conditions.
Design A field trial involving 1819 cows and heifers conducted on seven dairy herds in Victoria. The trial was done 'blind'; approximately half the animals were vaccinated and the remainder were untreated controls.
Procedure The vaccine was given twice during the last 10 weeks of pregnancy. Effects of vaccination were assessed, during the ensuing lactation, on the basis of clinical and sub-clinical mastitis and microbiological investigations of the milk.
Results A total of 273 cases of clinical mastitis were recorded. Staphylococcus aureus was isolated from 112 of these, 45 cases in vaccinates and 67 cases in controls; the difference was not statistically significant. One herd was notable in having a high incidence of clinical staphylococcal mastitis. This herd accounted for 15.8% of the animals in the field trial but 54.5% of cases of clinical staphylococcal mastitis. For this herd, vaccinated animals had significantly lower incidence of clinical staphylococcal mastitis and prevalence of subclinical mastitis, relative to controls. An unexpected feature of the trial as a whole was the low incidence of clinical mastitis from which S aureus was isolated in pure culture (26.3% of cases) and the high incidence of clinical Streptococcus uberis mastitis (22.7% of cases).
Conclusions The trial showed that the vaccine was efficacious in reducing the incidence of clinical mastitis and prevalence of subclinical mastitis in a herd that had a serious staphylococcal mastitis problem. 相似文献
Design A field trial involving 1819 cows and heifers conducted on seven dairy herds in Victoria. The trial was done 'blind'; approximately half the animals were vaccinated and the remainder were untreated controls.
Procedure The vaccine was given twice during the last 10 weeks of pregnancy. Effects of vaccination were assessed, during the ensuing lactation, on the basis of clinical and sub-clinical mastitis and microbiological investigations of the milk.
Results A total of 273 cases of clinical mastitis were recorded. Staphylococcus aureus was isolated from 112 of these, 45 cases in vaccinates and 67 cases in controls; the difference was not statistically significant. One herd was notable in having a high incidence of clinical staphylococcal mastitis. This herd accounted for 15.8% of the animals in the field trial but 54.5% of cases of clinical staphylococcal mastitis. For this herd, vaccinated animals had significantly lower incidence of clinical staphylococcal mastitis and prevalence of subclinical mastitis, relative to controls. An unexpected feature of the trial as a whole was the low incidence of clinical mastitis from which S aureus was isolated in pure culture (26.3% of cases) and the high incidence of clinical Streptococcus uberis mastitis (22.7% of cases).
Conclusions The trial showed that the vaccine was efficacious in reducing the incidence of clinical mastitis and prevalence of subclinical mastitis in a herd that had a serious staphylococcal mastitis problem. 相似文献
7.
8.
KR Arrigo DL Worthen MP Lizotte P Dixon G Dieckmann 《Science (New York, N.Y.)》1997,276(5311):394-397
A numerical model shows that in Antarctic sea ice, increased flooding in regions with thick snow cover enhances primary production in the infiltration (surface) layer. Productivity in the freeboard (sea level) layer is also determined by sea ice porosity, which varies with temperature. Spatial and temporal variation in snow thickness and the proportion of first-year ice thus determine regional differences in sea ice primary production. Model results show that of the 40 teragrams of carbon produced annually in the Antarctic ice pack, 75 percent was associated with first-year ice and nearly 50 percent was produced in the Weddell Sea. 相似文献
9.
A. Tullu L. Buchwaldt M. Lulsdorf S. Banniza B. Barlow A. E. Slinkard A. Sarker B. Tar’an T. Warkentin A. Vandenberg 《Genetic Resources and Crop Evolution》2006,53(1):111-119
Lentil anthracnose (Colletotrichum truncatum (Schwein.) Andrus et W.D. Moore is a potential threat in many lentil (Lens culinaris Medik.) production regions of North America. In the lentil germplasm maintained in Germany and North America, 16 lines were
reported to have resistance to race Ct1, but none has resistance reported to race Ct0. The objective of this study was to
examine accessions of wild Lens species for their resistance to races Ct1 and Ct0 of lentil anthracnose. Five hundred and seventy-four wild accessions of
six species and control lines were screened in two replications under both field and greenhouse conditions using a 1–9 scoring
scale (1, highly resistant; 2–3, resistant; 4–5, moderately resistant; 6–7, susceptible; and 8–9, highly susceptible). Indianhead
and PI 320937 were resistant while Eston and Pardina were susceptible to race Ct1 as expected. However, none of the check
lines were resistant to race Ct0. Among the six Lens wild species tested, accessions of Lens ervoides (Brign.) Grande had the highest level of resistance, 3–5 to race Ct1 and Ct0 followed by L. lamottei Czefr. in the field and greenhouse. Lens orientalis (Boiss.), L. odemensis L., L. nigricans (M. Bieb.) Godron and L. tomentosus L. were highly susceptible, 8–9 to race Ct0 in the greenhouse. The highest frequency of resistance, especially in L. ervoides (Brign.) Grande, was found in accessions originating from Syria and Turkey. The usefulness of these L. ervoides (Brign.) Grande accessions as sources of resistance to the more virulent race of anthracnose in a lentil breeding program
is discussed. 相似文献
10.
Raymond N. Yong Benno P. Warkentin Yuwaree Phadungchewit Rosa Galvez 《Water, air, and soil pollution》1990,53(1-2):53-67
The link between buffer capacity and the ability of clays to retain Pb in interactions between Pb contaminant leachate and the clays, has been studied, using a natural clay from Quebec and laboratory-prepared clays (kaolinite, illite, and smectite). The retention of Pb in the clay suspensions as they received increasing amounts of acid was investigated, and the results examined in terms of the buffer capacity of the clays. As the clays receive increasing amounts of acid (e.g. akin to addition of acid leachate), high amounts of Pb can be retained if the buffer capacity prevents the pH from dropping to values where precipitation mechanisms are not operative. The high carbonate content in the illite gave it a higher buffer capacity than the smectite and natural clay, and permitted it to retain high amounts of Ph. High Pb uptake by the clays can affect the buffer capacity and the Pb retention capacity. 相似文献