Herbage intake of dairy cows in mixed sequential grazing with breeding ewes as followers     

Juan Daniel Jiménez-Rosales  Ricardo Daniel Améndola-Massiotti  Juan Andrés Burgueño-Ferreira  Rodolfo Ramírez-Valverde  Pedro Topete-Pelayo  Maximino Huerta-Bravo 《Tropical animal health and production》2018,50(3):531-536

This study aimed to evaluate the hypothesis that mixed sequential grazing of dairy cows and breeding ewes is beneficial. During the seasons of spring–summer 2013 and autumn–winter 2013–2014, 12 (spring–summer) and 16 (autumn–winter) Holstein Friesian cows and 24 gestating (spring–summer) and lactating (autumn–winter) Pelibuey ewes grazed on six (spring–summer) and nine (autumn–winter) paddocks of alfalfa and orchard grass mixed pastures. The treatments “single species cow grazing” (CowG) and “mixed sequential grazing with ewes as followers of cows” (MixG) were evaluated, under a completely randomized design with two replicates per paddock. Herbage mass on offer (HO) and residual herbage mass (RH) were estimated by cutting samples. The estimate of herbage intake (HI) of cows was based on the use of internal and external markers; the apparent HI of ewes was calculated as the difference between HO (RH of cows) and RH. Even though HO was higher in CowG, the HI of cows was higher in MixG during spring–summer and similar in both treatments during autumn–winter, implying that in MixG the effects on the cows HI of higher alfalfa proportion and herbage accumulation rate evolving from lower residual herbage mass in the previous cycle counteracted that of a higher HO in CowG. The HI of ewes was sufficient to enable satisfactory performance as breeding ewes. Thus, the benefits of mixed sequential grazing arose from higher herbage accumulation, positive changes in botanical composition, and the achievement of sheep production without negative effects on the herbage intake of cows.  相似文献   

Morphological and Physiological Responses of Plantain (Plantago lanceolata) and Chicory (Cichorium intybus) to Water Stress and Defoliation Frequency          下载免费PDF全文

L. M. Cranston  P. R. Kenyon  S. T. Morris  N. Lopez‐Villalobos  P. D. Kemp 《Journal of Agronomy and Crop Science》2016,202(1):13-24

Plants are often subjected to periods of water stress. There are little data examining the effect of water stress on the forage species Plantago lanceolata and Cichorium intybus. In two pot experiments with P. lanceolata and C. intybus, morphological responses under optimum, dry, and very‐dry water treatments with weekly, fortnightly and 3‐weekly defoliation intervals and physiological responses under optimum and very‐dry water treatments were measured. A third experiment compared the rooting depths of P. lanceolata and C. intybus under field conditions. These findings suggest that both P. lanceolata and C. intybus can survive and continue to grow under water stress conditions with the main differences between the two species being attributable to morphological characteristics (root mass, taproot diameter and shoot mass fraction) rather than differences at a physiological level. Overall, the results suggest plantain may be more productive under moderate drought due to its greater shoot mass fraction, whereas chicory may be more productive and persistent under severe drought due to its greater root mass, taproot diameter and root depth under field conditions.  相似文献   

Validation of a multiplex PCR assay to detect Babesia spp. and Anaplasma marginale in cattle in Uruguay in the absence of a gold standard test     

Pablo Parodi  Luis G. Corbellini  Vanessa B. Leotti  Rodolfo Rivero  Cecilia Miraballes  Franklin Riet-Correa  Jos M. Venzal  María T. Armúa-Fernndez 《Journal of veterinary diagnostic investigation》2021,33(1):73

Detection of bovine Babesia spp. and Anaplasma marginale is based on the reading of Giemsa-stained blood or organ smears, which can have low sensitivity. Our aim was to improve the detection of bovine Babesia spp. and A. marginale by validating a multiplex PCR (mPCR). We used 466 samples of blood and/or organs of animals with signs and presumptive autopsy findings of babesiosis or anaplasmosis. The primers in our mPCR amplified the rap-1a gene region of Babesia bovis and B. bigemina, and the msp-5 region of A. marginale. We used a Bayesian model with a non-informative priori distribution for the prevalence estimate and informative priori distribution for estimation of sensitivity and specificity. The sensitivity and specificity for smear detection of Babesia spp. were 68.6% and 99.1%, and for A. marginale 85.6% and 98.8%, respectively. Sensitivity and specificity for mPCR detection for Babesia spp. were 94.2% and 97.1%, and for A. marginale 95.2% and 92.7%, respectively. Our mPCR had good accuracy in detecting Babesia spp. and A. marginale, and would be a reliable test for veterinarians to choose the correct treatment for each agent.  相似文献   

Effect of supplementation of beef cattle with different protein levels and degradation rates during transition from the dry to rainy season     

Rodolfo Maciel Fernandes  Chafic Mustafé de Almeida  Bruna Caldas Carvalho  João Alexandrino Alves Neto  Verônica Aparecida Costa Mota  Flávio Dutra de Resende  Gustavo Rezende Siqueira 《Tropical animal health and production》2016,48(1):95-101

  相似文献   

Near-Infrared Spectroscopy Coupled with Chemometrics Tools: A Rapid and Non-Destructive Alternative on Soil Evaluation     

Jéssica Bassetto Carra  Marciéli Fabris  Jeferson Dieckow  Osmar Rodrigues Brito  Pedro Rodolfo Siqueira Vendrame 《Communications in Soil Science and Plant Analysis》2019,50(4):421-434

Near-infrared (NIR) spectroscopy is a rapid, non-destructive and accurate technique for analyzing a wide variety of samples, thus, the growing interest of using this technique in soil science. The objective of this study was to evaluate the potential of NIR spectroscopy to predict organic carbon (OC), total nitrogen (TN), available phosphorus (P) and available potassium (K) in the soil. NIR spectra from 20 cm³ of soil samples were acquired on the range of 750 to 2500 nm in diffuse reflectance mode, resolution of 16 cm^?1 and 64 scans. Eight models of calibration/validation were constructed. Calibration and validation models showed that the predictive potential of NIR varied with the specific soil property (OC, TN, P and K) under evaluation and according to the methodology employed in the model construction (cross-validation or test set). Good prediction models were obtained for OC and TN content based on the statistical parameters. Test set methodology was able to predict soil OC, TN, P, and K better than cross-validation methodology.  相似文献   

Current status and future strategy in breeding grasspea (Lathyrus sativus)     

C. G. Campbell  R. B. Mehra  S. K. Agrawal  Y. Z. Chen  A. M. Abd El Moneim  H. I. T. Khawaja  C. R. Yadov  J. U. Tay  W. A. Araya 《Euphytica》1993,73(1-2):167-175

Efforts in grasspea (Lathyrus sativus) improvement have increased since the development of lines that are very low in the neurotoxin Beta-N-oxalyl-L-alpha-beta-diamino propionic acid (ODAP); also referred to as Beta-N oxalyl-amino-L-alanine (BOAA). Many programs now address several related aspects of improvement simultaneously. These include reduced ODAP concentrations, insect and disease resistance, nitrogen fixation, agronomic practices, fodder and forage production, and components for increased yielding ability. The coordinated, multidisciplinary approach now being applied to the genetic improvement of grasspea should allow the potential of this largely neglected grain legume to be fully realized.  相似文献   

Use of nootkatone as a senescence indicator for Rouge La Toma Cv. grapefruit (Citrus paradisi Macf.)     

Biolatto A  Sancho AM  Cantet RJ  Güemes DR  Pensel NA 《Journal of agricultural and food chemistry》2002,50(17):4816-4819

The objective of this research was to study the usefulness of nootkatone as a senescence indicator for Rouge La Toma cv. grapefruit (Citrus paradisi Macf.), simulating different treatments that included the normal postharvest handling of citrus fruits: temperature conditioning, cold storage, shipment periods to overseas markets such as Japan and the U.S., marketing conditions, and storage at nonchilling temperature (control treatments). The highest nootkatone levels, determined by GLC-MS analyses, were detected in fruits subjected to control treatments. No significant differences were observed in nootkatone levels between treatments either with or without temperature conditioning prior to the start of the cold storage. Levels of nootkatone increased throughout time for all assayed treatments. The linear regressions of nootkatone levels showed correlation coefficients of 0.80 and 0.83 with storage time (29 and 42 days, respectively). Therefore, nootkatone appears to be a good indicator of senescence for Rouge La Toma grapefruit.  相似文献   

长期秸秆还田对白浆土物理性质及水稻产量的影响   总被引：10，自引：1，他引：10  

王秋菊  常本超  张劲松  韩东来  隋玉刚  陈海龙  杨兴玉  王雪冬  焦峰  常本超  新家宪  刘峰 《中国农业科学》2017,50(14):2748-2757

【目的】明确长期秸秆还田对白浆土土壤物理性质及水稻产量的影响。【方法】开展秸秆还田长期定位试验。试验设置4个处理,分别为对照(CK),单施秸秆(S),秸秆+化肥(SNPK),单施化肥(NPK)。在2005年后连年处理,并于试验处理前和2010年、2015年试验处理期间调查土壤容重、硬度、孔隙、三相组成以及水稻产量。【结果】白浆土长期秸秆还田有利于水稻产量提高,10年产量平均,秸秆还田配施肥料处理水稻产量比对照和秸秆单独还田处理增产275.70%和133.23%,比单施化肥处理增产14.17%。秸秆还田处理水稻产量在还田第5—10年平均产量比第1—5年有增加趋势;长期秸秆还田可以改善土壤物理性质,降低土壤容重、硬度,还田10年后,秸秆还田配施化肥处理土壤容重低于化肥单施、秸秆单施及对照处理,SNPK处理0—20、20—30 cm土层土壤容重与对照相比分别降低6.34%和10.00%,与还田5年后同类处理相比仍呈下降趋势;秸秆还田配施化肥处理土壤硬度10年后在10、20、30 cm土层与处理前相比分别降低为26.87%、5.68%和4.62%,在20—30 cm土层与对照相比差异显著,还田10年与5年后相比有下降趋势,其他处理变化不明显;还田5年后,秸秆还田配施化肥处理在0—20、20—30、30—40 cm土层土壤固相比例与对照相比分别下降8.82%、8.36%和3.65%,还田10年后分别下降10.87%、10.61%和4.67%,10年后要比5年后下降幅度大,秸秆还田配施化肥比秸秆单施和化肥单施处理下降幅度大;长期秸秆还田可以增加土壤有效孔隙的数量,在处理间和年限间差异极显著,还田10年后,在0—20、20—30、30—40 cm土层秸秆还田配施化肥土壤有效孔隙比对照增加28.86%、63.85%和23.40%,在20—30 cm和30—40 cm土层比化肥单施增加12.55%和62.96%,在0—20、20—30、30—40cm土层比秸秆单施增加19.68%、56.52%和24.46%;与还田5年后相比,土壤有效孔隙度均呈现增加的趋势。【结论】长期秸秆还田可以改善白浆土不良物理性状,降低白浆层的容重、硬度,增加土壤总孔隙度和有效孔隙的比例,提高水稻产量。秸秆还田年限越长改善土壤不良物理性质效果越明显。单独进行秸秆还田改善土壤效果不明显,秸秆还田配施肥料处理效果明显;在不同处理上,秸秆还田配施化肥处理既有改土效果,又可提高水稻产量,而单施化肥和单独秸秆还田均达不到此类效果。  相似文献   

Effect of three diets on the gametogenic development and fatty acid profile of Paracentrotus lividus (Lamarck, 1816) gonads     

Andreia I. G. Raposo  Susana M. F. Ferreira  Rodolfo Ramos  Pedro M. Santos  Catarina Anjos  Teresa Baptista  Carla Tecelo  Jos L. Costa  Ana Pombo 《Aquaculture Research》2019,50(8):2023-2038

In this study, the effects of three diets were investigated to enhance Paracentrotus lividus production for commercial purposes. P. lividus were fed ad libitum for 80 days with: diet A—fresh Codium tomentosum Stackhouse, 1797; diet B—formulated using a jellified mix of macroalgae and vegetables, including C. tomentosum (20%), Coralina sp. Linnaeus, 1758 (17%), cabbage Brassica oleracea var. capitata Linnaeus, 1753 (30%), carrot Daucus carota Linnaeus, 1753 (30%) and agar (3%) as a gelling agent. Diet C consisted of maize Zea mays Linnaeus, 1753 (56%) and New Zealand spinach Tetragonia tetragonoides (Pallas, 1781) Kuntze, 1891 (44%). Their effects on the gonadal and somatic growths, gonadosomatic index (GI) and gametogenesis were evaluated, as well as on the total lipid content and fatty acid composition of sea urchin's gonads. Diet A provided high values of eicosapentaenoic acid (EPA). Gonads of sea urchins fed with diet A were found mostly in growth and maturation stages of gametogenesis and showed the lowest lipid content. Sea urchins fed with diet B presented their gonads in the reabsorption stage and had the highest values of omega‐3 polyunsaturated fatty acids (PUFAs). Sea urchins fed with diet C were in the early stages of gametogenesis and had the highest values of lipid content, plus omega‐6 PUFAs. Once as an ingredient in a balanced mix with vegetables, C. tomentosum can be a key factor to the development of new promising high‐quality and low‐cost feed for P. lividus roe enhancement.  相似文献   

Source of mycorrhizal inoculum influences growth of Faidherbia albida seedlings     

Emiru Birhane  Mengsteab Hailemariam  Girmay Gebresamuel  Tesfay Araya  Kiros Meles Hadgu  Lindsey Norgrove 《林业研究》2020,31(1):313-323

Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on different land uses.We quantified the growth and nutrient uptake of F.albida seedlings inoculated with AM from different sources.These efforts were based on soil and fine root samples from the rhizosphere soils of F.albida trees.AM root colonization was determined using the gridline intersect method.Spores were extracted by the wet sieving and decanting method and identified to genus level.The seedling experiment had a completely randomized onefactorial design with four treatments and five replications.Faidherbida albida seedlings were grown in a greenhouse.All in situ F.albida trees were colonized by AM fungi.AM root colonization of F.albida trees was significantly higher(P<0.0086)in area exclosures than on lands used for grazing or cultivation.Spore abundance was significantly higher(P<0.0014)in area exclosures followed by cultivated land and grazing land.Glomus was the dominant genus in all land-uses.AM-inoculated F.albida seedlings grew better(P<0.05)than non-inoculated controls.Seedlings inoculated with AM from area exclosure had significantly(P<0.05)higher growth and nutrient uptake than those inoculated with AM from grazing and cultivated land.This emphasizes the importance of the native soil AM potential for better establishment of seedlings to achieve optimum plant growth improvement and assist in rehabilitation of degraded arid lands.  相似文献