Simulation of the intake and partition of nutrients by the dairy cow: Part I — Management control in the dairy enterprise; philosophy and general model construction     

A. C. Bywater  J. B. Dent 《Agricultural Systems》1976,1(4):245-260

The development of management control techniques for the dairy derd is discussed in this paper in relation to the rationale behind the construction of a detailed model of milk production in the individual cow. The movement towards a more flexible and individualised basis for predicting yield, which does not depend on historical records or standard energy systems, is highlighted.The overall concept and approach of the model are set out and the control aspects and structural framework of the program explained. Subsequent papers in the series will deal in more detail with the major sections of the program in order to illustrate how the mechanisms of the model actually operate and to provide results and an account of the validation procedure.  相似文献   

Reviews section     

Dr Bill Symondson  W. O. C. Symondson  Dr Peter McEwen  Simon Oxley  Dr Patthumal Beevi  Houston Hobbs  Keith Harris  Dr R. T. Plumb  Professor P. G. Mantle  Professor J. Hemingway  Dr Barbara B. Shew  R. M. Baker  Professor P. A. Langley  David Dent 《Integrated Pest Management Reviews》1996,1(2):111-123

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ADVANCE NOTE ON RESEARCH     

B. F. Bland  J. W. Dent 《Grass and Forage Science》1962,17(2):157-158

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Collaborative study of the extraction of light filth from canned whole shrimp     

R G Dent 《Journal of the Association of Official Analytical Chemists》1974,57(3):691-692

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Collaborative study of the extraction of light filth from canned whole and cream style corn     

R G Dent 《Journal of the Association of Official Analytical Chemists》1973,56(3):634-636

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Cryopreservation of Piau‐Breed Wild Boar Sperm: Assessment of Cooling Curves and Centrifugation Regimes          下载免费PDF全文

HH Shiomi  RO Pinho  DMA Lima  JB Siqueira  MCR Santos  EV Costa  PS Lopes  SEF Guimarães  JD Guimarães 《Reproduction in domestic animals》2015,50(4):545-553

This study aimed to assess the effects of different cooling curves and centrifugation regimes used in cryopreservation protocols on the post‐thaw viability of Piau‐breed wild boar (Sus scrofa) sperm using in vitro assessment tests. Two centrifugations (800  g for 10 min and 2400  g for 3 min) and two cooling curves (conventional cooling using nitrogen vapour – freezing 1 and automated cooling using a programmed freezing machine – freezing 2) were tested. Therefore, the treatments were divided into M3 – centrifugation at 2400  g for 3 min and freezing 2; M10 – centrifugation at 800  g for 10 min and freezing 2; R3 – centrifugation at 2400  g for 3 min and freezing 1; and R10 – centrifugation at 800  g for 10 min and freezing 1. No significant differences (p > 0.05) between treatments occurred post‐thawing regarding the total sperm motility means recorded. The mean values of the different treatments were not different from each other regarding the supravital staining (SV), hypo‐osmotic test (HO), sperm–egg binding assay or sperm morphology. This study showed that both the cooling curve and the centrifugation regime affected the quality of post‐thaw sperm, and centrifugation for shorter times and cooling curves using automated cooling are the most suitable for minimizing sperm injury.  相似文献   

Collaborative study of a new method for the extraction of light filth from black and white ground pepper     

R G Dent  P M Brickey 《Journal of the Association of Official Analytical Chemists》1972,55(1):83-84

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Rehabilitating Abandoned Pastures in Panama: Control of the Invasive Exotic Grass,Saccharum spontaneum L., Using Artificial Shade Treatments     

Taek Joo Kim  Florencia Montagnini  Daisy Dent 《Journal of Sustainable Forestry》2013,32(3):192-203

ABSTRACT

The exotic grass, Saccharum spontaneum L., has invaded abandoned agricultural lands in the Panama Canal Watershed for decades. The grass aggressively competes with regenerating tree seedlings preventing natural forest regeneration. To estimate effectual light level for controlling the grass, the growth of S. spontaneum was measured under a range of artificial shading conditions. Five shade treatment subplots–light intensities of 100% (full sunlight), 50, 25, 15, and 5%–were established at each of eight plots in land adjacent to the Panama Canal Watershed. Each site was cleared of S. spontaneum and then the regrowth was harvested. The regrowth of the grass was harvested and measured four times every one and half months for six months. The biomass of S. spontaneum was significantly less in lower light conditions than in full sunlight. The results showed that comparing growth of the grass at each harvest date, except for the first harvest date, there were significant differences between full sunlight and light intensities of 5, 15 and 25%. When compared by different harvest dates for each light level, only full sunlight showed a significant difference in biomass of the grass. The study demonstrates that shading is an effective method for controlling S. spontaneum. The results can be applied to developing reforestation strategies for abandoned lands occupied by S. spontaneum.  相似文献   

Use of a temporalis fascia transposition flap for ventral orbital stabilization after ventral orbitectomy in a dog     

Brian Dent  Vincent A. Wavreille  Laura E. Selmic 《Veterinary surgery : VS》2019,48(6):1058-1063

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SYSTEMATIC TESTING OF QUALITY IN GRASS VARIETIES     

J. W. Dent    D. T. A. Aldrich  V. Silvey 《Grass and Forage Science》1967,22(4):270-276

The degree of precision obtained In the quality testing of grass varieties under two systems of management was examined (1) in a single cut, (2) under a system of proportionate bulking of produce from individual cuts during a season, and (3) after pooling two seasons' data from two centres.
Crude protein, crude fibre, soluble carbohydrate, and in vitro digestible dry matter were determined. The components of variance were analysed and in the data from single cuts varietal differences in digestibility of 2.10 were significant (P=0.05). Using data from two seasons at two centres, a high degree of precision was obtained for all attributes in a grazing management system and varietal differences in digestibility of 1.25% were significant.
Variation due to location and season was greater in hay cuts taken 10 days after ear emergence. In both systems varieties differed more in soluble carbohydrate content than in the other chemical components.  相似文献