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101.
B. G. Wilkinson R. O. Sharples 《The Journal of Horticultural Science and Biotechnology》2013,88(1):67-82
In four successive seasons. Cox’s Orange Pippin apples were picked at weekly intervals and stored under various conditions to assess the effect of time of picking on wastage from different causes.Mean fruit weight increased by up to 20% over the 6 to 10 weeks of the picking periods.The maturity of the fruit when picked was assessed by following the respiration pattern of samples kept at 12°C.The results for successive pickings of fruit kept at 37°-38° F. (2.8°-3 ·3° C.) (normal cold storage temperature for Cox) and all removed from store at the same time, showed more core flush in early-picked apples, and more senescent breakdown and rotting in late-picked apples. There was no sudden change in liability to any of these disorders which could be associated with any particular stage of maturity. There were no consistent effects of time of picking on the amount of bitter pit or on weight loss during storage.Storage at 32° F. (o° C.) (below the recommended temperature for the storage of Cox’s Orange Pippin) resulted in low temperature breakdown. This disorder tended to be less severe in apples picked just before the climacteric rise in respiration rate.It is concluded that, for any particular orchard, picking date should be based not only on maturity as judged by colour and size, but on the expected liability of the fruit to disorders, such as core flush and rotting due to Gloeosporium, and on the type and period of storage required. 相似文献
102.
C Zondervan S Muresan H G de Jonge E U van Velzen C Wilkinson H H Nijhuis T Leguijt 《Journal of agricultural and food chemistry》1999,47(11):4746-4749
An electronic nose has been used to classify blockmilk products subjected to various heating processes based on their volatile composition. Multivariate analyses of electronic nose and GC/MS data are highly comparable with respect to relative changes in aroma profile going from raw to final product. Predictive properties of various neural networks based on the raw sensor output were moderate to good. 相似文献
103.
Acorn production is one of the most important products in silvopastoral systems in the Mediterranean region. In the present
study we carried out two preliminary trials to analyze the distribution of production over time and the effect of pruning.
The objective was to develop tools to manage this valuable resource within these systems. In the first part of the study,
we analyzed the total acorn production of a holm oak stand, and its seasonal distribution (October–January) over two years
(1997–1998 and 1998–1999) in five sites in the southwest of Spain. Mean total acorn production ranged from 590 to 830 kg ha−1. There was considerable variation between the different sites and years studied, as was expected from studies on other oak
species. A comparison was also made of acorn production, comparing annual acorn production between 40 pruned and 40 non-pruned
trees, for the period 1994–1999. There was an interaction between ‘pruning treatment’ and ‘year’. Pruning, significantly decreased
acorn production in all but two years when production was above the average, whereas production was not affected by pruning
the three years that acorn yield was below the average. The study of acorn production and the analysis of the effect of pruning,
needs to be studied over a longer time period. 相似文献
104.
105.
MJ Lancaster JS Nimmo C Lenghaus IJ Gill RD Crawford RT Badman JL Samuel CJ Werner C Button N Kvalheim 《Australian veterinary journal》2009,87(12):476-479
Objective To document an ovine disease attributed to the consumption of Lythrum hyssopifolia (lesser loosestrife). Procedures Historical and histological review of field and experimental cases. Results 1–20% mortality occurred in sheep flocks grazing paddocks where L. hyssopifolia was the predominant green vegetation. Well‐documented disease outbreaks occurred in summer on nine farms across Victoria between 1974 and 2002. Liver damage occurred in all nine outbreaks, with kidney damage in at least eight. Hepatocyte necrosis was usually zonal to midzonal (zone 2) in the liver samples from four farms and periacinar (zone 3) in those from three farms, but some livers showed only single‐cell necrosis. Multinucleate hepatocytes near necrotic areas were a feature in six cases. Proximal tubular epithelium appeared to be the primary renal target and brown granules were often present in renal tubules. Biochemical and histological evidence of liver and kidney damage was obtained from two sheep experimentally pen‐fed harvested L. hyssopifolia. Conclusion Chemicals in L. hyssopifolia are toxic to ovine hepatocytes and renal tubular epithelial cells. 相似文献
106.
B. Louise Chilvers Ian S. Wilkinson Darryl I. Mackenzie 《Journal of Agricultural, Biological & Environmental Statistics》2010,15(2):259-278
The trade-off between survival and reproduction by individuals is central to understanding life-history parameters of a species.
Few mammal species have life-history information from long-term research. Instead, demographic models are commonly utilized
to investigate an individual’s life-history strategy, species dynamics, and population trends. This research investigates
age-related survival and reproductive performance of adult female New Zealand (NZ) sea lions (Phocarctos hookeri), using multi-state mark-recapture data from known-age branded individuals over five years. The mark-recapture analysis was
integrated with a population model to predict the lifetime reproductive output of female NZ sea lions. The integration of
an analysis of short-term datasets with population modeling allows for the prediction of life-history parameters of long lived
animals when long-term information is not available. While such approaches involve some caveats, it provides a framework for
investigating population dynamics and is preferential to unsubstantiated assumptions. This technique can lead to better design
and implementation of conservation management for long lived species. 相似文献
107.
Peterson TE McDowell LR McMahon RJ Wilkinson NS Rosendo O Seymour WM Henry PR Martin FG Shearer JK 《Journal of animal science》2004,82(4):1165-1169
The objective of this study was to test the hypothesis that serum biotin concentration and biotin balance (consumed - [urinary output + fecal output]) measured as total avidin-binding substances (biotin + biotin metabolites) are responsive to changes in the proportions of dietary alfalfa meal and concentrate fed to sheep. Eight sheep (initial BW = 40 kg) consumed a pelleted alfalfa meal-based diet that had 95:5, 48:52, 23:77, or 9:91% alfalfa meal:concentrate ratios (DM basis) in a replicated 4 x 4 Latin square design with 20-d periods (10 d of acclimation, 7 d of adaptation, and a 3-d collection period with jugular blood drawn on the last day). Replacing alfalfa meal with concentrate in the pelleted diets decreased dietary concentrations of biotin proportionally. As the percentage of alfalfa meal in the diet decreased, there was a linear decrease in daily DM intake (1,128 to 901 g of DMI/d; P < 0.01), with a linear (P < 0.01) and quadratic (P < 0.01) increase in the apparent total-tract DM digestibility of diets (51.0 to 80.0%). The biotin consumed decreased with alfalfa meal proportion in the diet (linear, P < 0.01). Both fecal biotin concentration (linear, P < 0.01) and fecal biotin output (quadratic, P < 0.05) increased, reaching peaks at 23% alfalfa meal. Fecal biotin output was not correlated with biotin intake, DMI, or intake of digestible DM. Mean urinary output, urinary biotin concentration, urinary biotin output, and serum biotin concentration were not affected by treatments. Means of biotin balance were negative and revealed the same trends among treatments as did fecal output. Biotin balance was a quadratic (P < 0.05) function of decreasing alfalfa meal in the diet, with more negative values at the alfalfa meal:concentrate ratio of 23:77. Results suggest that the greatest synthesis of biotin in the total digestive tract occurs with diets of either 52 or 77% concentrate for sheep; however, research addressing the significance of biotin metabolites on biotin balance and plasma biotin pool is needed. 相似文献
108.
109.
110.
Effects of residual and reapplied biosolids on performance and mineral status of grazing beef steers 总被引:4,自引:0,他引:4
Tiffany ME Mcdowell LR O'Connor GA Martin FG Wilkinson NS Percival SS Rabiansky PA 《Journal of animal science》2002,80(1):260-269
An experiment was designed to assess the mineral status of 60 Angus yearling beef steers grazing bahiagrass pastures fertilized with large amounts of biosolids from three sources: Baltimore, MD; Tampa, FL; and Largo, FL. Biosolids were classified as exceptional quality and thus had no regulatory restrictions on loading rate. They differed primarily in concentration of Mo (12 to 56 mg/kg of DM). Residual treatments (biosolids applied only the previous year) for Baltimore biosolids were applied at 22.4 and 44.8 t/ha, and Tampa biosolids were either 16.8 or 33.6 t/ ha. The reapplied treatments (applied in consecutive years) for both Baltimore and Tampa sludges were applied at 22.4, 44.8, 16.8 , and 33.6 t/ha, respectively. The two Largo biosolids treatments were either 56 or 112 t/ha and were applied only in the 2nd yr. Liver biopsies and blood samples were collected on d 1, 95, and 180. Liver and plasma were analyzed for minerals and blood was analyzed for hemoglobin, hematocrit, and superoxide dismutase of polymorphonuclear neutrophils. Experimental animals were generally adequate in macromineral status and Co, Fe, and Mn throughout the experiment. Copper deficiency was evident based on the clinical signs of hair coat discoloration, very low plasma Cu at d 95, and the continuous decline in liver Cu over 180 d. A sharp decline in plasma Cu was observed for all treatments from d 1 to 95, after which Cu concentrations rebounded to normal concentrations (> 0.65 microg/mL) by d 180. Liver Mo was well below concentrations indicating toxicity (> 5.0 mg/kg). The steep decline in liver Cu over the first 95 d reflects the dietary Cu deficiency and the possibility of high forage S (0.26 to 0.52%) interfering with Cu metabolism. Biosolids application to bahiagrass pastures was not detrimental to mineral status except for declining Cu stores; however, the controls likewise declined, but to a lesser degree. 相似文献