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501.
Growth of grass herbage in Ireland is highly seasonal with little or no net growth from November to February. As a result, feed demand exceeds grass supply during late autumn, winter and early spring. At low stocking rates [≤2 livestock units (LU) ha?1], there is potential to defer some of the herbage grown in autumn to support winter grazing. This study examined the effects of four autumn‐closing dates and four winter‐grazing dates in successive years on the accumulation of herbage mass and on tiller density in winter and subsequent herbage production at two sites in Ireland, one in the south and one in the north‐east. Closing swards from grazing in early and mid‐September (north‐east and south of Ireland respectively) provided swards with >2 t DM ha?1 and a proportion of green leaf >0·65–0·70 of the herbage mass above 4 cm, with a crude protein (CP) concentration of >230 g kg?1 DM and dry matter digestibility (DMD) of >0·700. The effects of autumn‐closing date and winter‐grazing date on herbage production in the subsequent year varied between the two sites. There was no significant effect of autumn‐closing date in the north‐eastern site whereas in the south earlier autumn closing reduced the herbage mass in late March by up to 0·34 t DM ha?1 and delaying winter grazing reduced the herbage mass in late March by up to 0·85 t DM ha?1. The effects of later grazing dates in winter on herbage mass continued into the summer at the southern site, reducing the herbage mass for the period from late March to July by up to 2 t DM ha?1. The effects of imposing treatments in successive years did not follow a consistent pattern and year‐to‐year variation was most likely linked to meteorological conditions. 相似文献
502.
Superficial, circular necrotic lesions develop on cultivar Ramacimiento (Solanum tuberosum ssp.andigena) tubers in plantings at elevations above 2,500 m in the Peruvian Andes. After drying or storage the lesions become sunken or cankerous. A virus was transmitted mechanically toChenopodium quinoa andC. amaranticolor with leaf and fruit saps from Renacimiento plants grown from symptomed tubers. The virus is a strain of potato mop-top virus which causes milder tuber symptoms in European cultivars.C. quinoa was better thanC. amaranticolor as an indicator host; its spreading local lesion reaction was most sensitive at 15 C, less at 10 and 20, and nil at 25 C. Sap inoculum from fruit resulted in symptoms in 7 days, that from leaves in 13 days, and that from tubers produced no symptoms. 相似文献
503.
Archer DC Barrie Edwards G Kelly DF French NP Proudman CJ 《Veterinary journal (London, England : 1997)》2006,171(3):504-512
Idiopathic focal eosinophilic enteritis (IFEE) is a rare disease in the horse and few cases have been reported in the literature. The objective of this paper was to describe the clinical, surgical, histological features and post-operative progress of 12 horses with IFEE, a disease that had not been identified in the authors' hospital population prior to 2000. Diagnosis of IFEE was made at laparotomy and confirmed by histological examination of resected abnormal small intestine. In all 12 horses colic was associated with jejunal obstruction involving visibly striking and palpably thickened serosal plaques or circumferential constrictions. Surgical resection of affected intestine was performed in 10 horses, of which seven completely recovered. In one horse, on which surgical resection was not performed, ingesta re-obstructed post-operatively at one of the lesions. Histological examination of resected intestines revealed, in all cases, severe transmural enteritis in which eosinophilic leucocytes were the predominant inflammatory cells. No helminths were identified and the cause of this lesion is not known. IFEE is an uncommon but significant cause of small intestinal obstruction for which surgical resection can be curative. The gross lesions may be under-recognised and histology is essential for diagnosis. 相似文献
504.