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991.
M W Verstegen D Zwart W van der Hel B O Brouwer T Wensing 《Journal of animal science》1991,69(4):1667-1677
A study was conducted using 32 mature 22-kg West African Dwarf Goats to measure the effect of Trypanosoma vivax infection on energy and nitrogen metabolism. Sixteen goats were infected intravenously with 14 X 10(6) T. vivax. Sixteen control goats were sham-injected. Digestibility and metabolizability of energy and N balance were measured for each goat. Heat production and energy balances were measured per treatment group from 1 wk before infection to 6 wk after infection. Goats were fed alfalfa pellets (10% above maintenance). Treated goats had a reduced (P less than .05) packed cell volume (38 to 40% before infection vs 20 to 25% 6 wk after infection) and an increased (P less than .05) rectal temperature. Log parasitemia/ml was about 6.0 to 6.2. Parasitized goats showed increased urine creatinine excretion at wk 2 postinfection. After infection, feed intake was reduced (about 15%; P less than .05) and greater variability in intake was noted. Treated and control goats had similar N output and energy output in urine. Metabolizability of energy intake was similar at 42.7 vs 42.1% in treated vs control goats, respectively. Heat production in infected goats was increased by about 15%. Treated goats lost more weight and had a lower N balance than control goats (P less than .05). The calculated maintenance energy requirement for infected goats (464 kJ ME/kg.75) was 25% greater than for control goats (375 kJ ME/kg.75). 相似文献
992.
Banana is an increasingly demanded food and cash crop in sub-Saharan Africa. Reported yields in smallholder farms vary substantially. The importance and spread of yield constraints have not been properly quantified. A study was carried out in Central Kenya to (i) quantify the yield levels, the primary yield constraints, and the spatial production gradients in such systems (ii) explore how soil fertility gradients relate to gradients in soil fertility management, and whether this is a function of farmer resource availability. Data was collected on crop management aspects, pests and diseases, and soil and plant tissue samples analyzed for nutrient contents. Bunch yields were higher near homesteads (29.8 t ha−1 yr−1) than at mid-distance (26.8 t ha−1 yr−1), or far away 20.2 t ha−1 yr−1. Yields were much higher than previously reported (11–14 t ha−1 yr−1) in Kenya. Both soil and tissue K levels were higher near and mid-distance, than far from the homestead. Gradients of soil pH, total N, available P and Organic carbon were found, being higher near the homestead, while Mg and Ca were lowest near the homesteads. K was the most deficient nutrient, with tissue K index (IK) decreasing when moving away from the homesteads. P and Ca deficiencies were also observed. Resource-poor farmers’ soils were higher in exchangeable K and Mg, pH, and total N, and supported higher mat densities compared to resource-endowed farmers’ farms. Soil quality problems were the biggest yield loss factors and not pests and diseases. 相似文献
993.
V. Gunes A. C. Onmaz A. Pavaloiu G. Kaya Karasu R. van den Hoven 《Equine Veterinary Education》2022,34(9):467-472
The aim of our retrospective study was to produce and analyse epidemiological data on gastrointestinal (GI) disorders of Austrian leisure horses. Case records of horses referred to the Equine Clinic of the Veterinary University of Vienna were collected from an electronic hospital information system using its search options. All cases reported to have suffered a GI disorder between March 2003 and February 2015 were selected. In this period of 4314 days, data of 1833 GI cases, mostly accompanied by colic signs, were analysed. The vast majority of our GI cases appeared in the abdominal parts of the GI tract 96% (1760/1833) while just 1.3% (24/1833) could be definitively attributed to oesophageal disorders, whereas in 2.7% (49/1833) of the cases a definitive diagnosis could not be made. The highest prevalence of GI disorders was seen in July and October/November. A breakdown of figures for cases clustered under the colic syndrome showed that colon impactions in left ventral large and/or pelvic flexure (35%) were the major problem followed by gastric disorders (18%), spasmodic colic (9%), enteritis (7%), caecal tympany (6%); caecal impaction (4%), colitis (3%), abnormal anatomical positions of large colon including complete and partial strangulation/volvulus, nephrosplenic entrapment of the left ventral and dorsal colon and right dorsal displacement of the large colon (3%) and small intestinal volvulus (2.7%). In 12% of the cases, the cause of the abdominal discomfort was likely idiopathic paralytic ileus. The searching tool of the electronic patient data also brought up cases with malabsorbtion/IBD syndrome and GI ruptures, both these contributed less than 1% of the referred GI cases. Results suggested that the causes of colic are diverse, but the major reasons for referred cases of colic in the east Austrian horse population are large colon impaction or displacements. Seasonal distribution and specific causes of gastrointestinal disorders should be considered essential components of the initial clinical assessment of horses presenting with colic. 相似文献
994.
995.
Summary Colonization patterns of Pseudomonas fluorescens and Bacillus subtilis on roots of wheat seedlings growing on water agar were studied qualitatively by replica printing and quantitatively by the plate count method. The results indicated a stronger colonization potential for P. fluorescens (up to 107 cfu/cm root) than for B. subtilis (up to 105 cfu/cm root). Although the numbers of both species were lower when inoculated together, the observed colonization patterns on the roots were comparable to those found with single inoculations. For none of these bacteria was active migration along the root surface in any direction observed, indicating that distal positions are reached mainly by a passive displacement on the root tip and elongating cells. Ecological implications of the observed phenomena are discussed. 相似文献
996.
Food security policy, programs, and infrastructure have been incorporated into Public Health and other areas of the Provincial Government in British Columbia, including the adoption of food security as a Public Health Core Program. A policy analysis of the integration into Public Health is completed by merging findings from 48 key informant interviews conducted with government, civil society, and food supply chain representatives involved in the initiatives along with relevant documents and participant/direct observations. The paper then examines the results within the context of historic and international trends and theoretical models of food policy, community food security, and applied policy research. Public Health re-emerged as a driver of food security in BC—both as a key player and in positing the public’s health as a driver in food security and food systems. While Public Health’s lead role supported an increase in legitimacy for food security in BC, interviewees described a clash of cultures between Public Health and civil society. The clash of cultures occurred partly as a result of Public Health’s limited food security mandate and top down approach. Consequently civil society voice at the provincial level was marginalized. A social policy movement toward a new political paradigm—regulatory pluralism—calls for greater engagement of civil society, and for all sectors to work together toward common goals. A new, emerging policy map is proposed for analyzing the dynamics of food security and health promotion initiatives in BC. 相似文献
997.
Hiller NL Bhattacharjee S van Ooij C Liolios K Harrison T Lopez-Estraño C Haldar K 《Science (New York, N.Y.)》2004,306(5703):1934-1937
Malaria parasites secrete proteins across the vacuolar membrane into the erythrocyte, inducing modifications linked to disease and parasite survival. We identified an 11-amino acid signal required for the secretion of proteins from the Plasmodium falciparum vacuole to the human erythrocyte. Bioinformatics predicted a secretome of >320 proteins and conservation of the signal across parasite species. Functional studies indicated the predictive value of the signal and its role in targeting virulence proteins to the erythrocyte and implicated its recognition by a receptor/transporter. Erythrocyte modification by the parasite may involve plasmodial heat shock proteins and be vastly more complex than hitherto realized. 相似文献
998.
Brommer H Sloet van Oldruitenborgh-Oosterbaan MM 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2001,15(5):482-485
Forty-three Dutch Warmblood foals were divided at random into 3 rearing groups immediately after birth: a box-rest group, a box-rest with exercise group, and a pasture group. All stabled foals (box-rest and exercise groups) were fed freshly cut grass harvested from the same pastures on which the pasture group foals were grazing. Blood samples were obtained monthly for CBC and biochemical analyses. At 1-3 months of age, the foals at pasture were active but the foals in the box-rest and exercise groups were listless. Mean hemoglobin concentrations, PCVs, blood iron concentrations, and saturation of total iron binding capacity were significantly lower (P < .05) in the box-rest group (11.3+/-1.2 g/dL, 33+/-3%, 123+/-67 microg/dL, and 18+/-9%) and the exercise group (11.6+/-1.5 g/dL, 34+/-4%, 101+/-61 microg/dL, and 15+/-10%) compared with the pasture group (14.0+/-0.8 g/dL, 42+/-3%, 212+/-67 microg/dL, and 32+/-10%). Oral supplementation of iron to all foals resulted in significant increases in the values of these variables in the box-rest group and exercise group at 4-5 months of age, and the stabled foals were as active as the foals at pasture. In the pasture group, no significant changes occurred. Management practices clearly influence the iron state in young growing foals from 1 to 3 months of age, and although not a frequent cause of anemia in the horse, an absolute deficit of body iron may occur in stabled foals fed freshly cut grass. 相似文献
999.
W.I. Kuller H.M.G. van Beers-Schreurs N.M. Soede P. Langendijk M.A.M. Taverne B. Kemp J.H.M. Verheijden 《Livestock Science》2007,108(1-3):99-101
The aim of the study was to measure the effect of creep feeding during lactation on net absorption in the small intestine at 4 days after weaning. Intermittent suckling was used to increase creep feed intake during lactation. Creep feed containing chromic oxide was provided. Based on the colour of the faeces, piglets were classified as ‘eaters’ or ‘non-eaters’, respectively. At day 4 after weaning, an in vivo small intestine segment perfusion test was performed at 5 sites along the small intestine in 24 piglets (12 eaters and 12 non-eaters). At both sides of each intestinal segment a tube was fitted to perfuse and drain fluid in order to assess net absorption. Net absorption was higher in eaters than in non-eaters (P < 0.001). Net absorption varied greatly between and within piglets and was highest in the caudal segments of the small intestine (P < 0.001). These data suggest that creep feeding could be a useful tool in the prevention of post-weaning diarrhoea. 相似文献
1000.
Genetic and phenotypic parameter estimates for body weights and egg production in Horro chicken of Ethiopia 总被引:1,自引:0,他引:1
Nigussie Dana E. H. vander Waaij Johan A. M. van Arendonk 《Tropical animal health and production》2011,43(1):21-28
A breeding program has been established in 2008 to improve productivity of Horro chicken, an indigenous population in the
western highlands of Ethiopia. The pedigree descended from 26 sires and 260 dams. Body weights were measured every 2 weeks
from hatch to 8 weeks then every 4 weeks for the next 8 weeks. Egg production was recorded to 44 weeks of age for one generation.
Genetic parameters were estimated using animal model fitted with common environmental effects for growth traits and ignoring
common environment for egg production traits. Direct heritabilities ranged from low (0.15 ± 0.08), for body weight at 6 weeks,
to moderate (0.40 ± 0.23), for hatch weight. Heritabilities of common environmental effects on growth were high at hatch (0.39 ± 0.10)
and remained low afterwards. Age at first egg showed a very low heritability (0.06 ± 0.15). Heritabilities of egg numbers
in the first, second, third, and fourth months of laying were 0.32 (±0.13), 0.20 (±0.16), 0.56 (±0.15), and 0.25 (±0.14),
respectively. Heritabilities of cumulative of monthly records of egg numbers were from 0.24 ± 0.16 (for the first 2 months,
EP12) to 0.35 ± 0.16 (over the 6 months, EP16). Body weight at 16 weeks of age (BW16) has a strong genetic correlation with
the cumulative of monthly records: 0.92 (with EP12), 0.69 (with EP36), and 0.73 (with EP16). Besides their strong association,
BW16 and EP16 showed higher heritability, relative to their respective trait categories. These two traits seemed to have common
genes and utilizing them as selection traits would be expected to improve both egg production and growth performance of local
chicken. However, the standard errors of estimates in this study were mostly high indicating that the estimates have low precision.
Parameter estimations based on more data are needed before applying the current results in breeding programs. 相似文献