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1. Brown egg layers were fed diets differing in oil content, oil source and linoleic acid concentration and the effect on performance from 22 to 69 weeks of age was studied.
2. The birds responded with an increasing mean egg weight up to a linoleic acid intake of 2.75 g/bird d.
3. Increasing the intake of readily absorbable oil without increasing linoleic acid concentration did not increase mean egg weight. 相似文献
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Travis J 《Science (New York, N.Y.)》1994,264(5161):906
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Travis J 《Science (New York, N.Y.)》1994,264(5166):1668
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Travis J 《Science (New York, N.Y.)》1995,267(5205):1768-1769
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Agnes Agunos Sheryl P. Gow David F. Lger Logan Flockhart Danielle Daignault Andrea Desruisseau Erin Zabek Frank Pollari Richard J. Reid-Smith 《Canadian journal of veterinary research》2021,85(1):27
Eggs are important to the diet of Canadians. This product is one of the supply-managed commodities in Canada, but unlike other commodities, where food safety risks are extensively explored and reported, information on the prevalence of enteric organisms (e.g., Salmonella, Campylobacter) and antimicrobial resistance (AMR) in layers in Canada are limited. This study was conducted to determine the prevalence of select bacteria and the associated AMR patterns in layer flocks using 2 sample matrices. Farms were located within FoodNet Canada and the Canadian Integrated Program for Antimicrobial Resistance Surveillance sentinel sites (SS). Fecal samples (Ontario: ONSS1a, ONSS1b) and environmental sponge swabs (British Columbia: BCSS2a) were collected. Salmonella prevalence was 29% and 8% in ONSS1a and ONSS1b, respectively, and 7% in BCSS2a. S. Kentucky and S. Livingstone were the most frequently isolated serovars and no S. Enteritidis was detected. Campylobacter was not detected in the BC sponge swabs but was isolated from 89% and 53% of Ontario fecal samples (ONSS1a and ONSS1b, respectively). Seven C. jejuni from Ontario were ciprofloxacin-resistant. Escherichia coli prevalence was high in both sample types (98%). Overall, tetracycline resistance among E. coli ranged from 26% to 69%. Resistance to ceftiofur (n = 2 isolates) and gentamicin (n = 2) was relatively low. There were diverse resistance patterns (excludes susceptible isolates) observed among E. coli in Ontario (10 patterns) and British Columbia (14 patterns). This study revealed that fecal samples are more informative for farm-level monitoring of pathogen and AMR prevalence. Without further validation, sponge swabs are limited in their utility for Campylobacter detection and thus, for public health surveillance. 相似文献
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