RESUMO
BACKGROUND: Lactoferrin (LTF) is an iron-binding glycoprotein found in milk and other exocrine secretion with antibacterial activity proposed as an alternative to mastitis treatment or prevention. LTF has been proposed as a candidate gene for mastitis resistance selection. The aim of this paper was to assess LTF promotor to explore variations with potential association to mastitis resistance in dairy cows from Honduras. METHODS: A resequencing of promotor and Exon I of LTF gene in extreme mastitis susceptibility cows (126 Holstein and Holstein crossbred) was performed. RESULTS: Eight polymorphisms were found in promotor region, four of them were novel variations. Two were important by frequency among extreme groups, but a polymorphism in - 421 A/T position was significantly (P = 0.0188) associated to mastitis susceptibility. CONCLUSION: Results support the key role of regulatory region of LTF gene. Some candidate genes are proposed in association with mastitis traits and implications are discussed.
Assuntos
Lactoferrina , Mastite Bovina , Feminino , Bovinos/genética , Animais , Humanos , Lactoferrina/genética , Genótipo , Polimorfismo Genético , Leite , Mastite Bovina/genética , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
The aim of this study was to determine the selection of bedding material by broiler chickens during the rearing period and whether the choice was determinant to their performing a specific behavior. To achieve this objective, a choice test was designed. A choice pen was constructed where birds could move freely around the four selected materials (straw, wood shavings, rice hulls and sand). Chickens were introduced in this pen in four groups of eight birds, three days a week for one hour per day and group, for four weeks. The location and the activity performed by each broiler were recorded every five minutes. Results showed a preference for sand compared with the other three substrates. However, differences between the behaviors performed in each bedding material were shown mainly for resting (preferably performed on wood shavings and straw), dust bathing (on sand), pecking and scratching (on rice hulls). Other factors, such as the time of day, were also found to have effects on fighting and drinking, and changes in behavioral patterns (resting, preening, eating, standing and pecking) were also detected as broilers grew older.(AU)
Assuntos
Animais , Aves Domésticas/classificação , Aves Domésticas/crescimento & desenvolvimento , Comportamento Animal , Substratos para Tratamento BiológicoRESUMO
The aim of this study was to determine the selection of bedding material by broiler chickens during the rearing period and whether the choice was determinant to their performing a specific behavior. To achieve this objective, a choice test was designed. A choice pen was constructed where birds could move freely around the four selected materials (straw, wood shavings, rice hulls and sand). Chickens were introduced in this pen in four groups of eight birds, three days a week for one hour per day and group, for four weeks. The location and the activity performed by each broiler were recorded every five minutes. Results showed a preference for sand compared with the other three substrates. However, differences between the behaviors performed in each bedding material were shown mainly for resting (preferably performed on wood shavings and straw), dust bathing (on sand), pecking and scratching (on rice hulls). Other factors, such as the time of day, were also found to have effects on fighting and drinking, and changes in behavioral patterns (resting, preening, eating, standing and pecking) were also detected as broilers grew older.
RESUMO
The aim of this study was to determine the selection of bedding material by broiler chickens during the rearing period and whether the choice was determinant to their performing a specific behavior. To achieve this objective, a choice test was designed. A choice pen was constructed where birds could move freely around the four selected materials (straw, wood shavings, rice hulls and sand). Chickens were introduced in this pen in four groups of eight birds, three days a week for one hour per day and group, for four weeks. The location and the activity performed by each broiler were recorded every five minutes. Results showed a preference for sand compared with the other three substrates. However, differences between the behaviors performed in each bedding material were shown mainly for resting (preferably performed on wood shavings and straw), dust bathing (on sand), pecking and scratching (on rice hulls). Other factors, such as the time of day, were also found to have effects on fighting and drinking, and changes in behavioral patterns (resting, preening, eating, standing and pecking) were also detected as broilers grew older.
RESUMO
SETTING: Nicaragua, a country where the DOTS strategy has been successfully implemented since 1984. OBJECTIVE: To estimate the prevalence and trends of Mycobacterium tuberculosis resistance to first-line anti-tuberculosis drugs. DESIGN: A prospective national survey carried out in 2004 according to the standardised model developed by the World Health Organisation and the International Union Against Tuberculosis and Lung Disease. RESULTS: A total of 423 M. tuberculosis strains were studied. Among the 320 strains evaluated for initial resistance, 13.1% displayed resistance to any drug, lower than the 1998 figure of 15.6%. Overall initial resistance to isoniazid (INH), rifampicin (RMP) and multidrug resistance (MDR) was respectively 6.6%, 0.9% and 0.6%. Initial resistance was higher in older age groups. Overall acquired resistance was 35.9% (n = 103); resistance to INH was 29.3% and to RMP 8.9%, while MDR was 7.9%. The acquired MDR rate was clearly higher in Category I failures (44.4%) than in relapses (3.8%) and retrieved defaulters (2.7%). All resistance rates found in this study were lower than those detected in 1998. CONCLUSION: This study shows low rates of resistance and MDR and a downward trend in all rates, undoubtedly related to the proper implementation of the National Tuberculosis Programme.