RESUMO

Este estudo teve como objetivo avaliar silagem de cana-de-açúcar (Saccharum officinarum L) tratada com hidróxido de cálcio - Ca(OH)2 - (cal hidratada) como único volumoso em ração para confinamento de gado de corte, com respeito ao desempenho e qualidade da carne dos animais. Quarenta e cinco novilhos Canchim (22 meses de idade, 345 kg de peso vivo- PV) foram distribuídos, em um delineamento em blocos casualizados, em três tratamentos (rações totais - RTs - com 35% de volumoso): T1 - RT com cana-de-açúcar fresca; T2 - RT com silagem de cana-de-açúcar tratada com hidróxido de cálcio (10 g Ca(OH)2/kg de forragem fresca); T3 - RT com silagem de milho. Foram avaliados o consumo de matéria seca (CMS), consumo de MS digestível (CMSD), consumo de proteína bruta (CPB), eficiência alimentar (EA), ganho médio diário (GMD) e rendimento de carcaça (RC). A carne foi avaliada quanto a parâmetros de qualidade (pH, capacidade de retenção de água, perdas no cozimento, cor e força de cisalhamento) e de análise sensorial descritiva. Os novilhos alimentados com a silagem de cana-de-açúcar tratada com hidróxido de cálcio apresentaram similares (P>0.05) CMS (10,8 kg/d), CMSD (8,5 kg/d) e RC (52,6%); mais alto (P0.05) (1,5 kg PV/d e 0,15 kg PV/kg CMS, respectivamente). As diferentes rações não afetaram (P>0.05) os parâmetros de qualidade e os atributos sensoriais da carne, com exceção da cor da gordura e sabor estranho na carne. Concluiu-se que o hidróxido de cálcio pode ser indicado como um eficiente aditivo para...

This study aimed to evaluate sugarcane (Saccharum officinarum L) silage treated with calcium hydroxide - Ca(OH)2 - (slacked lime) as the only roughage source in a feedlot ration, regarding animal performance and meat quality. Forty five Canchim steers (22 months old, 345 kg body weight - BW) were assigned, in a complete randomized block design, to three treatments (total mixed rations - TMRs - with 35% roughage): T1- TMR with fresh sugarcane; T2 - TMR with sugarcane silage treated with calcium hydroxide (10 g Ca(OH)2/kg of fresh forage); T3 - TMR with corn silage. Dry matter intake (DMI), digestible DM intake (DDMI), crude protein intake (CPI), feed efficiency (FE), average daily gain (ADG) and dressing percentage (DP) were evaluated. Meat was analyzed for quality parameters (pH, water holding capacity, cooking loss, color and shear force) and sensory attributes. Steers fed the silage treated with calcium hydroxide presented similar (P>0.05) DMI (10.8 kg DM/d), DDMI (8.5 kg/d) and DP (52.6%); higher CPI (1.8 vs. 1.4 kg/d) and lower (P0.05) ADG and FE (1.5 kg BW/d and 0.15 kg BW/kg DMI, respectively). The different rations did not affect (P>0.05) meat quality parameters and sensory attributes, except for fat color and off flavor sensory attribute. It was concluded that calcium hydroxide can be indicated as an efficient additive for sugarcane ensilage. Feedlot cattle fed TMR containing sugarcane silage treated with Ca (OH)2, as the only roughage source, presented adequate performance and meat quality.

Assuntos

RESUMO

Este estudo teve como objetivo avaliar silagem de cana-de-açúcar (Saccharum officinarum L) tratada com hidróxido de cálcio - Ca(OH)2 - (cal hidratada) como único volumoso em ração para confinamento de gado de corte, com respeito ao desempenho e qualidade da carne dos animais. Quarenta e cinco novilhos Canchim (22 meses de idade, 345 kg de peso vivo- PV) foram distribuídos, em um delineamento em blocos casualizados, em três tratamentos (rações totais - RTs - com 35% de volumoso): T1 - RT com cana-de-açúcar fresca; T2 - RT com silagem de cana-de-açúcar tratada com hidróxido de cálcio (10 g Ca(OH)2/kg de forragem fresca); T3 - RT com silagem de milho. Foram avaliados o consumo de matéria seca (CMS), consumo de MS digestível (CMSD), consumo de proteína bruta (CPB), eficiência alimentar (EA), ganho médio diário (GMD) e rendimento de carcaça (RC). A carne foi avaliada quanto a parâmetros de qualidade (pH, capacidade de retenção de água, perdas no cozimento, cor e força de cisalhamento) e de análise sensorial descritiva. Os novilhos alimentados com a silagem de cana-de-açúcar tratada com hidróxido de cálcio apresentaram similares (P>0.05) CMS (10,8 kg/d), CMSD (8,5 kg/d) e RC (52,6%); mais alto (P<0.05) CPB (1,8 vs. 1,4 kg/d) e menor (P<0.05) GMD (1,58 vs. 1,81 kg PV/d) comparados aos que receberam silagem de milho. Comparados aos animais alimentados com cana-de-açúcar fresca, os novilhos alimentados com silagem de cana-de-açúcar tratada com hidróxido de cálcio apresentaram maior (P<0.05) CMS (10,9 vs. 9,4 kg MS/d), CMSD (8,70 vs. 7,4 kg/d), CPB (1,8 vs. 1,1 kg/d) e RC (52,7 vs. 51,2%), mas o GMD e EA foram similares (P>0.05) (1,5 kg PV/d e 0,15 kg PV/kg CMS, respectivamente). As diferentes rações não afetaram (P>0.05) os parâmetros de qualidade e os atributos sensoriais da carne, com exceção da cor da gordura e sabor estranho na carne. Concluiu-se que o hidróxido de cálcio pode ser indicado como um eficiente aditivo para...(AU)

This study aimed to evaluate sugarcane (Saccharum officinarum L) silage treated with calcium hydroxide - Ca(OH)2 - (slacked lime) as the only roughage source in a feedlot ration, regarding animal performance and meat quality. Forty five Canchim steers (22 months old, 345 kg body weight - BW) were assigned, in a complete randomized block design, to three treatments (total mixed rations - TMRs - with 35% roughage): T1- TMR with fresh sugarcane; T2 - TMR with sugarcane silage treated with calcium hydroxide (10 g Ca(OH)2/kg of fresh forage); T3 - TMR with corn silage. Dry matter intake (DMI), digestible DM intake (DDMI), crude protein intake (CPI), feed efficiency (FE), average daily gain (ADG) and dressing percentage (DP) were evaluated. Meat was analyzed for quality parameters (pH, water holding capacity, cooking loss, color and shear force) and sensory attributes. Steers fed the silage treated with calcium hydroxide presented similar (P>0.05) DMI (10.8 kg DM/d), DDMI (8.5 kg/d) and DP (52.6%); higher CPI (1.8 vs. 1.4 kg/d) and lower (P<0.05) ADG (1.58 vs. 1.81 kg BW/d) and FE (0.15 vs. 0.17 kg BW/kg DMI) in comparison to those receiving corn silage. Compared to animals fed the fresh sugarcane, steers fed sugarcane silage treated with calcium hydroxide presented higher (P<0.05) DMI (10.9 vs. 9.4 kg DM/d), DDMI (8.7 vs. 7.4 kg/d), CPI (1.8 vs. 1.1 kg/d) and DP (52.7% vs. 51.2%) but similar (P>0.05) ADG and FE (1.5 kg BW/d and 0.15 kg BW/kg DMI, respectively). The different rations did not affect (P>0.05) meat quality parameters and sensory attributes, except for fat color and off flavor sensory attribute. It was concluded that calcium hydroxide can be indicated as an efficient additive for sugarcane ensilage. Feedlot cattle fed TMR containing sugarcane silage treated with Ca (OH)2, as the only roughage source, presented adequate performance and meat quality.(AU)

Assuntos

RESUMO

The aim of this study was the indication of an additive for the ensilage of sugarcane (Saccharum officinarum L.). In a laboratory trial, nine treatments were applied (g of additive/kg of fresh forage - FF) to the sugarcane (RB867515), before ensiling in minisilos (15 x 30 cm PVC tubes) during 78 days: untreated; urea (5) + sodium benzoate (0.5); urea (7.5) + benzoate (0.5); urea (5) + benzoate (0.75); urea (7.5) + benzoate (0.75); sodium propionate (1, 2 and 4); calcium hydroxide (10). Urea + benzoate in the lowest doses, propionate in the higher concentration and calcium hydroxide were selected, considering the ethanol content (26.5, 27.2 and 7.4 g/kg DM, respectively), total DM loss (88, 46 and 58 g/kg DM, respectively) and digestibility (541, 496 and 516 g/kg DM, respectively) of the silages. Silages treated with these doses of additives and the untreated silage (80 d of storage) were fed (nine + seven d) to 16 castrated male sheep (Santa Inês) housed in metabolic cages. The silage with calcium hydroxide presented coefficients of apparent digestibility of DM (0.44), of NDF (0.4) and DM intake (20 g/kg live weight) in the higher levels. Calcium hydroxide was superior to propionate and urea + benzoate, considering alcoholic fermentation control and reduction of losses in the silage and the forages nutritional value.

O objetivo deste estudo foi indicar um aditivo para a ensilagem da cana-de-açúcar (Saccharum officinarum L.). Em um ensaio de laboratório, nove tratamentos foram aplicados (g de aditivo/kgde forragem fresca - FF) à cana-de-açúcar (RB867515) antes da ensilagem em minisilos (tubos de PVC de 15 x 30 cm) durante 78 d: sem tratamento; uréia (5) + benzoato de sódio (0,5); uréia (7,5) + benzoato (0,5); uréia (5) + benzoato (0,75); uréia (7,5) + benzoato (0,75); propionato de sódio (1, 2 e 4); hidróxido de cálcio (10). Uréia + benzoato nas doses mais baixas, propionato na dose mais alta e hidróxido de cálcio foram selecionados, considerando a concentração de etanol (26,5; 27,2 e 7,4 g/kgMS, respectivamente), perda total de MS (88, 46 e 58 g/kg MS, respectivamente) e digestibilidade (541, 496 e 516 g/kg MS, respectivamente) das silagens. Silagens tratadas com estas dosagens dos aditivos e silagem não tratada (80 d estocagem) foram fornecidas (nove + sete d) a 16 carneiros (Santa Inês) machos castrados mantidos em gaiolas metabólicas. A silagem com hidróxido de cálcio apresentou coeficientes de digestibilidade aparente da MS (0,44), da FDN (0,40) e de ingestão da MS (20 g/kg peso vivo) nos níveis mais altos. Hidróxido de cálcio foi superior ao propionato e à uréia + benzoato, considerando-se o controle da fermentação alcoólica, a redução de perdas e o valor nutritivo da silagem.

Assuntos

RESUMO

The aim of this study was the indication of an additive for the ensilage of sugarcane (Saccharum officinarum L.). In a laboratory trial, nine treatments were applied (g of additive/kg of fresh forage - FF) to the sugarcane (RB867515), before ensiling in minisilos (15 x 30 cm PVC tubes) during 78 days: untreated; urea (5) + sodium benzoate (0.5); urea (7.5) + benzoate (0.5); urea (5) + benzoate (0.75); urea (7.5) + benzoate (0.75); sodium propionate (1, 2 and 4); calcium hydroxide (10). Urea + benzoate in the lowest doses, propionate in the higher concentration and calcium hydroxide were selected, considering the ethanol content (26.5, 27.2 and 7.4 g/kg DM, respectively), total DM loss (88, 46 and 58 g/kg DM, respectively) and digestibility (541, 496 and 516 g/kg DM, respectively) of the silages. Silages treated with these doses of additives and the untreated silage (80 d of storage) were fed (nine + seven d) to 16 castrated male sheep (Santa Inês) housed in metabolic cages. The silage with calcium hydroxide presented coefficients of apparent digestibility of DM (0.44), of NDF (0.4) and DM intake (20 g/kg live weight) in the higher levels. Calcium hydroxide was superior to propionate and urea + benzoate, considering alcoholic fermentation control and reduction of losses in the silage and the forages nutritional value.(AU)

O objetivo deste estudo foi indicar um aditivo para a ensilagem da cana-de-açúcar (Saccharum officinarum L.). Em um ensaio de laboratório, nove tratamentos foram aplicados (g de aditivo/kgde forragem fresca - FF) à cana-de-açúcar (RB867515) antes da ensilagem em minisilos (tubos de PVC de 15 x 30 cm) durante 78 d: sem tratamento; uréia (5) + benzoato de sódio (0,5); uréia (7,5) + benzoato (0,5); uréia (5) + benzoato (0,75); uréia (7,5) + benzoato (0,75); propionato de sódio (1, 2 e 4); hidróxido de cálcio (10). Uréia + benzoato nas doses mais baixas, propionato na dose mais alta e hidróxido de cálcio foram selecionados, considerando a concentração de etanol (26,5; 27,2 e 7,4 g/kgMS, respectivamente), perda total de MS (88, 46 e 58 g/kg MS, respectivamente) e digestibilidade (541, 496 e 516 g/kg MS, respectivamente) das silagens. Silagens tratadas com estas dosagens dos aditivos e silagem não tratada (80 d estocagem) foram fornecidas (nove + sete d) a 16 carneiros (Santa Inês) machos castrados mantidos em gaiolas metabólicas. A silagem com hidróxido de cálcio apresentou coeficientes de digestibilidade aparente da MS (0,44), da FDN (0,40) e de ingestão da MS (20 g/kg peso vivo) nos níveis mais altos. Hidróxido de cálcio foi superior ao propionato e à uréia + benzoato, considerando-se o controle da fermentação alcoólica, a redução de perdas e o valor nutritivo da silagem.(AU)

Assuntos

RESUMO

In contrast to the Mendelian inheritance model, parental alleles can contribute unequally to gene expression, which may result in phenotypic variance among individuals and bias in the predicted additive effect of molecular markers associated with production traits. Given the need to understand the effects of allelic variation and parent-of-origin effects on the expression of genes with a commercial interest in cattle, we analyzed the expression of KCNJ11 (potassium inwardly rectifying channel, subfamily J, member 11), which was previously described as a functional candidate gene for meat tenderness. Allele-specific and parent-of-origin-dependent expression of this gene were assessed in bovine muscle using the rs379610823 single nucleotide polymorphism as a reference. Biallelic expression was observed; however, the T allele was expressed at significantly higher levels than the C allele. Furthermore, increased expression of KCNJ11 was found in animals harboring the maternal T allele. This study is the first to describe the differential allelic expression of bovine KCNJ11. Our findings are important for understanding the mechanisms that underlie the pattern of KCNJ11 expression and its potential impact on the phenotypic variation of meat tenderness in Nelore beef cattle. This reinforces the need for further investigation of allelic- and parent-of-origin expression deviation in genetic markers eligible for the selection of target traits.

Assuntos

RESUMO

Avaliou-se a eficiência do teste de tuberculina intradérmico comparado, para identificar rebanhos suínos infectados com o complexo Mycobacterium avium (MAC), seu poder de discriminação entre rebanhos infectados com MAC e Mycobacterium bovis, e para estudar diferentes critérios de leitura e interpretação. Foram realizados três experimentos com rebanhos infectados naturalmente com MAC, com suínos inoculados com MAC e com suínos inoculados com M. bovis. Os testes foram comparados com a presença ou não de lesões macro e/ou microscópicas nos linfonodos de suínos em idade de abate. Verificaram-se reações cruzadas entre os testes intradérmicos, tanto com animais infectados com o MAC como com M. bovis. Reações acima de 0,5cm de diâmetro ou acima de 0,20cm no aumento da espessura da dobra da pele, entre a aplicação e a leitura, foram consideradas positivas no cálculo da média para rebanhos. Rebanhos infectados com MAC podem ser identificados por meio do teste intradérmico com PPD aviário e bovino. Tanto a medida do diâmetro quanto o aumento da espessura da dobra da pele das reações foram eficientes no diagnóstico da infecção por MAC. Recomenda-se a utilização do método da medição do diâmetro.(AU)

The efficiency of the tuberculin delayed-type skin hypersensitivity test was evaluated in swine. A comparison of the tuberculin skin tests was performed with avian and bovine protein derivatives (PPD), in the detection of Mycobacterium avium-Complex or M. bovis infected swine. The methods were evaluated as to define criteria for readings and results interpretation, to determine their capacity in detecting Mycobacterium avium complex (MAC) infected swine and their performance in differentiating MAC from M. bovis-infected individuals. Three trials were performed with naturally MAC-infected swine, experimentally MAC-infected or experimentally M. bovis-infected animals. The skin test readings positive or negative were, respectively, correlated to the presence or absence of gross lesions and histological alterations in lymph nodes at slaughter age. Reaction with both antigens were observed in MAC and M. bovis-inoculated animals as well. Reactions wider then 0.5cm in diameter or showing skin thickness increasing more then 0.2cm in the time frame between inoculation and reading were considered to be positive, as compared to the average results of the group. Herds with MAC-infected swine could be detected with either avian or bovine PPD. Both diameter and skin thickness were efficient in detecting MAC-infected swine, however, reading the diameter of the reaction was shown to be more easily and economically performed.(AU)

Assuntos

RESUMO

Avaliou-se a eficiência do teste de tuberculina intradérmico comparado, para identificar rebanhos suínos infectados com o complexo Mycobacterium avium (MAC), seu poder de discriminação entre rebanhos infectados com MAC e Mycobacterium bovis, e para estudar diferentes critérios de leitura e interpretação. Foram realizados três experimentos com rebanhos infectados naturalmente com MAC, com suínos inoculados com MAC e com suínos inoculados com M. bovis. Os testes foram comparados com a presença ou não de lesões macro e/ou microscópicas nos linfonodos de suínos em idade de abate. Verificaram-se reações cruzadas entre os testes intradérmicos, tanto com animais infectados com o MAC como com M. bovis. Reações acima de 0,5cm de diâmetro ou acima de 0,20cm no aumento da espessura da dobra da pele, entre a aplicação e a leitura, foram consideradas positivas no cálculo da média para rebanhos. Rebanhos infectados com MAC podem ser identificados por meio do teste intradérmico com PPD aviário e bovino. Tanto a medida do diâmetro quanto o aumento da espessura da dobra da pele das reações foram eficientes no diagnóstico da infecção por MAC. Recomenda-se a utilização do método da medição do diâmetro.

The efficiency of the tuberculin delayed-type skin hypersensitivity test was evaluated in swine. A comparison of the tuberculin skin tests was performed with avian and bovine protein derivatives (PPD), in the detection of Mycobacterium avium-Complex or M. bovis infected swine. The methods were evaluated as to define criteria for readings and results interpretation, to determine their capacity in detecting Mycobacterium avium complex (MAC) infected swine and their performance in differentiating MAC from M. bovis-infected individuals. Three trials were performed with naturally MAC-infected swine, experimentally MAC-infected or experimentally M. bovis-infected animals. The skin test readings positive or negative were, respectively, correlated to the presence or absence of gross lesions and histological alterations in lymph nodes at slaughter age. Reaction with both antigens were observed in MAC and M. bovis-inoculated animals as well. Reactions wider then 0.5cm in diameter or showing skin thickness increasing more then 0.2cm in the time frame between inoculation and reading were considered to be positive, as compared to the average results of the group. Herds with MAC-infected swine could be detected with either avian or bovine PPD. Both diameter and skin thickness were efficient in detecting MAC-infected swine, however, reading the diameter of the reaction was shown to be more easily and economically performed.

Assuntos

RESUMO

Reducing Salmonella contamination in poultry is of major importance to prevent the introduction of this microorganism into the food chain. Salmonellae may spread during storage time (shelf life) whenever pre-harvest control fails or post-harvest contamination occurs. Therefore, preventive measures should also be used in the post-harvest level of poultry production in order to control salmonellae. Chicken skin samples were experimentally contaminated by immersing whole legs (thighs and drumsticks) in a suspension containing 10(6) colony forming units per milliliter (CFU/mL) of Salmonella Enteritidis phage type 4 (SE PT4) at the slaughter day. One day later, samples from one group were immersed in a suspension pool containing 10(9) CFU/mL of each of three wild salmonella-lytic bacteriophages previously isolated from feces of free-range chickens. Salmonella counting was performed at three-day intervals in the chicken legs stored at 5°C and showed a significant reduction (P 0.05) of SE PT4 in bacteriophage-treated cuts on days 3, 6 and 9 post-treatment. These findings suggest that the use of bacteriophages may reduce SE PT4 in chicken skin. Further studies are encouraged and might demonstrate the potential of this approach as an efficient and safe technique to be routinelly used for Salmonella control in chicken products.

RESUMO

Reducing Salmonella contamination in poultry is of major importance to prevent the introduction of this microorganism into the food chain. Salmonellae may spread during storage time (shelf life) whenever pre-harvest control fails or post-harvest contamination occurs. Therefore, preventive measures should also be used in the post-harvest level of poultry production in order to control salmonellae. Chicken skin samples were experimentally contaminated by immersing whole legs (thighs and drumsticks) in a suspension containing 10(6) colony forming units per milliliter (CFU/mL) of Salmonella Enteritidis phage type 4 (SE PT4) at the slaughter day. One day later, samples from one group were immersed in a suspension pool containing 10(9) CFU/mL of each of three wild salmonella-lytic bacteriophages previously isolated from feces of free-range chickens. Salmonella counting was performed at three-day intervals in the chicken legs stored at 5°C and showed a significant reduction (P 0.05) of SE PT4 in bacteriophage-treated cuts on days 3, 6 and 9 post-treatment. These findings suggest that the use of bacteriophages may reduce SE PT4 in chicken skin. Further studies are encouraged and might demonstrate the potential of this approach as an efficient and safe technique to be routinelly used for Salmonella control in chicken products.

RESUMO

Occurrence of food poisoning related to Salmonella-contaminated eggs and chicken meat has been frequent in humans. Salmonella Enteritidis (SE) and Salmonella Typhimurium (ST) are included among the most important paratyphoid salmonellae associated with chicken meat and eggs. Elimination of Salmonella at the pre-harvest stage can play a significant role in preventing the introduction of this pathogen into the food chain and consequently in the reduction of food poisoning in humans. Bactericidal bacteriophages may provide a natural, nontoxic, feasible and non-expensive component of the multi-factorial approach for a pre-harvest control of Salmonella in poultry. Five bacteriophages lytic for SE PT4 and ST were obtained from 107 samples of feces of free-range layers in Brazil. All bacteriophages were characterized in vitro and in vivo, showing head and tail morphology and dsDNA as nucleic acids. Results of "in vivo" studies suggested that bacteriophages do not remain in Salmonella-free birds longer than one day, whereas they multiply in Salmonella-infected birds for longer periods. Besides, selection for phage-resistant SE PT4 did not seem to occur in the short term. Isolated bacteriophages will be investigated for their potential for pre-harvest biocontrol of SE PT4 in poultry.