Effects of antibiotic growth promoters and concentrate on intake, digestibility, degradability, and ruminal variables in beef steers / [Efeitos de antibióticos promotores de crescimento e do concentrado sobre o consumo, digestibilidade, degradabilidade e variáveis ruminais de novilhos de corte]

The objective of this study was to evaluate the addition of antibiotic growth promoters to concentrate on intake, digestibility, in situ degradability and ruminal variables in steers. Four steers in a Latin square design were fed hay (ad libitum), concentrate [10g kg-1 of body weight (BW)] and mineral mix (0.272g kg-1 of BW). The additives (0.75mg kg-1 of BW) were incorporated in the mineral mix as follows: Control (no antibiotics), lasalocid (LASA), salinomycin (SALI) or virginiamycin (VIRG). Antibiotic did not affect intake, pH, volatile fatty acids (VFA) and digestibility of dry matter (DM), organic matter, crude protein, ethereal extract, and non-fibrous carbohydrates. The LASA and SALI tended (P=0.09) to reduce the digestibility of neutral detergent fiber (NDF). The SALI and VIRG tended (P=0.09) to reduce the DM disappearance, and VIRG tended (P=0.06) to reduce the NDF disappearance in the rumen. The SALI and VIRG reduced the effective degradation and only SALI reduced the concentration of N-NH3 in the rumen. Thus, the antibiotics did not affect intake, pH, VFA and digestibility, but decreased the degradation of fiber and only SALI reduced the concentration of ammonia nitrogen (N-NH3) in the rumen.

O objetivo foi avaliar a adição de antibióticos promotores de crescimento ao concentrado sobre o consumo, digestibilidade, degradabilidade in situ e variáveis ruminais de novilhos. Quatro novilhos em um delineamento quadrado latino foram alimentados com feno (ad libitum), concentrado [10g kg-1 do peso corporal (PC)] e mistura mineral (0,272g kg-1 do PC). Os antibióticos (0,75mg kg-1 do PC) foram incorporados à ração: Controle (sem antibióticos), lasalocida (LASA), salinomicina (SALI) ou virginiamicina (VIRG). Os antibióticos não afetaram o consumo, pH, ácidos graxos voláteis (AGV) e digestibilidade da matéria seca (MS), matéria orgânica, proteína bruta, extrato etéreo e carboidratos não fibrosos. A LASA e a SALI tenderam (P=0,09) a reduzir a digestibilidade da fibra em detergente neutro (FDN). A SALI e a VIRG tenderam (P=0,09) a reduzir o desaparecimento da MS, e a VIRG tendeu (P=0,06) a reduzir o desaparecimento da FDN no rúmen. A SALI e a VIRG reduziram a degradação efetiva e somente a SALI reduziu a concentração de nitrogênio amoniacal (N-NH3) no rúmen. Assim, os antibióticos não afetaram o consumo, pH, AGV e digestibilidade, mas diminuiram a degradação da fibra e somente a SALI reduziu a concentração de N-NH3 no rúmen.

Prediction of acid lactic-bacteria growth in turkey ham processed by high hydrostatic pressure

High hydrostatic pressure (HHP) has been investigated and industrially applied to extend shelf life of meat-based products. Traditional ham packaged under microaerophilic conditions may sometimes present high lactic acid bacteria population during refrigerated storage, which limits shelf life due to development of unpleasant odor and greenish and sticky appearance. This study aimed at evaluating the shelf life of turkey ham pressurized at 400 MPa for 15 min and stored at 4, 8 and 12 ºC, in comparison to the non pressurized product. The lactic acid bacteria population up to 10(7) CFU/g of product was set as the criteria to determine the limiting shelf life According to such parameter the pressurized sample achieved a commercial viability within 75 days when stored at 4 ºC while the control lasted only 45 days. Predictive microbiology using Gompertz and Baranyi and Roberts models fitted well both for the pressurized and control samples. The results indicated that the high hydrostatic pressure treatment greatly increased the turkey ham commercial viability in comparison to the usual length, by slowing down the growth of microorganisms in the product.(AU)

Internal quality of conventional and omega-3-enriched commercial eggs stored under different temperatures

The internal quality of conventional and -3 enriched commercial eggs stored at different temperatures was evaluated. Eggs derived from Isa Brown layers fed two different diets. In Group 1, 432 hens were fed throughout their productive life with a diet based on corn and soybean meal (production of conventional eggs). In Group 2, starting at 22 weeks of age, other 432 hens were fed a diet containing 1.5% of marine algae substrate and 1.8% of fish oil (production of -3 enriched eggs). The following parameters were evaluated: Haugh unit, yolk index, albumen pH, and yolk pH. There were no significant differences between conventional and enriched with -3 eggs as to internal quality parameters. Only the interaction between storage time and temperature was significant, and therefore their effects were evaluated, independent of egg type (conventional eggs and -3 enriched eggs). Eggs stored at 25ºC presented lower Haugh units and yolk index, and higher albumen pH and yolk pH as compared to those kept at 5ºC. In addition, internal quality was reduced when eggs were stored for 7, 14, and 21 days, particularly when maintained at 25ºC. It was concluded that conventional and -3 enriched eggs have good internal quality; however, to maintain this quality, eggs must be stored under refrigeration.

Internal quality of conventional and omega-3-enriched commercial eggs stored under different temperatures

The internal quality of conventional and -3 enriched commercial eggs stored at different temperatures was evaluated. Eggs derived from Isa Brown layers fed two different diets. In Group 1, 432 hens were fed throughout their productive life with a diet based on corn and soybean meal (production of conventional eggs). In Group 2, starting at 22 weeks of age, other 432 hens were fed a diet containing 1.5% of marine algae substrate and 1.8% of fish oil (production of -3 enriched eggs). The following parameters were evaluated: Haugh unit, yolk index, albumen pH, and yolk pH. There were no significant differences between conventional and enriched with -3 eggs as to internal quality parameters. Only the interaction between storage time and temperature was significant, and therefore their effects were evaluated, independent of egg type (conventional eggs and -3 enriched eggs). Eggs stored at 25ºC presented lower Haugh units and yolk index, and higher albumen pH and yolk pH as compared to those kept at 5ºC. In addition, internal quality was reduced when eggs were stored for 7, 14, and 21 days, particularly when maintained at 25ºC. It was concluded that conventional and -3 enriched eggs have good internal quality; however, to maintain this quality, eggs must be stored under refrigeration.