The Impact of Bacillus subtilis PB6 and Chromium Propionate on the Performance, Egg Quality and Nutrient Metabolizability of Layer Breeders.

The objective of this study was to evaluate the effects of Bacillus subtillis PB6, chromium propionate or a combination of the two on the performance, egg and eggshell quality, nutrient metabolizability and serum biochemistry of layer breeders. White Plymouth Rock and Red Rhodes Island breeder hens at 55 weeks of age were allocated in individual cages using a completely randomized block design with 16 replicates. Hens were fed control, control + probiotic (500 g/ton of Bacillus subtilis PB6), control + CrProp (50 g/ton of chromium propionate) and control + probiotic + CrProp diets from 55 to 70 weeks of age. Productive parameters and eggshell quality as well as cortisol and blood biochemistry were grouped each 28 d as well as for the overall period. The metabolizability of nutrients and energy was determined at 70 weeks of age. In the overall period, hens fed the control + probiotic or control + probiotic + CrProp diets had significantly higher egg production, egg mass, shell percentage, thickness and shell strength. The metabolizability of dry matter, nitrogen and energy increased in hens that were fed the control + probiotic + CrProp diet. In conclusion, diets supplemented with Bacillus subtillis PB6 and chromium propionate resulted in improved productive performance, eggshell quality and nutrient metabolizability of layer breeders, without modifying serum cortisol, albumin and triglycerides.

Hipocalcemia em vacas leiteiras da agricultura familiar / Hypocalcemia in dairy cows of family agriculture

O objetivo deste trabalho foi avaliar a ocorrência de hipocalcemia associada ou não a hipomagnesemia em vacas leiteiras de propriedades de agricultura familiar. Foram avaliadas 22 vacas das raças Jersey, Holandesa e Jersolando, no período de transição, oriundas de pequenas propriedades de agricultura familiar, com produção média 12L/leite/dia. A concentração do cálcio total e do magnésio séricos foi determinada por metodologia colorimétrica e cálculo do cálcio ionizado estimado a partir das concentrações séricas do cálcio total, de proteína e albumina. Foi observada hipocalcemia em 50% dos animais no pré-parto (8,2±1,4mg/dL) e 63,6% no pós-parto (7,7±1,7 mg/dL). A redução do cálcio ionizado foi menos frequente, com grande parte dos animais apresentando cálcio ionizado estimado dentro da normalidade, com média de 4,6±0,83 mg/dL no pré-parto e 4,3±1,0 mg/dL no pós-parto. Todos os animais apresentaram concentrações de magnésio sérico dentro da normalidade, descartando-se hipomagnesemia. A concentração média de magnésio no pré-parto foi 2,4±0,3 mg/dL com elevação significativa (p<0,05) no pós-parto para 2,7±0,5 mg/dL. Conclui-se que as vacas leiteiras da agricultura familiar são susceptíveis à ocorrência de hipocalcemia e a ausência de sinais clínicos pode estar relacionada à manutenção da concentração de cálcio ionizado próxima da normalidade associada à ausência de hipomagnesemia.(AU)

The objective of this study was to evaluate the occurrence of hypocalcemia associated or not to hypomagnesemia in dairy cows of family farming properties. Were evaluated 22 cows, Jersey, Dutch and Jersolando breeds, during the transition period, from small family farming properties, with average 12 L/milk/day production. The concentration of serum total calcium and magnesium was determined by colorimetric methodology and calculation of ionized calcium estimated from the serum concentrations of total calcium, protein and albumin. Hipocalcemia was observed in 50% of the animals in prepartum (8.2 ± 1, 4 mg/dL) and 63.6% postpartum (7.7 ± 1.7 mg/dL). The reduction of ionized calcium was less frequent, with many of the animals presenting estimated ionized calcium within the normal range, averaging 4.6 ± 0.83 mg/dL in the prepartum and 4.3 ± 1.0 mg/dL in the postpartum. All animals presented concentrations of serum magnesium within normality, excluding hypomagnesemia. The average concentration of magnesium in the partum was 2.4 ± 0.3 mg/dL with significant elevation (p < 0.05) in postpartum to 2.7 ± 0.5 mg/dL. We concluded that dairy cows in the family agriculture are susceptible to hypocalcemia, and the absence of clinical signs may be relacionated with the maintenance of ionized calcium concentration into normal range, associeted with absence of hypomagnesemia.(AU)

Hipocalcemia em vacas leiteiras da agricultura familiar / Hypocalcemia in dairy cows of family agriculture

O objetivo deste trabalho foi avaliar a ocorrência de hipocalcemia associada ou não a hipomagnesemia em vacas leiteiras de propriedades de agricultura familiar. Foram avaliadas 22 vacas das raças Jersey, Holandesa e Jersolando, no período de transição, oriundas de pequenas propriedades de agricultura familiar, com produção média 12L/leite/dia. A concentração do cálcio total e do magnésio séricos foi determinada por metodologia colorimétrica e cálculo do cálcio ionizado estimado a partir das concentrações séricas do cálcio total, de proteína e albumina. Foi observada hipocalcemia em 50% dos animais no pré-parto (8,2±1,4mg/dL) e 63,6% no pós-parto (7,7±1,7 mg/dL). A redução do cálcio ionizado foi menos frequente, com grande parte dos animais apresentando cálcio ionizado estimado dentro da normalidade, com média de 4,6±0,83 mg/dL no pré-parto e 4,3±1,0 mg/dL no pós-parto. Todos os animais apresentaram concentrações de magnésio sérico dentro da normalidade, descartando-se hipomagnesemia. A concentração média de magnésio no pré-parto foi 2,4±0,3 mg/dL com elevação significativa (p<0,05) no pós-parto para 2,7±0,5 mg/dL. Conclui-se que as vacas leiteiras da agricultura familiar são susceptíveis à ocorrência de hipocalcemia e a ausência de sinais clínicos pode estar relacionada à manutenção da concentração de cálcio ionizado próxima da normalidade associada à ausência de hipomagnesemia.

The objective of this study was to evaluate the occurrence of hypocalcemia associated or not to hypomagnesemia in dairy cows of family farming properties. Were evaluated 22 cows, Jersey, Dutch and Jersolando breeds, during the transition period, from small family farming properties, with average 12 L/milk/day production. The concentration of serum total calcium and magnesium was determined by colorimetric methodology and calculation of ionized calcium estimated from the serum concentrations of total calcium, protein and albumin. Hipocalcemia was observed in 50% of the animals in prepartum (8.2 ± 1, 4 mg/dL) and 63.6% postpartum (7.7 ± 1.7 mg/dL). The reduction of ionized calcium was less frequent, with many of the animals presenting estimated ionized calcium within the normal range, averaging 4.6 ± 0.83 mg/dL in the prepartum and 4.3 ± 1.0 mg/dL in the postpartum. All animals presented concentrations of serum magnesium within normality, excluding hypomagnesemia. The average concentration of magnesium in the partum was 2.4 ± 0.3 mg/dL with significant elevation (p < 0.05) in postpartum to 2.7 ± 0.5 mg/dL. We concluded that dairy cows in the family agriculture are susceptible to hypocalcemia, and the absence of clinical signs may be relacionated with the maintenance of ionized calcium concentration into normal range, associeted with absence of hypomagnesemia.