Effect of prepartum feed restriction and bovine recombinant somatotropin injection on plasmatic parameters of prepartum Holstein heifers / Efeitos da restrição alimentar e administração de somatotropina recombinante bovina nos parâmetros plasmáticos de novilhas da raça Holandês durante o período pré-parto

Background: During the transition period negative energy balance (NEB) occurs due to the difference between input and output of nutrients. At this period, these nutrients are directed to milk production and lipolysis is the major mechanism of adaptation. There is an increase of the non-esterified fatty acids (NEFA) reduce dry matter intake (DMI). The feed restriction during the prepartum period improve milk production and plasmatic concentration of glucose and insulin through the adaptation of liver enzymes and increased DMI at the postpartum period. The administration of recombinant bovine somatotropin (rbST) also improve milk production on postpartum period and alters lipogenesis and lipolysis through effects on adipose tissue and lipid metabolism. The aim of this study was to evaluate the effects of feed restriction and injections of rbST onparameters of energetic, protein, enzymatic and mineral metabolism of prepartum dairy heifers. Materials, Methods & Results: Fourty four heifers with BW = 477.2 ± 7.4 kg at the beginning were used. The experimental period ranged from 35 days prepartum to calving. These heifers were divided in four groups with 11 heifers each: bST: fed to allow 100% of the DMI plus rbST injections; RbST: fed to allow 80% of the DMI plus rbST injections; CON: fed to allow 100% of the DMI plus placebo injections and RES: fed to allow 80% of the DMI plus

O periparto impõe grandes mudanças fisiológicas em vacas leiteiras, determinando um aumento na ocorrência de distúrbios metabólicos. Neste período, os nutrientes são direcionados para a produção de leite e como mecanismo de adaptação há um aumento na mobilização de tecido adiposo devido ao balanço energético negativo (BEN). Estudos mostram que a restrição de 20% da ingestão de matéria seca (IMS) e o uso de somatotropina bovina recombinante (rbST) no período pré-parto podem minimizar os efeitos indesejados do BEN pelo aumento da IMS pós-parto. [...]

Effect of prepartum feed restriction and bovine recombinant somatotropin injection on plasmatic parameters of prepartum Holstein heifers / Efeitos da restrição alimentar e administração de somatotropina recombinante bovina nos parâmetros plasmáticos de novilhas da raça Holandês durante o período pré-parto

Background: During the transition period negative energy balance (NEB) occurs due to the difference between input and output of nutrients. At this period, these nutrients are directed to milk production and lipolysis is the major mechanism of adaptation. There is an increase of the non-esterified fatty acids (NEFA) reduce dry matter intake (DMI). The feed restriction during the prepartum period improve milk production and plasmatic concentration of glucose and insulin through the adaptation of liver enzymes and increased DMI at the postpartum period. The administration of recombinant bovine somatotropin (rbST) also improve milk production on postpartum period and alters lipogenesis and lipolysis through effects on adipose tissue and lipid metabolism. The aim of this study was to evaluate the effects of feed restriction and injections of rbST onparameters of energetic, protein, enzymatic and mineral metabolism of prepartum dairy heifers. Materials, Methods & Results: Fourty four heifers with BW = 477.2 ± 7.4 kg at the beginning were used. The experimental period ranged from 35 days prepartum to calving. These heifers were divided in four groups with 11 heifers each: bST: fed to allow 100% of the DMI plus rbST injections; RbST: fed to allow 80% of the DMI plus rbST injections; CON: fed to allow 100% of the DMI plus placebo injections and RES: fed to allow 80% of the DMI plus

O periparto impõe grandes mudanças fisiológicas em vacas leiteiras, determinando um aumento na ocorrência de distúrbios metabólicos. Neste período, os nutrientes são direcionados para a produção de leite e como mecanismo de adaptação há um aumento na mobilização de tecido adiposo devido ao balanço energético negativo (BEN). Estudos mostram que a restrição de 20% da ingestão de matéria seca (IMS) e o uso de somatotropina bovina recombinante (rbST) no período pré-parto podem minimizar os efeitos indesejados do BEN pelo aumento da IMS pós-parto. [...]

Dynamics of nitrogen concentration on intercropped ryegrass - 10.4025/actascianimsci.v34i1.12661

The dynamics of nitrogen (N) in ryegrass intercropped with different forage species with regard to dry matter (DM) accumulation within an agroecological transition system was evaluated. Annual ryegrass was intercropped with black oats (RY + BO), white clover (RY + WC) and forage peanut (RY + FP). The experimental design was completely randomized, with three replications. The study applied the N dilution model for plant tissue which comparatively uses modifiable factors of the environment at optimal levels. The model shows decline in N concentration due to the DM accumulation of temperate grass pastures. Data were compared to model by the root mean square deviation analysis. Dilution coefficient (), used in all pasture samples, was lower than -0.60. Highest N concentration decline in plant tissues, due to DM accumulation, occurred in RY + WC pastures ( = -0.94), followed by RY + FP ( = - 0.86) and RY + BO ( = - 0.67), respectively. Ryegrass intercropped with white clover showed the highest N content in plant tissue, with a nitrogen nutrition index close to the proposed model.

Dynamics of nitrogen concentration on intercropped ryegrass - 10.4025/actascianimsci.v34i1.12661

The dynamics of nitrogen (N) in ryegrass intercropped with different forage species with regard to dry matter (DM) accumulation within an agroecological transition system was evaluated. Annual ryegrass was intercropped with black oats (RY + BO), white clover (RY + WC) and forage peanut (RY + FP). The experimental design was completely randomized, with three replications. The study applied the N dilution model for plant tissue which comparatively uses modifiable factors of the environment at optimal levels. The model shows decline in N concentration due to the DM accumulation of temperate grass pastures. Data were compared to model by the root mean square deviation analysis. Dilution coefficient (), used in all pasture samples, was lower than -0.60. Highest N concentration decline in plant tissues, due to DM accumulation, occurred in RY + WC pastures ( = -0.94), followed by RY + FP ( = - 0.86) and RY + BO ( = - 0.67), respectively. Ryegrass intercropped with white clover showed the highest N content in plant tissue, with a nitrogen nutrition index close to the proposed model.

Ocorrência de leite com instabilidade da caseína em Santa Vitória do Palmar, RS

O objetivo do presente trabalho foi determinar a ocorrência de leite com instabilidade da caseína no extremo sul do Brasil.Duzentas e oitenta e duas amostras de leite cru foram coletadas em estabelecimentos produtores de leite do município deSanta Vitória do Palmar, Rio Grande do Sul (RS). As amostras foram analisadas pelo teste do álcool etílico a 70% (v/v), acideztitulável e contagem de células somáticas (CCS). Leites com resultado positivo no teste do álcool, CCS menor que 1,8 x 106células/mL e acidez até 18ºD, foram considerados com instabilidade da caseína. Das amostras sem acidez adquirida e comCCS insuficiente para alterar a estabilidade da caseína, 33,93% apresentaram resultado positivo no teste do álcool. A maior ea menor ocorrência de leite com instabilidade da caseína foram observadas no outono (49,25%) e no verão (19,05%),respectivamente. Os resultados obtidos ressaltam a importância da pesquisa de leite com instabilidade da caseína,quantificando-a e disponibilizando dados para cálculo de impacto econômico do problema na região estudada.

Ocorrência de leite com instabilidade da caseína em Santa Vitória do Palmar, RS

O objetivo do presente trabalho foi determinar a ocorrência de leite com instabilidade da caseína no extremo sul do Brasil.Duzentas e oitenta e duas amostras de leite cru foram coletadas em estabelecimentos produtores de leite do município deSanta Vitória do Palmar, Rio Grande do Sul (RS). As amostras foram analisadas pelo teste do álcool etílico a 70% (v/v), acideztitulável e contagem de células somáticas (CCS). Leites com resultado positivo no teste do álcool, CCS menor que 1,8 x 106células/mL e acidez até 18ºD, foram considerados com instabilidade da caseína. Das amostras sem acidez adquirida e comCCS insuficiente para alterar a estabilidade da caseína, 33,93% apresentaram resultado positivo no teste do álcool. A maior ea menor ocorrência de leite com instabilidade da caseína foram observadas no outono (49,25%) e no verão (19,05%),respectivamente. Os resultados obtidos ressaltam a importância da pesquisa de leite com instabilidade da caseína,quantificando-a e disponibilizando dados para cálculo de impacto econômico do problema na região estudada.