Physical attributes of a dystrophic Regolithic Neosol under pasture submitted to mechanical forage harvestingor animal grazing / Atributos físicos do neossolo regolítico distrófico sob pastagem submetido à colheita mecanizada da forragem e pastejo animal

Cattle grazing and the use of machines for different operations such as tillage, sowing, cropping and harvesting in Brazilian soils have been indicated as the main cause of soil compac-tion. This effect reduces root growth and development and increases the loss of nitrogen due to denitrification and soil erosion due to reduced water infiltration. The objective of this study was to evaluate the physical attributes and basic water infiltration rate in a Regolithic Neosol under pasture submitted to different types of management (extensive grazing and mechanical forage harvesting). The study was conducted on the Roçadinho Farm, municipality of Capoeiras, Agreste de Pernambuco, under Buffel grass (Cenchrus ciliares L.) in a continuous grazing system of cattle, with an average stocking rate of 2 animal units (dairy cows with a mean live weight of 450 kg), and under growth of the same forage. Both areas were established more than 5 years ago, with mechanical forage harvesting where the harvester is coupled to the tractor and with trailer hitch. A completely randomized experimental design was used, with application of the F test at a 5% level of significance. Continuous grazing resulted in greater penetration resistance and bulk density and lower soil porosity compared to the area submitted to mechanical forage harvesting, as well as a lower basic soil infiltration rate. Animal trampling causes greater soil compaction than mechanical forage harvesting. Consequently, the extensive pasture area exhibits greater penetration resistance and bulk density and a lower total porosity and water infiltration rate in the superficial soil layer.(AU)

O pastejo de bovinos e a utilização de máquinas em várias operações de preparo, semeadura, tratos culturais, colheita, entre outros, nos solos brasileiros tem sido apontada como a principal causa da compactação. Esse efeito reduz o crescimento e o desenvolvimento radicular, aumenta a perda de nitrogênio por desnitrificação e a erosão do solo pela menor infiltração de água. Diante disso, objetivou-se determinar e avaliar os atributos físicos e a velocidade de infiltração básica de água em um Neossolo Regolítico sob pastagem com diferentes formas de manejo (área sob pastejo extensivo e colheita mecanizada de forragem). O estudo foi conduzido na Fazenda Roçadinho, município de Capoeiras, Agreste de Pernambuco, sob pastagem com capim Búffel (Cenchrus ciliares L.) em pastejo contínuo de bovinos, com lotação média de 2 unidades animais (vacas leiteiras com peso vivo médio de 450 kg), e sob cultivo da mesma forrageira, ambos estabelecidos há mais de 5 anos, com colheita mecanizada da forragem, com a colhedora acoplada ao reboque do trator e com engate para carreta. O delineamento experimental utilizado foi inteiramente casualizado, plicando-se o teste F a 5% de significância. O pastejo contínuo ocasionou maior resistência à penetração e densidade e menor porosidade do solo em comparação à área onde é realizada a colheita mecanizada de forragem, assim como uma menor velocidade de infiltração básica do solo. O pisoteio animal causa maior compactação do solo quando comparado à colheita mecanizada de forragem, portanto, a área de pastejo extensivo apresenta maior resistência à penetração e densidade, e obtém menor porosidade total e velocidade de infiltração da água na camada superficial do solo na camada superficial do solo.(AU)

Physical attributes of a dystrophic Regolithic Neosol under pasture submitted to mechanical forage harvestingor animal grazing / Atributos físicos do neossolo regolítico distrófico sob pastagem submetido à colheita mecanizada da forragem e pastejo animal

Cattle grazing and the use of machines for different operations such as tillage, sowing, cropping and harvesting in Brazilian soils have been indicated as the main cause of soil compac-tion. This effect reduces root growth and development and increases the loss of nitrogen due to denitrification and soil erosion due to reduced water infiltration. The objective of this study was to evaluate the physical attributes and basic water infiltration rate in a Regolithic Neosol under pasture submitted to different types of management (extensive grazing and mechanical forage harvesting). The study was conducted on the Roçadinho Farm, municipality of Capoeiras, Agreste de Pernambuco, under Buffel grass (Cenchrus ciliares L.) in a continuous grazing system of cattle, with an average stocking rate of 2 animal units (dairy cows with a mean live weight of 450 kg), and under growth of the same forage. Both areas were established more than 5 years ago, with mechanical forage harvesting where the harvester is coupled to the tractor and with trailer hitch. A completely randomized experimental design was used, with application of the F test at a 5% level of significance. Continuous grazing resulted in greater penetration resistance and bulk density and lower soil porosity compared to the area submitted to mechanical forage harvesting, as well as a lower basic soil infiltration rate. Animal trampling causes greater soil compaction than mechanical forage harvesting. Consequently, the extensive pasture area exhibits greater penetration resistance and bulk density and a lower total porosity and water infiltration rate in the superficial soil layer.

O pastejo de bovinos e a utilização de máquinas em várias operações de preparo, semeadura, tratos culturais, colheita, entre outros, nos solos brasileiros tem sido apontada como a principal causa da compactação. Esse efeito reduz o crescimento e o desenvolvimento radicular, aumenta a perda de nitrogênio por desnitrificação e a erosão do solo pela menor infiltração de água. Diante disso, objetivou-se determinar e avaliar os atributos físicos e a velocidade de infiltração básica de água em um Neossolo Regolítico sob pastagem com diferentes formas de manejo (área sob pastejo extensivo e colheita mecanizada de forragem). O estudo foi conduzido na Fazenda Roçadinho, município de Capoeiras, Agreste de Pernambuco, sob pastagem com capim Búffel (Cenchrus ciliares L.) em pastejo contínuo de bovinos, com lotação média de 2 unidades animais (vacas leiteiras com peso vivo médio de 450 kg), e sob cultivo da mesma forrageira, ambos estabelecidos há mais de 5 anos, com colheita mecanizada da forragem, com a colhedora acoplada ao reboque do trator e com engate para carreta. O delineamento experimental utilizado foi inteiramente casualizado, plicando-se o teste F a 5% de significância. O pastejo contínuo ocasionou maior resistência à penetração e densidade e menor porosidade do solo em comparação à área onde é realizada a colheita mecanizada de forragem, assim como uma menor velocidade de infiltração básica do solo. O pisoteio animal causa maior compactação do solo quando comparado à colheita mecanizada de forragem, portanto, a área de pastejo extensivo apresenta maior resistência à penetração e densidade, e obtém menor porosidade total e velocidade de infiltração da água na camada superficial do solo na camada superficial do solo.

Colostrum composition of Santa Inês sheep and passive transfer of immunity to lambs.

This study aimed to analyze the chemical composition and the IgG concentration of the colostrum, transitional milk, and mature milk of Santa Inês ewes as well as the transfer of passive immunity to lambs. Thirty-two pregnant ewes and 38 lambs were used. Ewes were milked immediately after lambing and at 12, 24, 36 h and 10 d postpartum. Colostrum was provided to the lambs at 40±15 min (mean±SE) after birth and then at 30-min intervals for obtaining the intake closest to 10% of body weight, and transitional milk was provided ad libitum. Blood from the lambs was collected 36 h after birth for measuring the serum concentrations of IgG, total protein, albumin, and gamma-globulin. The production was lower in primiparous than in multiparous ewes with body condition score (BCS)<2.75, but did not differ between primiparous and multiparous with BCS≥2.75 (interaction parity and BCS). The IgG concentration and fat, protein, lactose, and defatted dry extract percentages were not affected by the BCS of the ewe at lambing or by the parity. The total solids percentage in the colostrum was higher in ewes with BCS<2.75 (interaction BCS and time). The production and the protein, total solid, and defatted dry extract percentages showed quadratic behavior, the fat percentage decreased linearly, and the lactose percentage increased linearly with time postpartum. The IgG concentration in the colostrum was not correlated with the ewe's weight or BCS at the time of lambing. Moreover, the parity, the BCS, the ewe's type of gestation, and the lamb's sex did not influence the serum concentrations of IgG, total protein, albumin, and gamma-globulin in lambs. Adequate passive immune transfer (PIT) was observed in lambs for which the IgG intake was higher than 30 g. Failure in PIT was observed in 39.5% of lambs when considering a serum IgG concentration lower than 15 mg/mL and in 21% when considering a serum total protein concentration lower than 45 mg/mL. The mean apparent efficiency of absorption was 38.10%, with values between 0.02% and 98.80%. The serum IgG concentration was correlated with the total protein concentration (according to the enzymatic colorimetric method), the gamma-globulin concentration, and the absorption efficiency. The extreme variation on apparent efficiency of absorption may have an effect on the success of PIT. Lambs should consume at least 30 g of IgG in the first 24 h of life to ensure adequate PIT.