Efeito da somatotropina bovina recombinante (RBST) sobre a produção de leite e gordura em vacas da raça Holandesas.

Este estudo foi conduzido com o objetivo de avaliar os efeitos da aplicação de somatotropina bovina recombinante (rBST) sobre a produção de leite e gordura de vacas da raça Holandesa, durante os 60 aos 150 dias de lactação. O experimento foi desenvolvido no sistema de produção de leite do Centro de Pesquisa de Pecuária do Sudeste (Embrapa Pecuária Sudeste), em São Carlos, durante o período de abril a dezembro de 1999. Foram utilizadas 41 vacas distribuídas em um delineamento inteiramente casualizado, em três tratamentos: sem aplicação de rBST (controle) ? 15 vacas; aplicação de rBST 60 dias após o parto (rBST-60) ? 15 vacas; e aplicação de rBST 100 dias após o parto (rBST-100) ? 11 vacas. Foram realizadas análises de variância para as variáveis produção de leite; produção de leite corrigida a 4% de gordura e produção de gordura, tanto em porcentagem como em kg/dia. A suplementação com rBST aos 60 dias apresentou significativo aumento na produção de leite e na produção de leite corrigida em relação ao tratamento controle, entretanto esse fato não foi verificado para o tratamento com rBST aos 100 dias. Não ocorreram efeitos significativos da aplicação de rBST sobre a produção de gordura no leite, em % e em kg/dia. A suplementação com rBST aumentou a produção de leite e a produção de leite corrigida a 4% de gordura quando administrada aos 60 dias pós -parto. Não foram observados efeitos da suplementação de rBST sobre a porcentagem e produção de gordura do leite

Efeito da somatotropina bovina recombinante (RBST) sobre a curva de lactação de vacas da raça holandesas.

Foi conduzido um estudo com o objetivo de avaliar os efeitos da aplicaç ão de rBST sobre a curva de lactação de vacas da raça Holandesa. O experimento foi desenvolvido no sistema de produção de leite do Centro de Pesquisa de Pecuária do Sudeste (Embrapa Pecuária Sudeste), em São Carlos, durante o período de abril a dezembro de 1999. Foram avaliadas 41 vacas, dos 60 aos 150 dias de lactação, distribuídas em um delineamento inteiramente casualizado, em três tratamentos: sem aplicação de rBST (controle) ? 15 vacas; aplicação de rBST 60 dias após o parto (rBST-60) ? 15 vacas; e aplicação de rBST 100 dias após o parto (rBST- 100) ? 11 vacas. Foram realizadas análises de regressão da produção de leite em função dos dias de lactação. A aplicação de rBST aos 60 dias de lactação apresentou maior resposta no aumento da produção de leite e menor queda na produção. Com relação ao tratamento rBST-100, foi verificada uma estabilização seguida da diminuição menos acentuada na curva de lactação quando comparado com o tratamento controle. Todos os tratamentos apresentaram diminuição na produção de leite em função dos dias de lactação. No tratamento com rBST-60 durante o período de 75 a 120 dias de lactação, a cada dia da lactação, a produção de leite diminuiu 25,7 g, enquanto que para o mesmo período no tratamento controle, a produção decresceu 80,9 g/dia. A suplementação com rBST aumentou a persistência de lactação e a produção de leite quando administrada aos 60 dias pós -parto

Impacts of reduction of phosphorus in finishing diets for Holstein×Zebu steers

In Brazil, commonly males of dairy herd are destined to beef production. However, little is known about the mineral requirements for dairy males. Therefore, the objective of this experiment was to evaluate the calcium (Ca) requirements of Holstein×Zebu steers by determining Ca body tissue concentrations, true absorption and retention coefficients, as well as the requirements for maintenance and weight gain of steers fed diets containing or not containing dicalcium phosphate. Twenty-eight Holstein×Zebu steers with an average initial body weight of 377.5±49.4 kg were utilized. The experiment was conducted as a completely randomized design with a 2×2 factorial arrangement of treatments. Factors included 1) two concentrate levels (30% or 60%); and 2) two levels of dicalcium phosphate (DP), 0 or the amount necessary to attend the estimated dietary requirements. Absorption and retention coefficients, maintenance and gain requirements were estimated. The feedstuffs, refusals, feces, urine, blood and bone were sampled for Ca and phosphorus (P) analysis. Phosphorus intake was improved by the addition of concentrate and presence of DP. There were no variations in the daily fecal and urinary phosphorus excretion as a function of DP. The serum level of inorganic phosphorus was lower in non-supplemented animals, although it was within adequate concentrations for all treatments. Dry matter and organic matter intake, organic matter digestibility, performance, and efficiency were not affected by treatment. Absorption and retention coefficients, and the net requirements for maintenance are similar across treatments. Therefore, the lack of inorganic supplementary Ca and P in diets of feedlot finishing cattle does not change the concentrations of these minerals in bone. The dietary requirements of calcium and phosphorus obtained for cattle were lower than those described by the nutritional requirement systems from Brazil, USA, and UK

Effect of the addition of β-mannanase on the performance, metabolizable energy, amino acid digestibility coefficients, and immune functions of broilers fed different nutritional levels

Three experiments were conducted to evaluate the effect of β-mannanase (BM) supplementation on the performance, metabolizable energy, amino acid digestibility, and immune function of broilers. A total of 1,600 broilers were randomly distributed in a 4 × 2 factorial arrangement (4 nutritional levels × 0 or 500 g/ton BM), with 10 replicates and 20 broilers per pen. The same design was used in the energy and digestibility experiments with 8 and 6 replicates, respectively, and 6 broilers per pen. The nutritional levels (NL) were formulated to meet the nutritional requirements of broilers (NL1); reductions of 100 kcal metabolizable energy (NL2); 3% of the total amino acids (NL3); and 100 kcal metabolizable energy and 3% total amino acids (NL4) from NL1. The serum immunoglobulin (Ig) concentration was determined in two broilers per pen, and these broilers were slaughtered to determine the relative weight of spleen, thymus, and bursa of Fabricius. Throughout the experiment, the lower nutritional levels reduced (P < 0.05) body weight gain (BWG) and increased (P < 0.05) feed conversion (FCR) for the NL4 treatment. The BM increased (P < 0.05) the BWG values and improved (P < 0.05) the FCR of the broilers. The apparent metabolizable energy corrected for nitrogen balance (AMEn) values were reduced (P < 0.05) for NL2 and NL3. The BM increased (P < 0.05) the AMEn values and reduced (P < 0.05) the excreted nitrogen. NL3 and NL4 reduced (P < 0.05) the true ileal digestibility coefficients (TIDc) of the amino acids cystine and glycine, and BM increased (P < 0.05) the TIDc for all amino acids. The addition of BM reduced (P < 0.05) the relative weights of the spleen and bursa. NL2 increased (P < 0.05) the Ig values, whereas BM reduced (P < 0.05) the serum IgA, IgG, and IgM values of the broilers. This study indicates that using suboptimal nutrient levels leads to losses in production parameters, whereas BM-supplemented diets were effective in improving performance, energy values, and TIDc levels of amino acids and immune response of broilers

Milk fatty acid composition of Holstein x Gyr dairy cows fed sugarcane-based diets containing citrus pulp supplemented with sunflower oil.

Abstract Sugarcane is a strategic roughage source for milk production in the tropics, and its supplementation with plant oils offers great potential for obtaining milk enriched with beneficial fatty acids, such as oleic (cis-9 C18:1), vaccenic (trans-11 C18:1), and rumenic (cis-9, trans-11 CLA) acids. The aim of this study was to evaluate the milk fatty acid composition of cows fed 60% chopped sugarcane-based diets containing citrus pulp and 0.0% (control), 1.5%, 3.0% and 4.5% sunflower oil on a dry matter basis. Twelve multiparous Holstein x Gyr dairy cows with an average milk production of 17±5 kg day-1 and 96±25 days in milk were allocated in a triplicate 4 x 4 Latin square design. There was no effect of dietary treatment on milk production, but sunflower oil supplementation linearly reduced the milk fat content and yield. The milk fat contents of lauric (C12:0), myristic (C14:0), and palmitic (C16:0) fatty acids were linearly reduced with increasing sunflower oil levels. There was a quadratic effect on the milk fat oleic, vaccenic, and rumenic acid contents, while the concentrations of elaidic acid (trans-9 C18:1), trans-10 C18:1 and trans-10, cis-12 CLA linearly increased in response to sunflower oil inclusion. Diet supplementation with sunflower oil linearly reduced both the atherogenicity and thrombogenicity indices and linearly increased the ratio between hypo- and hypercholesterolemic fatty acids in milk fat. The inclusion of up to 4.5% sunflower oil in 60% chopped sugarcane-based diets improved the nutritional quality of milk fat from Holstein x Gyr dairy cows as a result of the increased content of oleic, rumenic and vaccenic acids, which are beneficial to human health, and the concomitant reduction of hypercholesterolemic lauric, myristic and palmitic acids. However, there was an increase in the milk content of trans-10 C18:1 and elaidic acid, which are associated with deleterious effects on cardiovascular health

Ruminal parameters and fatty acid composition of omasal digesta and milk in cows fed sugarcane-based diets supplemented with sunflower oil.

This study evaluates the intake and digestion of nutrients, parameters of rumen fermentation and degradation, omasal digesta and milk fatty acid composition, productive performance, and the concentration of serum metabolites in cows fed 600 g kg-1 sugarcane-based diets containing 0 (control), 15, 30, and 45 g kg-1 sunflower oil (SO) on a dry matter (DM) basis. Four rumen-cannulated Holstein x Gyr cows yielding 15±5 kg day-1 with 110±10 days in milk were allocated in a 4 x 4 Latin square design. Data were analyzed using mixed models, and significant differences were declared at P<0.05. There was no effect of SO on the intake and apparent digestibility of DM, crude protein, neutral detergent fiber (NDF) and nonfibrous carbohydrates, but there was a linear increase in the intake and digestibility of ether extract. Dietary SO levels did not alter the ruminal degradability parameters for DM and NDF, rumen pH and contents of ammonia N, acetate, propionate and volatile fatty acids. Milk fat content and yield were linearly decreased, whereas a linear increase in milk protein content was observed in response to increasing levels of SO, but with no effect on milk yield. Linear reductions in palmitic and &#945;-linolenic acid contents, a linear increase in trans-10 C18:1 and elaidic acids, and a quadratic effect on vaccenic and rumenic acids were observed in omasal digesta of cows fed increasing levels of SO. Overall, up to 45 g kg-1 SO can be included on DM of chopped sugarcane-based diets without reducing consumption, apparent digestibility and rumen degradability of DM and fiber. Supplementing chopped sugarcanebased diets with 30 to 45 g kg-1 SO (DM basis) promotes milk fat depression due to the inhibition of mammary lipogenesis by specific rumen-derived fatty acid intermediates of the biohydrogenation of unsaturated C18 fatty acids. The inclusion of 15 to 45 g kg-1 SO in chopped sugarcane-based diets improves the nutritional quality of milk fat, with increases in the levels of oleic, vaccenic and rumenic acids, beneficial to human health, and a reduction in the levels of the hypercholesterolemic lauric, myristic and palmitic acids.Suplemento

Mars Science Laboratory relative humidity observations : Initial results

The authors would like to express their gratitude to the MSL and REMS instrument teams in making this wonderful Mars mission come true. Ari‐Matti Harri and Hannu Savijarvi are thankful for the Finnish Academy grants 132825 and 131723.Peer reviewedPublisher PD

Dust Devil Tracks

Dust devils that leave dark- or light-toned tracks are common on Mars and they can also be found on the Earth’s surface. Dust devil tracks (hereinafter DDTs) are ephemeral surface features with mostly sub-annual lifetimes. Regarding their size, DDT widths can range between ∼1 m and ∼1 km, depending on the diameter of dust devil that created the track, and DDT lengths range from a few tens of meters to several kilometers, limited by the duration and horizontal ground speed of dust devils. DDTs can be classified into three main types based on their morphology and albedo in contrast to their surroundings; all are found on both planets: (a) dark continuous DDTs, (b) dark cycloidal DDTs, and (c) bright DDTs. Dark continuous DDTs are the most common type on Mars. They are characterized by their relatively homogenous and continuous low albedo surface tracks. Based on terrestrial and martian in situ studies, these DDTs most likely form when surficial dust layers are removed to expose larger-grained substrate material (coarse sands of ≥500 μm in diameter). The exposure of larger-grained materials changes the photometric properties of the surface; hence leading to lower albedo tracks because grain size is photometrically inversely proportional to the surface reflectance. However, although not observed so far, compositional differences (i.e., color differences) might also lead to albedo contrasts when dust is removed to expose substrate materials with mineralogical differences. For dark continuous DDTs, albedo drop measurements are around 2.5 % in the wavelength range of 550–850 nm on Mars and around 0.5 % in the wavelength range from 300–1100 nm on Earth. The removal of an equivalent layer thickness around 1 μm is sufficient for the formation of visible dark continuous DDTs on Mars and Earth. The next type of DDTs, dark cycloidal DDTs, are characterized by their low albedo pattern of overlapping scallops. Terrestrial in situ studies imply that they are formed when sand-sized material that is eroded from the outer vortex area of a dust devil is redeposited in annular patterns in the central vortex region. This type of DDT can also be found in on Mars in orbital image data, and although in situ studies are lacking, terrestrial analog studies, laboratory work, and numerical modeling suggest they have the same formation mechanism as those on Earth. Finally, bright DDTs are characterized by their continuous track pattern and high albedo compared to their undisturbed surroundings. They are found on both planets, but to date they have only been analyzed in situ on Earth. Here, the destruction of aggregates of dust, silt and sand by dust devils leads to smooth surfaces in contrast to the undisturbed rough surfaces surrounding the track. The resulting change in photometric properties occurs because the smoother surfaces have a higher reflectance compared to the surrounding rough surface, leading to bright DDTs. On Mars, the destruction of surficial dust-aggregates may also lead to bright DDTs. However, higher reflective surfaces may be produced by other formation mechanisms, such as dust compaction by passing dust devils, as this may also cause changes in photometric properties. On Mars, DDTs in general are found at all elevations and on a global scale, except on the permanent polar caps. DDT maximum areal densities occur during spring and summer in both hemispheres produced by an increase in dust devil activity caused by maximum insolation. Regionally, dust devil densities vary spatially likely controlled by changes in dust cover thicknesses and substrate materials. This variability makes it difficult to infer dust devil activity from DDT frequencies. Furthermore, only a fraction of dust devils leave tracks. However, DDTs can be used as proxies for dust devil lifetimes and wind directions and speeds, and they can also be used to predict lander or rover solar panel clearing events. Overall, the high DDT frequency in many areas on Mars leads to drastic albedo changes that affect large-scale weather patterns

Measuring local depletion of terrestrial game vertebrates by central-place hunters in rural Amazonia

The degree to which terrestrial vertebrate populations are depleted in tropical forests occupied by human communities has been the subject of an intense polarising debate that has important conservation implications. Conservation ecologists and practitioners are divided over the extent to which community-based subsistence offtake is compatible with ecologically functional populations of tropical forest game species. To quantify depletion envelopes of forest vertebrates around human communities, we deployed a total of 383 camera trap stations and 78 quantitative interviews to survey the peri-community areas controlled by 60 semi-subsistence communities over a combined area of over 3.2 million hectares in the Médio Juruá and Uatumã regions of Central-Western Brazilian Amazonia. Our results largely conform with prior evidence that hunting large-bodied vertebrates reduces wildlife populations near settlements, such that they are only found at a distance to settlements where they are hunted less frequently. Camera trap data suggest that a select few harvest-sensitive species, including lowland tapir, are either repelled or depleted by human communities. Nocturnal and cathemeral species were detected relatively more frequently in disturbed areas close to communities, but individual species did not necessarily shift their activity patterns. Group biomass of all species was depressed in the wider neighbourhood of urban areas rather than communities. Interview data suggest that species traits, especially group size and body mass, mediate these relationships. Large-bodied, large-group-living species are detected farther from communities as reported by experienced informants. Long-established communities in our study regions have not “emptied” the surrounding forest. Low human population density and low hunting offtake due to abundant sources of alternative aquatic protein, suggest that these communities represent a best-case scenario for sustainable hunting of wildlife for food, thereby providing a conservative assessment of game depletion. Given this ‘best-case’ camera trap and interview-based evidence for hunting depletion, regions with higher human population densities, external trade in wildlife and limited access to alternative protein will likely exhibit more severe depletion