Cattle loading rates in different truck models and their relationship with bruises on bovine carcasses / Taxa de lotação em diferentes modelos de carrocerias e sua relação com hematomas em carcaças bovinas

This study sought to evaluate the number of bruises on bovine carcasses and their relationship with loading rates in different truck models. Bruising percentages in the hindquarter, forequarter and short rib regions were evaluated. The space occupied on the truck by each animal in m² was defined as the Practiced area, obtained by dividing the body area by the number of males and females transported in straight trucks (10.60 x 2.40 m) and livestock trailers (14.80 x 2.60 m), 240 and 168, and 120 and 93, respectively, and 80 males in a straight truck with trailer configuration (17.50 x 2.60 m). The minimum area occupied by the animals was assessed according to the Farm Animal Welfare Council (FAWC) and Animal Welfare Advisory Committee (AWAC). The data was analyzed in a completely randomized design and included two sex classes, three carcass regions and three truck types. For males, the minimum areas (m²) calculated by the FAWC and AWAC were smaller (1.37 and 1.29 m², respectively) for the straight truck. The straight truck with trailer configuration had the lowest (P=0.0025) bruising index in the forequarter region (15.1%) and the highest (P=0.047) in the short rib region (30.5%). Females transported in the livestock trailer had a higher (P<0.001) percentage of bruises in the forequarter region (51.7%). There was a relationship between the high bruising rates and the loading rate Practiced for the males. Estimations made by the AWAC are close to those practiced in the upper Pantanal region of Mato Grosso do Sul, Brazil.(AU)

Este estudo teve por objetivo avaliar o número de hematomas em carcaças de bovinos e suas relações com as taxas de lotação em diferentes modelos de carrocerias. Foi avaliada a porcentagem de hematomas na região do traseiro, dianteiro e ponta da agulha (PA). O espaço ocupado por cada animal em m² foi definido como área Praticada, sendo obtido pela divisão da área da carroceria pelo número de machos e fêmeas transportados nos caminhões truck (10,60 x 2,40 m) e carreta baixa (14,80 x 2,60 m); 240 e 168; 120 e 93, respectivamente, e 80 machos em caminhão romeu e julieta (17,50 x 2,60 m). Avaliou-se a área mínima ocupada por animal pela Farm Animal Welfare Council (FAWC) e Animal Welfare Advisory Committee (AWAC). Os dados foram analisados em um delineamento inteiramente casualizado sendo duas classes sexuais, três regiões da carcaça e três tipos de caminhões. Para machos, as áreas mínimas (m²) pela FAWC e AWAC foram menores (1,37 e 1,29 m², respectivamente) para o caminhão truck. O caminhão romeu e julieta apresentou o menor (P=0,0025) índice de hematomas na região dianteiro (15,1%) e o maior (P=0,047) na PA (30,5%). As fêmeas transportadas no caminhão carreta baixa, apresentaram maior (P<0,001) porcentagem de hematomas na região dianteiro (51,7%). Houve relação entre os altos índices de hematomas e a taxa de lotação Praticada para o caminhão carreta baixa e romeu e julieta para machos. As determinações realizadas pela AWAC estão próximas das Praticadas no Alto Pantanal sul-mato-grossense.(AU)

Soil compaction on traffic lane due to soil tillage and sugarcane mechanical harvesting operations

Mechanical sugarcane harvesting increases soil compaction due to the intense traffic of agricultural machinery, reducing longevity of sugarcane crops. In order to mitigate the harmful effects caused by agricultural traffic on the soil structure in sugarcane fields, this study evaluated impacts of mechanical sugarcane harvesting on traffic lane under two soil tillage systems based on load bearing capacity models. The experiment was carried out in the region of Piracicaba, state of São Paulo, Brazil, on a Rhodic Nitisol, under conventional tillage (CT) and deep strip-tillage (DST). For CT soil tillage was applied to the entire area with a heavy disk harrow, at operating depths from 0.20 to 0.30 m followed by a leveling harrow at a depth of 0.15 m. For DST, soil tillage was performed in part of the area at a depth of 0.80 m, forming strip beds for sugarcane planting, while the traffic lanes were not disturbed. Undisturbed soil samples from traffic lanes were used in the uniaxial compression test to quantify preconsolidation pressure and to model the soil load bearing capacity. The surface layer (0.00-0.10 m) was most susceptible to compaction, regardless of the tillage system (CT or DST) used. In the DST, the traffic lane maintained the previous soil stress history and presented higher load bearing capacity (LBC) than the traffic lane in the CT. As in CT the soil was tilled, the stress history was discontinued. This larger LBC in DTS minimized the impacts of the sugarcane harvest. Under CT, additional soil compaction due to mechanical sugarcane harvesting in the traffic lane was observed after the second sugarcane harvest. There was a reduction in load bearing capacity from 165 kPa to 68 kPa under CT and from 230 kPa to 108 kPa under DST, from the first to the second harvest at surface layer. Water content at mechanical harvesting was the most relevant factor to maximize impacts on the soil structure in traffic lanes, for both tillage systems.

Soil compaction on traffic lane due to soil tillage and sugarcane mechanical harvesting operations

Mechanical sugarcane harvesting increases soil compaction due to the intense traffic of agricultural machinery, reducing longevity of sugarcane crops. In order to mitigate the harmful effects caused by agricultural traffic on the soil structure in sugarcane fields, this study evaluated impacts of mechanical sugarcane harvesting on traffic lane under two soil tillage systems based on load bearing capacity models. The experiment was carried out in the region of Piracicaba, state of São Paulo, Brazil, on a Rhodic Nitisol, under conventional tillage (CT) and deep strip-tillage (DST). For CT soil tillage was applied to the entire area with a heavy disk harrow, at operating depths from 0.20 to 0.30 m followed by a leveling harrow at a depth of 0.15 m. For DST, soil tillage was performed in part of the area at a depth of 0.80 m, forming strip beds for sugarcane planting, while the traffic lanes were not disturbed. Undisturbed soil samples from traffic lanes were used in the uniaxial compression test to quantify preconsolidation pressure and to model the soil load bearing capacity. The surface layer (0.00-0.10 m) was most susceptible to compaction, regardless of the tillage system (CT or DST) used. In the DST, the traffic lane maintained the previous soil stress history and presented higher load bearing capacity (LBC) than the traffic lane in the CT. As in CT the soil was tilled, the stress history was discontinued. This larger LBC in DTS minimized the impacts of the sugarcane harvest. Under CT, additional soil compaction due to mechanical sugarcane harvesting in the traffic lane was observed after the second sugarcane harvest. There was a reduction in load bearing capacity from 165 kPa to 68 kPa under CT and from 230 kPa to 108 kPa under DST, from the first to the second harvest at surface layer. Water content at mechanical harvesting was the most relevant factor to maximize impacts on the soil structure in traffic lanes, for both tillage systems.(AU)

Development and mechanical properties of a locking T-plate / Desenvolvimento e as propriedades mecânicas de uma placa bloqueada em formato de T

This study aimed to develop a locking T-plate and to evaluate its mechanical properties in synthetic models. A titanium 2.7mm T-plate was designed with a shaft containing three locked screw holes and one dynamic compression hole, and a head with two locked screw holes. Forty T-shaped polyurethane blocks, and 20 T-plates were used for mechanical testing. Six bone-plate constructs were tested to failure, three in axial compression and three in cantilever bending. Fourteen bone-plate constructs were tested for failure in fatigue, seven in axial compression and seven in cantilever bending. In static testing higher values of axial compression test than cantilever bending test were observed for all variables. In axial compression fatigue testing all bone-plate constructs withstood 1,000,000 cycles. Four bone-plate constructs failure occurred before 1,000,000 cycles in cantilever bending fatigue testing. In conclusion, the locking T-plate tested has mechanical properties that offer greatest resistance to fracture under axial loading than bending forces.(AU)

O objetivo deste estudo foi desenvolver uma placa bloqueada em formato de T e avaliar as propriedades mecânicas em um modelo sintético. Uma placa-T em liga de titânio 2,7mm foi desenhada com uma haste contendo três orifícios para parafusos bloqueados e um orifício para realização de compressão dinâmica. 40 blocos de poliuretano em formato de T e 20 placas-T foram utilizados para os ensaios mecânicos. Seis montagens osso-placa foram testados até a falha, sendo três em força de compressão axial e três em flexão engastada. 14 montagens osso-placa foram testadas até a falha em fatiga, sendo 7 em força de compressão axial e 7 em flexão engastada. No teste estático, os valores mais altos foram observados em todas as variáveis no teste de compressão axial quando comparado à flexão engastada. Já nos testes de fadiga na força de compressão axial, todas as montagens osso-placa resistiram à 1000000 de ciclos. No teste de fadiga em flexão engastada, quatro montagens osso-placa falharam antes de alcançarem 1000000 de ciclos. Em conclusão, a placa-T estudada apresenta propriedades mecânicas que oferecem uma melhor resistência em estabilizar as fraturas na atuação das forças de compressão axial que nas forças de flexão.(AU)

Mechanical study in vitro of the resistance of axial forces of 3.5 mm cannulated and conventional screws in head and femoral neck fractures / Estudo mecânico in vitro da resistência a forças axiais dos parafusos canulado e convencional de 3, 5 mm de diâmetro em fraturas de cabeça e colo femoral

Background: Proximal femoral fractures account for 25% of all femoral fractures in dogs and are more common in younganimals. Osteosynthesis of femoral head and neck fractures is a complex procedure that can be performed using conventionalscrews or wires. However, proper fracture reduction and fi xation are diffi cult to achieve and, despite many advancements,such fractures remain challenging to solve. Cannulated screws have good compressive capacity and can be employed tosimplify the surgical procedure while optimizing outcomes. This study was designed to compare the resistance of conventional and cannulated screws to axial loading following experimental femoral neck fracture in dogs.Materials, Methods & Results: Fourteen cadaveric canine femurs were used in this study. Femurs were collected from dogsover 20 pounds in body weight with no gross or radiographic signs of orthopedic disease. Cadaveric femurs were submitted to experimental femoral neck fracture using a Gigli saw and allocated to osteosynthesis using either conventional orcannulated screws (seven bones each). All screws were inserted below the greater trochanter of the femur from the lateralaspect of the bone and screw topography confi rmed radiographically. Test specimens were then potted in polymethylmethacrylate, coupled to a hinged device and submitted to axial loading. Data on maximum load, maximum displacement, loadwithin the proportional limit, offset within the proportional limit and load required to produce a 3 mm displacement werecollected. Mean values were calculated and compared using the Students t test (P < 0.05). Mean values varied greatlywithin groups. Maximum load and displacement correspond to the critical point from which biomechanical testing becomesdestructive. Data were missing from one test specimen (conventional screw group) due to abrupt diaphyseal fracture atthe start of the axial loading trial...(AU)

Mechanical study in vitro of the resistance of axial forces of 3.5 mm cannulated and conventional screws in head and femoral neck fractures / Estudo mecânico in vitro da resistência a forças axiais dos parafusos canulado e convencional de 3, 5 mm de diâmetro em fraturas de cabeça e colo femoral

Background: Proximal femoral fractures account for 25% of all femoral fractures in dogs and are more common in younganimals. Osteosynthesis of femoral head and neck fractures is a complex procedure that can be performed using conventionalscrews or wires. However, proper fracture reduction and fi xation are diffi cult to achieve and, despite many advancements,such fractures remain challenging to solve. Cannulated screws have good compressive capacity and can be employed tosimplify the surgical procedure while optimizing outcomes. This study was designed to compare the resistance of conventional and cannulated screws to axial loading following experimental femoral neck fracture in dogs.Materials, Methods & Results: Fourteen cadaveric canine femurs were used in this study. Femurs were collected from dogsover 20 pounds in body weight with no gross or radiographic signs of orthopedic disease. Cadaveric femurs were submitted to experimental femoral neck fracture using a Gigli saw and allocated to osteosynthesis using either conventional orcannulated screws (seven bones each). All screws were inserted below the greater trochanter of the femur from the lateralaspect of the bone and screw topography confi rmed radiographically. Test specimens were then potted in polymethylmethacrylate, coupled to a hinged device and submitted to axial loading. Data on maximum load, maximum displacement, loadwithin the proportional limit, offset within the proportional limit and load required to produce a 3 mm displacement werecollected. Mean values were calculated and compared using the Student’s t test (P < 0.05). Mean values varied greatlywithin groups. Maximum load and displacement correspond to the critical point from which biomechanical testing becomesdestructive. Data were missing from one test specimen (conventional screw group) due to abrupt diaphyseal fracture atthe start of the axial loading trial...

Evaluation of mechanical and metal alloy composition of two sizes of circular external fixator rings for three different manufacturers for dogs / Avaliação mecânica e de composição de liga metálica de dois tamanhos de anéis para fixador externo circular de três diferentes fabricantes para cães

Background: Circular external skeletal fixator Ilizarov is a fixation method widely used to stabilize fractures. The method is performed using several components but the ring stands out as the fundamental component of this device, and compression loads in the same plane of the ring are mainly due to the wires connected from one side to another of the implant. The axial load is reached on the rings with a proper tension distractor device connected to the wires and fixed with bolts, washers and nuts during surgical procedure. Additional loads to axial tension are employed during patient`s physical activities after surgery. The study aimed to compare the resistance to axial compression load and analyze the alloy composition of the Ilizarov rings with different diameter sizes and alloys. Materials, Methods & Results: We tested two diameters of rings acquired from three manufacturers for mechanical axial compression. Manufacture sample (N = 30 rings of each trademark) was divided into two groups (60 and 80 diameter mm). The tests to evaluate strength and deformation parameters were performed in a universal testing machine Kratos ® 3.000 MP KE model, equipped with a load cell of 3000 N with test speed of 10 mm per minute. We also evaluated the elemental alloy composition by the method of the TTPIXE (Thick Target Proton Induced X-Ray Emission) in external PIXE...(AU)

Evaluation of mechanical and metal alloy composition of two sizes of circular external fixator rings for three different manufacturers for dogs / Avaliação mecânica e de composição de liga metálica de dois tamanhos de anéis para fixador externo circular de três diferentes fabricantes para cães

Background: Circular external skeletal fixator Ilizarov is a fixation method widely used to stabilize fractures. The method is performed using several components but the ring stands out as the fundamental component of this device, and compression loads in the same plane of the ring are mainly due to the wires connected from one side to another of the implant. The axial load is reached on the rings with a proper tension distractor device connected to the wires and fixed with bolts, washers and nuts during surgical procedure. Additional loads to axial tension are employed during patient`s physical activities after surgery. The study aimed to compare the resistance to axial compression load and analyze the alloy composition of the Ilizarov rings with different diameter sizes and alloys. Materials, Methods & Results: We tested two diameters of rings acquired from three manufacturers for mechanical axial compression. Manufacture sample (N = 30 rings of each trademark) was divided into two groups (60 and 80 diameter mm). The tests to evaluate strength and deformation parameters were performed in a universal testing machine Kratos ® 3.000 MP KE model, equipped with a load cell of 3000 N with test speed of 10 mm per minute. We also evaluated the elemental alloy composition by the method of the TTPIXE (Thick Target Proton Induced X-Ray Emission) in external PIXE...