Cardiorespiratory fitness: Reference on the six-minute walk test and oxygen consumption in adolescents from south-central chile

Indexación ScopusCardiorespiratory fitness (CRF) provides oxygen to the exercising muscles and is related to body adiposity, with cardiometabolic variables. The aim was to develop reference values and a predictive model of CRF in Chilean adolescents. A total of 741 adolescents of both genders (15.7 years old) participated in a basic anthropometry, performance in the six-minute walk test (SMWT), and in Course Navette was measured. Percentiles were determined for the SMWT, for the ˙VO2max, and an equation was developed to estimate it. The validity of the equation was checked using distribution assumptions and the Bland–Altman diagram. The STATA v.14 program was used (p < 0.05). The 50th percentile values for males and females in the SMWT and in the ˙VO2max of Course Navette were, respectively, from 607 to 690 and from 630 to 641 m, and from 43.9 to 45 and from 37.5 to 31.5 mlO2·kg·min−1, for the range of 13 to 17 years. For its part, the model to predict ˙VO2max incorporated gender, heart rate, height, waist-to-height ratio (WHR), and distance in the SMWT (R2 = 0.62; estimation error = 0.38 LO2·min−1; p <0.001). Reference values can guide physical fitness in Chilean adolescents, and ˙VO2max was possible to predict from morphofunctional variables. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.https://www.mdpi.com/1660-4601/18/5/247

Consumo, digestibilidade aparente dos nutrientes e comportamento ingestivo de bovinos da raça Holandesa alimentados com dietas contendo feno de capim-tifton 85 com diversos tamanhos de partícula Intake, apparent digestibility and ingestion behavior in Holstein steers fed diets containing Tifton 85 hay with different particle sizes

Avaliaram-se o consumo, a digestibilidade aparente de nutrientes da dieta e o comportamento ingestivo de novilhos recebendo dietas contendo feno de capim-tifton 85 com diferentes tamanhos de partícula (5, 7, 10 mm e inteiro). Utilizaram-se quatro novilhos da raça Holandesa, castrados, com peso vivo médio de 300 kg e idade média de 20 meses, em delineamento quadrado latino 4 &#215; 4, com quatro animais e quatro períodos. Os consumos de matéria seca, matéria orgânica, proteína bruta, extrato etéreo, fibra em detergente neutro, fibra em detergente ácido, carboidratos totais e carboidratos não-fibrosos não foram influenciados pelos perfis granulométricos das dietas experimentais. Os coeficientes de digestibilidade da matéria seca diferiram significativamente entre as dietas com feno com partículas de 7 e 10 mm (67,31 e 54,95%, respectivamente). No entanto, os resultados obtidos com essas dietas foram semelhantes aos encontrados com partículas de 5 mm e com feno inteiro, cujos valores foram intermediários, com média de 63,62%. O tempo de alimentação dos animais não diferiu entre as dietas com feno em artículas de 7 e 10 mm e inteiro. O tamanho de partícula do feno de capim-tifton 85 não influenciou o consumo, a digestibilidade dos nutrientes e o comportamento ingestivo de novilhos da raça Holandesa alimentados com dietas completas.<br>The intake, the apparent digestibility of nutrients and the ingestion behavior of four Holstein steers with average weight of 300 kg and 20 months of age, receiving diets containing Tifton 85 hay with different particle sizes (5, 7, 10 mm and whole) were evaluated. A 4 &#215; 4 Latin square experimental design with four steers and four periods was used. Intakes of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, total carbohydrates and non-structural carbohydrates were not influenced by the different granulometric profiles of the experimental diets. The DM digestibility were different between diets with particles size of 7 and 10 mm (67.31 and 54.95%, respectively). However, these diets were similar to that with 5 mm of particle size and whole hay, which showed intermediate values, with mean of 63.62%. The total feeding time of the animals that received diets with particles size of 7, 10 mm and whole did not differ. The Tifton 85 hay with different particles size did not affect the intake, digestibility of nutrients and the ingestion behavior of Holstein steers fed total mixed ration

Substituição do leite de cabra por soro de queijo bovino para cabritos alpinos Replacement of goat milk for cattle cheese whey in artificial feeding of Alpine kids

O trabalho foi conduzido para avaliar a substituição do leite de cabra por soro de queijo bovino no aleitamento de cabritos alpinos. Os animais foram distribuídos em delineamento inteiramente casualizado, em arranjo fatorial 4 &#215; 2, composto de quatro níveis de substituição do leite de cabra por soro de queijo (0, 15, 30 e 45%) e dois sexos (três machos e quatro fêmeas por tratamento). A inclusão do soro de queijo na dieta não afetou o desenvolvimento ponderal dos cabritos dos 7 aos 42 dias de idade. Os cabritos alimentados com leite de cabra apresentaram maiores pesos finais, em torno de 13,0 kg; consumiram 70,0 litros/animal de leite de cabra, 172,0 g MS/animal/dia de concentrado e tiveram ganho médio de 137,5 g/dia. Nos cabritos alimentados com a dieta com 15, 30 e 45% de soro de queijo, os pesos finais foram de 11,1; 9,88 e 10,27 kg; o consumo de leite foi de 59,5; 49,0 e 38,4 litros/animal; e o de concentrado, 148,0; 117,0 e 135 g MS/animal/dia, com ganhos de 122,2; 99,5 e 100,8 g/dia, respectivamente. A conversão alimentar não diferiu entre as dietas. O efeito do sexo evidenciou-se a partir dos 21 dias de idade, mas não houve interação dieta &#215; sexo. Ao final do estudo, aos 70 dias de idade, o peso dos machos (12,4 kg) foi maior que o das fêmeas (10,6 kg). A maior rentabilidade média (168,15%) foi obtida com o fornecimento dos níveis mais altos de soro de leite. O aleitamento de cabritos com até 45% de soro de queijo é tecnicamente viável e proporciona melhor retorno econômico. O uso de leite integral de cabra para criação de cabritos em rebanhos leiteiros é economicamente inviável.<br>The objective of this work was to evaluate the replacement of whole goat milk for cattle cheese whey in the artificial nursing of alpine kids. The animals were distributed in a complete randomized design in a 4 &#215; 2 factorial arrangement made up with four levels of goat milk replacing for cheese whey (0, 15, 30 and 45%) and two sexes (three males and four females per treatment). The inclusion of cheese whey in the diet did not affect the growth of the kids from 7 to 42 days of age. Kids fed whole goat milk showed higher final weights, around 13.0 kg. They intaked 70.0 L/animal of whole goat milk, 172.0 g DM/animal/day of concentrate and they had an average gain of 137.5 g/day. For the kids fed with 15, 30, 45% cheese whey diet, the final weights were 11.1; 9.88 and 10.27 kg; the whole goat milk consumption was 59.5, 49.0 and 38.4 L/animal, the concentrate consumption was 148.0; 117.0 and 135 g DM/animal/day with gains of 122.2; 99.5 and 100.8 g/day, respectively. Food conversion did not differ among diets. The sex effect was evident from the age of 21 days but there was not a treatment &#215; sex interaction. At the end of the work, at 70 days of age, the weight of the males (12.4 kg) was higher than the female weights (10.6 kg). The highest average yield (168.15%) was obtained when the kids received maximum level of whey. Nursing kids with up to 45% of cattle cheese whey is technically viable and increases economic return. However, using whole milk goat for nursing kids in milk cattle is economically unviable