This study aimed to evaluate the morphogenic, structural, chemical characteristics, and forage yield of Massai grass, as well as the performance of sheep under three pre-grazing canopy heights. Eighteen Dorper x crossbred sheep (12 males and 6 females) were subjected to three pre-grazing canopy heights of Massai grass (45, 35, and 25 cm). Rotational grazing was adopted, with a fixed rest period of 12 days and occupation of four days. Before placing animals in the paddock, stocking rate was estimated to ensure a reduction of about 50% in the initial height. Morphogenic and chemical characteristics of forage were evaluated, as well as animal intake and performance. Pasture managed at 25 cm height induced reductions in stem and sheath sizes, and phyllochron but an increased leaf: stem ratio. However, the pasture cut at 35 cm above ground promoted an increase in total dry mass and foliar leaf productions, in addition to greater forage availability and daily accumulation. Yet, pastures with a height of 45 cm had a higher percentage of stem and senescent material, decreasing leaf intake by animals. Among the studied heights, 35 cm is the most suitable for Massai grass, when used for rearing sheep for meat production under pasture conditions in the northern Tocantins. This is because this management provided a greater availability of good quality forage and thereby increasing weight gains per area in animals.
SUMMARY This studyaimed to assess the influence of three pre-grazing heights of Massai grass on the ingestive behavior of sheep under rotational stocking. Eighteen Dorper x nondescript crossbred sheep were used under rotational stocking on Massai grass at pre-grazing heights. The animal stocking was estimated to ensure a reduction of approximately 50% of the initial height. Behavior assessments were performed from 6 to 18 h at the entrance and exit of animals from paddocks. The longest activity was grazing, followed by rumination and other activities, and the period from 6 to 10 h showed the longest grazing.In the other periods, the animals in the 35-cm treatment grazed less when compared to those ofthe other treatments. Rumination in all treatments was more significant in the period from 14 to 18 h, but the animals in the 45-cm treatment spent more time doing this activity, which gave them a higher time of rumination of the food bolus, as well as ruminating chews. The bite rate was higher for the 25-cm treatment, followed by the 45 and 35-cm treatments, respectively.
This research aimed to determine the best inclusion level of crude glycerol in the diet of the Amazon catfish (Pintado), through zootechnical performance, body composition, metabolic profile and histopathology. The experiment was conducted at the Laboratory of Morphophysiology and Biochemistry of Neotropical Fishes of the Federal University of Tocantins. There was used 150 juvenilles of pintado, these with initial weight of 6,83 ± 1,11 (g) and 10,06 ± 0,57 (cm) lenght in a completely randomised design, with 3 replications (10 animals in each one). They were fed with five diets containing increasing levels of glycerol (0 g kg -1, 50 g kg -1 , 75 g kg -1 , 100 g kg -1 , and 125 g kg -1 ) during 90 days (30 days of adaption and 60 experimental days). The indexes were evaluated and they did not present statistical difference between each other, except for the specific growth rate, which showed a moderate linear behavior and muscular glycogen that at the level of 125 g kg -1 presented a lower concentration compared with the control diet (0 g kg -1 ). Regarding histology, the crude glycerin did not cause significant hepatic and renal changes in the referred specie, since the alterations found in the two tissues were considered lesions that did not compromise the functioning of the organ or that are reversible. Finally, it was indicated that the juveniles of Amazon Pintado are able to metabolize the crude glycerin up to 100 g kg -1 level.
This research was carried out to evaluate the effects of pregnancy, number of fetuses and feed restriction on nutrients intake and digestibility and on ruminal rate passage. Twenty-four ewes were used at 90, 110 and 130 days of pregnancy, and distributed among treatments according to the number of fetuses. They received balanced diet or restricted diet at 15% of energy and protein requirement. Ewes with two fetuses on feed restriction had more dry matter intake than those with one fetus. At 130 day, the highest dry matter and neutral detergent fiber intake occurred. Twin-pregnant ewes showed the highest nutrient digestibility, except for fiber fraction. Feed restriction caused smaller dry matter intake. Ruminal rate passage increased in late pregnancy.
RESUMO Suplementos com níveis energéticos semelhantes podem promover diferentes perfis metabólicos e respostas reprodutivas em função dos substratos gerados na fermentação ruminal e na digestão intestinal. Neste estudo, 28 ovelhas da raça Santa Inês com peso vivo e escore de condição corporal (ECC) médios de 39,40 kg e 2,55 respectivamente, receberam dieta basal mais um dos quatro concentrados (flushing): farelo de milho, polpa cítrica, grão de soja ou caroço de algodão (tratamentos). A suplementação foi realizada a partir de três semanas antes até três semanas depois do início da estação de monta, na quantidade de 0,5% do peso vivo dos animais, na matéria seca. Foram avaliados parâmetros reprodutivos (taxa de prenhes e prolificidade) e parâmetros metabólicos (energéticos, proteicos e hepáticos), além do peso e escore de condição corporal. O delineamento foi ao acaso com medidas repetidas no tempo. Houve um aumento significativo dos metabólitos sanguíneos energéticos (glicose, triglicérides, colesterol, lipoproteína de muito baixa densidade (VLDL), lipoproteína de baixa densidade (LDL) e lipoproteína de alta densidade (HDL)) e proteicos (proteína total, albumina, globulina, ureia e creatinina), das enzimas gamaglutamiltransferase (GGT) e aspartato aminotransferase (AST) e do escore de condição corporal (ECC) das ovelhas após seis semanas de suplementação. Os animais recebendo concentrado contendo caroço de algodão apresentaram maiores níveis plasmáticos de colesterol, LDL, HDL, GGT e albumina e maior ECC. Os maiores níveis plasmáticos de glicose, proteínas totais e AST foram encontrados nos tratamentos farelo de milho e polpa cítrica. Não houve diferença nos índices de fertilidade e prolificidade entre os tratamentos. A suplementação influenciou os níveis séricos dos metabólitos energéticos e proteicos e elevou o ECC a níveis satisfatórios, com potencial para
ResumoA ovinocultura esta amplamente distribuída pela as regiões do país, onde fatores climáticos afetam os animais diminuindo assim a produtividade, em consequência dos animais estarem fora da zona de conforto térmico. O organismo animal gasta energia nos mecanismos fisiológicos para esfriar ou aquecer o corpo, os nutriente ingeridos pelos animais transformados em energia, sendo que parte desta energia formada será translocada para os mecanismos fisiológicos, em detrimento da energia necessária para o crescimento e desenvolvimento. O estresse por calor influencia no consumo voluntário dos alimentos pelos animais.Palavras-chave: adaptação, desempenho, estresse térmico, tolerância. SANTOS, R.P. et al. Avaliação bioclimatológica em ovinos. PUBVET, Londrina, V. 6, N. 20, Ed. 207, Art. 1382, 2012 Assessment bioclimatology in sheep AbstractThe sheep production is widely distributed throughout the regions of the country, where climatic factors affect the animal thereby reducing productivity as a consequence of the animals is outside the zone of thermal comfort. The organism spends energy in animal physiological mechanisms to cool or warm the body, the nutrients ingested by the animal turned into energy, and part of this energy form is translocated to the physiological mechanisms, to the detriment of energy needed for growth and development. The heat stress influenced on the voluntary intake of food by animals.Keywords: adaptation, performance, thermal stress, tolerance INTRODUÇÃOO fator mais importante na determinação do clima é a posição geográfica do país. A maior parte do Brasil fica entre a linha do Equador, que corta o país na Região Norte, e o trópico de Capricórnio, que passa no Sudeste. As regiões do planeta que ficam entre essas duas linhas têm climas quentes e úmidos, e climas quentes e secos com temperatura media de 20ºC. Nas proximidades do Equador, são comuns temperaturas mais altas, sem grandes variações ao longo do ano. Já em regiões mais ao sul, as variações de temperatura são maiores. Outros fatores também podem interferir no clima, como altitude, proximidade do mar, presença de montanhas, ventos e massas de ar. (PEREIRA, 2005).A temperatura do ar é considerada o fator climático com influencia mais importante sobre o ambiente físico do animal (MCDOWELL, 1974). Dentro de ampla faixa de temperatura, podem ser definidas zonas térmicas que proporcionam maior ou menor conforto ao animal. Os animais para terem máxima produtividade, dependem de uma faixa de temperatura adequada, também chamada de zona de conforto térmico, em que não há gasto de energia ou atividade metabólica para aquecer ou esfriar o corpo. Do ponto de SANTOS, R.P. et al. Avaliação bioclimatológica em ovinos. PUBVET, Londrina, V. 6, N. 20, Ed. 207, Art. 1382, 2012 vista de produção, este aspecto reveste-se de muita importância, pelo fato de que dentro desses limites, os nutrientes ingeridos pelos os animais serem utilizados exclusivamente para seu crescimento e desenvolvimento (BAÊTA; SOUSA, 1997).A umidade atmosférica é outra variável q...
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