Nutritional evaluation and productivity of supplemented sheep grazing in semiarid rangeland of northeastern Brazil.

Sheep production systems in Brazilian caatinga rangelands require supplementation adapted to changes in floristic and chemical composition as dry seasons progress. Meeting sheep nutritional needs in extensive semiarid systems is challenging because of sheep dietary preferences and habits. The objective of this trial was to evaluate the substitutive effect of concentrate supplementation on grazing sheep in the Brazilian caatinga rangeland and its consequences on performance in different seasons. The trial was conducted from March to August 2013 at Embrapa Goat and Sheep in Sobral, Ceará State, Brazil. Thirty-two Brazilian Somali multiparous ewes were submitted to estrus synchronization and controlled breeding. At the start of the trial, ewes averaged 30.45 + 2.60 kg body weight (BW). Ewes were divided into four groups and individually offered 0, 200, 350, or 500 g supplement head-1 day-1. Intake prediction and digestibility trials were evaluated at three periods: rainy season (April), transition rainy-dry (June), and dry season (August). Sheep weights were taken every 14 days to measure their performance from late gestation until weaning. Ewe BW and body condition score changes were determined too. Lamb BW changes were also measured every 14 days from birth through weaning. A completely randomized design with split plot arrangement using eight replications was used for intake and digestibility measurements. The differences between supplement offered (0, 200, 350, and 500 g sheep-1) and season (rainy, transition rainy-dry, and dry) were submitted to analyses of variance and multiple means were separated, where differences were detected, using the Tukey's test. During lactation up through weaning, ewes supplemented at 500 g day-1 had greater BW than ewes without supplement. Ewes supplemented with 200 g concentrate head-1 day-1 had 9.1% greater (P ≤ 0.05) BW at weaning and their lambs had 19.7% greater birth and 16.6% heavier wean BW despite lower dry matter intake compared to unsupplemented animals. Supplementation with 200 g concentrate increased carrying capacity by 28.8% during the dry season and by 20.5% during the rainy season. This study confirmed that in the dry season, when quality of rangeland forages decreases, supplementation contributes to greater DMI, improves postpartum and lactation BW recovery of ewes, and contributes to greater lamb birth and wean weights. Moreover, supplementation leads to feed substitution effects that may increase rangeland resilience by mitigating overgrazing. Supplementation with 200 g concentrate can also prevent negative energy balance for grazing animals, improving longer postnatal recovery, longer intervals between parturitions, fewer double and is necessary to ensure a better BW at birth to lambs.

Composição química e digestibilidade da matéria seca do bagaço de cana-de-açúcar tratado com óxido de cálcio / Chemical composition and dry matter digestibility of sugarcane bagasse treated with calcium oxide

Avaliaram-se a composição química e a digestibilidade in vitro da matéria seca (DIVMS) do bagaço de cana-de-açúcar hidrolisado com óxido de cálcio em dois períodos. As doses de óxido de cálcio aplicadas ao bagaço foram 0; 1,25; 2,5 e 3,75 por cento (na base da MS) e os períodos de tratamento, 12 e 36 horas. O teor de matéria seca (MS) do bagaço de cana foi maior quando hidrolisado por 36 horas. O valor médio da proteína bruta foi de 2,4 por cento e não foi influenciado pelo período, pela dose de óxido de cálcio nem pela interação período × dose de óxido de cálcio. Os teores de fibra em detergente neutro, fibra em detergente ácido, celulose e lignina diminuíram linearmente com a adição de óxido de cálcio. A digestibilidade in vitro da matéria seca, no entanto, aumentou 1,2 por cento a cada unidade de óxido de cálcio adicionada ao bagaço da cana-de-açúcar. O tratamento com óxido de cálcio por 12 ou 36 horas melhora o valor nutritivo do bagaço de cana-de-açúcar.

The chemical composition and in vitro dry matter digestibility (IVDMD) of sugarcane bagasse hydrolyzed with calcium oxide (CaO) in two periods were evaluated. The doses of calcium oxide applied to bagasse were 0; 1.25; 2.5; and 3.75 percent (dry matter basis) and the treatment periods were 12 and 36 hours. The dry matter sugarcane bagasse was larger when hydrolyzed for 36 hours. The crude protein mean value observed was 2.4 percent, with no effects of period, CaO doses, or period and CaO interaction. The neutral detergent fiber, acid detergent fiber, celluloses, and lignin levels linearly reduced with CaO added. The IVDMD increased with CaO add, estimating increase of 1.2 percent for each CaO unit added to sugarcane bagasse. The periods of 12 or 36 hours can be adopted to sugarcane bagasse treatment with CaO. The CaO addiction to sugarcane bagasse improve its nutritive value.

Características fermentativas de silagens de capim-elefante emurchecido ou com adição de farelo de cacau / Fermentation characteristics of silage of elephantgrass wilted or with addition of cocoa meal

O experimento foi realizado para avaliar as características fermentativas da silagem de capim-elefante emurchecido ou adicionado de diferentes níveis de farelo de cacau. O capim-elefante utilizado foi colhido aos 50 dias de rebrota após o corte de uniformização e submetido aos seguintes tratamentos na ensilagem: capim-elefante emurchecido ao sol por oito horas e capim-elefante sem emurchecimento adicionado de 0, 7, 14, 21 e 28 por cento de farelo de cacau ( por cento da matéria natural). Foram utilizadas quatro repetições por tratamento. O material foi acondicionado em silos de PVC com 0,15m de diâmetro e 0,3m de altura, adotando-se compactação de 500kg/m³. O pH reduziu e os carboidratos solúveis (CHO S) aumentaram de forma linear (P<0,05) com a adição de farelo de cacau. O teor de N-NH3 aumentou com a adição de farelo de cacau na ensilagem, contudo, os teores dos ácidos orgânicos não diferiram entre a silagem com farelo de cacau e aquela com capim-elefante emurchecido. A inclusão de 0, 7, 14, 21 e 28 por cento de farelo de cacau provocou aumentos de 2,23; 2,48; 3,14; 3,49 e 3,47 por cento no teor de ácido lático, respectivamente. A qualidade fermentativa da silagem de capim-elefante melhorou com a adição de farelo de cacau.

The experiment was carried out to evaluate the fermentation characteristics of eight hours sun light wilted elephant grass silage in comparison to no sun light exposed silage added by 0, 7, 14, 21, and 28 percent of cocoa meal during the ensilage process. PVC silos, measuring 0.15m diameter x 0.30m height, were used to ensilage the elephantgrass using a compacting pressure of 500kg/m³. Soluble carbohydrates decreased but pH and N-NH3 increased (P<0.05) as the cocoa meal level increased in the silage. No difference between wilted and no wilted elephantgrass silages was observed for organic acid content. Addition of 0, 7, 14, 21, and 28 percent of cocoa meal caused an increase of 2.23, 2.48, 3.14, 3.49, and 3.87 percent of lactic acid contents. Addition of cocoa meal during the ensilage process enhanced fermentation quality of elephantgrass silage.