Evaluation of ruminal degradation profiles of forages using bags made from different textiles

Valente, Tiago Neves Pereira; Detmann, Edênio; Queiróz, Augusto César de; Filho, Sebastião de Campos Valadares; Gomes, Daiany Íris; Figueiras, Janderson Florêncio

doi:10.1590/s1516-35982011001100039

Cited by 213 publications

(158 citation statements)

References 22 publications

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“…The contents of dry matter (DM), crude protein (CP), and mineral matter (MM) were estimated according to AOAC (1995); neutral detergent fiber (NDF) according to Mertens (2002); and acid detergent fiber (FDA) according to van Soest and Robertson (1985). The indigestible neutral detergent fiber (iNDF) was estimated by the methodology described by Valente et al (2011). The potentially digestible dry matter (PDDM) was estimated according to the equation proposed by Paulino et al (2008).…”

Section: Methodsmentioning

confidence: 99%

Defoliation height and potassium fertilization of Mulato II grass

Cabral

Pesqueira-Silva

Barros

et al. 2017

SCA

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A pot trial in greenhouse conditions was carried out to identify at which defoliation height Mulato II grass (Urochloa hibrida cv. Mulato II) should be managed and to determine whether potassium fertilization is necessary in soil with high potassium content. The experiment was carried out in a greenhouse in a randomized block design with six treatments and five replications. Treatments consisted of a 3 × 2 factorial arrangement, with three defoliation heights (50, 65, and 80 cm) and with or without potassium maintenance fertilization. The production characteristics and chemical composition of the forage plant were evaluated. There was no interaction effect between defoliation height and fertilization with or without potassium on any of the analyzed variables, except for mineral content in Mulato II grass. The tillers and leaves number, shoot dry matter, leaf+sheath, root system, and residue were influenced by defoliation heights and potassium fertilization, except for the leaf blades and root dry matter, leaf blade/ stem+sheath ratio, and leaves number, which were not influenced by potassium fertilization. Higher shoot dry matter was observed at the heights of 65 and 80 cm; however, comparing these two heights, leaf + sheath dry matter was lower at 65 cm. Regarding the grass's chemical composition, there was an increase in neutral and acid detergent fiber and indigestible neutral detergent fiber contents as the defoliation height increased, which resulted in lower production of potentially digestible dry matter, which can compromise the potential use of the forage by animals. Among evaluated treatments, Mulato II grass defoliation is recommended for a maximum height of 65 cm. Potassium fertilization increases the yield and the potentially digestible dry matter content of Mulato II grass, even when cultivated in soil with high potassium content. teor de potássio. O experimento foi realizado em casa de vegetação, em delineamento experimental em blocos casualizados, com seis tratamentos e cinco repetições, em esquema fatorial 3x2. Os tratamentos consistiram em três alturas de desfolha (50, 65 e 80 cm), sendo cada altura de desfolha avaliada com ou sem adubação de manutenção com potássio. Foram avaliadas as características produtivas e a composição bromatológica da forrageira. As alturas de corte e adubação ou não com potássio não apresentaram efeito de interação para nenhuma das variáveis analisadas, exceto para teor de minerais no capim Mulato II. O perfilhamento, massa seca da parte aérea, colmo + bainha, número de folhas e massa seca de raiz e resíduos foram influenciadas pelas alturas de corte e adubação com potássio, com exceção a massa de lâminas foliares, raiz, relação lâmina foliar/colmo+bainha e número de folhas, que não foram influenciadas pela adubação potássica. Observou-se maior massa seca de parte aérea nas alturas de 65 e 80 cm, contudo, comparando estas duas alturas, houve menor massa seca de colmo+bainha na altura de 65 cm. Em relação à composição bromatológica do capim Mulato II, houve inc...

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Section: Methodsmentioning

confidence: 99%

Defoliation height and potassium fertilization of Mulato II grass

Cabral

Pesqueira-Silva

Barros

et al. 2017

SCA

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“…This specific point is defined as the point with the maximum distance between the adjusted model and a straight line linking the predicted response for minimum and maximum values of the independent variable. For non-linear models with an asymptotical response, it was identified the point where the response become stable as the value of the independent variable where the adjusted model enters the asymptotic 95% confidence interval for the asymptote (Valente et al, 2011). All statistical evaluations were considered significant at P ⩽ 0.05 as the critical (asymptotical) level for the occurrence of type I error.…”

Section: Methodsmentioning

confidence: 99%

The effect of CP concentration in the diet on urea kinetics and microbial usage of recycled urea in cattle: a meta-analysis

Batista

Detmann

Filho

et al. 2017

Animal

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In ruminants, urea recycling is considered an evolutionary advantage. The amount of urea recycled mainly depends of the nitrogen (N) intake and the amount of organic matter (OM) digested in the rumen. Because recycled N contributes to meeting microbial N requirements, accurate estimates of urea recycling can improve the understanding of efficiency of N utilization and N losses to the environment. The objective of this study was to evaluate urea kinetics and microbial usage of recycled urea N in ruminants using a meta-analytical approach. Treatment mean values were compiled from 25 studies with ruminants (beef cattle, dairy cows and sheep) which were published from 2001 to 2016, totalling 107 treatment means. The data set was analyzed according to meta-analysis techniques using linear or non-linear mixed models, taking into account the random variations among experiments. Urea N synthesized in the liver (UER) and urea N recycled to the gut (GER) linearly increased (P < 0.001) as N intake (g/BW 0.75 ) increased, with increases corresponding to 71.5% and 35.2% of N intake, respectively. The UER was positively associated (P < 0.05) with dietary CP concentration and the ratio of CP to digestible OM (CP:DOM). Maximum curvature analyses identified 17% dietary CP as the point where there was a prominent increase in hepatic synthesis of urea N, likely due to an excess of dietary N leading to greater ammonia absorption. The GER:UER decreased with increasing dietary CP concentration (P < 0.05). At dietary CP ⩾ 19%, GER:UER reached near minimal values. The fraction of UER eliminated as urinary urea N and the contribution of urea N to total urinary N were positively associated with dietary CP ( P < 0.05), both reaching values near the plateau when dietary CP was 17%. The fractions of GER excreted in the feces and utilized for anabolism decreased, whereas the fraction of GER returned to the ornithine cycle increased with dietary CP concentration (P < 0.05). Recycled urea N assimilated by ruminal microbes (as a fraction of GER) decreased as dietary CP and CP:DOM increased (P < 0.05). The efficiency of microbial assimilation of recycled urea N was near plateau values at 194 g CP/kg DOM. The models obtained in this study contribute to the knowledge on N utilization, and they could be used in feeding models to predict urea recycling and thus to improve formulation of diets to reduce N losses that contribute to air and water pollution.Keywords: cattle, mixed models, protein, recycling, ruminal bacteria ImplicationsIn cattle systems, many farmers utilize feeding models to estimate protein requirements. However, most models recognize the importance of urea nitrogen (N) recycling in the rumen, but not all account for it. In such situation, a tendency to oversupply dietary CP may occur, leading to higher feed costs and N excretion. As N excreted can contribute to air and water pollution, more efficient feeding strategies are required to maximize N utilization. In this study, we used a meta-analytical approach to obtain models that cou...

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“…Para isso, as amostras dos alimentos, sobras e fezes foram acondicionadas em sacos F57 (Ankon®) e incubadas in situ durante 288 horas (Valente et al, 2011). O resíduo obtido após incubação foi submetido à análise de FDN (sistema ANKOM®).…”

Section: Methodsunclassified