Chemical treatment of roughage

Abstract

Chemical treatment of roughage has been the aim of studies for a long time. However, until nowadays, many questions are arisen due to the efficiency of additives used in relation to the variation of answers, either in nutritive value of treated roughage or in performance of animals feed with diet containing such roughage. This revision will approach the main and most used products, which are anhydrous ammonia, urea, sodium hydroxide and calcium oxide. It has been noticed that ammonization (both for anhydrous ammonia and urea) has presented more efficient result in animal's performance when compared with sodium hydroxide or calcium oxide. However, regarding its nutritive value, both sodium hydroxide and calcium oxide have presented a higher efficiency in the decreasing of cell wall and in the increase of treated roughage' digestibility.

The impact of hydrolyzing and oxidizing agents on chemical composition and digestibility of various high‐fibre forages

“…Analogous to responses in CP, and in agreement with previous studies (Feist, Baker, & Tarkow, 1970;Vieira Pires et al, 2010), those HFF with the lowest digestibility, such as TW and WL (Exp. I) exhibited the greatest increases in IVDMD in response to urea treatment.…”

“…As expected, total forage N content was increased significantly in all experiments by urea application as noted in previous studies (Aregawi et al, 2013;Hanafi, el Khadrawy, Ahmed, & Zaabal, 2012;Kraidees, 2005;Mehra et al, 2001;Milad et al, 2010;Souza & dos Santos, 2002;Vieira Pires, Giordano Pinto De Carvalho, & Oliveira Ribeiro, 2010). All HFF treatments with urea alone or combined with other chemical agent resulted in final CP values above 60-80 g/kg DM.…”

“…The poorest quality forages (high NDF, low CP and digestibility), typically show the greatest response in digestibility to chemical treatment (Vieira Pires et al, 2010). In this study, TW and DS had the lowest CP content and exhibited the greatest increase in N content from urea application (Exp.…”

“…The treatments containing a urea solution do not show an impact of nutritional significance on cell wall concentration or ADL in any of the experiments, but IVDMD was improved, presumably due to an increase in cell wall porosity or fragility associated with cleavage of lignocellulosic linkages (Kraidees, 2005) and alteration of cellulose crystallinity (Mittal et al, 2011). Such changes make structural polysaccharides more susceptible to the enzymes produced by ruminal microbes (Hanafi et al, 2012;Vieira Pires et al, 2010).…”

“…Apart from the N level added and plant species treated; higher responses in final CP content were observed when combined treatments with H were used (Exp II). Under such conditions, a more aggressive breakdown of H bonds between cellulose-cellulose and cellulose-hemicellulose might be expected (Bidlack, Malone, & Benson, 1992;Mittal, Katahira, Himmel, & Johnson, 2011;Vieira Pires et al, 2010). Such changes in cell wall structure with combined treatments should lead to a new pattern of linkages and re-crystallization of cellulose structure (Mittal et al, 2011).…”