Effect of imbalance between energy and nitrogen supplies on microbial protein synthesis and nitrogen metabolism in growing double-muscled Belgian Blue bulls1

Abstract

Six double-muscled Belgian Blue bulls (initial weight: 345 ± 16 kg) with cannulas in the rumen and proximal duodenum were used in two juxtaposed 3 × 3 Latin squares to study the effect of a lack of synchronization between energy and N in the rumen on microbial protein synthesis and N metabolism by giving the same diet according to three different feeding patterns. The feed ingredients of the diet were separated into two groups supplying the same amount of fermentable OM (FOM), but characterized by different levels of ruminally degradable N (RDN). The first group primarily provided energy for the ruminal microbes (14.6 g of RDN/kg of FOM), and the second provided N (33.3 g of RDN/kg of FOM). These two groups were fed to the bulls simultaneously or alternately with the aim of creating three different time periods of imbalance (0, 12, or 24 h) between energy and N supplies in the rumen. The introduction of imbalance affected neither microbial-N flow at the duodenum (P = 0.65) nor efficiency of growth (P = 0.69), but decreased (P = 0.016)

Kinetics of digestion of low-quality forage grazed by beef cattle fed supplements containing increasing levels of rumen undegradable protein

“…This occurrence was supported by the fact that the main energy contribution of the forages originates from carbohydrate fraction B 2 (Malafaia et al, 1998;1999). This condition will provide the necessary synchronism between nitrogen and energy (from carbohydrates) for microbial protein synthesis (Vieira et al, 2000c;Valkeners et al, 2004;Yang et al, 2010), a situation similar to that found in the present study. The specific growth rate was not influenced by the treatments.…”

Effect of various levels of imbalance between energy and nitrogen release in the rumen on microbial protein synthesis and nitrogen metabolism in growing double-muscled Belgian Blue bulls fed a corn silage-based diet1

“…In the current experiment, there was no significant effect on the microbial protein synthesis when a 12-h imbalance of a daily OEB variation of 20 or 40 g of OEB/kg of DM was created. This lack of response to an increased level of imbalance between energy and N supplies for the ruminal microbes is in agreement with results obtained in a previous study (Valkeners et al, 2004), which demonstrated that a lack of imbalance in the diet between the energy and N supplies for ruminal microbes was not detrimental to their growth as long as nutrient supply was balanced on a 48-h basis and the level of imbalance did not exceed 30 g of OEB/kg of DM.…”

“…The total tract and ruminal digestibility of OM and NDF measured with L0 were consistent with those generally measured on double-muscled Belgian Blue bulls (Fiems et al, 1997;Valkeners et al, 2004). The theoretical ruminal N degradability (in sacco values), estimated from the Dutch tabular values (CVB, 2000) averaged 50.2 and 72.4%, respectively, for LRDN and HRDN.…”

“…Furthermore, the introduction of a 12-or 24-h imbalance between N and energy supplies in the rumen did not negatively influence microbial protein synthesis nor N use in sheep (Ludden et al, 2002a,b) or growing bulls (Valkeners et al, 2004). Both the ruminal microbes and their host animal possess the means to compensate for variations in kinetics of feed degradation to ensure a relatively continuous supply of nutrients to places of biosynthesis to optimize microbial growth (Dawson, 1999).…”

The Use of Cocoa Bean Waste as a Supplement in Male Bali Cattle Feeding

“…The consumption of protein and higher energy will generate faster growth rate (Soeparno 2005). Degradation of carbohydrate and N supply in the rumen of cattle affected the efficient use of energy and protein and the growth rate (Valkeners et al 2004). Changes source of carbohydrates and protein in the feed are influenced by specific changing substrates such as starch and protein NDF with the NPN important effect on the balance (Cabrita et al 2006).…”