Estimating ruminal crude protein degradation with in situ and chemical fractionation procedures

Estimating In Situ Effective Crude Protein Degradability with Cornell Net Carbohydrate and Protein System Parameters in Energy-Rich Feedstuffs for Ruminants

“…These regression relations did not improve when the different rumen outflow rates were used to estimate EPD. In Shannak et al [1] , Zhoa and Cao [16] (n = 30, R 2 =0.90, P<0.0001) and Westreicher-Kristen et al [17] similar to our findings, they reported that in situ rumen undegradable protein (1-EPD) obtained from nylon bag method may be the reliable and accurately predicted from CP fractions based on CNCPS. Zhoa and Cao [14] indicated that the regression equations could be used as a possible alternative, when rumen cannulated sheep or cattle are not available in some laboratories.…”

“…The mathematical models include in vivo, in situ and in vitro methods have been used to determine the ruminal protein digestibility of the feedstuff [1][2][3][4] . Although, in vivo method is the most proper method for these mathematical models, surgicial preparation for animals with duedonal and rumen cannula and suitable markers for calculating flow rate of digesta make it risky, labour-intensive and expensive [5] .…”

“…In situ Nylon Bag Method (NBM) is the most widely used research approach for measuring ruminal CP degradation [6] . This method also requires rumen cannulated animals, but it is relatively simple compared to in vivo method [1,7] . The CNCPS estimates the degradable proteins of the feedstuff using five CP fractions based on solubility in protein precipitant agents, buffer and detergent solutions: A represents the soluble non-protein nitrogen (NPN), B 1 (soluble true protein) is the albumins and globulins, B 2 is the most albumins and glutelins, B 3 is the prolamins, extension proteins and heat denatured proteins, and C is the unavailable N (N bound to lignin) [8][9][10] .…”

“…In recent years, the CNCPS as an alternative for estimation of degradable protein has become widely accepted in the studies [12][13][14] , because CNCPS can be applied at the farm level and CP fractions could be measured easily in most feed analyses laboratories [15] . Morever, some researchers stated that in situ rumen degradability may be reliably and accurately predicted from CNCPS parameters [1,16,17] . Energy-rich feedstuffs are sources of rumen degradable protein and glutelin levels (B 2 fraction) are generaly high in cereals.…”

Relationship between chemical composition and in situ rumen degradation characteristics of maize silages in dairy cows

“…Information on the relationship between chemical composition and in situ rumen degradation characteristics of dry matter (DM), organic matter (OM), CP, starch and neutral detergent fiber (NDF) of maize silages in the scientific literature is scarce. Several in situ studies have been conducted on maize silages to determine the effect of individual factors such as maturity stage (Johnson et al, 1999;Di Marco et al, 2002;Jensen et al, 2005), chop length (Fernandez et al, 2004) and ensiling (González et al, 2010) of maize crop on the rumen degradation of specific nutrients like DM (Von Keyserlingk et al, 1996), OM (Arieli et al, 1998), CP (Von Keyserlingk et al, 1996;Shannak et al, 2000), starch (Fernandez et al, 2004;Hindle et al, 2005) and NDF (Varga and Hoover, 1983;Stensig et al, 1994;Jensen et al, 2005). In addition, often in these studies only a limited number (n = 1 to 12) of samples were investigated and compared with other feedstuffs.…”