Effect of Synchronizing Starch Sources and Protein (NPN) in the Rumen on Feed Intake, Rumen Microbial Fermentation, Nutrient Utilization and Performance of Lactating Dairy Cows

Abstract

Eight crossbred (75% Holstein Friesian) cows in mid-lactation were randomly assigned to a switchback design with a 2x2 factorial arrangement to evaluate two nonstructural carbohydrate (NSC) sources (corn meal and cassava chips) with different rumen degradability and used at two levels of NSC (55 vs. 75%) with protein source (supplied by urea in the concentrate mix). The treatments were 1) Low degradable low level of corn (55%) 2) Low degradable high level of corn (75%) 3) High degradable low level of cassava (55%) and 4) High degradable high level of cassava (75%). The cows were offered the treatment concentrate at a ratio to milk yield at 1:2. Urea-treated rice straw was offered ad libitum as the roughage and supplement with 1 kg/hd/d cassava hay. The results revealed that total DM intake, BW and digestion coefficients of DM were not affected by either level or source of energy. Rumen fermentation parameters; NH 3 -N, blood urea nitrogen and milk urea nitrogen were unaffected by source of energy, but were dramatically increased by level of NSC. Rumen microorganism populations were not affected (p>0.05) by source of energy, but fungal zoospores were greater for cassava-based concentrate than corn-based concentrate. Milk production and milk composition were not affected significantly by diets containing either source or level of NSC, however milk fat percentage showed a trend towards higher levels for cassava-based concentrate than corn-based concentrate averaging (4.4 and 4.2, respectively). Likewise, income over feed, as estimated from 3.5% FCM, was higher on cassava-based concentrate than corn-based concentrate averaging (54.0 and 51.4 US$/mo, respectively). These results indicate that feeding diets containing either cassava-based diets and/or a higher of concentrates up to 75% of DM with NPN (supplied by urea up to 4.5% of DM) can be used in dairy rations without altering rumen ecology or animal performance compared with corn-based concentrate.

Effects of treating rice straw with urea or urea and calcium hydroxide upon intake, digestibility, rumen fermentation and milk yield of dairy cows

“…Ruminal pH and NH 3 -N were found higher (P b 0.05) as compared with urea-treated rice straw fed group, while BUN and MUN were in normal ranges as compared with the result reported by Hwang et al (2001). In addition, the result obtained was closer to optimal ruminal NH 3 -N (15-30 mg%, Wanapat and Pimpa, 1999;Chanjula et al, 2003Chanjula et al, , 2004Wanapat et al, 2008) for rumen fermentation and feed intake in swamp buffaloes offered urea-treated rice straw for microbial growth. In addition, Preston et al (1965) and Lewis (1975) reported that the concentration of BUN is correlated to the level of ammonia production in the rumen.…”

Starch in ruminant diets: a review

“…Mosavi et al (2012) also observed slower ruminal degradation for corn starch compared with wheat, barley or potato, as well as increased acetate and butyrate production along with higher milk fat (3.43% vs. 3.12, 3.09, and 3.13%, respectively). Contrary to these findings, Chanjula et al (2004) did not observe differences in milk production and compositional quality by adding corn (low degradability) or cassava (high degradability) at two inclusion levels (55 vs. 75%).…”

Investigation of Dietary Lysophospholipid (LipidolTM) to Improve Nutrients Availability of Diet with In Vitro Rumen Microbial Fermentation Test

“…Although pH values were appears to be decreased as increasing LPLs supplementation levels, the significant differences across the treatments is regardless of rumen microbial fermentation due to their optimal ranges. As shown in Table 2, the pH was within the optimum range (6.3 to 6.7) and the result was found to be similar to other studies (Chanjula et al, 2004Wanapat et al, 2009). In addition, rumen pH is one of the most critical determinants for rumen function as cellulolytic bacteria fail to grow below pH 6.0.…”