Effect of dietary level of barley-based supplements and ruminal buffer on digestion and growth by beef cattle1

Abstract

Six ruminally cannulated beef steers were used in a 6 x 6 Latin square experiment with a 3 x 2 factorial arrangement of treatments to evaluate the effects of barley supplementation (BS; 10, 30 or 50% of diet DM) and ruminal buffer (RB; Na sesquicarbonate at 0 or 4% of BS DM) addition to bromegrass hay-based diets on digestion. When early- (boot) and late- (full maturity) havested bromegrass and wheat straw substrates were incubated in situ, no interactions (P greater than .10) involving substrate with dietary BS or RB were observed, indicating that forages differing in fermentability responded similarly to different ruminal environments. Averaged across substrates, RB had no effect with 10% BS and a positive effect with 30% BS, but a negative effect with 50% BS diets (BS x RB, quadratic; P less than .05) for in situ DM and NDF disappearance for 18 and 24 h of incubation and for rate of disappearance of potentially degraded DM and NDF. Intakes of DM and digested DM were greater (P less than .01) for RB diets; however, RB had no effect (P greater than .10) on total tract DM and NDF digestibility. Intake and digestibility of DM increased linearly (P less than .01), whereas NDF digestibility decreased linearly (P less than .01) as BS percentage was increased in the diet. Sixty beef steers (avg initial wt 302 kg) were fed the same dietary treatments in a growth experiment. A numerical improvement in DM intake (P = .20) and ADG (P = .06) was observed when RB was provided with the 50% BS diet. Results of these experiments indicate that RB may moderate negative effects occurring on ruminal fiber digestion when grains are used to supplement forage-based diets; however, improvements in ruminal digestion were not translated effectively to improved animal productivity.

Metabolism and ruminal parameters of Holstein × Gir heifers fed sugarcane and increasing levels of crude protein

“…The increases observed were approximately 10, 11, 13 and 30% superior to those found before feeding, respectively, for the levels 13, 15, 19 and 22 g CP/100 g DM of the diet. The ammonia non-assimilated by the microorganisms is usually absorbed by the rumen wall, removed from the portal circulation by the liver, entering the urea cycle (Lobley et al, 1995). When the rate of ammonia synthesis is higher than its utilization by the microorganisms, there is elevation in the concentration in the rumen, with consequent increase in the excretion and in the energy cost of production of urea, resulting in loss of protein (Russell et al, 1992).…”

“…Analyzes of the SCFA were conducted according to method recommended by Leventini et al (1990), by means of gas chromatography (7890-A, Agilent Technologies, Palo Alto, CA, USA), equipped with flame ionization detector (7683B, Agilent Technologies, Palo Alto, CA, USA) and fused silica capillary column DB-WAX (30 m; 0.25 mm; 0.25 µm propylene glycol, Agilent Technologies, Palo Alto, CA, USA). The data acquisition was done by means of software ChemStation (Agilent Technologies, Palo Alto, CA, USA).…”

Increasing sodium bicarbonate level in high-concentrate diets for heifers. I. Effects on intake, water consumption and ruminal fermentation

“…However, Jackson et al (1992) observed a quadratic trend with the highest intake when 1.88% of BICARB was added to calves' starter diet. Leventini et al (1990) hypothesized that increases in liquid passage rate caused by BICARB addition lead to an increase in ruminal wash-out of particles with the corresponding increase in feed intake. The reduction in DMI observed at the highest level of BICARB is in agreement Effect of sodium bicarbonate level was significant at **P < 0.01, or at *P < 0.05: L 5 linear, Q 5 quadratic and C 5 cubic.…”

“…Ruminal pH has also been ameliorated in some studies (Nicholson et al, 1963;Okeke et al, 1983;Zinn, 1991), but no effects have been reported in many others (e.g. Thomas and Hall, 1984;Leventini et al, 1990). This fact could be the result of the different variables affected by buffer addition and interactions between them, such as intake level, ruminal -Present address: Animal Nutrition, Management, and Welfare Research Group, Universitat Autò noma de Barcelona, 08193-Bellaterra, Spain.…”

Effect of Addition of Urea or Urea Plus Molasses to Different Corn Silages Harvested at Dough Stage on Silage Quality and Digestible Dry Matter Yield

“…Using Whatman 64 filter paper, filtered silagc liquids and silage fluid were stored in deep freezer until they werc analyzed. Organic acid analyses were made according to method of Leventini et al (1990) using gas chromatography.…”