Effect of concentrate type on rumen fermentation and milk production of cows at pasture

Effect of palm kernel expeller as supplementation on production performance of Jersey cows grazing kikuyu-ryegrass pasture

“…The mean total VFA concentration obtained from cows on both treatments is very similar to the mean total VFA concentration of 120.9 mmol/L (range: 90.3 to 151.4 mmol/L) compiled by Bargo et al (2003) from grazing studies. Khalili and Sairanen (2000) reported no change in the three main VFA's which is in agreement with the results of the current study. Milk yield is positively correlated with rumen concentrations of butyric acid followed by propionic acid (Seymour et al, 2005).…”

“…The milk fat and milk protein results of the current study concur to the results obtained by (Khalili and Sairanen, 2000) and (Carvalho et al, 2006). A review by Bargo et al (2003) reported that milk protein content was reduced by -0.06 percentage units with fibre-based concentrates compared with starch-based concentrates, with a milk protein response range from -0.21 to 0.05 percentage units.…”

“…It is generally accepted that MUN ranges for fertilised pasture-based dairy systems are higher than that of cows on TMR systems. This is supported by a summary of MUN values of previous pasture-based studies where cows were supplemented with starch-or fibre-based concentrates: 20.1 mg/dL with a range of 9.9 to 40.0 mg/dL (Khalili and Sairanen, 2000;Delahoy et al, 2003;Gehman et al, 2006;Meeske et al, 2009;Lingnau, 2011). The MUN concentrations of the current study indicates that dietary protein was not limiting, but rather fed in excess to some extent, but still within an acceptable range for pasture-based systems.…”

“…A review by Bargo et al (2003) reported that milk protein content was reduced by -0.06 percentage units with fibre-based concentrates compared with starch-based concentrates, with a milk protein response range from -0.21 to 0.05 percentage units. Khalili and Sairanen (2000) reported a higher milk lactose yield for cows supplemented with barley (starch-based) than for cows supplemented with oats, wheat bran and beet pulp (fibre-based), however this could possibly be attributable to increased milk yield, with no alteration in milk lactose percentage. Carvalho et al (2006) found a tendency for SEPKC inclusion in a TMR to increase lactose contents in milk (0.10>P>0.05).…”

The Effect of Carbohydrate Source on Nitrogen Capture in Dairy Cows on Pasture

“…Delahoy et al (2003) also reported higher milk protein content in milk from grazing cows supplemented with ground corn compared with supplementation of nonforage fiber sources (beet pulp, soybean hulls, and wheat middlings; 3.23 vs. 3.19%). Khalili and Sairanen (2000) found no differences in milk protein percentage for grazing cows with no supplement or supplemented with barley or a mixture of concentrate sources that included nonforage fiber (wheat bran and molasses sugar beet pulp; 3.42 vs. 3.43 or 3.49%). However, protein yield was lower for cows on pasture only compared with cows fed barley, which was lower than that for cows fed nonforage fiber (0.61 vs. 0.67 and 0.73 kg/d) because of the lower milk yield.…”