Response of lactating dairy cows to degree of steam-flaked barley grain in low-forage diets
Safaei, K., Ghorbani, G.R., Alikhani, M., Sadeghi-Sefidmazgi, A., Yang, W.Z. (2017). Response of lactating dairy cows to degree of steam-flaked barley grain in low-forage diets. Journal of Animal Physiology and Animal Nutrition, [online] 101(5), e87-e97. http://dx.doi.org/10.1111/jpn.12565
Plain language summary
This study was conducted to investigate the effects of grinding versus steam flaking and increasing densities of steam-flaked barley grain on dry matter intake, rumen pH and fermentation characteristics, digestibility of dry matter in the total digestive tract, and milk production of dairy cows. Steam flaking of barley resulted substantial differences in particle size distribution, as compared with ground barley. Overall, cows fed ground-based diet had comparable feed intake, total digestibility and milk production, as compared with cows fed steam-flaked barley, thereby suggesting that both ground barley and steam-flaked barley could be fed to lactating dairy cows under current feeding conditions.
This study was conducted to investigate the effects of processing method (grinding vs. steam flaking) and increasing densities of steam-flaked barley grain on dry matter intake (DMI), rumen pH and fermentation characteristics, digestibility of dry matter in the total digestive tract (DDTT), and milk production of dairy cows. Eight multiparous mid-lactation Holstein cows averaging 103 ± 24 DIM, 44.5 ± 4.7 kg milk/day and weighing 611 ± 43 kg at the start of the experiment were used in a replicated 4 × 4 Latin square design with 21-day periods. Cows were fed diets consisting of (DM basis) 23.8% corn silage, 13.5% chopped alfalfa hay and 62.7% concentrate. The dietary treatments were either ground barley (GB) using a hammer mill or steam-flaked barley (SFB) – varying density at 390, 340 or 290 g/l. Processing method (GB vs. SFB) did not affect DMI (23.6 kg/day on average), DDTT (71.0% on average), milk yield (43.4 kg/day on average), milk components, rumen pH and molar proportions of acetate, propionate, butyrate and sorting activity. Ruminal isovalerate concentration tended (p = 0.06) to be higher for cows fed GB than those fed SFB-based diets. Decreasing the density of SFB from 390, 340 to 290 g/l tended to linearly increase DMI (p = 0.09), decrease total solids percentage of milk (p = 0.10) and linearly decreased milk urea nitrogen (12.8, 12.4 and 12.1 mg/dl; p = 0.04); also, the sorting index (SI) of the particles retained on the 19.0-mm sieve without affecting the SI of the particles retained on 8.0-mm, 1.18-mm or passed through 1.18-mm sieve (p = 0.05). These results indicated the limited effects of processing method (grinding vs. steam flaking) and densities of SFB (390, 290 or 290 g/l) on cows’ performance and feed utilization for dairy cows fed low-forage diets. Therefore, both processing methods could be recommended under current feeding conditions of dairy cows.