Effect of the Synchronization of the Degradation of Dietary Crude Protein and Organic Matter and Feeding Frequency on Ruminal Fermentation and Flow of Digesta in the Abomasum of Dairy Cows

Abstract

Four Holstein cows in midlactation were equipped with ruminal and abomasal cannulas and used to study the effect of synchronized degradation of crude protein (CP) and organic matter (OM) and feeding frequency on digestion and outflow of nutrients. A 4 x 4 Latin square design was used. Diets were arranged in a 2 x 2 factorial design; the four diets contained high ruminally degradable OM and high ruminally degradable CP, high ruminally degradable OM and low ruminally degradable CP, low ruminally degradable OM and high ruminally degradable CP, and low ruminally degradable OM and low ruminally degradable CP. In each period, cows were fed four times daily from d 1 to 14 and two times daily from d 15 to 28. Mean daily ruminal ammonia N concentration was reduced by high ruminally degradable OM, low ruminally degradable CP, and twice daily feeding. Fluctuation in ruminal ammonia N was lower when cows were fed four times daily than when cows were fed twice daily. Plasma urea N concentrations were lower for cows fed diets that were high in ruminally degradable CP. Higher CP flow in the abomasum was found for cows fed the diet containing high ruminally degradable OM and low ruminally degradable CP. Microbial dry matter and CP flow to the abomasum were higher for cows fed twice daily than for cows fed four times daily. Flow of OM in the abomasum was not altered by concentrations of ruminally degradable OM or CP. These results suggest that the available energy in the rumen (ruminally degradable OM) is the most limiting factor for ruminal N utilization under our experimental conditions. Use of these data may improve the prediction of plasma urea N.

Effects of feed refreshing frequency on growth and carcass characteristics of Awassi lambs

“…This might be attributed to a stimulation of the gastrointestinal system, the saliva glands and/or rumen secretions (Özen, 1995). Furthermore, feed refreshing at the 2-hour and 4-hour intervals might have affected ruminal comfort positively, as reported by Shabi et al (1998). They found that the fluctuation in ruminal ammonia-N concentrations was lower when cows were fed four times a day compared to twice a day.…”

Nutritional Strategies to Improve Nitrogen use Efficiency by Grazing Dairy Cows

“…A better ruminal synchrony could be achieved under grazing systems, when the CHO sources have a degradation rate of 13 to 14% h -1 , because this is similar to the RDP degradation rate of the pasture (Van Vuuren et al, 1990), although degradation rate of the pasture will vary with different circumstances (Aufrere et al, 2003). Table 2 shows the results obtained in experiments aiming at improving ruminal synchrony between CHO and N, either by changing the fermentation rates of CHO and N through modification of the diet ingredients (Shabi et al, 1998;Casper et al, 1999;Gehman et al, 2006) or changing the feeding patterns (Kolver et al, 1998;Trevaskys et al, 2004;Lund et al, 2008). Casper et al (1999) evaluated the supplementation with corn (Zea mays L.) or barley (Hordeum vulgare L.) plus soybean (Glycine max Merr.)…”

The effect of number of daily meals for dairy cows on milk yield and composition

“…Milk yield, milk composition, and ruminal ammonia were not affected by variable experimental feeding strategy in most cases. Increasing the feeding frequency improved fibre digestion and increased milk-fat (Sutton et al, 1988;Yang and Varga, 1989;French and Kennely, 1990;Shabi et al, 1998). Milk-fat increased when concentrates were fed more frequently.…”

“…Feeding frequency affects ruminal and blood metabolites (Sutton et al, 1986(Sutton et al, ,1988; a higher feeding frequency may counteract these effects, enhance diet utilization (Robinson and McNiven, 1994) and decrease ruminal ammonia N (NH 3 -N) and plasma urea-N (PUN) concentrations. In our previous study (Shabi et al, 1998), diets were fed to cows equipped with rumen and abomasum cannulas, four versus two daily meals. In that study, the concentrations of PUN, 2 and 4 h after feeding, were lower when cows were fed four meals than when cows were fed two meals daily.…”