Effects of the replacement of concentrate and fibre-rich hay by high-quality hay on chewing, rumination and nutrient digestibility in non-lactating Holstein cows

Abstract

The aim of this study was to investigate the effects of high-quality hay with an elevated sugar content alone or with graded amounts of concentrate feed on chewing and ruminating activity, apparent total tract digestibility (ATTD) and ruminal pH at different time points after feeding in the free ruminal liquid (FRL) and the particle-associated ruminal liquid (PARL). Eight rumen cannulated non-lactating Holstein cows were arranged in a Latin square design in four experimental runs lasting 25 d each. The four diets tested were 60NQ (60% normal-quality hay + 40% concentrate), 60HQ (60% high-quality hay + 40% concentrate), 75HQ (75% high-quality hay + 25% concentrate) and 100HQ (100% high-quality hay). Normal and high-quality hays differed in sugar contents (11.3% vs. 18.7% in dry matter [DM]), neutral detergent fibre (NDF; 57.7% vs. 46.3% in DM), acid detergent fibre (ADF, 35.0% vs. 23.5% in DM) and crude protein (CP, 11.3% vs. 23.5% in DM). Data showed that ATTD of DM, CP, NDF and ADF was higher with the high-quality hay diets. Time spent eating was reduced with high-quality hay. However, time spent ruminating was longest in Group 100HQ. In all groups, ruminal pH of FRL and PARL decreased with time after the morning feeding. But 10 h later, pH of Group 100HQ was higher again compared with the other groups. Considering the average pH in FRL over all measured time points, cows in Groups 60NQ and 100HQ had higher pH values of 6.85 and 6.83, respectively. Regarding pH values in PARL, animals of Group 60NQ displayed the highest pH value (6.68), whereas the lowest value of 6.21 was found in Group 60HQ. Overall, results suggest that high-quality hay maintains the diet's structural effectiveness by stimulating rumination and stabilising ruminal pH while greatly improving ATTD. However, the structural effectiveness of the high-quality hay gets impaired with increasing proportion of concentrate feed in the diet.

The effect of fructose supplementation on feed intake, nutrient digestibility and digesta retention time in Reeves’s muntjac (Muntiacus reevesi)

“…High and variable intake of WSC by browsers is also expected in captivity. For example, the sugar content of roughages routinely fed to ruminants in captivity (grass or lucerne hay) may range from 5% to over 12% of DM (Hall, ; Kleefisch et al, ). Furthermore, in several studies fruits and vegetables accounted even for 15% of DM fed to zoo ruminants (Ritz et al, ; Taylor et al, ; Verkammen et al, ), which had to result in high intake of mono‐ and disaccharides (even over 15% of consumed DM).…”

“…High and variable intake of WSC by browsers is also expected in captivity. For example, the sugar content of roughages routinely fed to ruminants in captivity (grass or lucerne hay) may range from 5% to over 12% of DM (Hall, 2010;Kleefisch et al, 2017). Furthermore,…”

Changes in the Rumen Epithelial Microbiota of Cattle and Host Gene Expression in Response to Alterations in Dietary Carbohydrate Composition

“…However, increased dietary starch resulting in increased rumen volatile fatty acid (VFA) production has also been shown to increase VFA transport-related gene expression, resulting in a positive increase in energy uptake for the animal (18). While the fermentation of starch in the rumen in more rapid than the fermentation of forages, previous research from our lab has shown the beneficial effects of feeding high-quality hay (HQH) with an elevated content of sugars and metabolizable energy, which shifts the energy intake away from starch-rich concentrates and toward a healthier forage-based product (19). We found that the addition of such forages provides the rumen microbiota with digestible substrate for VFA production while also providing sufficient structural fiber to promote rumen pH buffering through rumination (19).…”

“…While the fermentation of starch in the rumen in more rapid than the fermentation of forages, previous research from our lab has shown the beneficial effects of feeding high-quality hay (HQH) with an elevated content of sugars and metabolizable energy, which shifts the energy intake away from starch-rich concentrates and toward a healthier forage-based product (19). We found that the addition of such forages provides the rumen microbiota with digestible substrate for VFA production while also providing sufficient structural fiber to promote rumen pH buffering through rumination (19). Furthermore, it was seen that changes in the substrates provided with HQH resulted in changes in the digesta-associated microbiota of the rumen (20).…”

Proceedings of the 10th International Symposium on the Nutrition of Herbivores

“…Introduction It is common practise to feed high-yielding dairy cows high-grain diets. However, the disproportion between a high proportion of rapidly fermented carbohydrates and low physically effective NDF may cause impaired ruminal health through variation in the VFA and decreased ruminal fluid pH, which leads to SARA (Humer, 2017). Several studies have investigated the ethology and pathophysiology of SARA (Khafipour, 2009;Danscher, 2016), but still no clear definition of SARA exists.…”