Influence of Fiber Content and Concentrate Level on Chewing Activity, Ruminal Digestion, Digesta Passage Rate and Nutrient Digestibility in Dairy Cows in Late Lactation

Abstract

The influence of fiber content of hay (low-fiber 47% NDF and high-fiber 62% NDF of DM) and concentrate level (high 50% and low 20% of ration DM) on chewing activity, passage rate and nutrient digestibility were tested on four restrict-fed (11.1 to 13.7 kg DM/d) Holstein cows in late lactation. Aspects of ruminal fermentation and digesta particle size distribution were also investigated on two ruminally cannulated (100 mm i.d.) cows of the same group of animals. All digestion parameters studied were more affected by the fiber content of the hay and its ratio to non structural carbohydrates than by the concentrate level. Giving a diet of highfiber (62% NDF) hay and low concentrate level (20%) increased chewing activity but decreased solid passage rate and total digestibility of nutrients due to a limited availability of fermentable OM in the late cut fiber rich hay. A supplementation of high-fiber hay with 50% concentrate in the diet seems to improve the ruminal digestion of cell contents, whilst a depression of the ruminal fiber digestibility was not completely avoided. Giving a diet of low-fiber (47% NDF) hay and high concentrate level (50%) reduced markedly the chewing and rumination activity, affected negatively the rumen conditions and, consequently, the ruminal digestion of fiber. A reduction of the concentrate level from 50 to 20% in the diet of low-fiber hay improved the rumen conditions as reflected by an increase of the ruminal solid passage rate and of fiber digestibility and in a decrease of the concentration of large particles and of the mean particle size of the rumen digesta and of the faeces. Generally, it can be summarised that, (i) concentrate supplementation is not a strategy to overcome limitations of low quality (fiber-rich) hay, and (ii) increase of the roughage quality is an effective strategy in ruminant nutrition, especially when concentrate availability for ruminants is limited.

Balancing diets for physically effective fibre and ruminally degradable starch: A key to lower the risk of sub-acute rumen acidosis and improve productivity of dairy cattle

“…In addition, the use of elevated proportions of high-quality forages in the diet of dairy cows can help in maintaining high digestible energy intake of the cows despite decreasing concentrate inclusion, which may be beneficial particularly in terms of reducing costs associated with feeding. New studies have demonstrated that increasing the quality of forages by increasing the content of potentially degradable fibre exerts positive effects on production responses in dairy cows (e.g., feed and energy intake and milk production) without compromising rumen conditions (Tafaj et al, 2005;Eastridge, 2006). More recently, Zebeli et al (2006) reported that increasing the amount of degradable organic matter of forages in the TMR enhanced forage intake resulting in higher time spent chewing and ruminating as well as increased milk fat content.…”

“…The fibre quality and particularly its degradability characteristics may positively affect DMI. Enhanced ease of NDF hydrolysis may stimulate rapid turnover of NDF from the rumen and allow greater voluntary feed intake (Allen and Oba, 1996;Tafaj et al, 2005). In addition, Mertens (1994) proposed that NDF be used to define the upper and lower bounds of DMI.…”

Maize silage particle length modulates feeding patterns and milk composition in loose-housed lactating Holstein cows

“…This is beneficial both economically and health-wise because it lowers the cost associated with feeding, reduces the risk of ruminal disorders and promotes digestion and milk production in dairy cows (Tafaj et al, 2005;Eastridge, 2006). Maize silage (MS) is often viewed as an ideal forage source for dairy cattle because of its high starch and fiber contents and high-yielding properties.…”

Preferences of Rusa timorensis to Grasses and Their Body Morphometry and Velvet Antler Characteristics

“…High intake of fibrous feed creates high tention to the rumen wall and stimulate satietary effect and decreases dry matter intake (Toharmat et al, 2006). Low dry matter intake was highly corellated with low nutrien digestibily and the high rate of feed particles passage, which were mostly dictated by the level of fiber intake (Tafaj et al, 2005). A high fiber intake in Timor deer indicated that the deer were addapted and tolerant to the high fiber diet.…”