Fibrolytic Enzymes and Parity Effects on Feeding Behavior, Salivation, and Ruminal pH of Lactating Dairy Cows

Abstract

Four multiparous and four primiparous lactating dairy cows fitted with ruminal cannulas were used in a duplicated 4 x 4 Latin square design to study the effects of parity and inclusion of a fibrolytic enzyme product (Agribrands International, St. Louis, MO) on feeding and chewing behavior, salivation, and ruminal pH. Diets consisting of rolled barley, barley silage, and alfalfa haylage (55% forage, DM basis) differed in enzyme application: 1) control, 2) enzyme applied to concentrate (45% of TMR), 3) enzyme applied to supplement (4% of TMR), and enzyme applied to a premix (0.2% of TMR). Enzyme supplementation did not alter daily time spent eating or ruminating, but when enzymes were added to the ration daily, saliva production increased, with no difference among enzyme application treatments. Multiparous cows consumed a greater amount of feed, but spent a similar amount of time eating, compared to primiparous cows. Primiparous cows had shorter ruminating episodes, resulting in lower daily ruminating time compared with multiparous cows. Primiparous cows had lower daily saliva output compared with multiparous cows. These results indicate that application of this fibrolytic enzyme product did not alter the physical structure of the feed, as measured by feeding and chewing variables. The increase in total saliva production observed in cows fed enzyme-supplemented diets may be attributed to a physiological response to compensate for the increase in fermentation products during digestion. The increased intake for multiparous cows is attributed to increased eating rate and not to increased time spent eating. The higher DMI of multiparous cows resulted in increased rumination time needed to process the additional feed and increased salivation to buffer the greater production of VFA.

Variations in feeding behaviour of high-yielding dairy cows in relation to parity during early to peak lactation

“…Some differences between the present results and findings of BOWMAN et al (2003) may be partially caused by differences in the definition of visit and meal criterion. BOWMAN et al (2003) defined a visit as eating activity greater than 30 s and more than 300 g of feed being removed from the feeder, and also meals within close proximity had to be greater than 10 min apart to be considered separate and distinct meals. By contrast, in the current study, a visit was defined as the time spent by an individual cow with her head in one of the troughs, regardless of how the cow spent that time.…”

“…Although the number of visits per meal was similar between cows in the 1st and 2nd lactation, there was a significant difference between cows in the 1st lactation and cows in the 3rd-and-more-lactation. BOWMAN et al (2003) found a significant difference in daily time eating (347 vs. 323 min/d) and daily DMI (20.50 vs. 23.00 kg/d) but no difference in the number of meals per day (13.4 vs. 13.5) between primiparous and multiparous cows. Some differences between the present results and findings of BOWMAN et al (2003) may be partially caused by differences in the definition of visit and meal criterion.…”

“…BOWMAN et al (2003) found a significant difference in daily time eating (347 vs. 323 min/d) and daily DMI (20.50 vs. 23.00 kg/d) but no difference in the number of meals per day (13.4 vs. 13.5) between primiparous and multiparous cows. Some differences between the present results and findings of BOWMAN et al (2003) may be partially caused by differences in the definition of visit and meal criterion. BOWMAN et al (2003) defined a visit as eating activity greater than 30 s and more than 300 g of feed being removed from the feeder, and also meals within close proximity had to be greater than 10 min apart to be considered separate and distinct meals.…”

“…Multiparous cows consumed more DM, ate larger meals more quickly, ruminated longer and more efficiently, and drank more water than primiparous cows. BOWMAN et al (2003) reported that primiparous cows spent more time eating and had a smaller meal size as well as lower DMI compared to multiparous cows. However, the number of meals per day was similar for both parity groups.…”

“…The meal size may be limited by rumen volume. Behavioural studies suggest that different mechanisms may control individual meals and the total daily DMI of cows (FORBES 1995, BOWMAN et al 1994, BOWMAN et al 2003. VAN SOEST (1994) stated that there is a strong relationship between body weight and gastrointestinal capacity in herbivores.…”