Influence of dry matter intake, dry matter digestibility, and feeding behavior on body weight gain of beef steers1,2,3

Abstract

This study was conducted to determine the relative contribution of feeding behavior, DMI, apparent DM digestibility (DMD), and passage rate on variation in BW gain. One hundred forty-three crossbred steers were used in this study to determine the factors that contribute to variation in BW gain. Steers were 304 ± 1 d of age and had an initial BW of 338 ± 3 kg. Steers had ad libitum access to feed, and fresh feed was offered twice daily at 0800 and 1500 h. Individual feed intake and BW gains were determined for 106 d. Titanium dioxide was used as an external marker to estimate apparent DMD and passage rate. A multiple-regression analysis was used to determine the relative contribution of initial BW, feed intake, feeding behaviors, digestibility, and passage rate to variance in BW gain, and a path analysis was conducted to determine direct and indirect relationships of the variables. In the regression analysis, initial BW and DMI accounted for 33% of the variation in BW gain. Substituting meal events and meal size for DMI did not increase the amount of variance in BW gain (27%) accounted for by the regression model. There was a slight increase in the variance in BW gain (35%) when apparent DMD was added to initial BW and DMI. When meal events and meal size were substituted for DMI, there was a decrease (30%) in variance accounted for in BW gain. The regression coefficient for the passage rate did not differ from zero (P = 0.63) when the passage rate was substituted for apparent DMD in the regression model that also included initial BW and DMI, nor did it differ from zero (P = 0.39) in the model that substitutes meal events and meal size for DMI. Three models were used in the path analysis. For all 3 models there was a positive correlation (P < 0.001) between DMI and BW gain but not between apparent DMD and BW gain. In all 3 models there was a significant correlation between meal size, meal events, and initial BW on DMI (P < 0.001). Results of both the regression and path analyses suggest that both apparent DMD and passage rate accounted for small proportions of the variance, suggesting that they are minor contributors toward variance in BW gain among cattle fed the same concentrate diet.

Effect of dietary cation-anion difference on acid-base status and dry matter intake in dry pregnant cows

“…Intake of DM is a function of meal size and meal frequency. Davis et al (2014), studying feeding behavior in beef steers, showed that DMI was positively related to the number of meals consumed and the size of each meal. Cows fed the acidogenic diets had longer but fewer meals, with no difference in meal size or eating rate.…”

Relationships of feedlot performance, feeding behavior, rumen morphometrics, and carcass characteristics of Nellore cattle differing in phenotypic residual feed intake1

“…high-RFI animals because the reduced DMI and had similar ADG. The greater preference of low-RFI animals for particles larger than 19 and 8 mm may explain the fact that these animals took longer to consume and ruminate a kilogram of both NDF and DM, which may have led to greater ruminal retention time, potentially explaining the lower DMI (Davis et al, 2014). On the basis of this fact, several studies have shown that low-RFI animals have greater nutrient digestibility Nkrumah et al, 2006;Cruz et al, 2010) than high-RFI animals, which may also explain the greater G:F of low-RFI yearling bulls.…”

Performance, agronomic traits, ensilability and nutritive value of pearl millet cultivar harvested at different growth stages

“…In fact, Davis et al . (2014) demonstrated that DM digestibility was correlated with consumption, digestible DM intake and BW gain in multiple regression models.…”