Effect of structure of a tropical pasture on ingestive behaviour, digestibility of diet and daily intake by grazing cattle

Abstract

The effect of the structure of a tropical pasture, based on Dichanthium spp., on the ingestive behaviour, in vivo digestibility of the diet and herbage intake by eight Creole tethered heifers was studied. Two levels of nitrogen fertilizer (0 and 50 kg ha )1 ) were applied to plots after each grazing cycle and there were 28 d between each of the three grazing cycles. Four heifers grazed individual subplots daily on each plot for 14 d in each of the successive grazing cycles. Simultaneous measurements of bite depth, bite mass, biting rate, short-term intake rate and daily grazing time were made in two 4-d periods at the end of each 14-d period.The in vivo organic matter digestibility (OMD) and daily herbage organic matter intake (OMI, expressed on a kg LW 0AE75 basis) were also measured at the same times. Relationships among pasture characteristics and ingestive behaviour were similar to those reported in other short-term studies: pasture height was highly correlated with bite depth, bite mass and biting rate (r ¼ 0AE91, r ¼ 0AE79 and r ¼ )0AE68, respectively, P < 0AE001). Pasture variables had lower correlations with grazing time and short-term intake rate than with bite depth, bite mass and biting rate. Pasture structure was more highly correlated with OMD than OMI: leaf mass and length and also the extended tiller length were highly correlated with OMD (r ¼ 0AE77, r ¼ 0AE76 and r ¼ 0AE72, respectively, P < 0AE001) whereas the crude protein concentration of the herbage was correlated with OMI and digestible OMI (r ¼ 0AE50 and r ¼ 0AE69, respectively, P < 0AE001). Ingestive behaviour variables, as well as OMD, were correlated more with pasture characteristics than was OMI.

The seasonal and inter-annual patterns of biomass accumulation and crude protein in kleingrass (Panicum coloratum) in the semiarid Pampean region of Argentina

“…Verde, to the degree days (DD; base 10 ºC) beginning October 1 in growing seasons with different quantities of rainfall. pends on the bulk density and the proportion of morphological fractions with high and low nutritional value (e.g., leaves and stems) in the pasture (Benvenutti et al, 2006;Drescher et al, 2006;Boval et al, 2007;Benvenutti et al, 2008;Van Langevelde et al, 2008). Animals interact with the structure of the pasture by adjusting bite dimensions (e.g., bite area and bite depth) allowing the selection of the more nutritive parts of the sward and increasing the nutritional value of their diets.…”

A meta-analysis of nutrient intake, feed efficiency and performance in cattle grazing on tropical grasslands

“…However, some studies have already reported that intake is a major determinant, since long time (Coleman and Moore, 2003). According to Milford and Minson (1965), Lippke (1980) and Boval et al (2007), the digestible DMI of tropical grasses and animal gain correlated more with the intake of DM than with its digestibility. More recently, considering a wide range of forage mass or allowance, a high proportion of variation in ADG (60% to 90%) was explained by the forage quantity and its relationships with animal performance, whereas several measures of forage nutritive value were not significant (Garay et al, 2004;Sollenberger and Vanzant, 2011).…”

Simulating the effect of climate on star grass growth and quality and its capacity to support milk production in the tropical regions of Mexico

“…These factors can have a direct effect on animals' ingestive behaviour. For example, sward height is highly correlated with bite depth, bite mass and biting rate (r=0·91, r=079 and r=-0·68, respectively (BOVAL et al, 2007). In the same manner animals have an effect on pasture performance, for example high stocking rates would be associated with less herbage mass.…”