Abstract

SANTANA JUNIOR, H.A. et al. Correlation between digestibility and ingestive behavior of heifers supplemented at pasture. Arch. zootec. [online]. 2012, vol.61, n.236, pp.549-558. ISSN 1885-4494.  https://dx.doi.org/10.4321/S0004-05922012000400007.

The objective of this study was to evaluate the correlation between the apparent digestibility and ingestive behavior of crossbred heifers in grass. The experiment was conducted at Princesa do Mateiro farm, Ribeirao do Largo, Bahia. Were used 20 heifers with blood level 5/8 Guzerá milk lineage and 3/8 Holstein, with an average of 18 months of age and body weight of 187±13.1 kg. The experiment lasted 224 days and the animals raised in a rotational grazing on Brachiaria brizantha 'Marandu'. It was a positive correlation between grazing time and digestibility of neutral detergent fiber (CDFDN). Negative correlations were found between the time from other activities and CDFDN. Feeding time at trough showed negative correlations with digestibility of dry matter (CDMS), organic matter (CDMO), non-fibrous carbohydrates (CDCNF), total carbohydrates (CDCHOT). A positive correlation between total time spent eating and chewing with the total CDFDN was observed. The number of periods of grazing and rumination showed negative correlations with CDMS, CDMO, CDCNF, CDCHOT. Also, there was a correlation above 0.90 to the total digestible nutrients (TDN) and may also be included in intake prediction equations. The number of feeding periods at trough showed a negative correlation with CDMO and digestibility of crude protein (CDPB). The time spent for rumination was positively correlated with CDMO, CDCNF, CDCHOT, NDT and CDPB. The time spent for other activities positively correlated with CDCNF and TDN. Negative correlations were found between bite rate and CDMS, CDMO, CDCNF, CDCHOT and CDPB. Time swallowing positively correlated with CDMS, CDMO, CDCNF, CDCHOT, NDT, CDPB. The mass of the bit and mastications for swallowing did not correlate with any variable of digestibility. The number of ruminating chews per day correlated negatively with TDN. Grazing and ruminating times did not show any other relation with apparent digestibility of crossbred heifers on pasture. The coefficient of digestibility of neutral detergent fiber causes changes in grazing time.

Keywords : Mouthful; Cattle; Digestion; Grazing.

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