Heinrichs, A. J.

Lascano, G. J.

Suarez-Mena, F. X.

English

DigitalCommons@CalPoly

   M155 Chewing activities of dairy heifers precision-fed a low orhigh forage ration at four levels of dry distillers grain. F. X. Suarez-Mena*, G. J. Lascano, and A. J. Heinrichs, The Pennsylvania State University, University Park. The objective of this study was to determine the effects of differing forage to concentrate ratios (F:C) and corn dry distillers grain with solubles (DDGS) inclusion rates on chewing behavior, rumen pH, and UXPHQ¿OOLQSUHFLVLRQIHGGDLU\KHLIHUUDWLRQV$VSOLWSORWGHVLJQZLWK F:C as whole plot and DDGS inclusion level as sub-plot was adminis­tered in a 4-period (19 d) 4 × 4 Latin square. Eight rumen cannulated Holstein heifers (12.5 ± 0.5 mo and 344 ± 15 kg, age and BW respec­tively) housed in individual stalls were allocated to 2 F:C (50:50 LF or 75:25 HF; DM basis) and to a sequence of DDGS inclusion (0, 7, 14 and 21%; DM basis). Forage was a mix of 50% corn silage and 50% grass hay (DM basis). Diets were fed to provide equal amounts of nutrients to allow 800 g/d BW gain and fed 1X/d. Chewing behavior was visually monitored for 48 h at 5–min intervals. Rumen contents were sampled at –2, 0, 2, 4, 6, 8, 10, 12, and 20 h after feeding for pH determination. Total rumen evacuation was performed at –2 and 5 h after feeding. Statistical analysis was conducted using the MIXED procedure of SAS. DMI linearly decreased as DDGS increased (6.61to 6.11 ± 0.09 kg/d; P < 0.01). No differences were found for rumen pH. Time spent eating tended to be longer for HF (151 vs. 112 ± 14 min/d; P = 0.09) and was not different for DDGS inclusion. Ruminating time did not differ by F:C but linearly increased as DDGS increased (421 to 450 ± 15 min/d; P = 0.03). Total chewing time tended to be longer for HF (593 vs. 516 ± 28 min/d; P = 0.10) and to increase linearly as DDGS increased (553 to 579 ± 23 min/d; P = 0.09). Wet rumen digesta weight (46.6 vs. 37.6 ± 2.2 kg; P = 0.03) and volume (51.5 vs. 41.5 ± 2.5 L; P = 0.03) were greater for HF. Total chewing time increased E\WKHDGGLWLRQRI''*6DQGKLJKHU)&''*6LQÀXHQFHGUXPLQDW ­ing time with no effect on eating time while F:C affected eating time. Higher F:C increased rumen digesta weight and volume. F:C or DDGS levels in the ration did not affect rumen pH. Key words: heifer, chewing, dry distillers grain with solubles 60 J. Anim. Sci. Vol. 89, E-Suppl. 1/J. Dairy Sci. Vol. 94, E-Suppl. 1 

Chewing activities of dairy heifers precision-fed a low or high forage ration at four levels of dry distillers grain

https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1065&amp;context=dsci_fac

Chewing activities of dairy heifers precision-fed a low or high forage ration at four levels of dry distillers grain

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