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Optimizing Dairy Cow Production through Multisource Starch Feeding
The objective of this study was to determine feed intake and milk production responses to feeding diets based on either solely barley grain or a choice of multiple grains. Eight multiparous (642 ± 57 kg body weight; 72 ± 58 days in milk; mean ± SD) lactating Holstein cows were experimented in a cross-over design study with two 21-d periods. Cows were kept in free individual boxes and fed alfalfa hay-corn silage based total mixed rations with either barley as the only grain (BR) or a mixture of barley, corn, wheat and sorghum (MG). Proportion of cereals in the multigrain treatment was equal or 25% each. Grains were included as 30% of total dietary dry matter. Diets were prepared as total mixed rations and offered for 5-10% daily orts. Cows were milked at 0500, 1300 and 2100 h and fed at 0530, 1330 and 2130 h. Feed intake and milk production were monitored for the entire experiment and subjected to data analysis only for the third week of both periods. Statistical data analysis was conducted using Mixed Models Procedures of SAS program. Feed intake was improved when MG was fed instead of BR (21.2 vs. 19.9 kg/d, P<0.05). Milk yield was also increased by feeding MG vs. BR (35.0 vs. 33.1 kg/d, P<0.05). As such, milk fat percent (3.5% vs. 3.2%) and yield (1.23 vs. 1.06 kg/d) were higher for MG vs. BR (P<0.05). Milk protein content (3.0% vs. 2.9%) but not protein yield (0.99 vs. 1.02 kg/d) was higher for BR vs. MG (P<0.05). Average rumen pH at 4 h post-feeding (5.7 vs. 5.9, P=0.06) and fecal pH (5.9 vs. 6.4, P<0.05) were lower for BR vs. MG. Results indicate that feeding a multigrain choice of barley, wheat, corn and sorghum instead of solely barley grain improves feed intake and milk production parameters. Increased rumen and fecal pH by feeding the multigrain diet possesses health and metabolic implications.
Keywords: Starch, Multigrain, Dairy cow