Chewing, rumen pool characteristics, and lactation performance of dairy cows fed 2 concentrations of a corn wet-milling coproduct with different forage sources

Abstract

We used a novel corn wet-milling coproduct [CMP; approximately 70% dry matter, 28% crude protein, 36% neutral detergent fiber (NDF), and 18% nonstructural carbohydrates] in diets formulated to contain 18.4% forage NDF, 17.4% crude protein, 20.2% starch, and 3.7% sugar. Six primiparous, rumen-cannulated Jersey cows were assigned to a 6 × 6 Latin square design with a 2 × 3 factorial arrangement of treatments. Diets were formulated to contain 20 and 30% CMP with 3 forage sources [corn silage (CS) and 40.5% NDF, CS replaced with 10% alfalfa hay (AH) and 45.0% NDF, or CS replaced with 7% grass hay (GH) and 67.4% NDF], with each providing 18.4% forage NDF in the diet. Total-tract digestibilities of NDF, N, and organic matter were not affected by treatment. Similarly, no treatment effects were detected for kinetics of NDF disappearance in situ from CMP or respective forage source or for N disappearance in situ from CMP. Grass hay increased total and liquid pool size of rumen contents compared with AH (by 3.2 and 3.0kg, respectively). Total time spent chewing increased in cows fed GH by over 35min compared with those fed AH, partially due to a trend for increased minutes spent ruminating. Mean particle size of rumen contents also tended to be higher in the GH (0.55mm) than AH (0.69mm) diets. No effects on production of milk or milk components were detected, but dry matter intake (DMI) tended to decrease when CMP increased from 20 to 30%. Gross feed efficiency (fat-corrected milk/DMI) tended to be greater when cows were fed AH and GH compared with CS and was greater for AH than GH diets. In diets containing low starch, increasing CMP from 20 to 30% potentially maintained similar fat-corrected milk production with lower DMI. However, more consideration also should be given to interactions among forages with respect to fill, digestion, and passage of fiber with increased inclusion rates of CMP.

Multi-omics reveals that forage fiber promotes rumen development of pre-weaning calves compared to non-forage fiber

“…In the current study, our results on ruminal pH were not different between the SO and SS groups, which ranged between 5.59 and 5.38. This was consistent with previous studies, which reported that rumen pH was not changed by ber source [23,24]. As for the low pH value in calf rumen, it may be attributed to the fact that the absorption rate of VFA by the rumen epithelium of calves was lower than the production rate of VFA.…”

The Value of ‘Cow Signs’ in the Assessment of the Quality of Nutrition on Dairy Farms

“…It is important to differentiate between a depressed appetite and the inability to prehend food due to other causes (e.g., pain, paralysis). Dairy cattle with ad lib access to feed eat for 5.0 ± 2.5 h per day in a feedlot system (dependent on tie or free-stall system, diet, and physiological status of the dairy cattle individual of interest) and 7.0 ± 3.5 h in pasture-based systems (dependent on sward characteristics such as lush pasture or thorny bushes) in several eating bouts (4–20) [ 9 , 14 , 16 , 50 , 54 , 60 , 63 , 65 , 66 , 69 , 72 , 73 , 77 , 80 , 89 , 91 , 97 , 101 , 114 , 115 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 , 132 , 133 , 134 , 135 , 136 ]. Dairy cattle on pasture show a distinct diurnal feeding behavior [ 9 , 40 , 61 , 82 , 87 , 103 , 108 , ...…”

“…The maximum total chewing time has been estimated at 16 h per day [ 101 ]. Normal, healthy cattle ruminate for 7.0 ± 3.5 h a day in several rumination bouts (10 to 20) [ 9 , 14 , 21 , 48 , 54 , 59 , 63 , 66 , 69 , 72 , 76 , 77 , 89 , 114 , 117 , 119 , 121 , 122 , 123 , 124 , 126 , 127 , 128 , 129 , 130 , 132 , 133 , 134 , 135 , 139 , 142 , 143 , 159 , 162 , 163 , 164 , 169 , 173 , 176 , 177 ]. Each bout lasts 10–60 min (range 0.5–120.0 min) [ 76 , 101 ].…”