Effect of maturity and hybrid on ruminal and intestinal digestion of corn silage in dry cows

Abstract

The aim of this study was to evaluate the effect of stage of maturity at harvest on extent of starch, neutral detergent fiber (NDF), and protein digestion, and rumen fermentation in dry cows fed whole-plant corn silage from different hybrids. Four nonlactating Holstein cows cannulated at the rumen and proximal duodenum were fed 4 corn silages differing in hybrid (flint vs. flint-dent) and maturity stage (early vs. late) in a 4 × 4 Latin square design. From early to late maturity, starch content increased (from 234.5 to 348.5 g/kg), whereas total-tract (99.7 to 94.5%) and ruminal starch digestibility (91.3 to 86.5%) decreased significantly. The decrease in ruminal starch digestibility with increasing maturity was similar between hybrids. No effects were found of maturity, hybrid, or maturity × hybrid interaction on total-tract NDF digestibility, ruminal NDF digestibility, true digestibility of N and organic matter in the rumen, or microbial synthesis. Harvesting at later maturity led to increased ruminal ammonia, total volatile fatty acid concentrations, and acetate/propionate ratio but not pH. This study concludes that delaying date of harvest modifies the proportions of digestible starch and NDF supplied to cattle. Adjusting date of corn harvest to modulate amount of rumen-digested starch could be used as a strategy to control nutrient delivery to ruminants.

Effect of intercropping vetch (Vicia sativa L.), field pea (Pisum sativum L.) and triticale (X Triticosecale) on dry‐matter yield, nutritive and ensiling characteristics when harvested at two growth stages

“…The forage DM yields measured here were high compared to other studies on triticale–legume intercrops (Arrigo, , Arrigo et al., ; Jacobs & Ward, ; Lithourgidis et al., ). The values recorded at late stage were in the range of the maize silages grown in the same experimental site (Peyrat, Baumont, Le Morvan, & Noziere, ).…”

Technical note: use of internal transcribed spacer for ruminal yeast identification in dairy cows

“…Those parameters averaged 6.9 ± 0.01 for pH, 13.3 ± 1.2 mg/dl for NH 3 -N, 57.5 ± 6.3 mmol/l for total VFA, whereas molar proportions (mol/100 ml) for VFA were as follows: 63.8 ± 0.1 for acetate, 22.7 ± 0.2 for propionate, 11.2 ± 0.1 for butyrate and 2.4 ± 0.1 for valerate. The effect of the diet on the fermentation pattern is well known and the values obtained in the present study are similar to those reported for non-lactating cows fed corn-silage-based diets (Peyrat et al, 2016) and a diet with a 50 : 50 forage : concentrate ratio based on corn silage, alfalfa hay and soybean meal (Shahmoradi et al, 2016).…”

Effects of Hybrid and Grain Maturity Stage on the Ruminal Degradation and the Nutritive Value of Maize Forage for Silage

“…Vials containing only inoculum were used for blank correction. Once filled, the vials were sealed with rubber stoppers and aluminum caps, shaken and placed in an incubator (Shel Lab, Sheldon Manufacturing, Inc., Cornelius, OR, USA) at 39 ± 0.5 • C. The gas pressure in the headspace was measured manually by inserting a sterile needle connected to the pressure transducer at 3,6,9,12,15,18,21,24,30,36,48,60,72,96, and 144 h after inoculation. The volume of gas produced was estimated from the pressure values as proposed by López et al [13].…”