Feeding processed soybean to mid-lactation Holstein cows: ingestive behaviour and rumen fermentation characteristics

Abstract

The objective of this study was to evaluate the effects of roasted soybean (RSB), extruded soybean (ESB) and their equal blend (RSB + ESB) compared with soybean meal (SBM) on nutrient intake, feed preference, meal and rumination patterns, feeding and chewing behaviour and rumen fermentation characteristics of mid-lactation dairy cows. Eight Holstein dairy cows were used in a replicated 4 × 4 Latin square design with four 28-d periods. Cows received one of the four following experimental diets: (1) 13.88% of diet dry matter (DM) as SBM; (2) 15.22% of diet DM as RSB, (3) 15.55% of diet DM as ESB and (4) 7.69% RSB plus 7.69% ESB (RSB + ESB). Each experimental period consisted of a 21-d diet adaptation period and a 7-d data collection period. Meal patterns, including meal size and inter-meal interval, were not affected by the experimental diets and thereby DM intake was not different among diets. Sorting index was not different across dietary treatments but intake of particles retained on 1.18-mm sieve and on pan increased and decreased in both SBM and ESB as compared with RSB and RSB + ESM, respectively. Total time spent eating and ruminating and rumen volatile fatty acid concentrations were unaffected by dietary treatments. Feeding processed soybean instead of SBM had minimal effects on sorting behaviour and meal patterns and thereby no changes in feed intake occurred. Finally, RSB and ESB and their equal blend had a similar effect on feed intake and chewing behaviour of mid-lactation Holstein cows.Highlights Feeding processed soybean products had the minor effect on feed intake and can be considered as alternative feedstuffs when the price is competitive.

Keywords

• dairy cow
• soybean meal
• roasted and extruded soybean
• meal pattern
• sorting activity