Effect of raw soya bean particle size on productive performance and digestion of dairy cows

Abstract

Differing soya bean particle sizes may affect productive performance and ruminal fermentation due to the level of fatty acid (FA) exposure of the cotyledon in soya bean grain and because the protein in small particles is more rapidly degraded than the protein in large particles, which influence ruminal fibre digestion and the amounts of ruminally undegradable nutrients. The objective of this experiment was to investigate the effects of raw soya bean particle size on productive performance, digestion and milk FA profile of dairy cows. Twelve Holstein cows were assigned to three 4 × 4 Latin squares with 21-day periods. At the start of the experiment, cows were 121 days in milk (DIM) and yielded 30.2 kg/day of milk. Cows were fed 4 diets: (i) control diet (CO), without raw soya bean; (ii) whole raw soya bean (WRS); (iii) cracked raw soya bean in Wiley mill 4-mm screen (CS4); and (iv) cracked raw soya bean in Wiley mill 2-mm screen (CS2). The inclusion of soya beans (whole or cracked) was 200 g/kg on dry matter (DM) basis and partially replaced ground corn and soya bean meal. Uncorrected milk yield and composition were not influenced by experimental diets; however, fat-corrected milk (FCM) decreased when cows were fed soya bean treatments. Soya bean diets increased the intake of ether extract (EE) and net energy of lactation (NEL ), and decreased the intake of DM and non-fibre carbohydrate (NFC). Ruminal propionate concentration was lower in cows fed WRS than cows fed CS2 or CS4. Cows fed cracked raw soya bean presented lower nitrogen in faeces than cows fed WRS. The milk of cows fed WRS, CS2 and CS4 presented higher unsaturated FA than cows fed CO. The addition of raw soya bean in cow diets, regardless of the particle size, did not impair uncorrected milk yield and nutrient digestion, and increased the concentration of unsaturated FA in milk. Cows fed cracked raw soya bean presented similar productive performance to cows fed whole raw soya bean.

Effects of chitosan and whole raw soybeans on ruminal fermentation and bacterial populations, and milk fatty acid profile in dairy cows

“…Dietary fat supplementation often increases the lipoprotein cholesterol exportation by the intestine, the major site of cholesterol synthesis in ruminants (Noble, 1981). In agreement with the current study, Naves et al (2016) fed WRS to lactating cows and reported a trend to decreased blood glucose concentration and an increase in blood cholesterol concentration.…”

Faba bean (Vicia faba) inclusion in dairy cow diets: Effect on nutrient digestion, rumen fermentation, nitrogen utilization, methane production, and milk performance

“…This increase was mainly due to smaller particle size and higher degradability of CP of ground FB compared with SBM and rolled FB. Reducing particle size of peas (Vander Pol et al, 2009) and raw soybean (Naves et al, 2016) via physical processing has also been reported to enhance CP digestibility. In contrast, Zagorakis et al (2015) reported higher CP digestibility in rams fed SBM compared with those fed ground FB.…”

Sources of polyunsaturated fatty acids from oilseeds in dairy cows diets can alter yield of and fatty acid profile in milk

“…Although the DM intake of cows consuming whole soybean was not the highest observed, the consumption of CP was higher than the other diets, which, associated with a higher DTC, may explain the greater milk production. Naves et al (2016) reported similar values in the milk production of cows consuming whole soybean and a diet without added lipids.…”