The effect of the inclusion of pea in lamb fattening concentrate on in vitro and in situ rumen fermentation.

BACKGROUND

The objective of this study was to evaluate the effect of the proportion of pea (0%, 10%, 20%, and 30%), as a partial replacement for soybean meal (SBM) in the fattening concentrate, on ruminal fermentation in lambs. Gas and methane (CH ) production, in vitro dry matter degradability (IVDMD), ammonia (NH -N), and volatile fatty acid (VFA) production after 24 h of incubation were evaluated. The concentrates were also incubated in the rumen of the wethers for 2, 4, 6, 8, 12, and 24 h to evaluate the effects of pea inclusion on in situ dry matter degradability (DMD), organic matter degradability (OMD), nitrogen degradability (ND), NH -N, and VFA production.

RESULTS

In the in vitro assay, the inclusion of pea only affected gas production (mL day degraded dry matter), CH production (mL day degraded dry matter), and IVDMD (P < 0.05), and tended to affect NH -N content (P < 0.10) without affecting VFA production. In the in situ assay, the inclusion of pea increased DMD, OMD, and ND linearly (P < 0.001), whereas pea inclusion decreased NH -N content linearly (P < 0.05). Neither total VFA production nor the proportion of acetic acid were affected by pea inclusion (P > 0.05), but the propionic proportion increased with the proportion of pea included.

CONCLUSIONS

The best level of pea inclusion in the concentrate could not be established based on the results of this study. However, the results showed that the inclusion of pea provides a good alternative protein source. © 2020 Society of Chemical Industry.