Effect of the Replacement of Maize Silage and Soyabean Meal with Mulberry Silage in the Diet of Hu Lambs on Growth Performance, Serum Biochemical Indices, Slaughter Performance, and Meat Quality

Abstract

Maize silage has a high demand for fertilizer and water. As an unconventional feed resource, mulberry silage has the potential to replace most maize silage and to alleviate the shortage of roughage in the mutton sheep industry in China. The purpose of this experiment was to study the effect of the replacement of maize silage and soyabean meal with mulberry silage in the diet of Hu lambs on growth performance, serum biochemical indices, slaughter performance, and meat quality. Ninety-six healthy Hu lambs were randomly divided into four groups with six replicates per group and four lambs per replicate. The amounts of 0, 20, 40, and 60% of maize silage were replaced by mulberry silage in each group (denoted as CON, L, M, and H, respectively). The results showed that replacing maize silage with mulberry silage had no significant effect on the growth performance or the slaughter performance of Hu lambs (p > 0.05). Feeding Hu lambs with mulberry silage significantly reduced serum glucose (GLU) and the blood urea nitrogen (BUN) content (p < 0.05), and it increased the content of ether extract (EE) in the longissimus dorsi muscle (p < 0.05). Meanwhile, the percentage of EAA in the M and H groups was significantly lower than that in the CON and L groups (p < 0.05). In addition, in the fatty acid profile, the percentage of C16:1 in the M group was significantly increased, while the percentage of C18:0 and C20:0 were significantly decreased (p < 0.05). Based on these findings, it was recommended that 20–40% of maize silage be replaced by mulberry silage in the diet of Hu lambs.

Chemical characteristics, antioxidant capacity, bacterial community, and metabolite composition of mulberry silage ensiling with lactic acid bacteria

“…Firmicute s and Proteobacteria were the dominant phyla in both the control and SB-treated groups. This result was consistent with the results of a previous study (Wang et al, 2022 ). However, the relative abundance of Proteobacteria was reduced in other treatment groups.…”

“…Furthermore, the pH in the PP-, PP_SB-, and LP_PP_SB-treated groups was 4.58, 4.70, and 4.26, respectively. A previous study observed that Pediococcus can grow well under a pH range of 4.3–4.9 during ensiling (Wang et al, 2022 ). Additionally, the inoculation of Pediococcus was 1 × 10 6 log 10 CFU/g FW, 5 × 10 5 log 10 CFU/g FW, and 5 × 10 5 log 10 CFU/g FW in these groups, respectively.…”

“…However, the relative abundance of Proteobacteria was reduced in other treatment groups. Firmicutes and Proteobacteria were the most common phyla in silage, owing to their ability to adapt to anaerobic and acidic environments (Wang et al, 2022 ). pH (5.30) of the control group was the highest, and previous studies had indicated that an increased pH promotes the growth of Proteobacteria compared to Firmicutes (Tian et al, 2021 ).…”