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The aim of this experiment was to study the sustained effects of early supplementation with a starter on the performance of lambs during the pre-weaning, post-weaning, and fattening periods. Sixty male Hu lambs (3.59 ± 0.05 kg) were randomly assigned to two (30 lambs per group) treatments. The lambs were fed milk replacer from three days of age. The early supplementation (ES) group was supplemented with a starter ration at seven days of age, the control (CON) group was supplemented at 21 days of age, and lambs in both groups were weaned from milk replacer at 28 days of age. Eight lambs from each group were randomly slaughtered at 98 days of age, and the remaining lambs were fed the same nutrient level of a fattening ration until slaughter at 200 days of age. The results showed that early supplementation with starter significantly improved average daily feed intake (ADFI) and average daily weight gain (ADG) in the pre-weaning period (7–28 days of age), and ADFI and slaughter performance (live weight before slaughter, carcass weight and dressing percentage) in the post-weaning period (29–98 days of age, p < 0.05). In addition, early supplementation with the starter had no significant effect (p > 0.05) on ADFI, ADG, and slaughter performance, but significantly decreased (p < 0.05) the feed-to-gain ratio (F/G) of lambs during the fattening period (99–200 days of age). In addition, early supplementation with starter increased the ratio of rumen and reticulum weight to total stomach weight in lambs (p < 0.05). In conclusion, early supplementation with starter can reduce feed costs and improve the performance of lambs, while the growth advantage produced by early supplementation had initially disappeared by 154 days of age.

Maize silage has a significant environmental impact on livestock due to its high requirement for fertilizer and water. Mulberry has the potential to replace much of the large amount of maize silage grown in China, but its feeding value in the conserved form needs to be evaluated. We fed Hu lambs diets with 20–60% of the maize silage replaced by mulberry silage, adjusting the soybean meal content when increasing the mulberry silage inclusion rate in an attempt to balance the crude protein content of the diets. Mulberry silage had higher crude protein and lower acidic and neutral detergent fiber contents compared to maize silage. Replacing maize silage and soyabean meal with mulberry silage had no effect on the feed intake and growth rate of Hu lambs. However, the rumen pH increased, the acetate to propionate in rumen fluid increased, and the rumen ammonia concentration decreased as mulberry replaced maize silage and soyabean meal. This was associated with an increase in norank_f__F082 bacteria in the rumen. Rumen papillae were shorter when mulberry silage replaced maize silage, which may reflect the reduced neutral detergent fiber (NDF) content of the original silage. In conclusion, mulberry silage can successfully replace maize silage and soyabeans in the diet of Hu lambs without loss of production potential, which could have significant environmental benefits.