Year: 2024
Type: article
Abstract: The balance between forage and livestock production in grasslands is critical to the sustainable development of grassland animal husbandry. However, livestock production is often limited by the supply of forages. Supplemental feeding can improve livestock nutrient intake to improve livestock production, as well as reduce the amount of forage intake and the utilization of the grassland, thus improving forage productivity. Therefore, livestock with supplementation has the potential to achieve productivity synergy in grassland. The synergistic growth index, referring to the forage production saved by substitution effect converted to livestock production at the same supplementation, was used to evaluate this synergistic mechanism. In this study, three supplementations (0, 1%, 2% of body weight, NS, LS, HS respectively) and two grazing intensity (moderate grazing and high grazing, MG and HG) randomized block design experiment was conducted with 72 growing sheep grazed in the meadow steppe of Hulunbir China. We measured forage productivity, sheep intake and digestibility, sheep production, and synergistic growth. The results showed that dry matter intake (DMI) and crude protein intake (CPI) linearly increased (P<0.001) from 885.8 g/d to 1223.5 g/d and from 79.6 g/d to 162.4 g/d, respectively, with increasing supplementation. Grazing intensity affected sheep intake (DMI (P<0.001), CPI (P<0.05), NDF intake (P<0.001), and ADF intake (P<0.001)), which was higher in MG than in HG (1136.2 g/d vs. 1018.4 g/d, 128.9 g/d vs. 117.4 g/d, 681.8 g/d vs. 573.7 g/d, and 357.6 g/d vs. 303.6 g/d, respectively).The crude protein digestibility (CPD) of sheep increased linearly (P<0.001) from 42.11% to 59.15%, whereas the NDF digestibility and ADF digestibility decreased linearly (P<0.001) from 65.84% to 56.62% and 64.14% to 49.47%, respectively, with increased supplements. In addition, the interaction effect was significant in NDF digestibility (P<0.05), which was significantly higher in MG than HG with HS. The sheep grazing in MG had higher (P<0.001) average daily gain (ADG) (165.1 g/d vs. 147.6 g/d). The ADG of sheep was linearly increased (P<0.001) with an increased supplement, that is, 30.54% in LS and 74.16% in HS compared with NS. Furthermore, supplementation significantly reduced grassland utilization rate (P<0.05), increased livestock production (P<0.001), and slightly increased forage productivity under MG. Supplemental feeding significantly increased livestock production only under heavy grazing (P<0.001). In addition, the synergistic growth index increased with increasing supplements under moderate grazing, and 1% body weight of supplements can reach a high level. In contrast, the synergistic growth index of supplementation decreased and then increased under heavy grazing, and was lowest at 1% body weight of concentrate. In conclusion, the synergistic growth of grassland forage and livestock production in the meadow grassland was more favorable with 1% body weight of concentrate supplement under moderate grazing.
DOI: 10.1360/tb-2024-0289
Authors: Minle Xu, Nan Liu, Gaowen Yang, Yingjun Zhang
Language: English
Subfield: Forestry
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W4405023769