Department of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan, KS.
Department of Animal Sciences, University of Illinois, Urbana-Champaign, IL.
J Anim Sci. 2020 May 1;98(5). doi: 10.1093/jas/skaa120.
Five experiments were conducted to determine the standardized total tract digestibility (STTD) of P, digestible energy (DE), metabolizable energy (ME), and standardized ileal digestibility (SID) of amino acids (AA) in three sorghum varieties compared with corn and to determine the effects of sorghum varieties on nursery pig growth. In exp. 1, 48 barrows (initially 18.6 kg) were housed individually in metabolism crates. Treatments were arranged in a 2 × 4 factorial evaluating two levels of microbial phytase (0 or 500 units/kg) and four grain sources (corn, high-lysine, red, or white sorghum). Added phytase improved (P < 0.05) STTD of P in all ingredients, but was not different among the grains. In exp. 2, the DE and ME in the three sorghum varieties were not different from corn. In exp. 3, 10 growing barrows (initially 25.9 kg) with a T-cannula in the terminal ileum were used. Standardized ileal digestible Lys, Met, Thr, and Val were greater (P < 0.05) in corn than in the sorghum-based diets with no differences among the sorghum varieties. In exp. 4, 160 pigs (initially 6.3 kg) were randomly allotted to one of four dietary treatments with five pigs per pen and eight replicate pens per treatment in a 20-d experiment. Dietary treatments included corn or the three sorghum varieties, where the varieties of sorghum replaced corn on an SID Lys basis. No differences among treatments were observed in any growth performance parameters. In exp. 5, treatments consisted of a corn-based diet, a diet based on conventional sorghum (a mixture of red and white sorghum), and four diets with high-lysine sorghum containing increasing amounts of feed-grade AA, replacing soybean meal. Overall, pigs fed the high-lysine sorghum diet with the greatest amount of added feed-grade AA had the poorest gain:feed ratio (G:F; P < 0.05) compared with pigs fed all the other experimental diets. Within those fed the high-lysine sorghum and feed-grade AA, average daily gain, final body weight (linear, P < 0.10), and G:F (linear, P < 0.01) decreased as feed-grade AA increased. In summary, no differences in STTD of P or in DE and ME were observed among the grain sources. The SID AA values for the three sorghum varieties were not different; however, they were all lower than for corn. These results indicate that these varieties of sorghum can successfully replace corn in nursery pig diets if diets are formulated to account for differences in AA digestibility.
进行了五项实验，以确定三种高粱品种相对于玉米的磷的标准化总肠道消化率（STTD）、可消化能（DE）、代谢能（ME）和氨基酸（AA）的可标准化回肠消化率（SID），并确定高粱品种对仔猪生长的影响。在实验 1 中，将 48 头阉公猪（初始体重 18.6kg）单独饲养在代谢笼中。处理方式采用 2×4 因子设计，评估两种水平的微生物植酸酶（0 或 500 单位/千克）和四种谷物来源（玉米、高赖氨酸、红高粱或白高粱）。添加植酸酶提高了所有原料中磷的 STTD（P＜0.05），但谷物之间没有差异。在实验 2 中，三种高粱品种的 DE 和 ME 与玉米没有差异。在实验 3 中，用 10 头具有回肠末端 T 型管的生长阉公猪进行试验。玉米中可标准化回肠消化的赖氨酸、蛋氨酸、苏氨酸和缬氨酸均高于（P＜0.05）基于高粱的日粮，且高粱品种之间没有差异。在实验 4 中，160 头仔猪（初始体重 6.3kg）随机分为四种日粮处理组，每组 5 头猪，每个处理组 8 个重复。日粮处理包括玉米或三种高粱品种，高粱品种以可标准化回肠消化赖氨酸基础替代玉米。在任何生长性能参数方面，处理组之间均无差异。在实验 5 中，处理组包括以玉米为基础的日粮、以传统高粱（红高粱和白高粱的混合物）为基础的日粮和四种以高赖氨酸高粱为基础的日粮，其中高赖氨酸高粱含有越来越多的饲料级氨基酸，替代豆粕。总体而言，与其他所有试验日粮相比，饲喂含有最大添加量饲料级氨基酸的高赖氨酸高粱日粮的猪的增重与采食量比值（G:F）最差（P＜0.05）。在饲喂高赖氨酸高粱和饲料级氨基酸的猪中，平均日增重、最终体重（线性，P＜0.10）和 G:F（线性，P＜0.01）随着饲料级氨基酸的增加而降低。综上所述，在谷物来源之间未观察到磷的 STTD 或 DE 和 ME 的差异。三种高粱品种的 SID AA 值没有差异；然而，它们都低于玉米。这些结果表明，如果根据 AA 消化率的差异来配制日粮，这些高粱品种可以成功替代仔猪日粮中的玉米。
