Kang Hamin, Lee Mingyung, Jeon Seoyoung, Lee Sang Moon, Lee Ju Hwan, Seo Seongwon
Division of Animal and Dairy Sciences, Chungnam National University, Daejeon 34134, Korea.
Jeil Feed, Daejeon 34365, Korea.
J Anim Sci Technol. 2021 Sep;63(5):1018-1033. doi: 10.5187/jast.2021.e91. Epub 2021 Sep 30.
In this study, we aimed to assess the effect of flaking on the nutrient digestibility of corn grain in ruminants. In this regard, rumen fermentation, rumen degradability, and metabolic experiments were performed. The automated gas production technique was used for the fermentation experiments. Six types of corn flakes with various degrees of gelatinization (32%, 41%, 48%, 66%, 86%, and 89%) were ground and incubated in rumen fluid to measure rumen fermentation characteristics and digestion rate. The degradability of ground corn, whole corn, and corn flakes with 62% and 66% gelatinization was measured by incubation in the rumen of two cannulated Holstein cows. metabolic experiments were performed using 12 crossbred goats (29.8 ± 4.37 kg) using a 3 × 3 Latin square design. The dietary treatments consisted of ground corn and flaked corn with 48% or 62% gelatinization. experiments showed that as the degree of gelatinization increased, the digestion rate increased linearly, while the discrete lag time decreased linearly ( < 0.05). The effective rumen dry matter degradability, determined by fermentation, was 37%p lower in corn flakes than ground corn, assuming a passage rate of 6%/h ( < 0.01), and there was no difference between the two flakes. In the experiment, there was no difference in dry matter intake, average daily gain, feed efficiency, and nitrogen utilization among the treatment groups ( > 0.05); however, the crude fat digestibility was lower for corn flakes than for ground corn ( < 0.05). To summarize, the rate of fermentation of corn flakes increased as the degree of gelatinization increased. However, non-ground corn flakes had lower rumen digestibility and did not improve apparent nutrient digestibility, compared with ground corn. In contrast to the assumption that flaked corn provides more energy to ruminant animals than ground corn, we conclude that the digestibility and energy value of corn flakes are lower than those of ground corn if mastication does not sufficiently reduce the particle size of corn flakes.
在本研究中，我们旨在评估轧片对反刍动物玉米籽粒养分消化率的影响。在此方面，进行了瘤胃发酵、瘤胃降解率及代谢实验。发酵实验采用自动产气技术。将六种不同糊化度（32%、41%、48%、66%、86%和89%）的玉米片磨碎后在瘤胃液中培养，以测定瘤胃发酵特性及消化率。通过在两头装有瘤胃瘘管的荷斯坦奶牛瘤胃中培养，测定磨碎玉米、整粒玉米以及糊化度为62%和66%的玉米片的降解率。采用3×3拉丁方设计，使用12只杂交山羊（体重29.8±4.37千克）进行代谢实验。日粮处理包括磨碎玉米以及糊化度为48%或62%的轧片玉米。实验表明，随着糊化度增加，消化率呈线性增加，而离散滞后时间呈线性减少（P<0.05）。假设通过率为6%/小时，通过发酵测定的瘤胃有效干物质降解率，玉米片比磨碎玉米低37%（P<0.01），且两种玉米片之间无差异。在代谢实验中，各处理组间干物质摄入量、平均日增重、饲料效率及氮利用率无差异（P>0.05）；然而，玉米片的粗脂肪消化率低于磨碎玉米（P<0.05）。总之，玉米片的发酵速率随糊化度增加而提高。然而，与磨碎玉米相比，未磨碎的玉米片瘤胃消化率较低，且未提高表观养分消化率。与轧片玉米比磨碎玉米能为反刍动物提供更多能量这一假设相反，我们得出结论：如果咀嚼不能充分减小玉米片的颗粒大小，那么玉米片的消化率和能量值低于磨碎玉米。
