Department of Animal Science, Federal University of Lavras, Lavras, 37200000, Brazil.
Department of Animal Science, State University of Maringá, Maringá, 87020900, Brazil.
J Dairy Sci. 2018 May;101(5):4001-4019. doi: 10.3168/jds.2017-13703.
Silage making can be conveniently divided into field, ensiling, storage, and feed-out phases. In all of these stages, controllable and uncontrollable components can affect silage quality. For instance, silages produced in hot or cold regions are strongly influenced by uncontrollable climate-related factors. In hot regions, crops for silage are influenced by (1) high temperatures negatively affecting corn yield (whole-crop and grain) and nutritive value, (2) butyric and alcoholic fermentations in warm-season grasses (Panicum, Brachiaria, and Pennisetum genera) and sugarcane, respectively, and (3) accelerated aerobic deterioration of silages. Ensiling expertise and economic factors that limit mechanization also impair silage production and utilization in hot environments. In cold regions, a short and cool growing season often limits the use of crops sensitive to cool temperature, such as corn. The fermentation triggered by epiphytic and inoculated microorganisms can also be functionally impaired at lower temperature. Although the use of silage inoculants has increased in Northern Europe, acid-based additives are still a good option in difficult weather conditions to ensure good fermentation quality, nutritive value, and high intake potential of silages. Acid-based additives have enhanced the quality of round bale silage, which has become a common method of forage preservation in Northern Europe. Although all abiotic factors can affect silage quality, the ambient temperature is a factor that influences all stages of silage making from production in the field to utilization at the feed bunk. This review identifies challenges and obstacles to producing silages under hot and cold conditions and discusses strategies for addressing these challenges.
青贮制作可方便地分为田间、青贮、储存和投喂四个阶段。在所有这些阶段，可控和不可控因素都可能影响青贮质量。例如，在炎热或寒冷地区生产的青贮受到不可控气候因素的强烈影响。在炎热地区，青贮用作物受到以下因素的影响：（1）高温对玉米（全株和籽粒）和营养价值产生负面影响；（2）暖季草（百喜草、象草和狼尾草属）和甘蔗分别发生丁酸和酒精发酵；（3）青贮加速有氧变质。青贮制作专业知识和限制机械化的经济因素也会损害炎热环境下的青贮生产和利用。在寒冷地区，短暂而凉爽的生长季节通常限制了对凉爽温度敏感的作物的使用，如玉米。在较低温度下，由附生和接种微生物引发的发酵也可能受到功能损害。尽管青贮接种剂在北欧的使用有所增加，但在恶劣天气条件下，酸基添加剂仍然是确保良好发酵质量、营养价值和青贮高采食量的不错选择。酸基添加剂提高了圆捆青贮的质量，这已成为北欧常见的饲料保存方法。尽管所有非生物因素都会影响青贮质量，但环境温度是影响从田间生产到饲料槽利用青贮制作各个阶段的一个因素。本综述确定了在炎热和寒冷条件下生产青贮的挑战和障碍，并讨论了应对这些挑战的策略。
