环境温度对不同油脂配制的母猪预混料氧化酸败的影响

Effect of ambient temperature on oxidation rancidity of sow feed premixed with different oils

大比例预混料中经常使用油脂作为能源,以提高饲料的能值,减少饲料的粉尘,提高动物的生产性能,但环境温度对不同油脂配制的预混料在储存期间其氧化规律的研究却很少。采用2×3双因素区组设计,将用大豆油、鱼油和脂肪粉配制的10%母猪预混料分别放置在常温(25℃)和高温(35℃)下,6个处理组,每个处理4个重复,共24个样品。在0、15、30、45和60 d检测各组预混料的外观、水分含量、酸价、过氧化值和茴香胺值。结果表明,无论环境温度高低,随着储存时间的延长,10%母猪预混料的酸价、过氧化值、茴香胺值均呈极显著线性升高(P<0.01)。在贮存期间,无论是常温还是高温,鱼油配制的预混料各氧化指标都是增长最快,其次是大豆油,脂肪粉增长慢(P<0.01)。相对于常温来说,高温促进了油脂的氧化,高温下不同油脂配制的预混料的酸价、过氧化值和茴香胺值均极显著升高(P<0.01)。研究表明,高温加速油脂的氧化,脂肪粉相对于大豆油和鱼油,其氧化速度慢。建议配制母猪预混料时,使用脂肪粉作为油脂原料。

In order to improve the energy value of feed, reduce the dust in feed and improve the production performance of animals, oils are often used as energy sources in large proportion of premixes. However, there were few studies concerning the effects of different ambient temperatures on the oxidation rancidity of premixes prepared with different oils during storage. A 2×3 factor block design was adopted in this experiment. The 10% sow feed premix was prepared with soybean oil, fish oil and fatty powder which were stored either at room temperature(25 ℃) or high temperature(35 ℃). The experiment had six group treatments with 4 replicates per treatment. Samples of 10% sow premix from different groups were collected at 0, 15, 30, 45 and 60 days of storage in order to investigate the appearance, moisture, acid value, peroxide value and anisamine value. The results were as follows: The acid value, peroxide value and anisamine value of the 10% sow feed premix increased linearly with the storage time(P<0.01), regardless of the environment. Compared with the normal temperature, higher temperature promoted the oxidation of oil. The acid value, peroxide value and anisidine value of both premixed prepared with fish oil and soybean oil and fatty powder were significantly increased at high temperature(P<0.01). Regardless of normal temperature or higher temperature during storage, the acid value, peroxide value and anisidine value of the 10% sow feed premix were linearly increased with higher levels of oils, especially for the fish oil group, followed by soybean oil, and fatty powder(P<0.01). Compared with the normal ambient temperature, the acid value, peroxide value and anisamine value in the permix under high ambient temperature during the storage were significantly increased(P<0.01). In conclusion, higher ambient temperature during storage enhanced oxidation rancidity of feed premix. Compared with the soybean oil and fish oil, the rate of oxidation rancidity was slowest in the feed premix prepared by fatty powder. Therefore, it is recommended to use fatty powder as oil supplements when preparing premix for sows.