The oil content of sesame is 45%~50%, the protein content is 15%~20%, and the carbohydrate content is 10%~15%. Sesame meal is a by-product of sesame oil extraction. Its main component is sesame protein, which is mainly composed of a-globulin, accounting for about 80%. Its isoelectric point is pH 3.8~4.0. The crude protein content of sesame meal is more than 45%, the amino acid composition is similar to soybean meal with equal protein content, and it is rich in a variety of essential amino acids for animal bodies. It is a highly nutritious plant protein resource. This article comprehensively discusses domestic and foreign research on the nutritional composition of sesame meal and its application in poultry feed.
1 Nutritional composition of sesame meal
Mamputu et al. [1] and Yamauchi et al. [2] analyzed the nutritional composition of sesame meal (see Table 1). Since the feed ingredients and nutritional value table of China (2010) [3] and France (2002) [4] published Therefore, the nutrient composition of pressed sesame cakes lacks certain comparability. However, it can be seen from Table 1 that sesame meal is rich in vitamins B2, B6, calcium, phosphorus, iron, manganese and zinc, and has high methionine content. It is a high-quality feed material for laying poultry, which is beneficial to improving eggshell quality and preventing laying hens. Egg-laying fatigue syndrome. In addition, with the advancement of oil extraction technology, there are very few sesame cakes on the market. In order to improve the nutritional database, it is necessary for animal nutritionists to strengthen basic research on sesame meal.
2 Application of sesame meal in poultry feed
Lysine is the first limiting amino acid in sesame meal, but the methionine content of sesame meal reaches more than 1.2%, which is the highest among all cakes and twice that of soybean meal and cottonseed meal. Studies have shown that sesame meal can partially replace soybean meal in poultry production. Mamputu et al. [1] reported that when sesame meal replaced 15% of dietary crude protein, there was no difference in production performance compared with the soybean meal control group. However, when the amount of sesame meal reached 8% and replaced 30% of dietary protein, the growth of broiler chickens decreased. be inhibited. Yamauchi et al. [2] studied the effects of different dietary sesame meal levels on the production performance and intestinal tissue morphology of 17- to 21-week-old White Leghorn laying hens. The results showed that 10% of dietary sesame meal was beneficial to improving growth performance, 20 % sesame meal in the diet has no significant effect on growth performance, but when it reaches 30%, the growth performance is significantly reduced. Comprehensive analysis of the growth performance and intestinal tissue morphology of laying hens, and the amount of sesame meal in the diet of high-yielding laying hens Up to 20%. Farran et al. [5] studied the effect of sesame shells (Sesamehu11) on the production performance of laying hens and broilers. The results showed that the amount of sesame shells in broiler feed should not exceed 8%, while in layer feed, 14% of sesame meal had no effect on the performance of laying hens and broilers. Feed intake, egg weight, Hastelloy units, yolk color and eggshell thickness were not affected.
3 Factors limiting the utilization of sesame meal
3.1 Appearance and smell
The appearance of sesame meal is generally dark brown with a pasty smell. If the dosage is too large, it will affect the look and smell of the feed. According to experience, if the dosage is greater than 7%, the finished feed will have a heavier paste smell, which will reduce the feed intake of poultry and affect production performance.
3.2 Protein solubility and ash content
Protein solubility is an important indicator for judging the quality of cake protein raw materials. The protein solubility of sesame meal is generally 45% to 55%, which is equivalent to cotton meal and high-quality rapeseed meal, and lower than soybean meal. Since sesame meal is rich in mineral elements, its ash content is relatively high, generally above 11%, which is 1.5 to 2 times that of soybean meal, cottonseed meal and rapeseed meal.
3.3 Phytic acid and oxalic acid
Different from other cake meal raw materials, sesame meal contains 3.6%~5.2% phytic acid, which is the most important factor limiting the utilization of sesame meal. Kaneko [6] et al. reported that when the proportion of sesame meal in the diet reaches 14%, the growth performance of broiler chickens is significantly inhibited, which may be due to the excessive phytic acid content. The high phytic acid content of sesame meal also affects the apparent digestibility of protein. At the same time, phytic acid can also combine with mineral elements such as calcium, phosphorus, and zinc, interfering with the digestion and absorption of mineral elements. There are few reports on the oxalic acid content in sesame meal. Farran et al. [5] measured the oxalic acid and phytic acid content of sesame shells. The results showed that the oxalic acid content of sesame shells was as high as 13%, but the phytic acid content was low, only 1.12%. . It can be speculated that the oxalic acid content of sesame meal should also be high, which together with phytic acid interferes with the absorption of dietary mineral elements.
4 Conclusion
In short, sesame meal has high nutritional value and is a high-quality plant protein raw material. At a time when the price of soybean meal is high, it is increasingly favored by feed manufacturers. Due to its low lysine content, attention should be paid to adding additional lysine when using it to balance the amino acid pattern and improve feed digestion and utilization. According to experience, the amount of sesame meal is affected by its appearance, smell, phytic acid and oxalic acid content, etc. Therefore, it is recommended that the amount used in poultry feed should not exceed 10%, and the amount used in egg and poultry feed is greater than that in broiler and poultry feed. At the same time, as the amount of sesame meal in the diet increases, the dietary calcium, phosphorus and other minerals should be increased accordingly. The level of the element.