Liquid methionine added to diets for lactating sows leads to both more fat and lactose concentration in the milk as well as a better gut absorption of nutrients in the suckling piglets’ guts. Jointly, these factors explain a higher piglet body weight before and after weaning.
在哺乳母猪日粮中添加液态蛋氨酸有助于提高乳汁中的脂肪及乳糖含量，同时可以提高哺乳仔猪肠道对营养物质的吸收率。总体而言，这都可以提高仔猪断奶前后的体重。
Nutritionists must find solutions to feed the modern and hyper-prolific sows and develop new strategies to meet increasing nutrient requirements. Lactation is an essential phase, as sow milk quantity and quality play a central role in the growth of suckling piglets.
营养学家需要找到新办法饲喂现代化的高产母猪，满足其不断增长的营养需求。母乳量及质量在哺乳仔猪生长中发挥着重要作用，因此，保证哺乳期营养十分重要。
Comparing methionine
Recently, a trial was carried out in China on cross-bred primiparous sows in order to compare lactating sow diets with an extra supply of methionine with a control diet containing 0.25% of total methionine, at a level in agreement with the recommendations of the United States National Research Council (NRC). Three methionine sources are available for the feed industry. In this trial, 2 forms of methionine were compared: a powder form, DL-methionine (1.34 kg/tonne) and a liquid form: DL-hydroxy methionine, DL-HMTBA (1.51 kg/tonne).
对比试验
近期，中国进行了一项实验，实验对象为杂交的初产母猪，目的是对比日粮中不同蛋氨酸含量对母猪的影响，其中一组添加了额外的蛋氨酸，对照组的蛋氨酸添加量则为NRC(美国国家研究理事会)推荐量0.25%。饲料行业中有3种蛋氨酸来源。该试验对其中2种进行了对比：粉末状DL-蛋氨酸(1.34kg/t)、液态DL-羟基氨基酸即DL-HMTBA(1.51kg/t)。
Compared to the control diet and the DL-methionine diet, the diet containing DL-HMTBA leads to a significant improvement of fat and lactose content of the milk of the sows (Figure 1), the 2 sources of energy supply for suckling piglets. The authors also demonstrated that a better milk composition stimulates intestinal gene expression and increases absorption capacity of the suckling piglets gut.
与对照组及添加DL-氨基酸的日粮相比，添加了DL-HMTBA的日粮使母猪乳汁中的脂肪及乳糖含量显著提高(见图1)。同时，研究员也表示，更优质的乳汁成分可以刺激肠道基因表达，并提高哺乳仔猪肠道的吸收率。
As a consequence of the higher nutritional milk content regarding macronutrients and amino acids, the body weight of suckling piglets at day 14 post-farrowing in the DL-HMTBA group was significantly higher (+510 g) than in the control group and tended to be higher (+310 g) than in the DL-methionine group.
由于乳汁中含有更多多量元素及氨基酸，DL-HMTBA组的哺乳仔猪在分娩后第14天，体重显著高于对照组仔猪(+510g)，并且高于DL-蛋氨酸组的仔猪(+310g)。
图1 饲喂不同来源蛋氨酸的母乳中脂肪和乳糖的含量
Figure 1 - Content of fat and lactose in milk of sows fed with different sources of methionine
Body weights increase
These new data confirm the better efficacy of the liquid form of methionine which were observed earlier by researcher Hao Li and his team, affiliated to Sichuan Agricultural University, China. In that trial, where both sows and piglets received a diet with increased levels of sulphur amino acids through DL-HMTBA or DL-methionine, the scientists demonstrated that the body weight of 35 day old piglets was significantly higher when sows and piglets received methionine as DL-HMTBA compared with DL-methionine, also seeFigure 2.
体重增长
这些新数据证实了四川农业大学研究员Hao Li团队的观点——液体形式的蛋氨酸功效更佳。在该试验中，母猪和仔猪饲料中通过添加DL-HMTBA或DL-蛋氨酸补充更高水平的含硫氨酸。研究人员发现DL-HMTBA组的35日龄仔猪的体重要明显高于DL-蛋氨酸组，见图2。
注：TSAA/Lys=含硫氨基酸/赖氨酸
图2 35日龄仔猪体重(kg)
Figure 2 Piglet weight at 35 days (kg).
Furthermore, those piglets had a better gut morphology, with higher villus heights and villus height/crypt depth ratio leading to a better absorption capacity. Moreover, during the post weaning period, the effect of dietary treatments on jejunal glutathione status showed that DL-HMTBA treatment allowed a better red-ox status than in the other treatments (as shown by higher reduced glutathione and lower oxidised glutathione to reduced glutathione ratio).
此外，DL-HMTBA组的小猪有更好的肠道形态，具有较高的绒毛高度和绒毛高度/隐窝深度比，从而使得它们拥有更好的吸收能力。
Higher feed intake
Another interesting finding was that weaned piglets receiving the DL-HMTBA source of methionine in their complete feed, show a higher feed intake across post-weaning days (P<0.05) compared to those in the control or dl-methionine groups, leading to a better average daily weight gain.
更高的采食量
另一个有趣的发现是，与对照组和DL-蛋氨酸组相比，DL-HMTBA组的断奶仔猪在断奶后采食量更高(P <0.05)，因此DL-HMTBA组的平均增重也较高。
The researchers also concluded that increased consumption of methionine as DL-HMTBA might alleviate stresses associated with early weaning. Compared to the control group, higher villus height, villus height/crypt depth ratio and number of goblet cells were observed in the DL-HMTBA treatment group providing evidence for its positive effect on weaning stress.
研究人员还得出结论，增加DL-HMTBA形式的蛋氨酸补充可以缓解断奶早期的应激反应。与对照组相比，在DL-HMTBA组中观察到更高的绒毛高度及绒毛高度/隐窝深度比和杯状细胞数，这也证实了为何DL-HMTBA组能更好的克服断奶应激。
The team at Sichuan Agricultural University concluded that early-weaning induced growth retardation appears to be attenuated through changes in plasma amino acid profiles and elevation of growth performance and intestinal antioxidant capacity in piglets, following increased consumption of methionine as DL-HMTBA.These observations offer novel insights into the mechanism of sulphur amino acids metabolism, with important nutrition and health implications.
四川农业大学的研究小组得出结论，断奶早期造成的发育迟缓似乎可通过改变血浆中氨基酸的构型得到改善。仔猪的生长性能及肠道抗氧化能力随DL-HMTBA形式蛋氨酸消耗的增加而提高。这些发现为含硫氨酸代谢机制提供了新的见解，对营养和健康的研究具有重要意义。
