Tributyrin Can Improve Egg Production Rate and Egg Quality in Very Old Layers by Increasing The Digestibility of Calcium and Phosphorus

In the past few decades in South East Asia (SEA), with a moderate increase in the layer hen population, egg production rate and lifespan have greatly improved. However, when compared with the global egg production per capita (less than 7 vs. more than 10), there is still a significant opportunity to further increase egg production in this area. In SEA, the top challenges for the layer industry are egg quality and egg production rate, especially for old flocks. In old layers, especially after 50 weeks of age, the aging of the intestinal tract can negatively impact nutrient digestion and absorption (Sakdee et al., 2018). As a well-known supplement for improving intestinal development and gut health, butyrate based products have been widely used in the layer industry since late last century. Until very recently, tributyrin (TBU) as the carrier of both butyrate and monobutyrin (MBU), was regarded as an ideal replacement for, or more accurately an upgrade of, the generic butyrate-based product (Bedford and Gong, 2018). Within the gastrointestinal tract of farm animals, one unit of tributyrin is hydrolyzed by lipase into, approximately, two units of butyrate ions and one unit of α-MBU (Perstorp, internal data). The benefits from butyrate will be retained in TBU, and more functions from α-MBU. Therefore various tributyrin-based products (e.g. ProPhorce^TM SR130 from Perstorp) were used to improve the performance of layers in terms of egg production and egg quality.

Twelve pens of 144 layers at 86 weeks of age (Bovan White Leghorn) were used to evaluate the effect of a butyrate-based product (SR130) on egg production rate and quality. Two groups of layers were fed ad libitum with either a standard diet (SD) or SD with SR130 supplement at the level of 50 grams/ton feed. After 14 weeks, i.e. when the layers were 100-week old, feed efficiency, egg production rate and egg quality were measured. During the duration of the trial, the group treated with SR130 (SRT) had a consistently significantly higher (P < 0.05) average daily feed intake (104.9 g/hen/day vs. 102.2 g/hen/day) than the control group (CTR). Similar trends for average egg production rate (66.68% vs 66.02%) and average egg weight (66.92g vs. 65.93g) were also observed in the two groups with significant differences (P < 0.05). Furthermore, as of week 4 of the trial, we found a continuous significant increase of egg shell strength in SRT as compared with CTR (P < 0.05). This was partially due to the significant increase (P < 0.05) in both the calcium digestibility (from 25.91% to 35.94%) and phosphorous digestibility (from 25.75% to 28.43%) in SRT as compared with CTR.

It is well documented that butyrate can have positive effects on gut morphology and gut integrity in farm animals (Bedford and Gong, 2018). The additional functional molecule MBU, released from TBU, can synergistically balance the microbiota with butyrate and it can also contribute to capillary network development. With the combination of butyrate and MBU derived from TBU, egg production rate and egg quality were improved in the very old laying hens.