In a recent issue of Journal of Animal Science, Jack Odle from North Carolina State University and co-authors there and with Milk Specialties Global describe their experiment to explore the interplay between diet physical form (liquid versus dry), fatty acid chain length [medium- versus long-chain triglyceride; MCT versus LCT) and emulsification as determinants of fat utilisation and growth of newly weaned pigs.

Ninety-six pigs were weaned at 20.0±0.3 days of age (6.80±0.04kg) and fed ad libitum one of eight diets for 14 days according to a 2×3 factorial arrangement of treatments with six pens per diet and two pigs per pen.

The MCT contained primarily C8:0 and C10:0 fatty acids, whereas the LCT mainly contained C16:0, C18:0, C18:1 and C18:2.

They found that diet physical form greatly impacted piglet growth (P<0.001), with liquid-fed pigs (486g per day) growing faster than dry-fed pigs (332g per day) by 46 per cent.

Pigs fed LCT grew 22 per cent faster (P=0.01) than MCT-fed pigs; however, effects of emulsifier were not detected (P>0.1). Furthermore, feed intake and gain:feed ratio were 15 per cent and 29 per cent greater for liquid-fed pigs, and intake also was 21 per cent greater for pigs fed LCT (P=0.01).

Diet physical form had no effect on apparent ileal fatty acid digestibility but as expected, digestibility was greater (P<0.001) for the MCT than the LCT diet (98.5 per cent versus 93.4 per cent). Emulsification improved digestibility of most fatty acids in pigs fed LCT but not MCT (interaction, P<0.01).

Both jejunal and ileal villi height increased from seven to 14 days post-weaning (P<0.01). Liquid-fed pigs had greater jejunal crypt depth (P<0.05) than those fed the dry diet but ileal morphology was not affected by diet physical form, fat chain length or emulsification.

Plasma ketone body concentrations were six-fold greater in pigs fed MCT than LCT, and the difference was greater in pigs fed dry diets (interaction, P=0.01). The bile salt concentration in jejunal digesta was 2.2-fold greater in pigs fed LCT than in pigs fed MCT (P<0.001).

Collectively, the researchers concluded that feeding liquid diets containing emulsified LCT can improve fat utilisation and markedly accentuate feed intake, growth and feed conversion efficiency in weaned pigs.

Reference

Price K.L., X. Lin, E. van Heugten, R. Odle, G. Willis and J. Odle. 2013. Diet physical form, fatty acid chain length, and emulsification alter fat utilization and growth of newly weaned pigs. J. Anim. Sci., 91(2):783-792. doi: 10.2527/jas.2012-5307

Further Reading You can view the full report (fee payable) by clicking here.

April 2013