L-glutamine- and enzyme-supplementation via liquid feed to suckling piglets does not impact growth, health or intestinal structure

The provision of liquid creep feed to suckling pigs has been shown to increase dry matter intake compared to dry creep feeding. The increased feed intake associated with liquid feeding makes it attractive as a means of delivering feed additives to suckling pigs to optimize growth and health. The objective of this study was to determine the effect of L-glutamine and enzyme supplementation of liquid creep feed on pig growth up to target slaughter weight (~120 kg), health and intestinal structure. Sixty sows and their litters were blocked on sow parity, previous number of piglets weaned and sow weight at day 107 of gestation, and the litters were randomly assigned to one of 3 dietary treatments: 1) liquid starter diet (control); 2) control diet supplemented with 10 g of L-glutamine per kg of starter diet (glutamine); and 3) control diet supplemented with a cocktail of enzymes (lipase, protease and α-amylase included at 160 Lipase units, 30,000 New Feed Protein units and 67.5 Kilo Novozymes units, respectively per kg of starter diet). Dietary treatments were fed from day 8 of age to weaning at day 28. Pig weight and dry matter disappearance (DMd) were recorded during lactation and post-weaning until pigs reached target slaughter weight (~120 kg) at 158 d of age. Carcass weight and quality were recorded. Medication usage, and the number of injections and clinical cases of disease were recorded from birth to slaughter. At day 5 post-weaning, a subset of pigs (n = 30) were sacrificed and intestinal samples were collected for histological analysis. The DMd of creep feed did not differ between treatments (<i>P</i> > 0.05). Glutamine tended to reduce piglet body weight (BW) at day 21 (<i>P</i> = 0.09) and 28 (<i>P</i> = 0.08) of lactation and from day 14 to 21, glutamine decreased piglet average daily gain (ADG) compared to the control (<i>P</i> < 0.05). Post-weaning growth was not affected by treatment (<i>P</i> > 0.05). The amount of antibiotics or anti-inflammatories administered to piglets or sows was not affected by treatment, either pre- or post-weaning (<i>P</i> > 0.05). However, glutamine tended to increase diarrhea prevalence between day 8 and 27 of lactation compared to the control (<i>P</i> = 0.09). In conclusion, supplementing liquid creep feed with glutamine tended to reduce pre-weaning growth and to increase diarrhea prevalence in piglets. Additionally, supplementing liquid creep feed with enzymes had no effect on growth or medication usage in pigs.