Abstract To mitigate the post-weaning growth check, additional iron supplementation to improve haemoglobin at weaning (Chevalier et al., 2021) and low crude protein diets have been shown to reduce post-weaning diarrhoea (Batson et al., 2021), improving the transition. This is because piglets exhaust iron stores before weaning, and a change of diet results in gut dysbiosis. It was hypothesized that an additional iron injection and a low-protein (LP) diet would increase body weight gain after weaning. A total of 1600 piglets were assigned to one of four treatments: (1) diet (HP; 22.1% CP and LP; 18.5% CP) versus iron (day 2; 200mg injected intramuscularly (i.m.) at birth and weaning; 200mg i.m. at birth and at weaning) on a recently repopulated farm. Pigs were weaned at 27.5 days into four mixed-sex pens. Diets were fed for seven days, then all pigs were fed the same diet. CON weaning iron improved average daily gain (ADG; p 0.05) over the entire experimental period. Iron injections improved weights at day 14 and ADG (p 0.05) over the 14-days. Table 1: Weights and Average Daily Gain (ADG) of pigs (means ± SED) for 14 days after weaning. Data was analyzed using ANOVA, and a-c indicates p 0.05. Results show that a HP diet performed better than a LP diet, likely because of an increased supply of nutrients, which contrasted the original hypothesis. An additional iron injection also improved growth for the same reason. When a HP diet and additional iron injection are used in conjunction, produced improved growth compared to one factor.Batson, K. L., Calderón, H. I., Tokach, M. D., Woodworth, J. C., Goodband, R. D., Dritz, S. S., & DeRouchey, J. M. (2021). Effects of feeding diets containing low crude protein and coarse wheat bran as alternatives to zinc oxide in nursery pig diets. J Anim Sci, 99(5). Chevalier, T. B., Monegue, H. J., & Lindemann, M. D. (2021). Effects of iron dosage administered to newborn piglets on hematological measures, preweaning and postweaning growth performance, and postweaning tissue mineral content. Journal of Swine Health and Production, 29(4), 189-199.
Langley et al. (Wed,) studied this question.