This postweaning lag is a complex phenomenon and evidence suggests that it may be related in part to a limited capacity to maintain proper gastric pH (Cranwell and Moughan, 1989; Ravindran and Kornegay, 1993).

Insufficient hydrochloric acid (HCl) secretion impairs the enzyme inactivation and together with the stress of weaning and sudden change in feed consistency, may also disturb the balance of intestinal flora and allow the proliferation of coliforms resulting in scours and poor performance. The failure to maintain a low gastric pH has major implications for the performance of early weaned pigs. Dietary supplementation with acidifiers showed to decrease the occurrence of pathogenic bacteria in the gastrointestinal (GI) tract thus improving animals’ growth performance and health status. Additionally dietary acidification with organic acids has been shown to contribute to environmental hygiene preventing feed raw materials, compound feed and water from bacterial and fungal deterioration and reducing the transmission of disease to animal and human populations.

The extent to which acidifiers affect production performance of animal depends on the type and inclusion level of acid, as well as diet and animal factors. Various studies have been carried out to determine the efficacy of organic acids on performance in weaned pigs (Giesting and Easter, 1991; Ravindran and Kornegay, 1993; Partanen and Mroz, 1999). It was confirmed that individual organic acids are effective growth promoters, however, their efficacy might be improved by blending them together. In the present study performance improvements through supplementation of diet with a blend of formic (FO) and propionic (PR) acids were determined in weaned pigs.

Materials and methods

Sixty weaned pigs were randomly allocated into two groups with 5 replicates in each group and 6 piglets in each replicate according to genetics, sex and body weight (BW) (7.58±0.15). The piglets were kept in the cages, equipped with feeders and nipple drinkers. Feed and water was provided ad libitum. The basal diet was calculated to reach nutrient requirements for piglets 5 to 10 kg BW (NRC, 1998). The diet composition and nutrient analyses of the diets is shown in Table 1. The basal diet of control group contained no acidifier, whereas the basal diet of the trial group was supplemented with a blend of FO and PR acids (Biotronic® SE, BIOMIN, Austria) at inclusion level of 4 kg per ton of feed. The animals were weighed at the beginning and at the end of the trial. The trial was carried out in a period of 30 days. Feed intake (FI) was recorded daily.