Probiotics and enzymes in weaned piglets' diets can lower belly nosing frequency and improve performance and nitrogen balance.

Two studies were conducted to evaluate the effect of two classes of feed additives, probiotics and enzymes, on performance, diarrhea incidence, belly nosing frequency, and nutrient metabolism in post weaned piglets. The hypothesis was that the association of probiotics and multienzymes would reduce diarrhea, improve behavioral outcomes, and enhance nutrient digestion and absorption, leading to better performance and health. In the first trial, 80 weaned piglets, barrows and gilts, were distributed in four treatments using a randomized block design based on the initial weight. Each treatment had five replicates (pens), housing four piglets. The treatments were as follows: CON – no feed additives; AB – antibiotics (lincomycin and colistin); FA - probiotic (Bacillus subtilis, 3 × 108 CFU/g) and multienzymes (exoglycanase, endoglycanase, protease, pectinase, polygalacturonidase, and β-amylase); AB + FA - antibiotic, probiotics, and multienzymes. Piglets were weighed at the start of the trial and on days 7, 14, 21, 28, and 35. Feed intake was recorded to calculate body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and the feed-to-gain ratio (F: G). Diarrhea score and belly nosing behavior were evaluated daily by the same observer. In the second trial, 20 barrows were selected at the end of the nursery phase, allocated in a randomized block design based on their initial weight, and housed in metabolic cages. For 12 days, the piglets were subjected to the same four treatments as in the first trial. Total feces and urine were collected during the last four days to assess the dry matter digestibility coefficient, gross energy digestibility coefficient, digestible energy, metabolizable energy, absorbed nitrogen (NABS), retained nitrogen, and the ratio of retained to absorbed nitrogen. Statistical analysis was performed in SAS, linear mixed models and Tukey were used for performance variables and digestibility. For fecal score analysis and belly nosing frequency, Kruskal-Wallis and Dunn’s test were adopted. Means were considered statistically different when p < 0.05. In the first study, the BW and ADG of the AB + FA group were 7.56% and 56.86% higher, respectively, than those of the AB group. During the first week, the AB group had a lower ADFI compared to all other treatments. The AB + FA group exhibited a 20.17% lower frequency of belly nosing compared to piglets in the CON group. Additionally, the FA group had 7.14% higher NABS compared to the CON group. Within the conditions of the present study, supplementing piglet diets containing antibiotics with probiotics and a multienzyme blend appeared to improve performance, reduce undesirable behaviors, and enhance protein utilization.