The feeding behavior of growing-finishing pigs was analyzed to study prandial correlations and the probability of starting a new feeding event. The data were collected in real-time based on 157,632 visits by a group of 70 growing-finishing pigs (from 30.4 to 115.5 kg body weight, BW) to automatic feeders. The data were collected over 84 days, during which period the pigs were kept in conventional (by phase and by group) or precision (with daily and individual adjustments) feeding programs. A criterion to delimit each meal was then defined based on the probability of an animal starting a new feeding event within the next minute since the last visit. Prandial correlations were established between meal size and interval before meal (pre-prandial) or interval after meal (post-prandial) using Pearson correlation analysis. Post-prandial correlations (which can be interpreted as hunger-regulating mechanisms) were slightly stronger than pre-prandial correlations (which can be interpreted as satiety regulation mechanisms). Both correlations decreased as the animals’ age increased but were little influenced by the feeding programs. The information generated in this study allows a better understanding of pigs’ feeding behavior regulation mechanisms and could be used in the future to improve precision feeding programs.

This study was conducted to compare postprandial plasma concentrations of insulin, energy-related metabolites, and amino acids measured after a 6-week challenge consisting of exposure to good or poor hygiene of housing conditions of 24 growing pigs divergently selected for low-RFI (LRFI) and high-RFI (HRFI). Blood indicators of immune responses were assessed from samples collected before 0 (W0), and 3 (W3), and 6 weeks (W6) after pigs transfer to their respective hygiene of housing conditions. Plasma haptoglobin concentrations and blood neutrophil granulocyte numbers were greater in poor than in good hygiene of housing conditions at W3. Plasma concentrations of total immunoglobulin G were greater (p= 0.04) in poor than in good hygiene of housing conditions at W6. At W6, pigs were fitted with an intravenous catheter for serial blood samplings. Low-RFI pigs had greater insulin (p< 0.001) and lower triglyceride (p= 0.04) average plasma concentrations than HRFI pigs in both conditions. In poor hygiene of housing conditions, the peaks of insulin and glucose were observed earlier and that of insulin was greater in LRFI than in HRFI pigs. Irrespective of genetic line, average plasma concentrations of histidine, isoleucine, leucine, methionine, threonine, valine, and alanine were greater in poor compared with good hygiene of housing conditions. Only HRFI pigs had greater lysine, asparagine, proline, and tyrosine plasma concentrations in poor than in good hygiene of housing conditions. Conversely, arginine, tryptophan, proline, and tyrosine plasma concentrations were lower only for LRFI pigs housed in poor hygiene conditions. Our results suggest that, contrary to HRFI, LRFI pigs increase or maintain their utilization of tryptophan, arginine, and lysine when housed in poor hygiene conditions. This indicates that this difference may contribute to the better capacity of LRFI to cope with poor hygiene of housing conditions.

This study aimed to examine the nutritional diversity of distillers’ co-products in pigs. Two distinct databases were used in this study. The first was compiled through a systematic review of previous scientific publications that have evaluated the chemical composition and nutritional availability of these ingredients for pigs. The final database included information collected from 49 studies published between 2003 and 2022. Most of the studies focused on distillers’ co-products produced from corn (90%) and assessed dried distillers grains with solubles (DDGS; 92%). A wide variety of nutritional compositions was observed in the selected studies, with coefficients of variation of 8% for gross energy and 13% for crude protein in dried distillers grains (DDGs). In the general database, half of the studies were published from 2003 to 2015 and the other half from 2015 to 2022. Greater variability in the net energy content and standardized ileal digestible lysine concentrations from 2015 to 2022 were the main concerns. The second database included information on high-protein dried distillers grains (HP-DDGs) collected directly from several feed mills and was built using the results of chemical analyses. These results suggest that the nutritional matrix of co-products should be assessed for each processing plant. Nevertheless, a coefficient of variation of up to 6% was found for crude protein and up to 20% for ether extract. Variability in nutritional composition is an important challenge of using distillers’ co-products in pig feed.

(1) Background: This study was performed to evaluate whether the addition of β-mannanase alone or combined with a multi-carbohydrase complex can improve diet digestibility, nutrient and energy metabolism, and the gut health of growing pigs. (2) Methods: Twenty-four pigs (35.56 ± 3.81 kg) were fed a control corn–soybean meal-based diet (no addition) or a control diet with β-mannanase (BM; 300 g/ton) or control diet β-mannanase plus a multi-carbohydrase complex including xylanase, β-glucanase, and arabinofuranosidases (BM + MCC; 300 + 50 g/ton) for 13 days. Total fecal and urine samples were collected from days 6 to 12. The feces samples were collected from all the pigs to determine fecal biomarkers using commercial ELISA tests. Blood samples were collected from all the pigs on day 13 to assess the serum concentrations of acute-phase proteins. All the pigs were euthanized on day 13 for intestinal tissue collection for morphometric analysis. Data were submitted to variance analysis and differences were considered significant at p ≤ 0.05 and a trend for 0.05 < p ≤ 0.10. (3) Results: The addition of BM and BM + MCC resulted in greater dry matter, protein, and energy digestibility coefficients, and protein (2.87% and 2.60%) and energy (2.61% and 1.44%) metabolizability coefficients compared to control (p < 0.05). A greater retention of nitrogen ratio and lower fecal energy were observed in BM and BM + MCC than in the control (p < 0.01). Furthermore, the addition of BM and BM + MCC resulted in lower manure production (29.78 and 49.77%, respectively) and fecal moisture (p < 0.001) compared to the control. The BM addition resulted in a greater villus area and villi height to crypt depth ratio compared to the control (p < 0.05). The addition of BM and BM + MCC diets also reduced the fecal calprotectin levels by 52 and 56% in relation to the control pigs. (4) Conclusions: The use of β-mannanase alone or associated with multi-carbohydrase complex improved nutritional digestibility, nutrient and energy metabolism, and gut health, and reduced the manure production of growing pigs.

Gut health is crucial for pigs because it affects nutrient absorption, immune function, and growth performance. However, its definition remains unclear, particularly regarding measurable responses in scientific studies. This review critically analyzed studies assessing intestinal health in pigs during the nursery, growing, and finishing phases, focusing on the invasiveness of the applied techniques. Papers published between 2005 and 2023 were searched in PubMed, Web of Science, and Science Direct, resulting in 322 articles. Publications grew at an annual rate of 23%, with 84% of studies conducted in the nursery phase. In the database, 87% of intestinal health assessments were combined with growth performance measures. Semi-invasive methods, such as blood collection, were used in 65% of the studies. Non-invasive measures, such as fecal samples, were analyzed in 39% of the studies, whereas urine (7%) and saliva (0.6%) were used in only a small fraction of the studies. Invasive methods, including intestinal tissue collection, were employed in 89% of studies. Among these, 24% did not specify the euthanasia method or number of pigs euthanized. No significant association was found between invasive and non-invasive methods, limiting the ability to establish clear relationships. Future studies should integrate multiple levels of invasiveness to improve the understanding and reduce reliance on invasive techniques.

This study was conducted to evaluate the effect of genetic selection (Lines A and B; Line A pigs have a greater proportion of Pietrain genes than those from Line B and therefore, selected for improved lean tissue accretion) on the feeding behavior of group-housed pigs exposed to daily cyclic high ambient temperatures. Feeding behavior of 78 barrows housed together in a single room was recorded in real time by five automatic feeders. The feeders registered each visit of each pig (day, hour, min, and second) and the amount of feed requested. Daily cyclic high ambient temperature was induced exposing pigs at 22°C from 18.00 to 10.00 h and 30°C from 10.01 to 17.59 h. From this temperature variation, day-period was divided into: 22°C_(06-10h), from 6.00 to 10.00 h; 30°C_(10-18h), from 10.01 to 17.59 h; and 22°C_(18-06h), from 18.00 to 5.59 h. Meal criteria was estimated based on the probability of animals starting a new feeding event within the next minute since the last visit (Pstart). After defining the meal criteria, the number of meals (n), feed intake rate (g/min), feed intake (g/meal), feeder occupancy (min/meal), and interval between meals (min) of each animal were calculated. Greatest probability of starting to feed was observed at 22°C_(06-10h), followed by 30°C_(10-18h) and then 22°C_(18-06h). Regardless of time period, pigs from line A had greater feed intake rate and lower feed intake, feed occupancy per meal and probability of starting a meal when compared with line B pigs. Only line A pigs had greater feed intake and feeder occupancy per meal at 22°C_(18-06h) than remainder of the day. This indicates that pig feeding pattern is strongly related to the circadian rhythm. However, the genetic selection for improved lean tissue accretion may modulate pigs feeding behavior under daily cyclic high ambient temperatures.