Microencapsulation Improved Fumaric Acid and Thymol Effects on Broiler Chickens Challenged With a Short-Term Fasting Period.

The first objective of this study was to demonstrate the usefulness of the microencapsulation technique to protect fumaric acid and thymol, avoiding their early absorption and ensuring their slow release throughout the gastrointestinal tract (GIT). For this purpose, the release of a lipid matrix microencapsulated brilliant blue (BB) was assessed in vitro, using a simulated broiler intestinal fluid, and in vivo. In vitro results showed that more than 60% of BB color reached the lower intestine, including 26.6 and 29.7% in the jejunum and ileum, respectively. The second objective was to determine the effects of microencapsulated fumaric acid, thymol, and their mixture on the performance and gut health of broilers challenged with a short-term fasting period (FP). One-day-old male ROSS 308 chickens (n = 280) were randomly distributed into seven treatments, with 10 replicates of four birds each. Dietary treatments consisted of a basal diet as negative control (NC), which was then supplemented by either non-microencapsulated fumaric acid (0.9 g/kg), thymol (0.6 g/kg), or a mixture of them. The same additive doses were also administered in a microencapsulated form (1.5 and 3 g/kg for the fumaric acid and thymol, respectively). At day 21, chickens were subjected to a 16.5-h short-term FP to induce an increase in intestinal permeability. Growth performance was assessed weekly. At day 35, ileal tissue and cecal content were collected from one bird per replicate to analyze intestinal histomorphology and microbiota, respectively. No treatment effect was observed on growth performance from day 1 to 21 (p > 0.05). Microencapsulated fumaric acid, thymol, or their mixture improved the overall FCR (feed conversion ratio) and increased ileal villi height-to-crypt depth ratio (VH:CD) (p < 0.001) on day 35 of the experiment. The microencapsulated mixture of fumaric acid and thymol increased cecal abundance of Bacteroidetes, Bacillaceae, and Rikenellaceae, while decreasing that of Pseudomonadaceae. These results indicate that the microencapsulation technique used in the current study can be useful to protect fumaric acid and thymol, avoiding early absorption, ensure their slow release throughout the GIT, and improve their effects on fasted broiler chickens.

Effects of two zinc supplementation levels and two zinc and copper sources with different solubility characteristics on the growth performance, carcass characteristics and digestibility of growing-finishing pigs.

The present study was conducted to evaluate the effect of two Zn supplemented levels and two Zn and Cu sources (sulphate and hydroxychloride) on growing-finishing pigs. An in vitro study and an in vivo study were conducted. In the in vitro study, Zn solubility from each source at different Zn supplementation levels was evaluated, as well as the phytic phosphorus (PP) solubility derived from the interaction or not with phytic acid at similar conditions to those found in digestive tract. The most critical interaction of Zn with phytic acid was at pH 6.5 and with Zn sulphate, resulting in the reduction in PP solubility. In the in vivo experiment, a total of 444 pigs ([Duroc × Landrace]×Pietrain; initial BW: 18.7 ± 0.20 kg) were allotted to 36 pens in a randomized complete block design (2 × 2) factorial arrangement with two Zn and Cu sources and two Zn supplemental levels (20 and 80 mg/kg). The Cu supplementation was fixed at 15 mg/kg for all diets. There was no effect of the interaction between mineral source × Zn level or Zn level on growth performance or carcass characteristics (p > .10). Apparent total digestibility of Zn and Cu along with carcass yield was higher for pigs fed hydroxychloride than pigs fed the sulphate counterparts (p < .05). Feeding low levels of Zn decreased Zn (45.5%; p < .0001) and Cu(18.5%; p = .018) faecal excretion. In conclusion, under commercial conditions, feeding growing-finishing pigs with Zn levels below those established by the European Union regulation did not affect growth performance and carcass characteristics. Reducing dietary mineral (Zn and Cu) diet content resulted in a lower faecal mineral excretion. Pigs fed sulphate minerals had an improved performance during grower period, while pigs fed hydroxychloride minerals showed an improved performance during finishing period and a greater carcass yield and mineral digestibility than those fed sulphates.

Dietary Preference of Newly Weaned Pigs and Nutrient Interactions According to Copper Levels and Sources with Different Solubility Characteristics.

Two feeding preference experiments and an in vitro assay were performed to assess the weaned pig preference for Cu doses and sources based on their sensorial perception and on the likely post-ingestive effects of Cu. At day 7 post-weaning, a total of 828 pigs were distributed into two different experiments. In Exp.1 (dose preference) a diet with a nutritional Cu level (15 mg/kg) of Cu sulfate (SF) was pair offered with higher Cu levels (150 mg/kg) of either SF or hydroxychloride (HCl). In Exp.2 (source preference), a diet supplemented with Cu-SF at 150 mg/kg was compared to a Cu-HCl (150 mg/kg) diet. At the short-term (day 7-9) and for the entire experimental week (day 7-14), pigs preferred diets with a high Cu level than with Cu at a nutritional dose (p < 0.05). Likewise, pigs preferred diets supplemented with a Cu-HCl source compared to diets with Cu-SF (p < 0.05). In vitro assay results showed a greater solubility and interaction of Cu-SF with phytic acid compared to Cu-HCl. In conclusion, pigs chose diets with higher levels of Cu probably to re-establish homeostasis after weaning. Pigs preferred diets with Cu-HCl compared to Cu-SF probably due to their solubilities and chemical differences.