Standardized ileal digestible tryptophan and lysine affects the eating and sleeping behavior of 15-30 kg barrows.

The objective of this study was to evaluate the effect of standardized ileal digestible (SID) tryptophan (Trp) and lysine (Lys) levels on eating and sleeping behavior and the respective feed intake of barrows. Sixty-four pigs, averaging 15.00 ± 1.63 kg of initial body weight, were used and distributed in a randomized blocks design, in a 4 × 4 factorial scheme, consisting of four levels of SID Trp (0.155, 0.185, 0.215, 0.245%) and four levels of SID Lys (0.972, 1.112, 1.252, and 1.392%). Behavior evaluation was performed by an instantaneous sampling using 10-min intervals during 24 h, at each 7 days (days 7, 14, and 21), and each day was divided into four times of 6 h each one (08:30-14:20, 14:30-20:20, 20:30-02:20, and 02:30-08:20 h), during all the experimental period, yielding a total of 3 × 24 h behavior recordings (72 h) × 6 10-min intervals, totalizing 432 observations per animal. Data were analyzed by classifying behavior into eating or sleeping. All these behaviors were measured in order to obtain the estimated frequency of the eating and sleeping behaviors. Changes were observed (P<0.05) for all the behavioral parameters during the starting phase. SID Trp and SID Lys showed an interactive positive effect on the estimated frequency of eating behavior, and mainly SID Trp increased the estimated frequency of the sleeping behavior of starting pigs in the nocturnal time. Pig diets with increasing levels of SID Trp and SID Lys until 0.245 and 1.392%, respectively, increased the average daily feed intake, and the interaction of the amino acids increased the estimated frequency of eating behavior during all the starting phase, and mainly the increasing levels of SID Trp increased the estimated frequency of sleeping behavior of pigs from the middle to the end of the starting phase, from 2:30 to 8:20 h.

ß-mannanase supplementation in diets reduced in 85 kcal metabolizable energy/kg containing xylanase-phytase improves gain to feed ratio, nutrient usage, and backfat thickness in finisher pigs.

This study aimed to assess the effects of ß-mannanase supplementation in metabolizable energy (ME)-reduced diets containing xylanase-phytase on performance, fecal score, blood biochemical and immunological profile, apparent total tract digestibility (ATTD), digesta passage rate, fecal microbiome, carcass traits and meat quality in finisher pigs (n = 40 entire male hybrid, 26.0 ± 0.9 kg) randomly assigned to 1 of 4 dietary treatments: a control diet containing isolated phytase and xylanase valued at 40 kcal of ME/kg (CD0), CD0 + ß-mannanase (0.3 g/kg valued at 30 kcal of ME/kg) (CD70), CD0 + ß-mannanase (0.3 g/kg valued at 45 kcal of ME/kg) (CD85), and CD0 + ß-mannanase (0.3 g/kg valued at 60 kcal of ME/kg) (CD100), with 10 pen replicates. Pigs fed CD0 diet showed (P = 0.002) greater ADFI. However, pigs fed CD0 diet showed (P = 0.009) lower G:F than those provided CD70 or CD85 diets. A greater (P < 0.001) superoxide dismutase concentration was observed in pigs fed CD70 diet. Pigs fed CD85 diet showed (P = 0.002) greater digestible protein than pigs fed CD0 or CD100 diets. Pigs fed CD70 diet showed an increase of 11.3% in digestible protein than those fed CD0 diet. In addition, greater (P < 0.001) digestible energy was observed in pigs fed CD85 diet. Pigs fed CD0 or CD100 diets showed greater (P < 0.05) Firmicutes:Bacteroidota ratio than those fed CD85 diet. The Muribaculaceae was more abundant (P = 0.030) in pigs fed CD70 diet than in those fed CD0 diet. The Prevotella was more abundant (P = 0.045) in pigs fed CD85 diet than in those fed CD100 diet. In conclusion, ß-mannanase supplementation in diets containing xylanase-phytase allows reducing 85 kcal of ME/kg because it improves gain to feed ratio, energy and protein usage, and backfat thickness without metabolic and intestinal ecosystem disorders in finisher pigs.

Determinant production factors to the in vitro organic matter digestibility and protein oxidation of poultry by-product meal.

The quality of poultry by-product meal (PBM) is not standardized in the industry. Several factors are detrimental to PBM and compromise its nutritional value and shelf life. Therefore, this study was conducted to determine the main PBM production factors that directly affect its in vitro organic matter digestibility (IVDOM) and protein oxidation (POX). Data on the processing of PBM samples (n = 100) were recorded in a rendering plant. Two types of PBM were used: 1) Low ash (LA, n = 66) with mineral matter (MM) content of 11% and 2) High ash (HA, n = 34) with MM above 11%. Processing traits and chemical composition of PBM were considered independent variables. The IVDOM and POX were determined in each sample and considered dependent variables. Data on independent variables were submitted to factorial and principal components (PC) analyses. In vitro organic matter digestibility data were clustered (P = 0.001) in low (778.92 g/kg), average (822.85 g/kg), and high (890.06 g/kg). The best arrangement was composed of six independent variables distributed in two PC, which explained 82.10% of the total variation. The ash concentration, oil to raw material ratio, collagen, and crude protein comprised PC1 with greater relevance and explained 58.46% of the total variance. The PC2 was composed of the processing time and temperature and explained 23.64% of the total variance. Protein oxidation data were clustered (P < 0.001) in low (265.19 nmol/mg CP), average (393.07 nmol/mg CP), and high (524.40 nmol/mg CP). Based on our results, the composition of the raw material from the slaughterhouse holds most of the information on PBM composition and digestibility. Developing improvements in the slaughtering or in the screening of the raw material that will be used by the rendering process is important to obtain a more nutritionally standardized ingredient.

Characterization of the variations in the industrial processing and nutritional variables of poultry by-product meal.

The study aimed to measure variations in industrial process and nutritional variables of poultry by-product meal (PBM) in rendering plants from batch cookers. A total of 200 samples of low ash PBM with mineral matter (MM) content of 11% (LA, n = 104) or high ash with MM above 11% (HA, n = 96) were collected from 5 industrial processing plants. The highest coefficients of variation in chemical composition were for MM (LA - 19.70%; HA - 19.59%), ether extract (LA - 20.72%; HA - 14.86%), collagen (LA - 21.16%; HA - 30.00%) and water activity (LA - 24.54%; HA - 25.89%). However, the crude protein (LA - 5.07%; HA - 7.39%), dry matter (LA - 1.75%; HA - 2.90%) and organic matter digestibility (LA - 4.81%; HA - 6.78%) were lower. The variability of the data related to the process of PBM was: maximum process temperature (LA - 3.91%; HA - 3.56%), average process temperature (LA - 3.73%; HA - 4.71%), and processing time (LA - 27.37%; HA - 37.59%). This study evidenced that the corrective measures by limiting the amount of bones in the raw material, optimizing the pressing step for the poultry fat extraction, and also controlling the processing time of PBM may favor the production of more standardized PBM in terms of chemical composition and quality.