Search Results (45)

The objective of this study was to investigate alterations in nutrient utilization, standardized ileal digestibility of amino acids (SIDAA), and intestinal health in response to heat stress (HS) in Pekin ducks. A total of 240 healthy 28-day-old male Pekin ducks were randomly allocated to three groups: a normal control (NC) group, an HS group, and a pair-fed (PF; provided an amount of feed equal to that consumed by the HS group to eliminate the effects of feed intake) group, each with eight replicate cages of ten birds. The results showed that HS significantly reduced the apparent utilization of dietary energy, ether extract, and crude protein compared to both the NC and PF groups (p < 0.05), but yielded comparable SIDAA to the PF group. The HS group exhibited reduced mRNA levels of EAAT3 and PepT1, along with elevated mRNA levels of CAT1, GLUT5, and FATP6 in the jejunum compared to the NC or PF groups, respectively (p < 0.05). Furthermore, HS resulted in a significant deterioration of jejunal morphology and goblet cell count compared to the NC and PF groups (p < 0.05). Serum fluorescein isothiocyanate-dextran levels were significantly higher in HS ducks than in NC ducks (p < 0.05), but did not differ from PF ducks. At order-level classification of ileal mucosal microbiota, HS markedly increased the relative abundance of Bacillales, Deferribacterales, and Actinomycetales versus NC (p < 0.05), while significantly decreasing Bifidobacteriales abundance relative to PF (p < 0.05). Collectively, HS induces a leaky gut and microbiota dysbiosis that compromises gut health, thereby reducing dietary nutrient utilization in Pekin ducks. The observed reduction in feed intake constitutes a primary driver of intestinal health deterioration in heat-stressed Pekin ducks. Full article

Two trials evaluated the effects of dietary protease inclusion in weaned piglets fed diets with or without crude protein (CP) reduction, focusing on performance, intestinal health, and amino acid digestibility. In Trial I, 270 piglets (21–63 days) received six treatments: control (PC), PC with 100 g/ton protease A (PC+A), CP reduced by 1.0% (NC1) or 1.5% (NC1.5), NC1.5 with 50 g/ton protease A (NC1.5+A), and NC1.5 with 50 g/ton protease B (NC1.5+B). PC+A improved weight gain, feed intake, and feed conversion compared with NC1.5+A. The incidence of diarrhea was reduced in animals fed protease-supplemented diets (PC+A, NC1.5+A and NC1.5+B). PC had greater ileal villus height than NC1.5+B, and PC+A showed a higher jejunal villus-to-crypt ratio than reduced CP groups. NC1.5+B increased jejunal expression of IL-6, TNF-α, and haptoglobin. In Trial II, 12 ileal-cannulated piglets received diets with or without protease A. Protease improved the standardized ileal digestibility (SID) of methionine+cysteine and tryptophan but reduced the SID of glycine and proline. While protease supplementation can improve some amino acids (Met+Cys and Thr) protein digestibility, our findings suggest it cannot fully replace careful amino acid balancing in CP-reduced diets. However, protease-supplemented diets were associated with improved intestinal morphometry and a reduced incidence of diarrhea. Full article

Male Ross 308 finisher (19 to 33 days) broiler chickens (n = 672) were used to determine the standardized ileal digestible (SID) leucine (Leu)-to-lysine (Lys) ratio for the maximum growth performance and slaughter parameters. A basal diet (incl. wheat, triticale, soybean meal, sunflower meal, and synthetic amino acids) deficient in Leu was formulated, and supplementary L-Leu was used to achieve 0.9 and 1.25 SID Leu-to-Lys ratios in increments of 0.05. A slight deficiency in lysine was implemented to truly relate broiler performance to changes in the SID Leu-to-Lys ratio. Diets were fed to broilers in seven pens (12 broilers each). Eight birds per pen were used for carcass evaluation on day 33. Data analysis indicated that SID Leu-to-Lys ratios between 0.96 and 1.025 were required to achieve 95% and 98% of the maximum body weight gain, daily feed consumption, and the European production efficacy factor, respectively. The estimation of recommended SID Leu-to-Lys ratios for the feed conversion ratio and carcass parameters was not possible. Full article

The apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids, digestible energy (DE), metabolizable energy (ME), and the apparent total tract digestibility (ATTD) of nutrients in 10 fishmeal (FM) samples were evaluated in weaned barrows (Duroc × Landrace × Yorkshire) using two experiments. In Experiment 1, 11 piglets (18.87 ± 0.10 kg) fitted with T-cannulas were randomly allocated to an 11 × 6 Latin-square design with 11 diets (1 nitrogen-free diet and 10 assay diets) and six periods. The AID and SID of all amino acids (AAs) except proline showed significant differences among all FM (p < 0.05). Importantly, the SID of amino acids was positively correlated with key antioxidant markers and immune parameters, and it was negatively correlated with oxidative stress markers (MDA) and pro-inflammatory cytokines (IL-2 and IL-6). In Experiment 2, 11 piglets (18.05 ± 1.15 kg) were assigned to an 11 × 5 Latin-square design with 11 diets (a 96.35% corn diet and 10 assay diets) and five consecutive periods. Significant variations were observed in the DE, ME, and ATTD of dry matter among different FM samples (p < 0.05). Moreover, predictive equations for estimating the SID of lysine, methionine, threonine, and tryptophan, as well as DE and ME, were established using stepwise regression analysis based on the chemical composition of the FM. These findings demonstrate that the nutritional value of FM in nursery pig diets has been underestimated, and this study provides precise data and predictive methods for evaluating the nutritional quality of FM in precision nutrition. Full article

This study investigated the effects of a low-protein diet without soybean meal on the growth performance, nutrient digestibility, plasma-free amino acids, and meat quality of finishing pigs. A total of 81 barrows and 81 gilts ([Yorkshire × Landrace] × Duroc) of 150 days old with similar body weights (103.64 ± 3.65 kg) were selected and randomly allocated into three groups with three replicates in each group and 18 finishing pigs in each pen (4.5 m × 8.5 m). Three dietary formulations were established in this experiment: (1) 14% crude protein, and 14% soybean meal for the control group diet (CON); (2) 13% crude protein, and 7% soybean meal for half soybean meal group diet (HSB); (3) 12% crude protein, and 0% soybean meal for soybean meal free group diet (SBF). Three groups of diets were equal to standard ileal digestible amino acids and swine net energy. Results showed that (1) there was no significant difference in final body weight, average daily feed intake, and average daily gain in CON, HSB, and SBF groups (p > 0.05). However, the feed conversion rate was higher in the SBF but the differences were not significant (p = 0.08). (2) Compared with the CON group, the apparent digestibility of dry matter, crude protein, and calcium in the SBF group was significantly increased by 6.42%, 4.78%, and 9.82%, respectively (p < 0.05). However, ether extract and phosphorus did not differ significantly between the three groups (p > 0.05). All groups had no significant differences in serum biochemical indexes (p > 0.05). (3) Compared with the CON group, the plasma-free contents of glycine and glutamate in the HSB and SBF groups were significantly decreased by 42.90% and 37.06%, respectively (p < 0.05). Compared with the CON group, the contents of plasma-free histidine and valine in the SBF group were significantly decreased by 16.72% and 16.21%, respectively (p < 0.05), but there was no significant difference compared with the HSB group (p > 0.05). Compared with the CON group, plasma-free isoleucine content in the HSB group was significantly decreased by 50.39% (p < 0.05), but there was no significant difference compared with the SBF group (p > 0.05). (4) Backfat thickness in the SBF group was significantly increased by 3.53% compared with that in the CON group (p < 0.05), but there was no significant difference compared with the HSB group (p > 0.05). Compared with the CON group, lean meat percentage in the HSB and SBF groups showed a tendency to increase and decrease, respectively (p = 0.09). (5) The urine ammonia-nitrogen content of finishing pigs in the SBF group was significantly lower than that of the CON (p < 0.05), at a rate of 28.80%. H₂S content in the urine of the SBF group tended to decrease (p = 0.06). This study demonstrates that a low-protein diet without soybean meal can be applied as a dietary strategy for finishing pigs with no adverse influence on growth performance. Full article

This study evaluated the impact of reduced crude protein (CP) diets supplemented with four essential amino acids (EAAs) on production efficiency and meat quality characteristics in Bamei pigs. Thirty-six castrated Bamei pigs (half male and half female, 100 days old, with an average body weight of 50.65 kg) were randomly assigned to three different dietary CP levels: control group (16.0% CP), group I (14.0% CP + EAA), and group II (12.0% CP + EAA). In both experiments, the group I and group II diets were supplemented with crystalline AA to achieve equal contents of standardized ileal digestible (SID) lysine, methionine, threonine, and tryptophan. After a 70-day feeding trial, the results showed that (1) low-protein diets of different levels supplemented with four EAAs had no significant effect on the growth performance of Bamei pigs (p > 0.05) but had a tendency to increase average daily feed intake (ADFI). (2) In terms of slaughter performance, compared with the control group, the low-protein amino-acid-balanced diet significantly reduced the pH of gastric contents (p = 0.045), and tended to increase the backfat thickness and dressing percentage (p > 0.05). (3) The effect of low-protein diets on muscle amino acids showed that group I was significantly improved, including increased Threonine, Serine, Glycine and Bitter amino acids. (4) Compared with the control group, the low-protein group increased the ratio of unsaturated fatty acid (UFA)/total fatty acids (TFAs), Monounsaturated Fatty Acid (MUFA)/TFA, and Polyunsaturated Fatty Acid (PUFA)/TFA, and the content of decanoic acid, myristic acid, and cis-11-eicosenoic acid in group II was significantly higher than that in the other two groups (p ≤ 0.012). (5) The total number of flavor compounds in the muscle of the low-protein group was higher than that of the control group, including Aldehyde, Alcohol, sulfide, Alkane, and Furan compounds. Among them, the relative contents of Hexanal, Heptaldehyde, Benzaldehyde, E-2-Octenal, 2,3-Octanedione, and 2-Pentylfuran in group II were significantly higher than in those groups (p < 0.05). Notably, the 14% dietary protein level group had the most significant effect on the meat quality and flavor of Bamei pigs. Therefore, under the condition of amino acid balance, reducing the use of protein feed raw materials and adding synthetic amino acids can not only improve the meat quality and flavor of finishing pigs, but also save the feed cost. Full article

The objective was to determine the digestible indispensable amino acid score (DIAAS) of food sources using the pig model and in vitro procedures. The standardized ileal digestibility (SID) of amino acids (AA) in white rice, wheat, pea protein concentrate (PPC), soy protein isolate (SPI), and skim milk powder (SMP) were determined in pigs. Twelve barrows with an initial body weight of 28.4 kg (standard deviation = 4.0) equipped with a T-cannula at the distal ileum were allotted to a replicated 6 × 5 incomplete Latin square design with six diets and five periods. Five experimental diets contained each ingredient as the only source of AA. Additionally, a nitrogen-free diet was prepared to measure the basal endogenous losses of AA for the calculation of the SID of AA. The in vitro ileal disappearance (IVID) of crude protein (CP) in the five food sources was also determined using the conventional flask procedure and the multi-sample simultaneous in vitro procedure employing the Daisy^II incubator. The DIAAS values for white rice were 42, 50, and 60 for infants, children, and adults, respectively. For wheat, the DIAAS values were 46, 56, and 66, respectively. The DIAAS values for PPC were 47, 58, and 69 for infants, children, and adults, respectively. For SPI, the values were 61, 74, and 87, respectively. The DIAAS for SMP were 82, 112, and 131 for infants, children, and adults respectively. The IVID of CP in SMP was greater (p < 0.05) than that in other sources. The DIAAS calculated based on IVID of CP were similar to those determined based on the SID of AA in pigs. In conclusion, white rice, wheat, pea protein concentrate, and soy protein isolate were observed to have DIAAS values less than 100, indicating that these ingredients need to be combined with other protein sources to meet the indispensable AA requirements. Skim milk powder had a DIAAS greater than 100 for children and adults. Full article

Experiments were designed to investigate the effect of extrusion on the available energy and nutrient digestibility of wheat, and to further evaluate the effects of incorporating extruded wheat into the diet on growth performance, diarrhea rates, health status, and fecal microbiota of weaned piglets. In Exp. 1, twelve crossbred barrows, with an initial body weight (BW) of 12.0 ± 0.73 kg, were randomly assigned to two treatment groups (wheat and extruded wheat) to determine the digestible energy (DE) and metabolizable energy (ME). Additionally, nine crossbred barrows (initial BW, 13.73 ± 0.59 kg) fitted with ileal cannulas, were arranged in a 9 × 2 Youden square design, including three diets (N-free diet, wheat, and extruded wheat), aiming to measure the standard ileal digestibility of amino acids (AAs). In Exp. 2, 96 pigs (initial BW, 8.58 ± 0.52 kg) were randomly divided into two treatments (CON and 35% extruded wheat) based on BW, with each treatment having six pens, each pen containing four boars and four sows. The results indicated that extrusion significantly increased the DE and ME of wheat and the standard ileal digestibility of most AAs (p < 0.05). Incorporating 35% extruded wheat did not affect the growth performance, diarrhea rates, nutrient digestibility, or health status of the weaned piglets (p > 0.05). However, it tended to enhance the α-diversity of fecal microbiota (p = 0.07) and increased the relative abundance of beneficial bacteria (p < 0.05). In conclusion, extrusion increased the feeding value of wheat, and the inclusion of 35% extruded wheat in the diet increased the relative abundance of beneficial microbes in feces. Full article

This exploratory study expected crop management and climatic factors to significantly influence the nutrient composition and amino acid digestibility of tannin-free sorghum grain determined in broilers of 3 wks of age. Using data from six tannin-free sorghum samples harvested across the southeast USA, Pearson correlations were analyzed (r ≥ |0.8|; p < 0.05). Standardized ileal amino acid digestibility (SIAD) was determined in a previous study using eight replicate cages with 13 birds per sorghum sample. SIAD values were correlated with nitrogen fertilization, yield, seeding rate, and climatic data obtained by surveying the crop growers and from weather stations. Nitrogen fertilization positively correlated with dry matter and starch. Yield was positively associated with SIAD, while seeding rate was negatively correlated with dry matter and Lys. Fiber, particular neutral detergent fiber, showed an inverse relationship with SIAD. No significant correlations with climatic factors were found, which was likely due to the close proximity of growing locations (r ≤ |0.8|; p > 0.05). Despite the limitations of a small sample size (n = 6) and genetic variability within and between each sorghum sample, these findings provide preliminary insights into managing sorghum cultivation to enhance its nutritional value for poultry. Future research should explore larger datasets, from further locations apart, and standardized data collection measurements to be able develop predictive models for grain quality improvement. Full article

Two experiments were conducted with Ross 308 male broiler chickens to determine the standardized ileal digestible (SID) methionine (Met) requirement for maximum weight gain during the starter (0 to 10 days) and grower (10 to 21 days) phases. A total of 720 and 288 birds were allocated to Experiments 1 and 2, respectively, and assigned six dietary treatments in a randomized complete block design. The experimental diets were formulated with corn, soybean meal, and synthetic amino acids to achieve varying SID Met levels (3.8 to 5.8 g/kg in experiment 1 and 3.0 to 5.5 g/kg in experiment 2), with increments of 0.4 and 0.5 g/kg. Weight gain, feed intake, and the gain-to-feed ratio (G:F) increased quadratically (p < 0.05) as dietary SID Met increased. The SID Met requirements for maximum weight gain and G:F in the starter phase were 5.1 g/kg (79.5 mg/d) and 5.3 g/kg (89.8 mg/d), while in the grower phase, they were 5.5 g/kg (343.0 mg/d) and 5.4 g/kg (330.3 mg/d), respectively. These findings, divided into two growth phases, provide guidelines to facilitate the optimal and maximum performance of young male broilers, and this may facilitate the selection of appropriate values for formulating broiler feed. These findings also highlight the importance of Met supplementation strategies for improving performance. Full article

This study aimed to assess the standardized ileal amino acid (AA) digestibility (SIAD) values in broilers (3 weeks of age) for tannin-free sorghum samples collected from the Southeastern region of the USA as well as provide a general comparison between sorghum vs. corn. An incomplete block design was implemented using the direct method to assess the SIAD of eight sorghum samples and one corn sample as the standard. Three of these sorghum samples were obtained from North Carolina (NC-PL, NC-T2, NC-LW), four samples from South Carolina (SC-Flo, SC-Pei, SC-Tub, SC-Experience), and one from Georgia (GA-Gf). Each tested grain was assigned to eight cages, with thirteen birds/cage. Birds were reared for 3 wks using the last 4 d as the experimental phase when ileal digesta were collected for SIAD assessment. Each sorghum sample’s digestibility was compared to that of corn. Generally, the South Carolina sorghum varieties showed the lowest AA digestibility values, except for SC-Flo, which had the highest digestibility, surpassing corn in Lys, Thr, Gly, and Asp (p < 0.05). Then, the sorghums’ SIAD values were pulled together for a general comparison to corn. Overall, the sorghum SIAD was comparable to corn (p > 0.05), but variations were noted among the AAs. Sorghum had better digestibility for Lys, Thr, and Asp while corn had more digestible Met, Leu, Pro, and Phe (p < 0.05). By integrating the crude protein content with SIAD data, this study provides an updated assessment of tannin-free sorghum’s protein quality. The findings suggest that tannin-free sorghum could serve as a practical alternative to corn in poultry feed, providing a comparable nutritional profile. Full article

Accurate prediction of amino acid requirements in fast-growing broilers is crucial for cost-effective diet formulation and reducing nitrogen excretion to mitigate environmental impact. This study developed a dynamic model to predict standardized ileal digestible amino acid requirements throughout broiler growth using a factorial approach and the comparative slaughter technique, considering maintenance, growth, and gender factors. The model was based on an experiment were designed using 480 15-day-old Arbor Acres chickens randomly assigned to 10 groups. A linear equation was derived using established growth and protein deposition curves to calculate maintenance and growth coefficients. Models for five essential amino acids under different amino-acid-to-protein ratios were created (R² > 0.70). The model effectively estimated daily amino acid needs and specific time intervals. Comparisons with NRC (1994), BTPS (2011), and Arbor Acres manual (2018) showed higher predicted requirements for lysine, methionine, valine, and threonine than Arbor Acres (2018) and BTPS (2011), significantly exceeding NRC (1994). Arginine predictions aligned with BTPS in early stages, but were slightly lower in later stages. This supports the further development of dynamic amino acid models. Full article

Twenty-seven gestating primiparous sows (203 ± 9.1 kg initial body weight on d 89 ± 1 of gestation) were selected to determine the effect of standardized ileal digestible (SID) sulfur-containing amino acid (SAA) intake during late gestation on whole-body nitrogen (N) retention and subsequent litter performance. Primiparous sows were assigned to one of two experimental diets that provided SAAs at 63 or 200% of the estimated requirements during late gestation (0.29 and 0.92% SID SAAs, respectively; n = 15 and 12, respectively). The diets were isoenergetic, and the SID Lys was 0.80% in both diets. Each gilt received 2.50 kg of the assigned diet between gestation d 90 and farrowing. Common lactation and nursery diets were provided to all primiparous sows after farrowing and offspring after weaning, respectively. Gilt whole-body N balance was determined between d 107 and 109 of gestation using total urine collection and fecal grab sampling. After farrowing, litters were standardized to 13 piglets and were not offered creep feed. Whole-body N retention was greater in primiparous sows fed the diet containing 0.92 vs. 0.29% SID SAAs in late gestation (27.2 vs. 19.3 ± 1.8 g/d; p < 0.05), but the number of piglets born alive, litter birth weight, subsequent piglet growth rates, and litter size at weaning were not different between the treatment groups. The post-weaning growth performance of the offspring was not influenced by maternal dietary treatment in late gestation. At farrowing, the post-absorptive plasma concentration of Tau was greater (p < 0.01) for primiparous sows fed 0.92 vs. 0.29% SID SAAs in late gestation, and offspring from primiparous sows fed 0.92% SID SAAs tended to have greater plasma homocysteine (Hcys; p = 0.066). Post-absorptive plasma AAs Ile, Leu, Val, and Tyr were greater (p < 0.05), and Ser tended to be greater (p = 0.071) in sows fed 0.92 vs. 0.29% SID SAAs. For the offspring, there were no diet effects on any of the dispensable and indispensable AA concentrations in plasma at birth, at weaning, or 3 and 6 weeks post-weaning. The primary finding is that the sow has a remarkable ability to buffer dietary AA imbalances, ensuring fetal growth even when SAA intake is below the current requirement estimates. While sufficient supplemental SAA intake is essential for the sow’s well-being, excessive SAA levels may not confer additional advantages in terms of sow or piglet growth and the production of vital metabolites. This research emphasizes the importance of meticulously balanced diets for pregnant sows to simultaneously support maternal growth and nitrogen retention, which may also have an impact on the synthesis of biomolecules linked to improving health outcomes for the offspring. Full article

This study aimed to evaluate the digestible energy (DE), metabolizable energy (ME), and standardized ileal digestibility (SID) of amino acids (AA) in fermented soybean meal (FSBM) fed to growing pigs. In experiment 1, twenty-two growing pigs (Duroc × Landrace × Yorkshire; 32.0 ± 4.2 kg BW) were fed one of 11 diets in a replicated 11 × 3 incomplete Latin square design to determine the DE and ME of FSBM. The diets included a corn-based diet and 10 experimental diets formulated by replacing the corn with 29.10% FSBM. In experiment 2, eleven growing pigs (Duroc × Landrace × Yorkshire; 24.3 ± 2.3 kg BW) were surgically equipped with a T-cannula and arranged in an 11 × 6 incomplete Latin square design with 11 diets and six periods. The diets included an N-free diet and 10 experimental diets containing 40% FSBM as the sole source of AA. The results showed that the contents of dry matter (DM), gross energy, crude protein, crude fiber, neutral detergent fiber, acid detergent fiber, calcium, and phosphorus averaged 91.83% (ranging from 89.24 to 94.55%), 18.44 MJ/kg (ranging from 18.00 to 18.95 MJ/kg), 50.63% (ranging from 50.00 to 51.81%), 4.51% (ranging from 3.41 to 5.40%), 9.17% (ranging from 7.02 to 10.30%), 6.38% (ranging from 4.97 to 7.45%), 0.32% (ranging from 0.29 to 0.34%), and 0.67% (ranging from 0.61 to 0.84%), respectively. The average DE and ME were 17.55 and 16.33 MJ/kg DM, respectively, with ranges of 15.72 to 18.80 MJ/kg DM and 14.30 to 17.72 MJ/kg DM, respectively. Significant differences were observed in the SID of essential AA (p < 0.05), except for Thr and Arg. The SID of Lys, Met, Trp, and Thr ranged from 68.13 to 83.27% (mean = 76.62%), 62.23 to 89.30% (mean = 75.25%), 72.30 to 90.29% (mean = 80.96%), and 74.17 to 84.41% (mean = 77.90%), respectively. These results indicate significant variability in chemical composition, energy content, and the SID of AA among the selected FSBM samples. The chemical composition of FSBM can be used to predict DE and ME values. Full article