Search Results (73)

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

The objective of this study was to determine the effects of two levels of a precision biotic (PB) within a reduced CP diet for performance, digestibility, and blood biomarkers in Dekalb White laying hens from 24 to 42 weeks of age. A total of four diets were fed: (1) an industry-standard positive control (PC) diet with a formulated CP level of 17.5%; (2) a negative control (NC) diet with a formulated CP level of 15.5%; (3) NC with 0.5 kg/ton PB (NC+PB1); (4) NC with 0.7 kg/ton PB (NC+PB2). The NC diet decreased hen–day egg production compared to the PC diet, and supplementation with both levels of PB led to intermediate levels of production. There was a similar trend for the feed conversion ratio (FCR), measured in kilograms of feed per dozen eggs. Feed cost was lower in the reduced CP diets compared to the PC. Apparent total tract digestibility was decreased with PB supplementation without differences in apparent ileal digestibility. The increased plasma uric acid levels in the NC+PB2 group suggest a shift in protein metabolism toward higher efficiency in ammonia detoxification. While more research is needed on PB, this research suggests that supplementation with PB in laying hens could potentially improve performance parameters. 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 use of lower crude protein (CP) diets immediately after weaning has long been associated with reduced post-weaning diarrhoea (PWD). However, failing to maintain an appropriate standardized ileal digestible lysine ratio (SID: Lys) may outweigh the benefits in improving PWD outcomes. In this experiment, 560 weaners were fed either a control diet (CON; 20.6% crude protein 1.34% standardized ileal digestible lysine, SID Lys: CP = 0.06), LH: a low crude protein, higher SID Lys: CP ratio diet (19.0% CP, 1.34% SID Lys, SID Lys: CP = 0.07), or LL: a low crude protein control SID Lys: CP ratio diet (18.7% CP, 1.1% SID Lys, SID Lys: CP = 0.05) for 1 week after weaning. Pigs were scored for the presence or absence of diarrhoea for 12 days after weaning. Blood samples were taken on days 5, 12 and 28 for inflammatory marker analyses and plasma creatinine analyses. Relative to the CON diet, there was a 42% reduction in the diarrhoea index in pigs fed the LH diet and a 63% reduction in those fed the LL diet (p < 0.05), but LH was significantly higher than LL. There tended to be a greater average daily gain in the LH diet in the first week post-wean (p = 0.054). In summary, lower crude protein diets, irrespective of Lys: CP ratio, were found to be effective at reducing PWD. Moreover, increasing the SID Lys: CP ratio by reducing the CP content of diets from 20.6 to 19% appeared to improve post-weaning growth. 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

Limited published data areavailable on the current DLys requirements of Hy-Line Silver-Brown layers. The effects of energy (AMEn) and standardized ileal digestible lysine (DLys) concentration on the performance of Hy-Line Silver-Brown layers were studied from 20 to 35 weeks of age. The experimental design was randomized with twenty-four dietary treatments arranged as a 2 × 12 factorial with two AMEn concentrations (2750 and 2900 kcal/kg feed) and twelve levels of DLys (4.2, 4.5, 4.8, 5.1, 5.4, 5.7, 6.0, 6.6, 6.3, 6.9, 7.2, and 7.5 g/kg). Total egg weight (TEW), average egg weight, total egg number (TEN), laying rate, total feed intake, average daily feed intake (ADFI), mortality, hen body weight, hen body weight gain, eggshell thickness, eggshell breaking strength, yolk weight, albumen weight, and eggshell weight were recorded. An increase in energy content from 2750 to 2900 kcal AMEn/kg reduced ADFI (p < 0.001), egg mass output (p = 0.042), and feed conversion ratio (p = 0.018, g/g; p = 0.001, g/dozen) and increased the fat percentage in the liver (p = 0.028). An increased DLys intake from 529 to 882 mg/hen/day increased the TEN (p = 0.001), TEW (p < 0.001), and egg mass output (p < 0.001); improved the feed conversion ratio (p < 0.001); and reduced carcass (p = 0.001) and liver fat percentage (p = 0.05). Hy-Line Silver-Brown hens require no more than 780 mg (optimized egg production) and 880 mg (maximized egg weight) DLys/hen/day during pre-peak and peak production phases. Full article

One way to reduce the environmental impact of the European poultry industry is to feed birds with low crude protein (CP) or low soybean meal (SBM) diets, leading to less SBM import. In this paper, the objective was to examine if low CP and a feed limitation of SBM could be applied to reduce the global warming potential (GWP) of feed without a negative impact of the performance and slaughter parameters. Male Ross 308 birds (n = 1350) were divided between six treatments in a completely randomized design. In a three-phase feeding system, the dietary CP was reduced either only in the finisher phase (from 19% to 17% CP), in the grower phase (from 20% to 19% CP) and finisher phase, or in the starter (from 21% to 20% CP), grower, and finisher phases. In two additional groups, SBM inclusion in feed was reduced in each life phase either to a maximum of 15% SBM (low) or 0% SBM (zero) compared to a positive control (PC) group based on Aviagen 2019 recommendations, modified to 112% for standardized ileal digestibility (SID) arginine (Arg) to lysine (Lys) and 38% for SID histidine (His) to Lys. Data were analyzed with R (Version 4.2.0) using linear regression models. Opteinics™ (Chemovator, Mannheim, Germany) was used to calculate feed GWP. Means were compared with multiple comparisons corrected with Tukey’s test. Low CP diets had no negative effect on performance, carcass weight, and breast meat weight compared to the PC irrespective of the phase in which CP reduction was initiated. Both zero and low SBM groups had superior body weight (p < 0.05), weight gain (p < 0.05), and FCR (p < 0.05) compared to PC at d35. The low and zero SBM groups had higher carcass weight (p < 0.05) and breast meat weight (p < 0.05) compared to the PC. Both low CP and limiting SBM inclusion in feed positively improved the feed GWP compared to the PC. In conclusion, low CP diets can be applied in broilers during a 35 d growth period or specific phases thereof, with no negative impacts on performance parameters. Low and zero SBM-based diets showed superior performance and carcass weight in comparison to a conventional SBM-driven diet. Both strategies can be used to reduce the GWP of feed. Full article

A 2 × 3 factorial design was used to examine the effects of maternal probiotic supplementation (Bacillus subtilis and Bacillus amyloliquefaciens) and/or piglet dietary Trp levels on sow performance and fecal microbiota composition, as well as offspring pre-weaning performance and intestinal health parameters on the day of weaning. On day 83 of gestation, 48 sows were allocated to either: (1) control, or (2) control + probiotic (1.1 × 10⁹ colony forming units/kg of feed). Their litters were assigned to 0.22, 0.27, or 0.33% standardized ileal digestible (SID) Trp diets (0.17, 0.21 and 0.25 SID ratio of Trp to lysine (Trp:Lys), SID lysine = 1.3%). At weaning, one piglet per litter was sacrificed for intestinal health analysis. Diet had no effect on sow reproductive or offspring growth performance pre-weaning (p > 0.05). Maternal probiotic supplementation led to distinct microbial communities in the sow feces on day 114 of gestation, increasing the relative abundance of Anaerocella and Sporobacter, while decreasing Lactobacillus, Ruminococcus, and Christensenella (p < 0.05). In the offspring colonic digesta, maternal probiotic supplementation increased Dorea, Sporobacter, and Anaerobacterium, while reducing the potentially harmful phylum Proteobacteria, specifically the family Enterobacteriaceae (p < 0.05), with a tendency for a reduction in the genus Escherichia (p < 0.1). Maternal probiotic supplementation enhanced duodenal morphology and modulated the expression of genes in the ileum, including a downregulation of certain immune and barrier defense genes (p < 0.05). Piglets from probiotic sows had reduced branch chain fatty acids (BCFA) in the cecal digesta and an increase in the total VFA and acetate in the colonic digesta (p < 0.05). There were limited effects of Trp level in the offspring’s creep diet or maternal × creep interactions, though this analysis was likely confounded by the low creep feed intake (total of ~0.83 kg/litter). Full article

This study aimed to evaluate the effects of the standardized ileal digestible tryptophan-to-lysine (SID Trp–Lys) ratio through the supplementation of different levels of L-tryptophan on pig performance and immune response following an LPS challenge. A total of 120 entire male pigs, with an average body weight of 16.5 ± 0.50 kg, were allocated in a randomized block design with four treatments, ten replicates per treatment, and three animals per experimental unit. The experimental treatments consisted of SID Trp–Lys ratios of 16%, 18%, 21%, and 24%, achieved through L-tryptophan supplementation. The evaluated performance parameters included the final body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR). Blood samples were collected on day 21 to determine serum serotonin levels, and on day 26, pigs were inoculated with LPS to induce an immune challenge, followed by blood sampling to assess cytokine responses. The results showed that pigs fed the 16% SID Trp–Lys ratio exhibited a lower FBW (p < 0.05). The SID Trp–Lys ratios influenced performance parameters, with quadratic responses (p < 0.05) observed for the FBW and FCR, where the highest FBW and lowest FCR were recorded at 22.05% and 21% SID Trp–Lys, respectively. A linear increase (p < 0.05) was observed for ADG, with a trend for a linear increase (p = 0.056) in ADFI. No effects (p > 0.10) of the SID Trp–Lys ratios were detected on serum serotonin levels. An increase in cytokine levels (GM-CSF, IFN-γ, IL-1α, IL-1β, IL-1ra, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, and TNF-α) was observed in pigs challenged with LPS (p < 0.10) compared to non-challenged animals. An interaction effect (p < 0.10) was detected for IL-2 and IL-18. SID Trp–Lys ratios between 21% and 24% optimize growth performance in pigs from 16 to 33 kg and modulate the immune response under LPS-induced challenge conditions. 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