Search Results (165)

This study evaluated the effects of forage-free diets with reduced starch levels on the productive performance, metabolism, ruminal fermentation, nutrient digestibility, and meat quality of feedlot beef cattle. Two experiments were conducted. In Experiment 1, forty uncastrated Nellore steers were distributed into 20 pens in a completely randomized design, receiving diets with increasing inclusion levels of ground corn in the total diet: C400 (400 g kg⁻¹), C200 (200 g kg⁻¹), C100 (100 g kg⁻¹), and C50 (50 g kg⁻¹), formulated without forage and based on fibrous co-products. Increasing ground corn inclusion promoted linear improvements in final body weight and average daily gain, while dry matter intake and feed efficiency showed quadratic responses. Meat quality parameters were not affected by dietary treatments. In Experiment 2, eight crossbred steers were assigned to a double 4 × 4 Latin square design and fed the same experimental diets. Higher corn inclusion increased starch and fat intake, whereas dry matter, organic matter, and protein intake showed quadratic responses. Apparent total-tract digestibility of dry matter, organic matter, and starch also followed a quadratic pattern. Ruminal fermentation parameters were affected by dietary treatments, with greater ammoniacal nitrogen concentrations at higher corn levels and quadratic responses for propionate, butyrate, and methane production. Nitrogen metabolism indicated increased urinary nitrogen and uric acid excretion with increasing dietary corn inclusion. These results demonstrate that forage-free diets based on citrus pulp and soybean hulls with different levels of ground corn can be effectively used in finishing beef cattle, improving performance without impairing meat quality while modulating ruminal fermentation and nutrient utilization. Full article

Global population growth has intensified the demand for productive and sustainable livestock systems. Lithothamnium calcareum, a calcareous marine alga, has been investigated as a natural feed additive for cattle diets. This study evaluated the effects of L. calcareum supplementation on performance, carcass traits, nutrient digestibility, nitrogen metabolism, urinary and fecal pH, and enteric methane emissions in Nellore heifers during the finishing phase. Thirty-six heifers (BW = 268.8 ± 7.3 kg) were assigned to individual pens in a completely randomized design and fed ad libitum diets (25:75 forage-to-concentrate ratio, DM basis). Treatments were: (1) sodium bicarbonate (110 g/heifer/day) and (2) L. calcareum (60 g/heifer/day). The 96-day trial included 12 days of adaptation and 84 days on the finishing diet. Methane emissions were measured using the sulfur hexafluoride (SF₆) tracer technique. L. calcareum did not affect performance, carcass traits, nitrogen metabolism, or apparent total tract digestibility (all p ≥ 0.106), but reduced urine pH (p ≤ 0.001) and tended to lower methane emissions (−8.2%; p = 0.079). Thus, L. calcareum appears to be a viable natural alternative to sodium bicarbonate in finishing diets for Nellore heifers, maintaining productive performance and potentially reducing enteric methane output. Full article

Accurate and physiologically relevant in vitro models are needed to predict nutrient digestibility and hindgut fermentation in pigs, as conventional in vivo trials are resource-intensive and raise animal welfare concerns. This study evaluated and compared the predictive performance of three in vitro digestion approaches—shaking (S), dialysis (D), and a combined shaking plus dialysis (SD) method—for estimating in vivo apparent total tract digestibility (ATTD) and fermentation characteristics across weaning, growing, and finishing pigs. Commercial diets were subjected to simulated gastric and small-intestinal digestion using S, D, or SD, followed by fecal inoculation to model hindgut fermentation for 12 and 48 h. During the gastrointestinal phase, crude protein digestibility was highest with D (>75%), intermediate with SD, and lowest with S (50–60%), indicating that product removal by dialysis mitigated enzyme inhibition from metabolite accumulation. After 48 h of fermentation, all methods showed strong linear correlations with in vivo ATTD (r > 0.93), but only D achieved high absolute agreement (Lin’s CCC > 0.95 for dry matter and crude protein). Moreover, D and SD at 48 h closely reflected in vivo fecal profiles of skatole, indole, and microbial enzyme activities, with D at 12 h showing an especially strong correlation for protease (r = 0.98). While D provided the most precise predictions of absolute values, the SD method offered an optimal balance between physiological relevance and operational efficiency, supporting its use as a robust, high-throughput platform for porcine feed evaluation and fecal nitrogenous odorant prediction. Full article

This study evaluated the impact of incorporating citrus pulp (CiP) into the rations of high-producing dairy cows under tropical conditions. Eighteen lactating dairy cows were assigned to two dietary treatments: corn meal (CM) or CiP as the main energy source. Dairy cows were allocated to a crossover design comprising two 21-day periods. The rations were formulated to be isocaloric and isonitrogenous. Replacing CM with CiP reduced the intakes of dry matter (19.9 vs. 19.5 kg/d), organic matter (17.9 vs. 17.4 kg/d), digestible organic matter (12.3 vs. 11.7 kg/d), and crude protein (3.43 vs. 3.35 kg/d), while increasing neutral detergent fibre intake (7.39 vs. 7.63 kg/d). Apparent total tract digestibility decreased for all nutrients, including DM, OM, CP, NDF, and ADF, when CiP replaced CM. Milk production was lower in cows fed CiP than in those fed CM (23.7 vs. 22.7 kg/d), although milk feed efficiency (milk/DMI) was not different. An economic analysis showed that cows fed CM had higher milk gross income and income over feed cost. These results suggest that the partial replacement (60%) of CM with CiP may negatively affect feed intake, nutrient digestibility, milk production, and profitability in dairy cows in tropical regions. Full article

The hypothesis that the values obtained for the apparent total tract digestibility (ATTD) of energy and digestible energy (DE) and metabolizable energy (ME) in pistachio shell powder are not different from the values obtained for soybean hulls when fed to growing pigs. A basal diet containing corn, a diet containing corn and 20% pistachio shell powder, and a diet containing corn and 20% soybean hulls were formulated. Twenty-four growing pigs (initial body weight: 32.0 ± 1.7 kg) were allotted to the three diets in a randomized complete block design with eight pigs per diet. After a 7-d adaptation period, feces and urine were quantitatively collected for 4 days. The diets and feces were analyzed for dry matter, and all samples were analyzed for gross energy (GE). The results indicated that the ATTD of GE was greater (p < 0.05) for soybean hulls than for pistachio shell powder, but less (p < 0.05) than for corn. Pistachio shell powder provided less (p < 0.05) DE than corn (i.e., 1778 kcal/kg vs. 3787 kcal/kg; dry matter basis), but the DE in pistachio shell powder was not different from that in soybean hulls (i.e., 2010 kcal/kg; dry matter basis). In conclusion, pistachio shell powder can be used as an alternative ingredient in diets for growing pigs and provides 1778 kcal/kg of DE on a dry matter basis. Full article

This study was conducted to investigate the effects of dietary polyunsaturated fatty acid (PUFA) levels and FME (flavor and multiple enzymes) on the reproductive performance, nutrient digestion, and metabolism, immunity, and antioxidant capacity of sows and piglets. Forty primiparous sows [Duroc × (Landrace × York)] were randomly assigned from day 107 of gestation to day 7 post-weaning to one of four dietary treatments, low PUFA (4.6% tallow, LP), high PUFA (4.6% fish oil, HP), and LP and HP, each supplemented with 600 mg/kg FME (LP + FME, HP + FME). Results showed that dietary HP + FME supplementation significantly alleviated sow backfat loss during lactation (p < 0.05). Dietary FME supplementation significantly increased milk lactose and solids-non-fat (p < 0.05) on day 15. Meanwhile, milk protein and true protein contents were significantly lower in the LP treatment than in the LP + FME and HP treatments. The apparent total-tract digestibility (ATTD) of ash and phosphorus was improved (p < 0.05) by both HP diets and FME supplementation. The ATTD of energy and dry matter was significantly higher in LP + FME treatment than in LP and HP + FME treatments (p < 0.05). HP diets increased serum malondialdehyde (MDA, p < 0.01), total superoxide dismutase (p < 0.05) in sows, and increased serum MDA and decreased hydrogen peroxide (H₂O₂) contents in piglets (p < 0.05). Dietary FME supplementation decreased serum H₂O₂ contents and increased serum catalase activity of sows and/or piglets (p < 0.05). The serum immune markers, lipid, and protein metabolites of sows and piglets were altered (p < 0.05 or p < 0.10) by HP diets and/or FME supplementation. In conclusion, dietary fish oil (4.6% of diet replacing tallow) and FME (600 mg/kg) supplementation improved lactating performance by improving nutrient digestibility, body reserve mobilization, antioxidant capacity, and health state of sows and piglets. Full article

This study aimed to test the additivity of digestible phosphorus (P) in mixed diets fed to pigs and to investigate the effects of P expressions in diet formulations on P excretion from pigs. In experiment 1, eight castrated male pigs (30.5 ± 1.5 kg) were allotted to a replicated 4 × 4 Latin square design. Three experimental diets contained wheat, soybean meal, or both as the sole P source, and a P-free diet was prepared to determine the basal endogenous losses of P. In experiment 2, twenty-four castrated male pigs (18.1 ± 0.7 kg) were allotted to a completely randomized design. Three experimental diets were prepared based on the total, apparent total tract digestible (ATTD), or standardized total tract digestible (STTD) P. In experiment 1, the measured ATTD of P in the mixed diet was greater (p < 0.05) than the predicted values, but no difference was observed in the STTD of P in the mixed diet. In experiment 2, the daily P output of the pigs fed the diet based on ATTD P was greater (p < 0.05) than that based on the total or STTD P. Overall, the STTD P provides a more accurate and additive measure of biologically available P in mixed diets for pigs, and the use of STTD P in formulations may reduce P excretions. Full article

Weaned piglets have a fragile gastrointestinal tract and immature digestive function. Supplementation of Bacillus can enhance intestinal barrier function and improve nutrient digestion and absorption efficiency. It is an important nutritional regulation method to alleviate weaning stress, reduce the incidence of diarrhea and promote growth performance. This experiment was conducted to investigate the effects of Bacillus subtilis, Bacillus pumilus and their combination on growth performance, diarrhea incidence, nutrient apparent digestibility, intestinal morphology and barrier function of weaned piglets. A total of 128 weaned piglets weighing 6.68 kg (±0.35 kg) were selected, divided into 4 treatment groups, and fed with a basal diet (CTR), a Bacillus subtilis (BS1), a Bacillus pumilus (BS2) and a Bacillus subtilis + Bacillus pumilus (BS1 + BS2) for 42 days. Each group had 8 replicates with 4 piglets per replicate. One piglet was selected from each replicate and euthanized to collect intestinal samples. The results showed that compared with the CTR group, the BS1 + BS2 group significantly increased the average daily gain (ADG) of weaned piglets on days 0–14 (p < 0.05), and the BS2 group significantly increased the ADG on days 0–42 (p < 0.05). Compared with the CTR group, the BS1 + BS2 group significantly reduced the full-time diarrhea rate (p < 0.05), and weaned piglets of the BS2 group significantly reduced the incidence of diarrhea on days 0–14, 15–28, and 0–42 of the study, in comparison to the control (p < 0.05). Compared with the CTR group, the piglets in the BS1 + BS2 group significantly decreased the serum tumor necrosis factor-α (TNF-α) content on day 21 (p < 0.05), and the BS1, BS2, and BS1 + BS2 groups significantly decreased the serum TNF-α content on day 42 (p < 0.05). Compared with the CTR group, the BS1 + BS2 group significantly reduced the expression of Interleukin-8 (IL-8) mRNA in the ileum (p < 0.05). The BS1, BS2, and BS1 + BS2 groups significantly reduced the expression of TNF-α mRNA in the ileum, IL-8 mRNA in the jejunum, and TNF-α mRNA in the jejunum (p < 0.05). In addition, compared with the CTR group, the BS2 and BS1 + BS2 groups significantly increased Claudin-1 mRNA expression in the jejunum (p < 0.05). Compared with the CTR group, the BS1 and BS2 groups significantly increased Occludin mRNA expression in the jejunum (p < 0.05). In summary, dietary supplementation with Bacillus-based probiotics can significantly improve growth performance in weaned piglets, reduce diarrhea incidence, alleviate inflammation, and enhance intestinal barrier function. Full article

The study was conducted to determine the apparent total tract digestibility, the rate of digesta passage, growth performance, and physicochemical properties of the digesta of Windsnyer pigs fed on increasing levels of potato hash silage. Diets were formulated to contain 0, 80, 160, 240, 320, and 400 g potato hash silage/kg of diet. Pigs were randomly assigned to six diets according to a completely randomised design. Six pigs were allocated to each dietary treatment. All diets were blended with chromic oxide (Cr₂O₃) to calculate apparent total tract digestibility and rate of passage. Pigs were fed diets containing different levels of potato hash silage for 5 d, following 7 d of adaptation. Thereafter, pigs were subjected to a 35-day growth performance experiment. Thirty-six pigs were slaughtered and eviscerated to determine digesta characteristics and gut compartment weights. There was a positive correlation (p < 0.05) between mean retention time and each of digestibility of dry matter, organic matter, and crude protein. There was a quadratic increase (p < 0.05) in digestibility of organic matter, crude protein, fibre and feed intake as dietary levels of potato hash silage increased. Average daily gain and gain-to-feed ratio decreased linearly (p < 0.05) in pigs as levels of potato hash silage increased. The swelling capacity (SWC) of the digesta from ileum decreased linearly (p < 0.05) as dietary levels of potato hash silage increased. The SWC of the digesta from the caecum increased linearly (p < 0.05) as dietary levels of potato hash silage increased. The water holding capacity (WHC) of the stomach digesta decreased linearly (p < 0.05) as dietary levels of potato hash silage increased. The WHC of the digesta from the ileum and caecum displayed negative quadratic responses (p < 0.05) as dietary levels of potato hash silage increased. The WHC of digesta from the proximal colon showed a linear decline (p < 0.05) as dietary levels of potato hash silage increased. The WHC of digesta from the distal colon increased linearly (p < 0.05) as dietary levels of potato hash silage increased. The results indicated that Windsnyer pigs can effectively utilise potato hash silage in diets until the 240 g/kg inclusion level beyond which total tract digestibility and feed intake are compromised. Full article

This study investigates the digestibility, fecal characteristics, and palatability of plant-based protein sources in canine diets. With an increasing number of pet owners adopting vegan lifestyles for ethical, health, and environmental reasons, the demand for plant-based dog diets has risen. Using plant by-products can also be a practical and sustainable option for feeding pets. This study included eight healthy female dogs fed four different plant-based diets using a Latin square (4 × 4) crossover design, with linseed press cake, sunflower press cake, pumpkin press cake, and soy press cake as protein sources. To measure the acceptance of the protein sources, a five-bowl test was used. The apparent total tract digestibility of the different diets and the fecal quality were compared as well as the acceptability of the individual protein sources. The results showed significantly (p < 0.0001) better acceptance for the pumpkin press cake compared to the other three tested press cakes, whereas the addition of potato flakes changed the acceptance and showed no significant (p = 0.1105) differences between the press cakes. Among the tested diets, the highest protein digestibility was observed for the pumpkin diet (85.11% ± 1.77%), followed by the sunflower (84.23% ± 2.20%) and soy diets (82.35% ± 3.37%), while the linseed diet showed the lowest protein digestibility (77.52% ± 6.04%). Full article

The aim of this study was to evaluate two proteases (P1 and P2) on the apparent and standardized ileal digestibility (AID and SID, respectively), of crude protein (CP) and amino acids (AAs) and apparent total tract digestibility (ATTD) of nutrients and gross energy (GE) of corn and soybean meal, with 46% and 48% CP, in pigs by the index method. Ninety crossbred castrated male piglets (13.52 ± 1.96 kg body weight) were fed a nitrogen-free diet, or diets containing corn or soybean meal as the sole sources of CP and AAs, supplemented or not with 0.05% of P1 or 0.01% of P2, an acid protease. Treatment differences were considered statistically significant at p < 0.05. The inclusion of proteases in corn and of P1 in soybean meal diets did not improve the digestibility of nutrients and energy. Otherwise, the addition of P2, an acid protease, in soybean meal diets increased (p < 0.05) the AID and SID of Lys, Met, Phe, Ala, Cys, and Glu, and the respective digestible AA values, from 7.5% to 22%, compared to soybean meal without proteases. The use of the acid protease can be an important tool to enhance the digestibility of the AAs of soybean meal in piglets. Full article

This study evaluated the effects of dietary potassium diformate supplementation on growth performance, nutrient digestibility, gastrointestinal pH, jejunal morphology, digestive enzyme activity, and antioxidant status of weaned piglets in a 28-day trial. Twenty-four weaned piglets were selected and, after a 4-day adaptation period, randomly assigned to 4 treatment groups (n = 6). The dietary treatments included a control diet (basal diet) and 3 diets supplemented with 0.6%, 1.2%, or 1.8% potassium diformate in the basal diet. The results indicated that the feed conversion ratio (FCR) of piglets was reduced by all three potassium diformate supplementation levels compared to the control group (p < 0.05). Additionally, the FCR was decreased in piglets fed the 1.8% potassium diformate-supplemented diet compared to those fed the 1.2% potassium diformate-supplemented diet (p < 0.05). Piglets fed the three potassium diformate-supplemented diets exhibited higher apparent total tract digestibility (ATTD) of dry matter and crude protein than the control group (p < 0.05). The 1.8% potassium diformate groups also showed increased ATTD of calcium and phosphorus compared to the control group (p < 0.05). Supplementation with 1.2% or 1.8% potassium diformate reduced the digesta pH in the proximal stomach, distal stomach, and duodenum, while increased jejunal villus height (VH), VH/crypt depth (VH/CD) ratio, and catalase and total superoxide dismutase activities in the jejunal mucosa compared to the control group (p < 0.05). The 1.2% potassium diformate group showed higher α-amylase activity than the control group (p < 0.05). Correlation analysis revealed that FCR negatively correlated with ATTD of dry matter, crude protein, calcium, phosphorus, and jejunal VH, while positively correlating with digesta pH in the proximal stomach (p < 0.05). The ATTD of dry matter negatively correlated with digesta pH in the proximal stomach, distal stomach, and duodenum, and positively correlated with jejunal VH/CD ratio and catalase activity (p < 0.05). The ATTD of crude protein negatively correlated with digesta pH in the proximal stomach, distal stomach, and duodenum (p < 0.05). Collectively, dietary supplementation with 1.8% potassium diformate reduced FCR of weaned piglets, which was associated with enhanced nutrient digestibility, reduced pH in the anterior gastrointestinal tract, and improved jejunal morphology. Full article

This study evaluated the effects of adding a Saccharomyces cerevisiae fermentation product (SCFP) to adult cat diets on palatability, intestinal health, nutrient digestibility, immune parameters, and the fecal microbiome over 42 days. Sixty-three healthy Domestic Short-hair cats were randomized to three diets: a control diet (CD) without SCFP, or the same diet containing 1.0% or 2.0% SCFP, targeting daily intakes of 150 or 300 mg/kg body weight, respectively. Body weight and blood parameters remained within reference ranges across all groups. Stool quality was largely not affected, although compared with controls, SCFP-supplemented cats had slightly firmer stools at day 21, and increased fecal pH. Shotgun metagenomic sequencing revealed that microbiome diversity remained steady in SCFP-fed cats, whereas diversity in the control group declined over time. Fecal immunoglobulin A concentrations were lower in cats supplemented with SCFP at 150 mg/kg BW by the end of the study, and positive shifts in the circulatory leukocyte profile were observed at both inclusion levels. Apparent total tract macronutrient digestibility did not differ among groups. Palatability tests showed diets with SCFP were generally preferred, indicating a potential benefit for commercial feline feeds, particularly at the 150 mg/kg BW level, which was preferred over 300 mg/kg BW. Overall, these findings suggest that SCFP can act as a functional ingredient in feline nutrition to maintain microbial diversity and enhance diet acceptance without compromising digestibility. Full article

This study aimed to investigate the effects of dietary selenium (Se) supplementation levels on the apparent total tract digestibility (ATTD) of crude protein, crude fat, and crude ash, and cecal microbiota diversity and composition in nursery piglets challenged with deoxynivalenol (DON). Twenty-four weaned piglets were allocated to four dietary treatment groups (n = 6). The four treatment diets were as follows: (1) post-weaning diet containing 0.3 mg/kg of Se; (2) post-weaning diet without supplemental Se + 3 mg/kg DON; (3) post-weaning diet containing 0.3 mg/kg Se + 3 mg/kg DON; and (4) post-weaning diet containing 0.5 mg/kg Se + 3 mg/kg DON. The native Se levels in the feedstuffs were 0.03–0.06 mg/kg. The Se source was supplemented in the form of selenomethionine. The trial lasted 28 days, with fecal samples collected during the final 4 days for ATTD analysis of crude protein, crude fat, and crude ash. Upon trial completion, cecal digesta was sampled for microbial diversity and composition analysis. The results showed that piglets in the 0.5 mg/kg Se + DON group had a higher ATTD of crude fat than the 0 mg/kg Se + DON group and a greater ATTD of crude ash than the 0.3 mg/kg Se + DON group (p < 0.05). Additionally, the 0.5 mg/kg Se + DON group displayed increased Shannon and Chao 1 indices compared to the 0 mg/kg Se + DON group (p < 0.05). Microbial composition analysis revealed higher Firmicutes abundance in the 0.5 mg/kg Se + DON group than in the 0.3 mg/kg Se + DON group, along with reduced Euryarchaeota abundance relative to the 0 mg/kg Se + DON group (p < 0.05). The 0.5 mg/kg Se + DON group also had higher Selenomonadaceae abundance than the other groups (p < 0.05). Pearson correlation analysis indicated a negative correlation between Selenomonadaceae abundance and the ATTD of ash, whereas [Eubacterium]_coprostanoligenes_group abundance was positively correlated with the ATTD of ash (p < 0.10). Collectively, dietary Se supplementation at 0.5 mg/kg improved nutrient digestibility in DON-exposed nursery piglets, which was potentially associated with the modulation of cecal microbiota diversity and composition. Full article

Based on an established appropriate substitution level for corn distillers dried grains with solubles (DDGSs) replacing energy-supplying components in the basal diet for pregnant sows, the substitution method was employed to determine the available energy values of corn DDGSs. In Exp. 1, forty pregnant sows (gestation day = 50 ± 5 d; body weight = 220 ± 24.9 kg; parity, 4 to 6) were randomly allocated into five treatments. The control group was fed a corn–soybean basal diet, while test diets contained 20%, 30%, 40%, 50% corn DDGSs replacing the energy-supplying portion of the basal diet. In Exp. 2, the available energy of five corn DDGS sources was determined using the substitution method at a 30% substitution level. Twelve pregnant sows (gestation day = 50 ± 5 d; body weight = 225.4 ± 29.2 kg; parity, 4 to 6) were arranged in a 6 × 3 Youden square design. Dietary treatments consisted of the corn–soybean basic diet and five test diets incorporating different corn DDGS types. Increasing the substitution level of corn DDGSs displayed both linear and quadratic effects (p < 0.05) on the apparent total tract digestibility (ATTD) of dry matter (DM), organic matter (OM), acid detergent fiber (ADF), ether extract (EE) and gross energy (GE) in diets. The ATTD of neutral detergent fiber (NDF), digestible energy (DE) and metabolizable energy (ME) was quadratically affected by different substitution levels (p < 0.05), with the highest value achieved at the 30% substitution level. As the substitution level of corn DDGSs increased, the ATTD of ADF in corn DDGSs decreased. In contrast, the ATTD of crude protein (CP) increased either linearly or quadratically (p < 0.05), and a significant quadratic effect was observed for the ATTD of EE in corn DDGSs (p < 0.05). Although the GE, DE, and ME of corn DDGSs were not significantly influenced by the substitution level, the 30% corn DDGSs resulted in the lowest coefficients of variation (CV). Therefore, a 30% substitution level of corn DDGSs is recommended for energy-supplying components in the basal diet of pregnant sows using the substitution method. The ranges of DE, ME and net energy (NE) of five corn DDGSs samples were 15.58–18.07, 12.17–16.42 and 8.76–15.88 MJ/kg DM, respectively. The absolute value of relative error (|RE|) between the predicted available energy values obtained from the prediction equations established in Exp. 2 and the determined values were below 5%, except for ME for corn DDGSs N3 (5.81%). Full article