Neutral detergent fiber increases endogenous ileal losses but has no effect on ileal digestibility of amino acids in growing pigs

Two experiments were conducted to determine the effect of neutral detergent fiber (NDF) on endogenous amino acids and protein ileal losses; and also apparent ileal digestibility (AID), and standardized ileal digestibility (SID) of amino acids and crude protein. Sixteen barrows were fed four protein‐free diets containing graded NDF levels in Experiment 1. NDF was a mixture of sugarcane bagasse and corn leaves (SBCL). Twenty‐four barrows were fed diets with soybean protein concentrate (SPC) or casein as protein sources and SBCL or corncobs (CC) as NDF sources in Experiment 2. In Experiment 1, a linear increase (P < 0.05) in endogenous amino acid and protein ileal losses was observed with increased NDF levels, except for arginine, histidine, methionine and proline. In Experiment 2, protein (P < 0.001) and NDF (P < 0.01) sources significantly affected AID of dry matter, which was higher in casein diets (71.7%) and CC diets (70.7%). Protein and NDF sources significantly affected (P < 0.05) SID of crude protein, which was higher in casein diets (92.8%) and CC diets (92.7%). NDF source had no effect (P > 0.05) on SID of amino acids. Overall, this study showed that NDF increased endogenous amino acid and protein ileal losses, but did not affect ileal digestibility of amino acids.     

Effects of different fermented soy protein and apparent ileal digestible lysine levels on weaning pigs fed fermented soy protein‐amended diets

Two experiments were conducted to evaluate the effect of different fermented soybean proteins and the apparent ileal digestible lysine levels on weaning pigs fed fermented soy protein (FSP)‐amended diets. In Exp. 1, 70 crossed piglets (6.25 ± 0.40 kg) were used in a 5‐week trial to evaluate two different FSP. In Exp. 2, 20 weaning barrows (6.15 ± 0.45 kg) were used in a metabolism trial to determine the effects of the apparent ileal digestible (1.2, 1.3, 1.4 and 1.5%) lysine levels in weaning pigs fed FSP (5%) diet. In Exp. 1, pigs fed the diet containing Lactobacillus spp. FSP showed higher nitrogen (N) digestibility (P < 0.05), lower blood urea nitrogen and serum creatinine levels (P < 0.05) than those fed the Aspergillus oryzae FSP diet. In Exp. 2, increasing dietary lysine levels increased the average daily gain, apparent dry matter, N digestibility, N retention and essential amino acids in the current study (P < 0.05), with the 1.5% showing the highest value. In conclusion, pigs fed Lactobacillus spp. FSP had a higher N digestibility than those fed A. oryzae FSP. The optimal apparent ileal digestibility lysine level in fermented soy protein diets (3550 kcal/kg metabolizable energy) for maximizing growth performance and N utilization in the first 7 days (6.25 kg) was 1.5%.     

Ileal digestibility of nutrients and amino acids in unfermented,fermented soybean meal and canola meal for weaning pigs

Apparent ileal digestibility (AID) of energy, dry matter, nitrogen and amino acids and standardized ileal digestibility (SID) of nitrogen and amino acids were evaluated in six weanling pigs ((Landrace × Yorkshire) × Duroc)) fed unfermented soybean meal (SM), yeast fermented soybean meal (SMY), bacillus fermented soybean meal (SMB), yeast and bacillus fermented soybean meal (SMYB), canola meal (CM) and nitrogen‐free diet. Pigs having body weights 17.00 ± 0.3 kg were surgically equipped with T‐cannulas of approximately 15 cm prior to the ileo‐cecal junction and randomly allotted to one of five dietary treatments and a nitrogen‐free diet in 6 × 6 Latin squares. AID and SID of nitrogen (N) was greater (P < 0.05) in SMYB and SMB compared with SM and CM. AID and SID of amino acids such as, Lys (lysine) and Phe (phenylalanine) as well as total essential amino acids were greater (P < 0.05) in SMB and tended to be low in CM compared with SM. AID and SID of aspartic acid (Asp) and glycine (Gly) tended to be higher in SMB compared with SM and other diets except CM. In conclusion, fermentation of soybean meal by Bacillus showed better digestibility of amino acid and nutrients.     

Amino acid digestibility in low-fat distillers dried grains with solubles fed to growing pigs

The objective of this experiment was to determine the standardized ileal digestibility (SID) of amino acids (AA) in 3 sources of distillers dried grains with solubles (DDGS) with different concentrations of fat. Twelve growing barrows (initial body weight: 76.1 ± 6.2 kg) were randomly allotted to a replicated 6 × 4 Youden square design with 6 diets and 4 periods. The fat content of the 3 sources of DDGS were 11.5, 7.5, and 6.9% respectively. Diets contained 60% DDGS and fat concentration of the diets were 7.5, 5.2, and 5.2%, respectively. Two additional diets containing the 2 sources of DDGS with 7.5 and 6.9% fat were also formulated, and corn oil was added to these diets to increase the concentration of fat in the diets to levels that were calculated to be similar to the diet containing conventional DDGS with 11.5% fat. A N-free diet was also formulated to calculate endogenous losses of crude protein (CP) and AA from the pigs. Pigs were fed experimental diets during four 7-d periods. The first 5 d of each period were an adaptation period and ileal digesta were collected on d 6 and 7 of each period. The apparent ileal digestibililty (AID) and SID of CP and all indispensable AA, except AID Pro and SID of Trp, were greater (P < 0.01) in conventional DDGS than in the 2 sources of DDGS with reduced fat. Adding oil to the diets containing the 2 sources of DDGS with reduced fat did not consistently increase SID of AA. In conclusion, conventional DDGS has greater SID values for most AA compared with DDGS that contains less fat and inclusion of additional oil to diets containing low-fat DDGS does not increase AID or SID of AA. The lower AA digestibility in low-fat DDGS could not be overcome by the inclusion of additional fat to the diets.     

Standardized ileal digestibility of proteins and amino acids in sesame expeller and soya bean meal in weaning piglets

Apparent ileal digestibility (AID) of diets containing sesame expeller (SE) and soya bean meal (SBM) was determined using 15 piglets (Genetiporc^®), weaned at 17 ± 0.4 days with average body weight of 6.4 ± 0.7 kg (Fertilis 20 × G Performance, Genetiporc^®, PIC México, Querétaro, México). Piglets were randomly assigned to three treatments: (i) a reference diet with casein as the sole protein source; (ii) a mixed diet of casein–SE; and (iii) a mixed diet of casein–SBM. The chemical composition of SE and SBM was determined, and AID and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AAs) were determined for each protein source. SE contained greater quantities of ether extract, neutral detergent fibre, phytic acid, methionine and arginine than SBM. Lysine and proline contents and trypsin inhibitor activity were higher in SBM than in SE. The AID and SID of CP and AA (except for lysine and proline) were similar in SE and SBM. The AID of lysine and proline was higher in SBM than in SE (p < 0.05), and the SID of proline was higher in SE than in SBM (p < 0.05). These findings indicate that SE is an appropriate alternative protein source for early weaned pigs.     

Comparative standardized ileal amino acid digestibility and metabolizable energy contents of main feed ingredients for growing pigs when adding dietary β-mannanase

The present study was conducted to test whether the dietary supplementation of β-mannanase affects amino acids (AA) digestibility, metabolizable energy (ME) contents of corn, wheat, soybean meal, distillers dried grains with solubles, and palm kernel meal (PKM), nutrient digestibility, and growth performance of pigs. In Exp. 1, 22 cannulated pigs were used for 10 dietary treatments including 5 feed ingredients and 2 β-mannanase concentrations (0 and 0.5 g/kg of the diet) in 6 periods in an incomplete Latin square design to determine the AA and energy digestibility. In Exp. 2, 200 growing pigs were randomly allotted to 4 treatments with 2 nutrient levels (high and low) and 2 concentrations of β-mannanase (2 × 2 factorial arrangement) in 2 phases (phase 1, d 0 to 21; and phase 2, d 22 to 42). In Exp. 1, β-mannanase increased the mean standardized ileal digestibility (SID) of AA in all feed ingredients. The amount of digestible energy was increased (P < 0.05) in β-mannanase-treated PKM. Pigs fed β-mannanase showed a greater (P < 0.05) digestibility of gross energy (GE). The feed-to-gain (F:G) ratio was improved (P < 0.01) in pigs fed high-nutrient diets. Pigs fed β-mannanase in the diets had greater (P < 0.05) average daily gain and F:G. In phase 2, the concentration of fecal ammonia was decreased (P < 0.05) in pigs fed β-mannanase. Considering the 2 experiments, it can be concluded that β-mannanase increases the SID of AA, which has to be considered in balancing the rations.     

Amino acid digestibility of corn distillers dried grains with solubles, liquid condensed solubles, pulse dried thin stillage, and syrup balls fed to growing pigs

Distillers dried grains with solubles (DDGS) has low and variable AA digestibility. The variability is often attributed to damage during the heating process, and it has been suggested that the damage happens to the soluble components of DDGS such as reducing sugars. Combining solubles and grains sometimes produces syrup balls (SB); their digestibility is unknown. The objective of this experiment was to identify potential sources of poor and variable AA digestibility in DDGS. Specifically, our objective was to determine whether the problems are associated with the solubles component or with SB. The ingredients evaluated were DDGS, intact SB, ground SB, liquid condensed solubles (LCS), and pulse dried thin stillage (PDTS) obtained from the same ethanol plant. The LCS is produced by evaporation of thin stillage. Each ingredient was used as the only source of AA in an experimental diet. In a duplicate 6 × 6 Latin square design with 7-d adaptation and collection periods, the 6 treatments consisted of an N-free diet and the 5 test ingredients. Pigs had 5 d of adaptation to each diet, and on d 6 and 7 ileal digesta were collected from an ileal cannula for 8 h each day. Both SB treatments had apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA that were similar or greater (P < 0.05) than those of DDGS. The AID and SID values of Lys and a few other AA were similar in LCS (SID Lys: 63.1%) and DDGS (SID Lys: 61.5%), but the digestibility values of most AA in LCS were less than in DDGS (P < 0.05). The low digestibility of AA in LCS was most pronounced for Met (SID: LCS, 41.9% vs. DDGS, 82.8%). The LCS had less (P < 0.05) AID and SID of CP (SID: 67.8%) than intact SB (SID: 85.2%) and ground SB (SID: 85.9%) as well as all AA. The PDTS generally had the least AID and SID and had less (P < 0.05) CP (SID: 55.3%) and several AA, including Lys, compared with LCS. In conclusion, the presence of SB does not decrease AA digestibility of DDGS, and the LCS evaluated has less indispensible AA digestibility than DDGS. The LCS has low digestibility of AA that seems to not be caused by heat damage.     

饲粮蛋白源对早期断奶仔猪生产性能的影响

试验选用64头25日龄杜×(大×长)三元杂交断奶仔猪,随机分为4组:A、B、C为试验组,分别用猪肠膜蛋白粉(DPS)、大豆浓缩蛋白(SPC)、喷雾干燥猪血浆蛋白粉(SDPP)部分取代基础饲粮的鱼粉;D为对照组,饲喂基础饲粮(玉米-豆粕-鱼粉)。试验从仔猪25日龄断奶开始,70日龄结束。结果显示:试验组日增重均显著高于对照组,其中B组比对照组高13.18%(P<0.05);A组、C组分别比对照组高11.53%(P<0.05)、4.43%(P<0.05);B组和A组日增重差异不显著(P>0.05),但均显著高于C组,分别高8.38%(P<0.05)、6.80%(P<0.05)。B组日采食量比对照组高4.82%(P<0.05),A组、C组与对照组相比,日采食量有提高的趋势,但差异不显著(P>0.05)。A组、B组与对照组相比,料肉比有降低的趋势(P>0.05)。由此可见,本试验条件下,大豆浓缩蛋白、猪肠膜蛋白粉、猪血浆蛋白粉对早期(25日龄)断奶仔猪的饲喂效果均优于鱼粉,且大豆浓缩蛋白、猪肠膜蛋白粉对仔猪日增重的改善幅度大于喷雾干燥猪血浆蛋白粉(P<0.05)。     

Apparent and standardised ileal digestibility of amino acids in wheat,triticale and barley for broiler chickens at two different ages

ABSTRACT

1. The influence of the age of broiler chickens on ileal amino acid (AA) digestibilities in three cereals was examined. The digestibility estimates, including both apparent (AID) and standardised (SID) coefficients, for wheat, triticale and barley samples were determined using 14 and 28 d old broilers of mixed sex, fed diets containing the test grains as the only source of protein.

2. Each assay diet was offered to five replicate cages of 14 and eight birds respectively, for the 14 and 28 day samplings. On both sampling days, the contents from the lower half of the ileum were collected for determination of the AID coefficients. The SID coefficients were calculated using ileal endogenous amino acid (EAA) losses previously determined from birds fed an N-free diet.

3. The average AID for essential AA (EAA) in triticale and barley were significantly higher at 28 day compared to those at 14 days. In contrast, the magnitude of AID coefficients of AA in wheat was found to be in larger in the younger chickens.

4. Correction of AID for EAA losses increased the values of digestibility coefficients by an average of about 7%. The SID values of AA in wheat was not influenced by the age of broilers. The SID of most AA in triticale, and of all the AA in barley, were higher in 28-day-old chickens compared with their 14-day-old counterparts. The results suggested that the SID coefficients of EAA in wheat determined at day 28 could be applied to feed formulations for 14-day-old broilers, but in the case of triticale and barley, the values obtained in older chickens were not applicable in younger birds and vice versa.     

Determination and prediction of the apparent and standardized ileal amino acid digestibility in cottonseed meals fed to growing pigs

This experiment was conducted to evaluate the chemical composition and apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) in cottonseed meals (CSM) and to develop prediction equations for estimating AA digestibility for growing pigs based on the chemical composition and AA content of CSM. 10 CSM were collected from 10 provinces in China. 11 barrows (initial body weight: 34.4 ± 1.9 kg), fitted with an ileal T‐cannula, were allotted to 6 × 11 Youden square with 6 periods and 11 diets. The diets included one N‐free diet and 10 CSM test diets containing 40% CSM as the sole source of AA. The nitrogen‐free diet was used to measure the basal endogenous losses of CP and AA. The AID and SID for crude protein (CP), Lys, Met, Trp, and Thr among the 10 CSM differed (p < 0.05). With R² values exceeding 0.30, significant linear regression equations for CP, Lys, and Thr were obtained. The best fit equations for predicting the AID and SID of Lys were: AID of Lys = 82.94–0.65 neutral detergent fiber, with R² = 0.44, residual standard deviation (RSD) = 4.03 and p = 0.04; and SID of Lys = 135.34–1.01 neutral detergent fiber + 34.27 Thr – 58.06 Trp – 84.93 Met, with R² = 0.90, RSD = 1.42 and p = 0.01. In conclusion, the results of AID, SID and prediction equations could be used to evaluate the digestibility of CSM in growing pigs.     

Factors affecting the variability in ileal amino acid digestibility in corn distillers dried grains with solubles fed to growing pigs

Two experiments were conducted to compare the ileal digestibility of AA in distillers dried grains with solubles (DDGS) sourced from different regions (IL, MN, KY), to compare AA digestibility in DDGS and in distillers dried grains (DDG) and to compare AA digestibility in DDGS from ethanol production (DDGS(ethanol)) and DDGS from beverage production (DDGS(beverage)). In Exp. 1, five samples of DDGS(ethanol) were sourced from Minnesota (MN1, MN2), Illinois (IL1, IL2), and from Kentucky (KY). In Exp. 2, six samples of DDGS(ethanol), 1 sample of DDG, and 1 sample of DDGS(beverage) were used to compare values for apparent ileal digestibility and standardized ileal digestibility (SID) of AA between DDGS(ethanol) and DDGS(beverage) and between DDG and DDGS(ethanol). Results of Exp. 1 showed that the SID of Lys in DDGS from MN2 (72.8%) was greater (P < 0.01) than in DDGS from MN1 (66.8%), IL1 (66.8%), and KY (65.8%) but not different from IL2 (70.1%). Except for Leu and Glu, no differences in SID for any of the other AA were observed among the 5 sources of DDGS. In Exp. 2, the SID for Lys in DDGS(beverage) was greater (P < 0.01) than in DDGS(ethanol) (69.3 vs. 64.8%), but for CP and all other AA except His, no differences between the 2 types of DDGS were observed. The SID for most AA in DDG were greater (P < 0.05) than in DDGS(ethanol), which suggests that the AA in the solubles that are added to DDGS may be less digestible than the AA in DDG. In conclusion, results of these experiments confirm that the digestibility of Lys is more variable among sources of DDGS than the digestibility of other AA. However, the SID of AA among DDGS sources within a region can vary as much as among DDGS sources from different regions, and AA in DDGS(beverage) may be as digestible as AA in DDGS(ethanol). The digestibility of AA in DDG is greater than in DDGS, which indicates that AA in the solubles have a lower digestibility than AA in DDG.     

Additivity of values for apparent and standardized ileal digestibility of amino acids in mixed diets fed to growing pigs

The objective of this experiment was to determine whether the digestibility of CP and AA in a mixed diet fed to growing pigs is better predicted when based on standardized ileal digestibility coefficients (SID) or apparent ileal digestibility coefficients (AID). Eight growing pigs (initial BW = 92.1 +/- 3.19 kg) were surgically equipped with a T-cannula in the distal ileum and arranged in an 8 x 8 Latin square design with eight diets and eight periods. Three of the diets contained corn, soybean meal (SBM), or canola meal (CM) as the sole source of CP and AA. Four mixed diets also were formulated using corn and soybean meal (CS); corn and canola meal (CCM); soybean meal and canola meal (SCM); or corn, soybean meal, and canola meal (CSCM). A N-free diet was used to measure the basal ileal endogenous losses (IAAend) of CP and AA. Pigs were fed each of the eight diets during one 7-d period, and ileal digesta were collected during two 10-h periods on d 6 and 7. The AID values were calculated for CP and AA in all diets, except the N-free diet. By correcting the AID for IAAend, the SID for CP and AA in each of the seven protein-containing diets were calculated. As expected, the AID for CP and the majority of AA were greater in SBM than in corn and CM (P < 0.05); however, the SID for CP and most AA did not differ between corn and SBM. For the majority of the AA, SID were less (P < 0.05) in CM than in the other two ingredients. Using the AID and the SID that were measured for CP and AA in corn, SBM, and CM, the AID and the SID in the four mixed diets were predicted and compared with the measured values for these diets. For the three mixed diets containing corn, the measured AID for CP and most AA were greater (P < 0.05) than the predicted AID, but with a few exceptions, no differences between predicted and measured values for SID were observed. For the diet based on SCM, there were no differences between predicted and measured values regardless of the procedure used, except for the AID of Ser. The results of this experiment demonstrate that the digestibility coefficients for a mixed diet containing low-protein feed ingredients, such as corn, are more accurately predicted using SID than AID.     

Rearing conditions affected responses of weaned pigs to organic acids showing a positive effect on digestibility,microflora and immunity

Three experiments were conducted to assess the response of weaned pigs to organic acid SF3, which contains 34% calcium formate, 16% calcium lactate, 7% citric acid and 13% medium chain fatty acids. Dietary treatments had no effect on growth performance of piglets (21‐day weaning) fed the commercial prestart diet for 1 week before receiving the experimental diets supplemented with SF3 at 0, 3 or 5 g/kg diet (Exp. 1), whereas diarrhea frequency averaged across a week was decreased by SF3 supplementation (5 g/kg diet) in piglets fed the experimental diets immediately after weaning (Exp. 2). In Exp. 3, piglets (28‐day weaning) were fed the control (containing pure colistin sulfate and enramycin, respectively, at 20 mg/kg diet) for 1 week and then were fed the control or SF3‐supplemented (5 g/kg diet) diet for 2 weeks. The SF3‐fed piglets had greater apparent ileal digestibility of calcium and dry matter, while also demonstrating greater overall gross energy, up‐regulated jejunal expression of sodium‐glucose cotransporter‐1 and transforming growth factor‐β, down‐regulated jejunal expression of tumor necrosis factor (TNF)‐α, higher ileal Lactobacillus, with lower total bacteria content, lower plasma TNF‐α but higher IgG levels than the control‐fed piglets. Collectively, SF3 consumption improved diarrhea resistance of weaned pigs by improving nutrient digestibility, piglet immunity and intestinal bacteria profile. © 2016 Japanese Society of Animal Science     

Amino acid and energy digestibility of protein sources for growing pigs

Two experiments were conducted to determine the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA and DE, and to estimate ME and NE of rice protein concentrate, salmon protein hydrolysate, whey protein concentrate, and spray-dried plasma protein. In Exp. 1, 6 barrows (initially 29.5 +/- 2.5 kg of BW) were fitted with ileal T-cannulas and fed each of 5 cornstarch-based diets in a balanced crossover design over 35 d. During a given week, there were either 1 or 2 replications of each treatment, resulting in 6 total replications over 5 wk. The 4 test diets (fed from d 0 to 28) were formulated to contain 12.5% CP by using analyzed nutrient compositions of rice protein concentrate, salmon protein hydrolysate, whey protein concentrate, or spray-dried plasma protein. The fifth (N-free) diet was fed from d 28 to 35 to estimate basal endogenous losses of CP and AA, which were used to calculate SID. Ileal digesta were collected and analyzed, and AID and SID values were calculated. Apparent ileal digestible Lys, Met, and Thr values were 80.0 +/- 3.3, 65.6 +/- 3.1, and 68.4 +/- 4.5% for rice protein concentrate; 85.6 +/- 4.8, 85.5 +/- 4.3, and 69.8 +/- 8.5% for salmon protein hydrolysate; 93.3 +/- 1.4, 89.9 +/- 5.8, and 83.6 +/- 5.3% for whey protein concentrate; and 92.8 +/- 0.9, 85.7 +/- 2.1, 86.5 +/- 2.3% for spray-dried plasma protein, respectively. In Exp. 2, 6 barrows (initially 37.6 +/- 1.7 kg of BW) were fed each of 5 corn-based diets in a balanced crossover design over 35 d. During a given week, there were either 1 or 2 replications of each treatment, resulting in 6 total replications over 5 wk. The 4 diets containing the test ingredients were formulated to contain approximately 20% CP by using their analyzed nutrient compositions. The fifth (corn control) diet containing 8.2% CP was also used to calculate energy values by difference. Feces were collected to determine DE. The ME and NE contents were estimated using published regression equations. The DE, ME, and NE (as-fed) values were 4,724 +/- 461, 4,226 +/- 437, and 3,235 +/- 380 kcal/kg for rice protein concentrate; 4,173 +/- 1,052, 3,523 +/- 1,002, and 2,623 +/- 872 kcal/kg for salmon protein hydrolysate; 4,949 +/- 1,002, 4,352 +/- 955, and 3,344 +/- 831 kcal/kg for whey protein concentrate; and 4,546 +/- 673, 3,979 +/- 652, and 3,020 +/- 567 kcal/kg for spray-dried plasma protein, respectively. The excellent AA digestibility and relatively high DE, ME, and NE values indicate that these protein sources warrant further investigation as ingredients for growing pig diets.     

Comparison of digestible and metabolizable energy and digestible phosphorus and amino acid content of corn ethanol coproducts from Brazil and the United States produced using fiber separation technology for swine

Three experiments (exp.) were conducted to determine and compare the digestibility of nutrients and energy of corn distillers dried grains with solubles (DDGS) from the United States (USDDGS), a dried mixture of corn bran with solubles (CBS) from Brazil (BRCBS), and high protein corn distillers dried grains (HP-DDG) from the United States (USHPDG) and Brazil (BRHPDG) in growing pigs. The feed ingredients were evaluated for apparent total tract digestibility (ATTD) of gross energy (GE), dry matter (DM), crude protein (CP), ether extract, neutral and acid detergent fiber (NDF and ADF, respectively), and digestible and metabolizable energy (DE and ME, respectively) using the total collection and index methods in exp. 1; ATTD and standardized total tract digestibility (STTD) of phosphorus (P) in exp. 2; and apparent (AID) and standardized (SID) ileal digestibilities of CP and amino acids (AA) in exp. 3. Fifty crossbred barrows (32.4 ± 6.9, 38.3 ± 5.2, and 46.2 ± 5.3 kg body weight [BW], in exp. 1, 2, and 3, respectively) were fed a corn basal diet in exp. 1, a P-free diet in exp. 2, and an N-free diet in exp. 3 or diets with 40% inclusion of test ingredients to provide 10 replications per treatment. Pigs were housed individually in metabolism cages (exp. 1) or in pens (exp. 2 and 3) and fed at 2.8 times the maintenance DE requirement (110 kcal/kg BW^0.75) based on their BW at the beginning of each experiment. Except for ATTD of NDF, which tended (P = 0.058) to be greater by the index method compared with the total collection method, no difference between the total collection and index methods was observed for ATTD of remaining nutrients and DE. The ATTD of DM, GE, NDF, and DE content of BRHPDG were greater (P < 0.001) than USHPDG, BRCBS, and USDDGS. The AID of CP, Arg, His, Ile, Leu, Lys, Thr, and Val and the SID of His, Leu, Lys, and Val of BRHPDG were 8% to 36% greater (P < 0.05) than those from USHPDG. Except for Trp, all AID and SID AA values were greater (P < 0.05) in BRHPDG than in USHPDG. The ATTD of DM, GE, NDF, and ADF; DE and ME content; AID of CP, Arg, Ile, Leu, Phe, Thr, and Trp; and SID of CP, Arg, Phe, and Thr of USDDGS were 9% to 45% greater (P < 0.05) than those in BRCBS. The ATTD and the STTD of P in USHPDG and USDDGS were 26% to 42% greater (P < 0.05) compared with BRHPDG and BRCBS. In conclusion, BRHPDG had a greater digestibility of energy and most of the AA than USHPDG, while the BRCBS evaluated had lower nutritional value than the USDDGS source.     

ORIGINAL ARTICLE: Effects of herbage ingestion upon ileal digestibility of amino acids in heavy Iberian pigs fed on an acorn‐based diet

We conducted two experiments with heavy Iberian pigs to determine the ileal digestibility of amino acids (AA) in acorns and freshly cut herbage, and the effects of adding fresh herbage upon the supply of ileal digestible AA when pigs were fed on holm‐oak acorns. In Experiment 1, carried out in cannulated pigs of 107 kg bodyweight (BW), daily intake of acorns reached 44.9 g DM/kg^0.75 BW. Arg, His and Thr showed the lowest apparent ileal digestibility (AID) values, whereas Met, the branched‐chain AA and Phe had the highest coefficients. The AID of total EAA was 0.716 but only 0.222 for NEAA. Most of the digestive and absorptive processes of acorn protein occurred before the hindgut. Acorn provides (per kg DM) 2.27 g apparent ileal digestible Lys and 22.7 g apparent total digestible AA. Standardized ileal digestibility (SID) values for EAA, NEAA and total AA were 0.924 ± 0.020, 0.784 ± 0.041 and 0.860 ± 0.029. In Experiment 2 fresh herbage was given to six cannulated Iberian pigs of 140 kg either as a single feed (13.7 g DM/kg^0.75 BW) or as a supplement to acorns (28.4 g DM/kg^0.75 BW). When only freshly cut forage was offered the AID of the EAA, NEAA and total AA was close to 0.65 and supplied (per kg DM ingested) 5.61 g AID Lys and 91.7 g digestible AA. Standardized ileal values were 0.744 ± 0.023, 0.912 ± 0.038 and 0.831 ± 0.030 respectively. The addition of fresh forage to the acorns led to a significant decrease in AID of AA in acorn due to digesta transfer to the hindgut: His (p < 0.01), Met (p < 0.001), Phe (p = 0.092), Thr (p < 0.05) and Val (p < 0.05), but Arg, Lys and the branched‐chain AA remained unaffected. The main contribution of herbage to AA nutrition of the grazing Iberian pig relies mainly on increasing the supply of digestible AA for pig tissues.     

Ileal digestibility of protein and amino acids from canola meal in weaned piglets and growing pigs

Two experiments were conducted to measure the apparent ileal digestibility coefficients (AID) of protein and amino acids from canola meal (CM) and a pelleted canola meal (PCM) and their effect on specific activity (SA) of pancreatic proteases in weaned piglets and growing pigs. In experiment one, 24 piglets weaned at 17 days and weighing 5.5 kg were used. Treatments were a reference diet with 200 g of crude protein (CP) kg^− 1 elaborated with casein (C) as the sole protein source, a diet containing C–CM and a diet containing C–PCM. These diets were obtained using the reference diet plus 100 g kg^− 1 of CM or PCM that substituted an isoproteic mixture of casein and maize starch from reference diet, so that the AID coefficients for their protein and amino acids could be calculated by difference. In experiment two, nine castrated pigs weighing 39.5 kg were used. Treatments were a reference diet with 160 g of CP kg^− 1 elaborated with casein (C) as the sole protein source, diet C–CM and diet C–PCM. These diets were obtained using the reference diet plus 300 g kg^− 1 of CM or PCM that substituted an isoproteic mixture of casein and maize starch from reference diet. In piglets, the AID coefficients for casein were highest (P < 0.05), those of PCM were intermediate, and those of CM were the lowest. In older pigs, the AID coefficients for casein were highest, and those of CM and PCM were similar (P > 0.05). The SAs of chymotrypsin, trypsin and carboxypeptidases A and B were lower in piglets than in heavier pigs. Moreover, the SAs of trypsin, chymotrypsin, and carboxypeptidase B were lower (P > 0.05) in animals fed casein. The results showed in piglets that whereas CM was less digestible, pelleted canola meal improved protein and amino acid ileal digestibility, resulting in similar AID coefficients to those of growing pigs.     

Acanthopanax senticosus extract as a dietary additive enhances the apparent ileal digestibility of amino acids in weaned piglets

The present study was conducted to determine the effects of Acanthopanax senticosus (AS) extract as a dietary additive on serum contents and apparent ileal digestibility (AID) of amino acids (AA) in weaned piglets. In Exp. 1, 60 piglets with an average body weight (BW) of 5.64 kg were randomly assigned into 3 treatment groups who received maize-soybean-based diets supplemented with 0 or 1 g/kg of AS extract or 0.2 g/kg of colistin (n = 20 in each group). Blood samples were randomly collected from 5 piglets per group on days 7, 14 and 28 after the initiation of supplementation to determine the serum contents of free AA. In Exp. 2, 12 barrows with an average initial BW of 7.64 kg were also randomly assigned into 3 dietary treatment groups after being surgically fitted with a simple T-cannula at the terminal ileum. Samples of terminal ileal digesta were collected on day 7 for analysis of the AID of AA. The data showed that the serum contents and AID of most AA in the AS extract-supplemented group gradually increased by 15.3–80.8% and 4.1–30.8%, respectively, as the experiment proceeded in comparison with the colistin-supplemented group and/or control group. In conclusion, these findings indicated that AS extract could enhance the digestion and absorption of AA, which may be a potential mechanism of growth promotion.     

Effects of different protein sources completely replacing fish meal in low‐protein diet on growth performance,intestinal digestive physiology,and nitrogen digestion and metabolism in nursery pigs

The study compared the effects of selected proteins replacing fish meal in low‐protein diets on piglets’ growth performance, intestinal digestive physiology, and nitrogen digestion and metabolism. Five reduced CP, amino acid (AA)‐supplemented diets containing 4% of either S50, HP300, concentrated degossypolized cottonseed protein (CDCP), P50, or fish meal were assigned to six pens with 11 pigs for a 28‐day study period. Compared with fish meal, dietary proteins did not affect growth performance, apparent total tract digestibility (ATTD) of nutrients, serum hormone levels and biochemical parameters, apparent ileal digestibility (AID) of CP and most AA, colonic short‐chain fatty acid (SCFA) contents, duodenal and ileal morphology, digestive enzyme activity, and pH in small intestine of piglets. However, HP300, CDCP, and P50 decreased (p < 0.05) fecal N excretion per weight gain. AID of Ile in S50 and HP300 and Glu in P50 were improved (p < 0.05), and AID of Gly in other proteins was reduced (p < 0.05). S50 and P50 lowered (p < 0.05) the contents of colonic isobutyric and isovaleric. S50 and HP300 reduced (p < 0.05) jejunal villus height. CDCP increased (p < 0.05) the pepsin activity in stomach. S50, HP300, and CDCP decreased (p < 0.05) pH in the proximal colon. Overall, the selected proteins could completely replace fish meal in low‐protein diet without impairing piglets’ growth via maintaining intestinal digestive physiology, and nitrogen digestion and metabolism.     

Is the kafirin profile capable of modulating the ileal digestibility of amino acids in a soybean meal-sorghum diet fed to pigs?

The effects of kafirins on protein and amino acid ileal digestibility have not been evaluated in vivo in pigs. The aim of this study was to determine the effects of protein profile on apparent ileal digestibility (AID) of amino acids. We used a sorghum hybrid with low tannin content (<0.5%). The same hybrid was harvested from 2 different plots with different kafirin profile. Sorghum with greater content of total kafirins had less content of γ- and α1-kafirins and higher content of β- and α2-kafirins than that with lower content of total kafirins. Two sorghum-soybean meal (SBM) diets were formulated: 1) low kafirin (LK) content (32.2 g/kg) and 2) high kafirin (HK) content (48.1 g/kg). A control diet (maize-SBM) and a reference SBM-diet were also prepared. The reference diet was fed to all pigs following the experimental period and was used to estimate the AID of cereals by the difference method. “T” cannulas were fixed in the distal ileum of 18 barrows (6 by treatment), divided into 2 groups of 9 pigs. The pigs were fed 2.5 times their maintenance requirement of digestible energy (110 kcal/kg BW^0.75). The AID of dry matter, protein, amino acids, and energy of the experimental diets was measured; the AID of cereals (maize, LK sorghum and HK sorghum) was estimated by the difference method. The maize-SBM diet was more digestible than the sorghum-SBM diets, only with respect to valine (P < 0.05). The AID of valine in the maize-SBM diet was higher than that in sorghum-SBM diets. The changes in kafirin profile between the diets only affected the AID of threonine (P < 0.01), which decreased by 9.5 percentage units in LK diet compared with HK diet. Regarding the AID of cereals, maize exhibited greater AID than sorghum, with respect to valine (P < 0.01) and serine (P < 0.10). A comparison of sorghum with LK and HK content showed that the AID of threonine and serine increased by 50.5 (P < 0.001) and 19.2 percentage units (P < 0.05) in the latter, respectively. The higher content of γ-kafirins in LK sorghum negatively affected threonine and serine digestibility, implying that the AID of amino acids is affected more by the profile than the content of kafirins.