Effect of extrusion on available energy and amino acid digestibility of barley, wheat, sorghum, and broken rice in growing pigs

OBJECTIVE

The main objective of this study was to determine available energy and nutritional digestibility of extruded cereals and the effect of extrusion on the nutritional value of feed ingredients, aiming to provide scientific basis for efficient application of extrusion in the diets of growing pigs.

METHODS

In Exp. 1, 48 crossbred growing pigs (Duroc×Landrace×Yorkshire) with an initial body weight (BW) of 34.6±2.2 kg were selected and fed with eight diets (non-extrusion or extrusion) to determine the digestible energy (DE), metabolizable energy (ME), and nutrients digestibility. Eight diets included extruded grains (barley, wheat, sorghum, or broken rice), while four had unprocessed grains. In Exp. 2, 9 diets were formulated including 4 cereals with extrusion or non-extrusion and a N-free diet. In addition, 9 growing pigs (BW = 22.3±2.8 kg) were fitted with T-cannula in the distal ileum and arranged in a 9×6 Youden square design.

RESULTS

Results show that apparent total tract digestibility of gross energy, dry matter, organic meal, ether extract, neutral and acid detergent fiber was not affected by the extrusion process and there was no interaction between cereal type and extrusion treatment on DE, ME. However, the apparent total tract digestibility for crude protein (CP) increased markedly (p<0.05). The standardized ileal digestibility (SID) of all amino acids (AA) except for leucine remarkably increased by extrusion (p<0.05). There was an interaction on the SID of arginine, leucine, isoleucine, methionine, phenylalanine, cystine, and tyrosine in growing pigs between type of grain and extrusion treatment (p<0.05).

CONCLUSION

Extrusion increased the ileal digestibility of CP and most AA in cereals, however, the DE and ME of cereals were not affected in growing pigs.

Dietary 25(OH)D3 supplementation to gestating and lactating sows and their progeny affects growth performance, carcass characteristics, blood profiles and myogenic regulatory factor- related gene expression in wean-finish pigs

Objective

This experiment investigated the effects of supplementing vitamin D₃-fortified sow and progeny diets with 25(OH)D₃ on growth performance, carcass characteristics, immunity, and pork meat quality.

Methods

The present study involved the assessment of supplementing the diet of sows and their progeny with or without 25 (OH)D₃ in a 2×2 factorial arrangement on the performance and production characteristics of wean-finish pigs. Forty-eight multiparous sows were assigned to a basal diet containing 2000 IU/kg vitamin D₃ and supplemented without (CON) or with (TRT) 50 μg/kg 25 (OH)D₃. At weaning, a total of 80 pigs each from CON and TRT sows were allocated to weaning and growing-finishing basal diets fortified with 2,500 and 1,750 IU/kg vitamin D₃ respectively and supplemented without or with 50 μg/kg 25(OH)D₃.

Results

Sows fed 25(OH)D₃-supplemented diets improved pre-weaning growth rate of nursing piglets. A significant sow and pig weaning diet effect was observed for growth rate and feed efficiency (p<0.05) during days 1 to 42 post-weaning. Pigs consuming 25(OH)D₃-supplemented diets gained weight faster (p = 0.016), ate more (p = 0.044) and tended to convert feed to gain more efficiently (p = 0.088) than those fed CON diet between days 98 and 140 post-weaning. Supplemental 25(OH)D₃ improved water holding capacity and reduced drip loss of pork meat, increased serum 25(OH)D₃ level, produced higher interleukin-1 and lower interleukin-6 concentrations in blood circulation, downregulated myostatin (MSTN) and upregulated myogenic differentiation (MYOD) and myogenic factor 5 (MYF5) gene expressions (p<0.05).

Conclusion

Supplementing vitamin D₃-fortified sow and wean-finish pig diets with 50 μg/kg 25(OH)D₃ significantly improved production performance suggesting their current dietary vitamin D₃ levels are insufficient. In fulfilling the total need for vitamin D, it is strongly recommended to add 50 μg/kg 25(OH)D₃ “on top” to practical vitamin D₃-fortified sow and wean-finish pig diets deployed under commercial conditions.

Achyranthes japonica extracts supplementation to growing pigs positively influences growth performance, nutrient digestibility, fecal microbial shedding, and fecal gas emission

Objective

An experiment was conducted to investigate the effects of Achyranthes japonica extracts (AJE) on the growth performance, nutrient digestibility, fecal microbial shedding, and fecal gas emission of growing pigs.

Methods

A total of 180 ([Landrace×Yorkshire]×Duroc) growing pigs with initial body weight (BW) of 23.94±1.54 kg were used in this study to investigate the effects of AJE as a feed additive. Dietary treatments included: i) CON (basal diet), ii) TRT1 (basal diet+0.05% AJE), and iii) TRT2 (basal diet+0.10% AJE).

Results

As a result of the dietary supplementation of 0% to 0.10% AJE, a linear increase of BW (p<0.05) on d 21 and 42, a linear increase of average daily gain (ADG) (p<0.05) during d 21 to 42, a trend in linear increase of ADG (p<0.10) during d 0 to 21 and d 0 to 42, a linear increase of gain to feed ratio (G:F) (p<0.05) during d 0 to 42, and a tendency in the linear increase of G:F during d 21 to 42 were observed in this study. Additionally, dietary supplementation of 0% to 0.10% AJE had a linear increase (p<0.05) on the apparent total tract digestibility of dry matter (DM) and energy, a linear increase (p<0.05) on lactic acid bacteria counts, a tendency in reducing (linear effect, p<0.10) coliform bacteria counts, and a linear decrease (p<0.05) in excreta H₂S emission content in growing pigs.

Conclusion

In conclusion, the results suggested that AJE had the potential to enhance growth performance, DM and energy digestibility, and fecal lactic acid bacteria counts, and decrease the fecal coliform bacteria counts and excreta H₂S emission in growing pigs.

Effects of mealworm (Tenebrio molitor) larvae hydrolysate on nutrient ileal digestibility in growing pigs compared to those of defatted mealworm larvae meal, fermented poultry by-product, and hydrolyzed fish soluble

OBJECTIVE

To investigate effect of mealworm (Tenebrio molitor) larvae hydrolysate on nutrient ileal digestibility compared to those of dried mealworm larvae meal, fermented poultry by-product, and hydrolyzed fish soluble in growing pigs.

METHODS

A total of 12 crossbred ([Landrace×Yorkshire]×Duroc) growing pigs with average body weight of 28.70±0.32 kg were surgically equipped with simple T-cannulas. A total of 12 pigs were assigned to individual metabolic crates and allotted to one of four treatments with 3 replicates in a fully randomized design.

RESULTS

Apparent ileal digestibility (AID) of dry matter (DM) was the highest in pigs fed HML diet. AIDs of crude protein (CP) were higher in pigs fed HML and DMLM diets than those in pigs fed the other two diets. AID of total amino acid was higher (p = 0.06) in pigs fed HML diet. AIDs of lysine (Lys), methionine (Met), and threonine (Thr) were similar in pigs fed DMLM and HML diets, but were higher (p = 0.05, p<0.05, and p = 0.05, respectively) than those in pigs fed FPBM or HFS diet. Pigs fed HML diet had higher standardized ileal digestibilities (SIDs) of DM and CP (p<0.05 and p<0.05, respectively) compared to pigs fed the other FPBM and HFS diets. SIDs of total amino acid were not different (p = 0.06) between treatments. For SIDs of Lys, Met, and Thr, pigs fed HML and DMLM diets showed higher SIDs (p = 0.05, p<0.05, and p<0.05, respectively) than pigs fed FPBM and HFS diets. SIDs of non-essential amino acids (aspartic acid, glycine, and alanine) were higher (p<0.05, p< 0.05, and p<0.05, respectively) in pigs fed HML, FPBM, and DMLM diets than those in pigs fed the HFS diet. AID and SID of glutamic acid were higher in pigs fed HML and FPBM diets.

CONCLUSION

In conclusion, dietary supplementation of mealworm larvae hydrolysate had higher digestibility in DM, CP, Lys, Met, and Thr compared to dietary supplementation with fermented poultry by-product and hydrolyzed fish soluble.

Physicochemical properties and energy content of yellow dent corn from different climatic origins in growing pigs

Objective

The objective of this study was to determine the digestible energy (DE) and metabolizable energy (ME) of yellow dent corn sourced from different meteorological origins fed to growing pigs and develop equations to predict the DE and ME of yellow dent corn from southwestern China.

Methods

Sixty crossbred barrows were allotted to 20 treatments in a triplicate 20×2 incomplete Latin square design with 3 replicated pigs per dietary treatment during 2 consecutive periods. Each period lasted for 12 days, and total feces and urine during the last 5 days of each period were collected to calculate the energy contents.

Results

On dry matter (DM) basis, the DE and ME in 20 corn grain samples ranged from 15.38 to 16.78 MJ/kg and from 14.93 to 16.16 MJ/kg, respectively. Selected best-fit prediction equations for DE and ME (MJ/kg DM basis) for yellow dent corn (n = 16) sourced from southwestern China were as follows: DE = 28.58–(0.12×% hemicellulose)+(0.35×% ether extract)–(0.83×MJ/kg gross energy)+(0.20×% crude protein)+(0.49×% ash); ME = 30.42–(0.11×% hemicellulose)+(0.31×% ether extract)–(0.81×MJ/kg gross energy).

Conclusion

Our results indicated that the chemical compositions, but not the meteorological conditions or physical characteristics could explain the variation of energy contents in yellow dent corn sourced from southwestern China fed to growing pigs.

Changes in growth performance, nutrient digestibility, immune blood profiles, fecal microbial and fecal gas emission of growing pigs in response to zinc aspartic acid chelate

Objective

This study was conducted to investigate the effect of zinc aspartic acid chelate (Zn-ASP) on growth performance, nutrient digestibility, blood profiles, fecal microbial and fecal gas emission in growing pigs.

Methods

A total of 160 crossbred ([Landrace×Yorkshire]×Duroc) growing pigs with an initial body weight (BW) of 25.56±2.22 kg were used in a 6-wk trial. Pigs were randomly allocated into 1 of 4 treatments according to their sex and BW (8 replicates with 2 gilts and 3 barrows per replication pen). Treatments were as follows: i) CON, basal diet, ii) TRT1, CON+0.1% Zn-ASP, iii) TRT2, CON+0.2% Zn-ASP, and iv) TRT3, CON+0.3% Zn-ASP. Pens were assigned in a randomized complete block design to compensate for known position effects in the experimental facility.

Results

In the current study, BW, average daily gain, and gain:feed ratio showed significant improvement as dietary Zn-ASP increased (p<0.05) in growing pigs. Apparent total tract digestibility (ATTD) of dry matter was increased linearly (p<0.05) in pigs fed with Zn-ASP diets. A linear effect (p<0.05) was detected for the Zn concentration in blood with the increasing levels of Zn-ASP supplementation. Lactic acid bacteria and coliform bacteria were affected linearly (p<0.05) in pigs fed with Zn-ASP diets. However, no significant differences were observed in the ATTD of nitrogen, energy and Zn. And dietary Zn-ASP supplementation did not affect fecal ammonia, hydrogen sulfide and total mercaptans emissions in growing pigs.

Conclusion

In conclusion, dietary supplementation with Zn-ASP of diet exerted beneficial effects on the growth performance, nutrient digestibility, blood profiles and fecal microbes in growing pigs.

Effect of supplementation with brewer's yeast hydrolysate on growth performance, nutrients digestibility, blood profiles and meat quality in growing to finishing pigs

Objective

This study was aimed to investigate the effects of brewer’s yeast hydrolysate (YH) on growth performance, nutrients digestibility, blood profiles and meat quality of growing pigs.

Methods

A total of 200 growing pigs ([Landrace×Yorkshire]×Duroc) (initial body weight, 25.31±1.29 kg) were allotted to 5 treatments as follow: CON, basic diet; and YH treatment, CON+0.05%, 0.1%, 0.5%, and 1.0% of YH, respectively.

Results

On wk 11, 16 and overall phase, pigs fed YH diet showed a linear improvement in average daily body gain and gain/feed (p<0.05). The pigs that received YH linearly increased the digestibility of dry matter, nitrogen, and energy on wk 11 and 16. The concentration of serum urea nitrogen was linearly increased in YH treatments on wk 16. However, the carcass weight, back fat and lean muscle percentage of pigs receiving YH had no significant change. Besides, no difference was observed in creatinine and total protein in the blood among treatments.

Conclusion

The pigs fed a graded YH diet had improved growth performance and nutrient digestibility, meanwhile, the YH increased the serum urea nitrogen in the growing pigs.

Metabolizable energy requirement for maintenance estimated by regression analysis of body weight gain or metabolizable energy intake in growing pigs

Objective

Feed energy required for pigs is first prioritized to meet maintenance costs. Additional energy intake in excess of the energy requirement for maintenance is retained as protein and fat in the body, leading to weight gain. The objective of this study was to estimate the metabolizable energy requirements for maintenance (ME_m) by regressing body weight (BW) gain against metabolizable energy intake (MEI) in growing pigs.

Methods

Thirty-six growing pigs (26.3±1.7 kg) were allotted to 1 of 6 treatments with 6 replicates per treatment in a randomized complete block design. Treatments were 6 feeding levels which were calculated as 50%, 60%, 70%, 80%, 90%, or 100% of the estimated ad libitum MEI (2,400 kJ/kg BW^0.60 d). All pigs were individually housed in metabolism crates for 30 d and weighed every 5 d. Moreover, each pig from each treatment was placed in the open-circuit respiration chambers to measure heat production (HP) and energy retained as protein (RE_p) and fat (RE_f) every 5 d. Serum biochemical parameters of pigs were analyzed at the end of the experiment.

Results

The average daily gain (ADG) and HP as well as the RE_p and RE_f linearly increased with increasing feed intake (p<0.010). β-hydroxybutyrate concentration of serum tended to increase with increasing feed intake (p = 0.080). The regression equations of MEI on ADG were MEI, kJ/kg BW^0.60 d = 1.88×ADG, g/d+782 (R² = 0.86) and ME_m was estimated at 782 kJ/kg BW^0.60 d. Protein retention of growing pigs would be positive while RE_f would be negative at this feeding level via regression equations of RE_p and RE_f on MEI.

Conclusion

The ME_m was estimated at 782 kJ/kg BW^0.60 d in current experiment. Furthermore, growing pigs will deposit protein and oxidize fat if provided feed at the estimated maintenance level.

Effect of keratinase on ileal amino acid digestibility in five feedstuffs fed to growing pigs

Objective

This study was conducted to evaluate the effect of keratinase (KE) on the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) in rice bran, cottonseed meal (CSM), rapeseed meal (RSM), corn distillers dried grains with solubles (DDGS), and peanut meal (PNM).

Methods

Twelve crossbred barrows (Duroc×Landrace×Yorkshire, 50.5±1.4 kg body weight [BW]) fitted with T-cannulas at the terminal ileum were allotted to a 12×6 Youden Square design with 12 diets and 6 periods. The treatment diets included rice bran, CSM, RSM, corn DDGS, PNM, or corn-soybean meal (cSBM) supplemented with 0.05% KE or not. Diets were given to pigs at a level of 3% BW in two equal meals. The endogenous AA losses were the mean results of three previously experiments determined by a same nitrogen-free diet fed to pigs. Pigs had free access to water during the experiment.

Results

The KE supplementation improved (p<0.05) the AID and SID of Met, Thr, Val, Asp, Cys, and Tyr in rice bran. Inclusion of KE increased (p<0.05) the AID and SID of Met and Val in CSM. The KE supplementation decreased (p<0.05) the AID and SID of His in RSM and all measured AA except for Arg, Met, Trp, Val, Gly, and Pro in corn DDGS. There was an increase (p<0.05) in AID and SID of Leu, Ile, Met, Ala, Cys, Ser, and Tyr in PNM supplemented with KE compared with that without KE. Inclusion of KE increased (p<0.05) the AID and SID of crude protein, Leu, Ile, Phe, Thr, Asp, and Ser in cSBM.

Conclusion

This study indicated that KE had different effects on ileal AA digestibility of feedstuffs for growing pigs, which can give some usage directions of KE in swine feed containing those detected feedstuffs.

Comparative energy content and amino acid digestibility of barley obtained from diverse sources fed to growing pigs

Objective

Two experiments were conducted to determine the content of digestible energy (DE) and metabolizable energy (ME) as well as the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in barley grains obtained from Australia, France or Canada.

Methods

In Exp. 1, 18 growing barrows (Duroc×Landrace×Yorkshire; 31.5±3.2 kg) were individually placed in stainless-steel metabolism crates (1.4×0.7×0.6 m) and randomly allotted to 1 of 3 test diets. In Exp. 2, eight crossbred pigs (30.9±1.8 kg) were allotted to a replicate 3×4 Youden Square designed experiment with three periods and four diets. Two pigs received each diet during each test period. The diets included one nitrogen-free diet and three test diets.

Results

The relative amounts of gross energy (GE), CP, and all AA in the Canadian barley were higher than those in Australian and French barley while higher concentrations of neutral detergent fiber, acid detergent fiber, total dietary fiber, insoluble dietary fiber and β-glucan as well as lower concentrations of GE and ether extract were observed in the French barley compared with the other two barley sources. The DE and ME as well as the SID of histidine, isoleucine, leucine and phenylalanine in Canadian barley were higher (p<0.05) than those in French barley but did not differ from Australian barley.

Conclusion

Differences in the chemical composition, energy content and the SID and AID of AA were observed among barley sources obtained from three countries. The feeding value of barley from Canada and Australia was superior to barley obtained from France which is important information in developing feeding systems for growing pigs where imported grains are used.

Evaluation of available energy and total tract digestibility of acid-hydrolyzed ether extract of cottonseed oil for growing pigs by the difference and regression methods

Objective

The objective of this study was to determine the effect of inclusion level on the digestible energy (DE), metabolizable energy (ME), and total tract digestibility of acid-hydrolyzed ether extract (AEE) of cottonseed oil when fed to growing pigs.

Methods

Forty-two barrows (initial body weight = 35.51±2.01 kg) were randomly allotted to a completely randomized design with a corn-soybean meal basal diet, five levels of cottonseed oil (2%, 4%, 6%, 8%, and 10%) and a 10% soybean oil diet. Each diet was replicated six times with one pig per replicate. The experiment lasted 19 days, 7 d for cage adaptation, 7 d for diets adaptation and last 5 d for feces and urine collection. The energy values and apparent total tract digestibility (ATTD) of cottonseed oil and soybean oil were calculated by the difference method, and regression equations were established to predict the energy values of cottonseed oil. The apparent digested fat of the entire intestinal tract was also regressed against dietary fat intake to determine the true total tract digestibility (TTTD) and endogenous loss of fat for cottonseed oil.

Results

The results showed that the DE and ME contents of cottonseed oil were not different as the inclusion level increased. The DE and ME values determined by the regression equation were 36.28 MJ/kg and 34.96 MJ/kg, respectively, and the values were similar to the mean DE and ME values calculated by the difference method (36.18 and 35.56 MJ/kg, respectively). The ATTD of cottonseed oil was also not affected by the inclusion level of cottonseed oil, and the TTTD and EFL determined by the regression method were 92.40% and 13.83 g/kg of dry matter intake for corn-soybean basal diet. The DE, ME, and ATTD of AEE in soybean oil determined by the difference method were 35.70 MJ/kg, 35.20 MJ/kg and 92.31%, respectively. There were no differences in the DE, ME, and ATTD between cottonseed oil and soybean oil, although the ratio of unsaturated to saturated fatty acids for soybean oil was higher than for cottonseed oil.

Conclusion

The DE, ME, and ATTD values of cottonseed oil were not affected by its dietary inclusion level. The energy values of cottonseed oil determined by the difference and regression methods were similar. Furthermore, the ratio of unsaturated to saturated fatty acid for oils was not the decisive factor to influence the energy values and ATTD of oils.

Effects of exogenous phytase and xylanase, individually or in combination, and pelleting on nutrient digestibility, available energy content of wheat and performance of growing pigs fed wheat-based diets

OBJECTIVE

Two experiments were conducted to determine the effects of adding exogenous phytase and xylanase, individually or in combination, as well as pelleting on nutrient digestibility, available energy content of wheat and the performance of growing pigs fed wheat-based diets.

METHODS

In Experiment 1, forty-eight barrows with an initial body weight of 35.9±0.6 kg were randomly assigned to a 2×4 factorial experiment with the main effects being feed form (pellet vs meal) and enzyme supplementation (none, 10,000 U/kg phytase, 4,000 U/kg xylanase or 10,000 U/kg phytase plus 4,000 U/kg xylanase). The basal diet contained 97.8% wheat. Pigs were placed in metabolic cages for a 7-d adaptation period followed by a 5-d total collection of feces and urine. Nutrient digestibility and available energy content were determined. Experiment 2 was conducted to evaluate the effects of pelleting and enzymes on performance of wheat for growing pigs. In this experiment, 180 growing pigs (35.2±9.0 kg BW) were allocated to 1 of 6 treatments according to a 2×3 factorial treatment arrangement with the main effects being feed form (meal vs pellet) and enzyme supplementation (0, 2,500 or 5,000 U/kg xylanase).

RESULTS

In Experiment 1, there were no interactions between feed form and enzyme supplementation. Pelleting reduced the digestibility of acid detergent fiber (ADF) by 6.4 percentage units (p<0.01), increased the digestibility of energy by 0.6 percentage units (p<0.05), and tended to improve the digestibility of crude protein by 0.5 percentage units (p = 0.07) compared with diets in mash form. The addition of phytase improved the digestibility of phosphorus (p<0.01) and calcium (p<0.01) by 6.9 and 7.6 percentage units respectively compared with control group. Adding xylanase tended to increase the digestibility of crude protein by 1.0 percentage units (p = 0.09) and increased the digestibility of neutral detergent fiber (NDF) (p<0.01) compared with control group. Supplementation of the xylanase-phytase combination improved the digestibility of phosphorus (p<0.01) but impaired NDF digestibility (p<0.05) compared with adding xylanase alone. In Experiment 2, adding xylanase increased average daily gain (p<0.01) and linearly improved the feed:gain ratio (p<0.01) compared with control group.

CONCLUSION

Pelleting improved energy digestibility but decreased ADF digestibility. Adding xylanase increased crude protein digestibility and pig performance. Phytase increased the apparent total tract digestibility of phosphorus and calcium. The combination of phytase-xylanase supplementation impaired the effects of xylanase on NDF digestibility.

Apparent or Standardized Ileal Digestibility of Amino Acids of Diets Containing Different Protein Feedstuffs Fed at Two Crude Protein Levels for Growing Pigs

The current study determined the apparent or standardized ileal digestibility of amino acids (AID or SID of AA) in growing pigs fed diets containing three protein feedstuffs with different fiber characteristics at two dietary crude protein (CP) levels. Twenty boars (Yorkshire×Landrace) with average initial body weight of 35 (±2.6) kg were fitted with a simple T-cannula at the distal ileum. These pigs were offered six diets containing soybean meal (SBM), canola meal (CM) or corn distillers dried grains with solubles (corn-DDGS) that were either adequate (19%) or marginal (15%) in CP using a triplicated 6×2 Youden Square Design. Except for Met, Trp, Cys, and Pro, AID of AA was greater (p<0.05) in the SBM diet compared with the CM diet. Apparent ileal digestibility for Gly and Asp was greater (p<0.05) in the SBM diet compared with the corn-DDGS diet. The AID of Ile, Leu, Phe, Val, Ala, Tyr, and Asp was greater (p<0.05) in the corn-DDGS diet compared with the CM diet. Standardized ileal digestibility of AA was greater (p<0.05) in the SBM diet compared with the CM diet for all AA except Trp and Pro. The SID of Ile, Leu, Val, Ala, Tyr, and Asp was greater (p<0.05) in the corn-DDGS diet compared with the CM diet. It was concluded that protein feedstuff affects ileal AA digestibility and is closely related to dietary fiber characteristics, and a 4-percentage unit reduction in dietary CP had no effect on ileal AA digestibility in growing pigs.

Prediction of digestible and metabolizable energy content of rice bran fed to growing pigs

Two experiments were conducted to determine the digestible energy (DE) and metabolizable energy (ME) content of 19 rice bran samples and to develop prediction equations for DE and ME based on their chemical composition. The 19 rice bran samples came from different rice varieties, processing methods and regions. The basal diet was formulated using corn and soybean meal (74.43% corn and 22.91% soybean meal and 2.66% vitamins and minerals). The 19 experimental diets based on a mixture of corn, soybean meal and 29.2% of each source of rice bran, respectively. In Exp. 1, 108 growing barrows (32.1±4.2 kg) were allotted to 1 of 18 treatments according to a completely randomized design with 6 pigs per treatment. The treatment 1 was the control group which was fed with basal diet. The treatments 2 to 18 were fed with experimental diets. In Exp. 2, two additional rice bran samples were measured to verify the prediction equations developed in Exp. 1. A control diet and two rice bran diets were fed to 18 growing barrows (34.6±3.5 kg). The control and experimental diets formulations were the same as diets in Exp. 1. The results showed that the DE ranged from 14.48 to 16.85 (mean 15.84) MJ/kg of dry matter while the ME ranged from 12.49 to 15.84 (mean 14.31) MJ/kg of dry matter. The predicted values of DE and ME of the two additional samples in Exp. 2 were very close to the measured values.

Determination and prediction of the amino Acid digestibility of sunflower seed meals in growing pigs

This experiment was conducted to evaluate the chemical composition and amino acid (AA) digestibility of sunflower seed meal (SFSM) and to use this data to develop prediction equations for estimating AA digestibility for growing pigs. Ten SFSM were collected from five provinces in China. Twelve barrows (38.8±4.6 kg), fitted with ileal T-cannula were allotted into two 6×6 Latin square designs. Each of six experimental periods comprised a 5-d adaption period followed by a 2-d collection of ileal digesta. The ten test diets contained 50% SFSM as the sole source of AA. Another nitrogen-free diet was used to measure the basal endogenous losses of crude protein (CP) and AA. Chromic oxide (0.3%) was used as an inert marker in each diet. There was considerable variation (CV>10%) among the ten SFSM in chemical composition (dry matter [DM]). The concentration of CP and ether extract (EE) ranged from 29.33% to 39.09% and 0.88% to 11.33%, respectively. Crude fibre (CF), neutral detergent fibre and acid detergent fibre ranged from 21.46% to 36.42%, 38.15% to 55.40%, and 24.59% to 37.34%, respectively. There was variation among the ten SFSM in apparent ileal digestibility (AID) and standardized ileal digestibility (SID) for lysine and threonine, which ranged from 63.16 to 79.21 and 55.19% to 72.04% for AID and 67.03% to 82.07% and 61.97% to 77.01% for SID, respectively. The variation in CP and methionine ranged from 60.13% to 74.72% and 74.79% to 88.60% for AID and 66.70% to 79.31% and 77.16% to 90.27% for SID, respectively. Methionine was a good indicator to predict AA digestibility. These results indicate that conventional chemical composition of SFSM was variable (CV>10%) among the ten SFSM (DM). The results of AID, SID and prediction equations could be used to evaluate the digestibility of SFSM in growing pigs.

Effect of different inclusion level of condensed distillers solubles ratios and oil content on amino Acid digestibility of corn distillers dried grains with solubles in growing pigs

The purpose of this experiment was to determine and compare the digestibility of crude protein (CP) and amino acids (AA) in full-oil (no oil extracted) and de-oiled (oil extracted) corn distillers dried grains with solubles (DDGS) with different condensed distillers solubles (CDS) ratios. Six barrows (29.6±2.3 kg) fitted with ileal T-cannula were allotted into a 6×6 Latin square design. Each period was comprised of a 5-d adaption period followed by a 2-d collection of ileal digesta. The five test diets contained 62% DDGS as the sole source of AA. A nitrogen-free diet was used to measure the basal endogenous losses of CP and AA. Chromic oxide (0.3%) was used as an index in each diet. The results showed that CP and AA were very similar in 5 DDGS, but the standardized ileal digestibility (SID) of lysine (from 56.16% to 71.15%) and tryptophan (from 54.90% to 68.38%) had the lowest values and largest variation within the essential AA, which suggests reduced availability of AA and different levels of Maillard reactions in the five DDGS. The apparent ileal digestibility and SID of CP and most of AA in full-oil DDGS (sources 1 and 2) were greater (p<0.05) than de-oiled DDGS (sources 3, 4, and 5). Comparing the AA SID in the 5 DDGS, full-oil with low CDS ratio DDGS (source 1) had non-significantly higher values (p >0.05) than full-oil with high CDS ratio DDGS (source 2); however, the SID of most AA of de-oiled with low CDS ratios DDGS (source 3) were non-significantly lower (p>0.05) than de-oiled with high CDS ratio DDGS (source 4); and the de-oiled DDGS with middle CDS ratio (source 5) but with different drying processing had the lowest SID AA values. In conclusion, de-oiled DDGS had lower SID of CP and AA than full-oil DDGS; a higher CDS ratio tended to decrease the SID of AA in full-oil DDGS but not in de-oiled DDGS; and compared with CDS ratio, processing, especially drying, may have more of an effect on AA digestibility of DDGS.

Effect of bacteriophage supplementation on the growth performance, nutrient digestibility, blood characteristics, and fecal microbial shedding in growing pigs

A total of 144 ((Duroc×Yorkshire)×Landrace)) pigs with an average initial BW of 28.85±0.63 kg were used in this 6-wk growth trial. Pigs were randomly allotted to 1 of 4 treatments in a completely random block design. Each dietary treatment consisted of 9 replicate pens, with 4 pigs per replicate. Dietary treatments included: i) NC (basal diet), ii) PC (NC+apramycin 0.5 g/kg), iii) BPT1 (NC+bacteriophage 0.25 g/kg) and iv) BPT2 (NC+bacteriophage 0.5 g/kg). The inclusion of antibiotics and bacteriophages did not affect the (p>0.05) ADG, ADFI and G:F compared with the basal diet. Dietary antibiotics and bacteriophages supplementation led to a higher (p<0.05) DM digestibility than the NC treatment. Pigs fed the bacteriophage supplemented diet increased (p<0.05) the N digestibility compared with those fed NC treatment. Supplementation of antibiotics led to a higher (p<0.05) energy digestibility than the NC treatment. No difference (p>0.05) was observed in the RBC, WBC, lymphocyte concentration and fecal moisture among treatments. Pigs fed PC and BPT2 treatments reduced (p<0.05) the E. coli concentration compared with those fed NC treatment. The inclusion of BPT2 treatment led to a higher (p<0.05) lactobacillus concentration compared with NC and PC treatment. Dietary antibiotic and bacteriophage supplementation reduced (p<0.05) the Salmonella concentration compared with NC treatment. In conclusion, our study suggested that bacteriophage at the level of 0.5 g/kg could be used as an antibiotics alternative for growing pigs.

Effects of Supplementation of β-Mannanase in Corn-soybean Meal Diets on Performance and Nutrient Digestibility in Growing Pigs

A total of 288 crossbred (Duroc×Landrace×Yorkshire) growing pigs were used in two experiments to investigate the effects of adding β-mannanase to corn-soybean meal-based diets on pig performance and apparent total tract digestibility (ATTD). Both experiments lasted 28 d and were split into two phases namely 1 to 14 days (phase 1) and 15 to 28 days (phase 2). In Exp. 1,144 pigs weighing 23.60±1.59 kg BW were assigned to one of four corn-soybean meal-based diets containing 0, 200, 400 or 600 U/kg β-mannanase. Increasing the level of β-mannanase increased weight gain (quadratic effect; p<0.01) and feed efficiency (linear and quadratic effect; p<0.01) during the second phase and the overall experiment. However, performance was unaffected (p>0.05) by treatment during phase 1. Increasing the amount of β-mannanase in the diet improved (linear and quadratic effect; p<0.05) the ATTD of CP, NDF, ADF, calcium, and phosphorus during both phases. Based on the results of Exp. 1, the optimal supplementation level was determined to be 400 U/kg and this was the level that was applied in Exp. 2. In Exp. 2, 144 pigs weighing 23.50±1.86 kg BW were fed diets containing 0 or 400 U/kg of β-mannanase and 3,250 or 3,400 kcal/kg digestible energy (DE) in a 2×2 factorial design. β-Mannanase supplementation increased (p<0.01) weight gain and feed efficiency while the higher energy content increased (p<0.01) feed intake and feed efficiency during both phases and overall. Increased energy content and β-mannanase supplementation both increased (p<0.05) the ATTD of DM, CP, NDF, ADF, phosphorus, and GE during both phases. There were no significant interactions between energy level and β-mannanase for any performance or digestibility parameter. In conclusion, the β-mannanase used in the present experiment improved the performance of growing pigs fed diets based on corn and soybean. The mechanism through which the improvements were obtained appears to be related to improvements in ATTD.

Determining of the Effect of Lysine:calorie Ratio on Growth Performance and Blood Urea Nitrogen of Growing Barrows and Gilts in Hot Season and Cool Season in a Commercial Environment

Two experiments were conducted to determine an optimum Lys:calorie ratio (g of total dietary Lys/Mcal of DE) for growing barrows and gilts in cool and hot seasons in a commercial environment. In Exp. 1, 96 barrows and 96 gilts were randomly allocated in 1 of 4 dietary treatments (2.7, 3.0, 3.3, 3.6 g of Lys/Mcal of DE). Each treatment had 12 replicate pens with 4 pigs per pen. The experiment lasted for 34 d in the cool season (March 12th to April 15th). Diets were based on corn-wheat-soybean meal. Lys:calorie ratio were attained by adjusting the amount of corn and soybean and supplementation of crystalline Lys. Total Lys intake and available Lys intake were increased (p<.05) as dietary Lys:calorie ratio increased. The BUN concentration on d 34 for barrows, and BUN change for barrows and gilts linearly increased (p<0.05) in response to increasing dietary Lys:calorie ratio. For gilts, back fat was decreased and then increased (Quadratically, p<0.05) as increasing dietary lys:calorie ratio. Exp. 2 had a similar design as Exp. 1 with the exception that Exp. 2 was conducted in hot season (June 30th to September 11th) for 42 d. Diet of Exp. 2 was the same as Exp. 1. Total Lys intake and available Lys intake increased (p<0.05) as dietary Lys:calorie increased. On d 42, the BUN concentration increased (p<0.05) in response to the increasing dietary Lys:calorie ratio. In conclusion, dietary Lys:calorie ratio of 2.7 g of Lys/Mcal of DE could satisfy the requirement of 25 to 50 kg growing pigs. Increasing dietary Lys:calorie ratio could increase BUN concentration in growing pigs.

Prediction of digestible and metabolizable energy content and standardized ileal amino Acid digestibility in wheat shorts and red dog for growing pigs

Two experiments were conducted to evaluate the effects of chemical composition of wheat shorts and red dog on energy and amino acid digestibility in growing pigs and to establish prediction models to estimate their digestible (DE) and metabolizable (ME) energy content and as well as their standardized ileal digestible (SID) amino acid content. For Exp. 1, sixteen diets were fed to thirty-two growing pigs according to a completely randomized design during three successive periods. The basal diet was based on corn and soybean meal while the other fifteen diets contained 28.8% wheat shorts (N = 7) or red dog (N = 8), added at the expense of corn and soybean meal. Over the three periods, each diet was fed to six pigs with each diet being fed to two pigs during each period. The apparent total tract digestibility (ATTD) of energy in wheat shorts and red dog averaged 75.1 and 87.9%. The DE values of wheat shorts and red dog averaged 13.8 MJ/kg (range 13.1 to 15.0 MJ/kg) and 15.1 MJ/kg (range 13.3 to 16.6 MJ/kg) of dry matter, respectively. For Exp. 2, twelve growing pigs were allotted to two 6×6 Latin Square Designs with six periods. Ten of the diets were formulated based on 60% wheat shorts or red dog and the remaining two diets were nitrogen-free diets based on cornstarch and sucrose. Chromic oxide (0.3%) was used as an indigestible marker in all diets. There were no differences (p>0.05) in SID values for the amino acids in wheat shorts and red dog except for lysine and methionine. Apparent ileal digestibility (AID) and SID values for lysine in different sources of wheat shorts or red dog, which averaged 78.1 and 87.8%, showed more variation than either methionine or tryptophan. A stepwise regression was performed to establish DE, ME and amino acid digestibility prediction models. Data indicated that fiber content and amino acid concentrations were good indicators to predict energy values and amino acid digestibility, respectively. The present study confirms the large variation in the energy content and amino acid digestibility in wheat shorts and red dog, and describes the factors that influence this variation and presents equations based on chemical composition that could probably be used to predict the DE and ME values as well as the amino acid digestibility of wheat shorts and red dog.

Evaluation of energy digestibility and prediction of digestible and metabolizable energy from chemical composition of different cottonseed meal sources fed to growing pigs

The present experiment was conducted to determine the digestible energy (DE), metabolizable energy (ME) content, and the apparent total tract digestibility (ATTD) of energy in growing pigs fed diets containing one of ten cottonseed meals (CSM) collected from different provinces of China and to develop in vitro prediction equations for DE and ME content from chemical composition of the CSM samples. Twelve growing barrows with an initial body weight of 35.2±1.7 kg were allotted to two 6×6 Latin square designs, with six barrows and six periods and six diets for each. A corn-dehulled soybean meal diet was used as the basal diet, and the other ten diets were formulated with corn, dehulled soybean meal and 19.20% CSM. The DE, ME and ATTD of gross energy among different CSM sources varied largely and ranged from 1,856 to 2,730 kcal/kg dry matter (DM), 1,778 to 2,534 kcal/kg DM, and 42.08 to 60.47%, respectively. Several chemical parameters were identified to predict the DE and ME values of CSM, and the accuracy of prediction models were also tested. The best fit equations were: DE, kcal/kg DM = 670.14+31.12 CP+659.15 EE with R² = 0.82, RSD = 172.02, p<0.05; and ME, kcal/kg DM = 843.98+25.03 CP+673.97 EE with R² = 0.84, RSD = 144.79, p<0.05. These results indicate that DE, ME values and ATTD of gross energy varied substantially among different CSM sources, and that some prediction equations can be applied to predict DE and ME in CSM with an acceptable accuracy.