Gloria A Casas

Effects of microbial phytase on the apparent and standardized total tract digestibility of phosphorus in rice coproducts fed to growing pigs

The objectives of this experiment were to determine the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P and the effect of microbial phytase on ATTD and STTD of P in full-fat rice bran (FFRB), defatted rice bran (DFRB), brown rice, broken rice, and rice mill feed when fed to pigs. Ninety-six barrows (initial BW of 19.4 ± 1.4 kg) were allotted to 12 diets with 8 replicate pigs per diet in a randomized complete block design. A basal diet based on corn and soybean meal was formulated. Five additional diets containing corn, soybean meal, and each rice coproduct were also formulated, and the ratio between corn and soybean meal in these diets was similar to that in the basal diet. Six additional diets that were similar to the initial 6 diets with the exception that 1,000 units of microbial phytase were added to the diets were also formulated. The ATTD and STTD of P were calculated for each diet using the direct procedure, and the ATTD and STTD of P in each rice coproduct were calculated using the difference procedure. Results of the experiment indicated that the concentration of P in feces was reduced (P < 0.05) from pigs fed diets with microbial phytase compared with pigs fed diets without phytase. No differences were observed between the basal diet and the broken rice diet, but the ATTD and the STTD of P in those diets was greater (P < 0.05) than in all other diets both without and with phytase. Among the rice coproducts, the greatest (P < 0.05) ATTD and STTD of P were observed for broken rice regardless of inclusion of phytase. If no microbial phytase was used, the values for STTD of P in brown rice, FFRB, DFRB, and rice mill feed were not different, but if microbial phytase was included in the diet, ATTD and STTD of P in brown rice was greater (P < 0.05) than in FFRB, DFRB, and rice mill feed. The STTD of P in brown rice, FFRB, and rice mill feed was greater (P < 0.05) if microbial phytase was used than if no microbial phytase was used. Addition of microbial phytase to the diets also increased (P < 0.05) the ATTD of Ca regardless of the rice coproducts used. In conclusion, the STTD of P is greater in broken rice than in all other rice coproducts. The STTD of P in brown rice, FFRB, DFRB, and rice mill feed is relatively low due to the high concentration of phytate in these ingredients, but addition of microbial phytase will increase the STTD of P in most rice coproducts.

Effects of microbial xylanase on digestibility of dry matter, organic matter, neutral detergent fiber, and energy and the concentrations of digestible and metabolizable energy in rice coproducts fed to weanling pigs

The objective of this experiment was to test the hypothesis that the apparent total tract digestibility (ATTD) of DM, OM, fiber, and GE by weanling pigs and the concentration of DE and ME in full-fat rice bran (FFRB), defatted rice bran (DFRB), brown rice, and broken rice is improved if microbial xylanase is added to the diet. Eighty pigs (13.6 ± 0.8 kg initial BW) were allotted to 10 diets with 8 replicate pigs per diet in a randomized complete block design with 2 blocks of 40 pigs. A basal diet based on corn and soybean meal and 4 diets containing corn, soybean meal, and each of the 4 rice coproducts were formulated. The rice coproducts and corn and soybean meal were the only sources of energy in the diets. Five additional diets that were similar to the initial 5 diets with the exception that they also contained 16,000 units of xylanase (Econase XT-25; AB Vista, Marlborough, UK) were also formulated. All diets also contained 1,500 units of microbial phytase (Quantum Blue 5G; AB Vista). The DE and ME and the ATTD of DM, OM, fiber, and GE in diets and ingredients were calculated using the direct method and the difference method, respectively. Results indicated that the concentrations of DE and ME (DM basis) in FFRB and DFRB increased ( < 0.05) if xylanase was used. Broken rice had a greater ( < 0.05) concentration of DE and ME than FFRB and DFRB if no xylanase was added to the diets, but if xylanase was used, no differences in ME among FFRB, brown rice, and broken rice were observed. The ATTD of DM was greater ( < 0.05) in ingredients with xylanase than in ingredients without xylanase and there was a tendency ( = 0.067) for the ATTD of OM to be greater if xylanase was used. The ATTD of NDF in FFRB was greater ( < 0.05) when xylanase was added than if no xylanase was used, whereas the ATTD of NDF in DFRB was not affected by the addition of xylanase. In conclusion, if no xylanase was used, broken rice and brown rice have greater concentrations of DE and ME than FFRB and DFRB, and these values were not increased by microbial xylanase. However, xylanase increased the concentration of DE and ME (DM basis) in FFRB and DFRB.

Effects of full fat or defatted rice bran on growth performance and blood characteristics of weanling pigs

The objective of this experiment was to determine the effect of increased concentrations of full fat rice bran (FFRB) or defatted rice bran (DFRB) in diets without or with supplementation of an exogenous xylanase on growth performance and blood characteristics in weanling pigs. A total of 532 pigs (9.3 ± 0.5 kg initial BW) were allotted to 14 diets in 4 blocks and 8 replicate pens per diet in a randomized complete block design. There were 4 or 5 pigs per pen. A basal diet containing corn, soybean meal, and whey powder and 6 diets containing corn, soybean meal, whey powder, and 10, 20, or 30% FFRB or 10, 20, or 30% DFRB were used. Seven additional diets that were similar to the initial 7 diets with the exception that they also contained 16,000 units/kg of microbial xylanase were also formulated. On the last day of the 23-d experiment, 2 blood samples were collected from 1 pig in each pen. Tumor necrosis factor-α (TNF-α), IgA, and peptide YY (PYY) were measured in plasma samples and blood urea nitrogen (BUN), total protein, and albumin were measured in serum samples. Initial and final BW were not affected by the inclusion level of FFRB or DFRB or by the addition of xylanase. The ADFI linearly decreased ( < 0.05) as inclusion of FFRB increased in diets and there was a tendency ( = 0.08) for reduced ADFI as DFRB was increased in the diets. Pigs fed diets containing DFRB had greater ADFI ( < 0.05) than pigs fed diets containing FFRB. The ADG increased and then decreased (quadratic, < 0.05) with increasing level of FFRB or DFRB in the diets. The G:F linearly and quadratically increased ( < 0.05) as the inclusion of FFRB increased, and the G:F was greater ( < 0.05) in pigs fed diets containing FFRB than in pigs fed diets containing DFRB. The concentration of BUN linearly decreased ( < 0.05) when pigs were fed diets containing increasing levels of FFRB or DFRB. There was a tendency for the concentrations of TNF-α and PYY to linearly decrease ( = 0.09 and = 0.075, respectively) as the inclusion of FFRB increased in the diet. In conclusion, ADG of weanling pigs was not affected by at least 20% FFRB or DFRB and inclusion of 30% DFRB had no effect on the G:F whereas 30% FFRB increased the G:F. However, microbial xylanase did not influence growth performance under the conditions of this experiment and there was minimal influence of rice coproducts or xylanase on blood characteristics.

Nutritional value of soy protein concentrate ground to different particle sizes and fed to pigs

Two experiments were conducted to determine the standardized ileal digestibility (SID) of CP and AA and concentrations of DE and ME in soy protein concentrate (SPC) ground to 3 particle sizes and in soybean meal and fish meal when fed to weanling pigs. An additional experiment was conducted to determine effects on growth performance and blood characteristics of including SPC in diets fed to weanling pigs. In Exp. 1, a N-free diet and diets containing soybean meal, fish meal, or SPC ground to a mean particle size of 70, 180, or 700 μm as the only source of AA were fed to 6 barrows (initial BW: 12.90 ± 1.51 kg) that had a T-cannula installed in the distal ileum. In Exp. 2, 36 barrows (13.70 ± 1.86 kg BW) were allotted to a randomized complete block design with 6 diets and 6 replicate pigs per diet. A corn-based diet and diets containing corn and soybean meal, fish meal, or SPC ground to the 3 particle sizes were used. In Exp. 3, 160 pigs (initial BW: 7.06 ± 1.07 kg) were allotted to 4 dietary treatments with 8 pens per treatment and 5 pigs per pen. Pigs were fed one of 4 diets during phase 1 (d 0 to 14 postweaning), and a common diet in phase 2 (d 14 to 28 postweaning). The 4 diets used in phase 1 included a control diet containing fish meal and spray-dried plasma protein, and diets in which fish meal, spray-dried plasma protein, or both fish meal and spray-dried plasma protein were replaced by SPC ground to 180 μm. Results of Exp. 1 indicated that the SID of His, Lys, and Thr tended ( < 0.10) to be greater in SPC ground to 180 μm than in soybean meal, and the SID of Arg, Ile, Phe, and Trp was greater ( < 0.05) in SPC ground to 70 or 180 μm than in soybean meal. There were no differences in the DE and ME (DM-basis) among corn, soybean meal, fish meal, and SPC ground to 70, 180, or 700 μm. Results of Exp. 3 indicated that growth performance of pigs fed the 4 experimental diets in phase 1 was not different in phase 1, phase 2, or in the entire experiment. In conclusion, grinding SPC to approximately 180 µm maximizes SID of indispensable AA without impacting ME and diets based on soybean meal and SPC as the main protein sources may be fed to pigs during the initial 2 wk postweaning without affecting growth performance.

Gestating sows have greater digestibility of energy in full fat rice bran and defatted rice bran than growing gilts regardless of level of feed intake

The first objective of this experiment was to test the hypothesis that apparent total tract digestibility (ATTD) of GE and nutrients in full fat rice bran (FFRB) and defatted rice bran (DFRB) determined in gestating sows is greater if feed is provided at 1.5 × the ME required for maintenance than at 3.5 × the ME requirement. The second objective was to test the hypothesis that the ATTD of GE and nutrients and the concentrations of DE and ME in FFRB and DFRB is not different between growing gilts and gestating sows if both groups of animals are fed 3.5 × the maintenance requirement for ME. Forty eight gestating sows (parity 2 to 6) were allotted to 3 diets and 2 levels of feed intake (i.e., 1.5 or 3.5 × the maintenance requirement for ME) in a randomized complete block design, with 4 blocks of 12 sows and 2 replicate sows per block for a total of 8 replicate sows per diet. Twenty four growing gilts (51.53 ± 3.1 kg BW) were randomly allotted to the same 3 diets, but all gilts were fed at 3.5 × the maintenance requirement for ME. A basal diet containing corn and soybean meal and 2 diets that consisted of 60% basal diet and 40% FFRB or DFRB were used. Results of the experiment indicated that there were no effects of level of feed intake of sows on ATTD of GE, DM, OM, or NDF, or on concentrations of DE and ME. However, concentrations of DE and ME were greater ( < 0.05) in FFRB than in DFRB regardless of feed intake level. The ATTD of GE, OM, DM, and NDF of diets containing FFRB or DFRB was less ( < 0.05) than in the basal diet, regardless of the physiological stage of the animals. However, the ATTD of GE, OM, and NDF of the basal diet and diets containing FFRB or DRFB was greater ( < 0.05) in gestating sows than in growing gilts. Concentrations of DE and ME in the diets were also greater ( < 0.05) if determined in gestating sows than in growing gilts. The ATTD of GE and the concentrations of DE and ME of FFRB were greater ( < 0.05) than in DFRB and these values were also greater ( < 0.05) in gestating sows than in growing gilts. In conclusion, the level of feed intake by gestating sows did not affect the digestibility of GE and nutrients or the concentrations of DE and ME in diets or in FFRB or DFRB, but the ATTD of GE and the concentration of DE and ME in diets and in FFRB and DFRB were greater in gestating sows than in growing gilts.

The ileal digestibility of most amino acids is greater in red dog than in wheat middlings when fed to growing pigs

The objective of this experiment was to determine the apparent ileal digestibility (AID) and the standardized ileal digestibility (SID) of CP and AA in 10 sources of wheat middlings and in 1 source of red dog. Ten diets that each contained 1 of the 10 sources of wheat middlings and 1 diet that contained red dog as the only source of protein and AA were formulated. An N-free diet was used to determine basal endogenous losses of CP and AA. Chromic oxide (0.4%) was added to all diets as an indigestible marker. Twelve pigs (BW: 29.23 ± 1.5 kg) were fitted with a T-cannula in the distal ileum. Pigs were allotted to a 12 × 8 Youden square design with 12 diets and eight 7-d periods. The initial 5 d of each period was the adaptation period, but ileal digesta were collected on the last 2 d of each period. Results indicated that the AID of CP in wheat middlings was 31.1 ± 6.9%, but the AID of CP in red dog (47.0%) was greater ( < 0.05) than the average AID of CP for wheat middlings. The AID of indispensable AA in wheat middlings ranged from 30.1 ± 5.4% for Lys to 67.7 ± 2.2% for His, and the AID of indispensable AA in red dog ranged from 53.7% in Val to 86.2% for Met. The average SID of CP in wheat middlings was 61.5 ± 5.1%, and there were no differences among the 10 sources of wheat middlings, but the SID of CP in red dog (78.5%) was greater ( < 0.05) than in wheat middlings. The SID of Arg, His, and Asp in wheat middlings was 81.4 ± 2.7%, 77.7 ± 2.1%, and 66.4 ± 2.7%, respectively, and no differences among sources of wheat middlings were observed for these AA. The SID of Met (73.6 ± 1.8%) and the SID of Ala (54.8 ± 4.9%) tended ( = 0.071 and = 0.090, respectively) to be different among sources of wheat middlings, and the SID of all other AA was different ( < 0.05) among the 10 sources of wheat middlings. There were no differences between red dog and wheat middlings for the SID of Arg, His, and Ser, and the SID of Cys was less ( < 0.05) in red dog than in wheat middlings, but for all other AA, the SID in red dog was greater ( < 0.05) than in wheat middlings. In conclusion, wheat middlings and red dog contain approximately the same quantities of AA, but the AID and SID of CP and most AA in red dog are greater than in wheat middlings.

Nutrient composition and digestibility of energy and nutrients in wheat middlings and red dog fed to growing pigs

This experiment was designed to determine nutrient composition and apparent total tract digestibility (ATTD) of GE, DM, OM, and NDF and the concentration of DE and ME in 10 sources of wheat middlings and in 1 source of red dog that were obtained from different flour mills in the United States. Twelve growing pigs (initial BW: 31.0 ± 1.0 kg) were randomly allotted to a 12 × 8 Youden square design with 12 dietary treatments and eight 14 d periods. Pigs were individually housed in metabolism crates for total collection of feces and urine. A basal diet based on corn and soybean meal, and 11 diets containing corn, soybean meal, and 39.4% of one of the 10 sources of wheat middlings or of red dog were formulated. The ATTD of GE, DM, OM, and NDF in all diets was calculated using the direct procedure, and the ATTD of GE, DM, OM, and NDF in each source of wheat middlings or red dog was calculated by difference. Values for DE and ME were calculated as well. The average concentration of CP was 17.67% in wheat midlings and 17.0% in red dog, and the concentration of acid hydrolyzed ether extract (AEE) and total dietary fiber (TDF) was 2.44 and 13.90% in red dog, but 4.07 and 36.45% in wheat middlings. Red dog also contained more starch (42.98%) than wheat middlings (20.28%). Red dog had greater bulk density (498.5 g/L) and smaller particle size (146 µm) compared with wheat middlings (315.1 g/L and 783 µm). The average ATTD of GE, DM, OM, and NDF in wheat middlings (67.2%, 71.2%, 72.9%, and 53.0%, respectively) was less (P < 0.05) than in red dog (79.35%, 82.9%, 86.6%, and 58.7%, respectively). The average concentrations of DE and ME in wheat middlings were 2,990 and 2,893 kcal/kg DM, and these values were less (P < 0.05) than the DE and ME in red dog (3,408 and 3,292 kcal/kg DM). In conclusion, wheat middlings contains more fiber and less starch than red dog and the ATTD of GE and nutrients is greater in red dog than in wheat middlings. As a consequence, concentrations of DE and ME are greater in red dog than in wheat middlings.

Effects of full fat rice bran and defatted rice bran on growth performance and carcass characteristics of growing-finishing pigs

The objective was to test the hypothesis that increasing inclusion levels of full fat rice bran (FFRB) or defatted rice bran (DFRB) are not detrimental to growth or carcass characteristics, longissimus muscle (LM) quality, or fat quality when fed to growing-finishing pigs. A total of 224 barrows and gilts were randomly allotted to 7 treatments, with 4 pigs per pen and 8 pen replicates per treatment. Pigs had an average initial BW of 28.2 ± 4.1 kg and a 3-phase feeding program was used. A basal diet containing corn and soybean meal, 3 diets containing corn, soybean meal, and 10, 20, or 30% FFRB, and 3 diets containing corn, soybean meal, and 10, 20, or 30% DFRB were formulated within each phase. Daily feed allotments and pig BW at the start of the experiment and at the conclusion of each phase were recorded. On the last day of the experiment, 1 pig per pen was harvested and carcass characteristics, LM quality, and fat quality were determined. For the overall experimental period, no effects of dietary treatments were observed for average daily gain. However, average daily feed intake (ADFI) decreased (linear, P < 0.05) and gain to feed ratio (G:F) increased (linear, P < 0.05) for pigs fed diets with increasing concentrations of FFRB. In contrast, ADFI increased linearly (P < 0.05) and G:F decreased (linear, P < 0.05) as DFRB was included in the diets. There were no effects of dietary treatments on LM quality. The length of the bellies decreased (linear and quadratic, P < 0.05) as the inclusion of FFRB or DFRB increased in the diets. The concentration of crude fat in the adipose tissue of pigs increased linearly (P < 0.05) as the concentration of FFRB or DFRB increased in the diets. The concentration of saturated fatty acids in the adipose tissue of pigs fed diets containing FFRB decreased (linear, P < 0.05), whereas the concentration of polyunsaturated fatty acids (PUFA) increased (linear, P < 0.05). In contrast, addition of DFRB did not affect the concentration of fatty acids in adipose tissues. In conclusion, 30% FFRB included in diets for growing-finishing pigs may improve G:F without affecting carcass characteristics or LM quality with the exception that PUFA in adipose tissues will increase. However, inclusion of DFRB in diets for growing-finishing pigs will reduce G:F without affecting the LM quality or composition of adipose tissues.

Ileal digestibility of amino acids in selected feed ingredients fed to young growing pigs

An experiment was conducted to determine the standardized ileal digestibility (SID) of CP and AA in brewers rice, full-fat rice bran (FFRB), defatted rice bran (DFRB), peanut meal, sesame meal, rapeseed meal, rapeseed expellers, soybean expellers, cassava meal, and bakery meal fed to young growing pigs. Twenty-two barrows (initial BW: 14.09 ± 1.48 kg) were surgically fitted with a T-cannula in the distal ileum and randomly allotted to a replicated 11 × 4 incomplete Latin square design with 11 diets and four 7-d periods in each square. Eleven experimental diets were prepared and test ingredients were the sole source of CP and AA in 10 diets and the eleventh diet was a N-free diet used to measure basal ileal endogenous losses of CP and AA. Chromic oxide (0.4%) was included in all diets as an indigestible marker and ileal digesta were collected on day 6 and 7 of each period. Results indicated that the SID of CP and AA was greatest (P < 0.05) in brewers rice and sesame meal and least (P < 0.05) in cassava meal. The SID of indispensable AA was greater (P < 0.05) in sesame meal compared with all other ingredients except brewers rice. Full-fat rice bran had greater (P < 0.05) SID of Arg, Ile, Leu, Lys, and Met compared with DFRB. The SID of CP and most AA was not different among rapeseed meal, rapeseed expellers, and soybean expellers. Bakery meal had the least (P < 0.05) SID of most AA compared with all other ingredients, with the exception of cassava meal. The concentration of standardized ileal digestible CP was greater (P < 0.05) in sesame meal and peanut meal (482.32 and 452.44 g/kg DM, respectively) than in all other ingredients. Soybean expellers had the greatest (P < 0.05) concentration of standardized ileal digestible Lys (22.98 g/kg DM) followed by rapeseed meal (16.11 g/kg DM) and rapeseed expellers (16.17 g/kg DM). Cassava meal and bakery meal had the least (P < 0.05) concentration of standardized ileal digestible CP and most AA compared with the other ingredients. Concentrations of standardized ileal digestible CP and AA in brewers rice, FFRB, and DFRB were less (P < 0.05) than in rapeseed meal, rapeseed expellers, and soybean expellers. In conclusion, peanut meal and sesame meal have greater concentrations of standardized ileal digestible CP and most AA, with the exception of Lys, than other ingredients. Rapeseed meal, rapeseed expellers, and soybean expellers have the greatest concentrations of standardized ileal digestible Lys.

The level of feed intake does not influence digestibility of calcium and phosphorus in diets fed to gestating sows, but gestating sows have reduced digestibility of calcium and phosphorus compared with growing gilts

Abstract: Level of feed intake did not affect the apparent total tract digestibility (ATTD) of calcium (Ca) and phosphorus (P) in gestating sows. Gestating sows had reduced ATTD of Ca and P compared with growing gilts. Formulating diets for sows using values obtained from growing pigs, therefore, may result in inaccuracies.