• Asian-Australasian Journal of Animal Sciences
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• v.4 no.3
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• pp.211-218
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• 1991

The effects of dietary fiber on true digestibility of amino acids by growing pigs were studied, using semi-purified diets formulated from alfalfa meal, cassava leaf meal, rubber seed meal and leucacna meal at 20% level. A protein-free diet including 5% cellulose was formulated for correcting the endogenous amino acid loss. Across all the diets, arginine was the most digestible while the least at ileal level was threonine; methionine and/or histidine at fecal level respectively. The true digestibility value of amino acids at ileal level were higher than at fecal level except control diet (cellulose). The true digestibility values at ileal level were similar for all diets but differed at fecal level in different magnitude. These results indicate that undigestible compound in individual feedstuff might confound. True digestibility should be studied together for accurate diet formulation as apparent digestibility decreased when their amino acid concentration in the diet was reduced.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.523-528
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• 2006

The digestibility of heat- or high-pres sure-treated beef extracts was evaluated with an in vitro simulated gastric digestion model and each sample also underwent immune assay to detect its antigenicity with the sera of beef allergic patients. Heat treatment of the beef extracts considerably decreased their digestibility, whereas high-pressure treatment at 200 MPa improved their digestibility compared with the control, but the difference was not significant. The digestibility of the high pressure-treated beef extract was generally higher than that of the heat-treated samples. Depending on the degree of digestion, the degree of antigenicity of the main beef allergens decreased. On the basis of these results, we hypothesized that the allergenicity of beef could be eliminated if the allergenic proteins are sufficiently digested in the digestive organ, leading to the suggestion that the digestibility of allergenic proteins must be improved in food processing. In conclusion, high-pressure processing is a more acceptable food processing technique for beef considering its digestibility.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.1
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• pp.57-63
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• 2017

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 $35.9{\pm}0.6kg$ were randomly assigned to a $2{\times}4$ 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 ($35.2{\pm}9.0kg\;BW$) were allocated to 1 of 6 treatments according to a $2{\times}3$ 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.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.232-236
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• 2008

This experiment was performed to investigate the effects of two energy levels and four lysine:digestible energy (DE) ratios on the apparent digestibility of nutrients in finishing pigs. The experiment was conducted using a $2{\times}4$ randomized complete block (RCB) design with three replicates. Twenty-four cross-bred finishing barrows ((Landrace${\times}$Yorkshire)${\times}$Duroc) with an average body weight of $64.2{\pm}0.69kg$ were assigned to one of eight treatments. Each barrow was placed in an individual metabolism crate and dietary treatment and water was provided ad libitum. Diets were designed to contain lysine:ME ratios of 1.5, 1.8, 2.1 and 2.4 g/Mcal at 3.35 and 3.6 Mcal/kg of diet in a $4{\times}2$ factorial arrangement. Dry matter (DM), ash, Ca and P digestibility were not affected by energy density or lysine:DE ratios. Crude fat digestibility increased as the energy density increased from 3.35 to 3.6 Mcal of DE/kg. Increasing the lysine:DE ratio also increased crude protein digestibility. There were no interactions between energy density and lysine:DE ratio in terms of nutrient digestibility. Nitrogen excretion via feces was not affected by energy density and lysine:DE ratio, while nitrogen excretion via urine was significantly affected by energy density and lysine:DE ratio. The apparent digestibility of all amino acids except for isoluecine, arginine and aspartic acid as well as average values of essential amino (EAA), non-essential amino acids (NEAA) and total amino acid digestibility (p>0.05) were not affected by energy density. The apparent digestibility of all amino acids except for leucine, proline, alanine and tyrosine, NEAA and total amino acid digestibility were significantly affected by lysine: DE ratio (p<0.05). Interactive effects of energy and lysine:DE ratio also significantly affected amino acid digestibility except for isoleucine, alanine, cystine, leucine, phenylalanine, glutamine and proline (p<0.05). In conclusion, these results suggest that maintaining the appropriate lysine:DE ratio becomes more important as the energy density of the diet increases. Consequently, increasing the lysine:DE ratio can result in increased crude protein digestibility and urinary nitrogen excretion, although apparent protein digestibility and nitrogen excretion were not affected by energy density Furthermore, increasing the lysine:DE ratio also increased the apparent digestibility of essential amino acids, except for leucine, regardless of energy density. The optimum lysine:DE ratio for maximum essential amino acid digestibility of the $64.2{\pm}0.69kg$ pig is approximately 2.4 g of lysine/Mcal of DE.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.1007-1010
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• 2011

The objective was to evaluate in vitro prediction of ileal digestibility of protein and amino acids (AA) for current nursery pig diets (n = 10) by using pepsin and pancreatin incubations. To compare in vivo ileal digestibility, forty nursery pigs (4 pigs per diet) with an initial BW of $12.2{\pm}2.7$ kg were surgically equipped with T-cannula in the distal ileum. In all cases, the values of in vitro digestibility were higher than those of in vivo digestibility (p<0.05). With regard to the relationships of essential and non essential AA (CP), the $r^2$ value was 0.76. With regard to AA, high relationships were observed in Ile, Thr, and Gly (0.85, 0.83, and 0.89, respectively). Also, there was a lower relationship for Arg, Met, Ala, Asp, Glu, Pro, Ser, and Tyr with $R^2$ values of 0.56, 0.54, 0.40, 0.54, 0.45, 0.24, 0.49, and 0.35, respectively between in vitro and in vivo digestibility. The EAA relationship ($R^2$ = 0.71) was generally higher than that of NEAA ($R^2$ = 0.50) numerically. In conclusion, there were strong linear relationships between in vivo and in vitro ileal digestibility (CP, Ile, Thr, and Gly). In vitro prediction of ileal digestibility (CP, Ile, Thr, and Gly) seems to have significant potential for practical application.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1228-1233
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• 1999

A study was conducted on four maize cultivars to determine the dry matter and fibre digestibility as influenced by advancing plant age. Samples of maize cultivars Akbar, Neelum, UM-81 and IZ-31 were harvested at weekly intervals/ growth stages. The samples of morphological fractions such as leaf and stem were also collected at various growth stages. Whole mixed fodder and different fractions of maize plant were analysed for their chemical composition and in vitro digestibility. The results showed that in vitro dry matter digestibility (IVDMD) of whole maize plant, leaf and stem decreased significantly with advancing stage of maturity. Digestibility of NDF, ADF, hemicellulose and cellulose decreased significantly in all plant parts with advancing plant age/growth stages. Maximum values for the digestibility of dry matter and various cell wall constituents were observed in leaf, followed by whole plant and stem fractions. Cultivars were observed to have significant effect of IVDMD and digestibility of NDF, ADF and cellulose in all plant fractions. The results indicated that digestibility of maize fodder was affected by stage of maturity and cultivars. However, maturity had a greater effect on digestibility in all plant fractions than did cultivars. Dry matter contents were found to be significantly and negatively correlated with IVDMD of whole plant and its leaf and stem fractions. Based on correlations, regression equations were computed to predict IVDMD.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.59-65
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• 2008

Six total mixed rations (TMR) containing 0, 4, 6, 8, 10, 12% tannin (TMR I-VI), using Accacia nilotica pods as a source of tannin, were used to study the effect of Acacia tannin on in vitro nutrient digestibility and gas production in goats. This study also investigated the degraded products of Acacia nilotica tannin in goat rumen liquor. Degraded products of tannins were identified using high performance liquid chromatography (HPLC) at different hours of incubation. In vitro digestibility of dry matter (IVDMD) and organic matter (IVOMD) were similar in TMR II, and I, but declined (p<0.05) thereafter to a stable pattern until the concentration of tannin was raised to 10%. In vitro crude protein digestibility (IVCPD) decreased (p<0.05) with increased levels of tannins in the total mixed rations. Crude protein digestibility was much more affected than digestibility of dry matter and organic matter. In vitro gas production (IVGP) was also reduced (p<0.05) with increased levels of tannins in the TMR during the first 24 h of incubation and tended to increase (p>0.05) during 24-48 h of incubation. Gallic acid, phloroglucinol, resorcinol and catechin were identified at different hours of incubation. Phloroglucinol and catechin were the major end products of tannin degradation while gallate and resorcinol were produced in traces. It is inferred that in vitro nutrient digestibility was reduced by metabolites of Acacia nilotica tannins and ruminal microbes of goat were capable of withstanding up to 4% tannin of Acacia nilotica pods in the TMR without affecting in vitro nutrient digestibility.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.800-805
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• 2002

Two experiments were conducted to compare digestibility of 12 diets in sheep, red and fallow deer. No differences (p>0.05) between sheep, red and fallow deer in digestibility of dry matter, organic matter and digestible energy content for all diets were found except for the sorghum diet and medic hay. Sheep and fallow deer digested the sorghum diet better than red deer. An in vitro study showed that sheep had a lower in vitro dry matter digestibility and digestible energy content than both red and fallow deer, with a significant interaction between animal species and feed ingredient. Deer digested straws and hays better (p<0.05) than sheep. In vitro digestibility was lower (p<0.05) than in vivo digestibility, but significantly correlated with in vivo digestibility for red and fallow deer. The in vitro method for digestibility estimation has potential as a rapid feed evaluation system for deer, but needs further validation.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.1
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• pp.1-9
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• 2014

Calcium (Ca) and phosphorus (P) are minerals that have important physiological functions in the body. For formulation of diets for pigs, it is necessary to consider an appropriate Ca:P ratio for an adequate absorption and utilization of both minerals. Although both minerals are important, much more research has been conducted on P digestibility than on Ca digestibility. Therefore, this review focuses on aspects that are important for the digestibility of Ca. Only values for apparent total tract digestibility (ATTD) of Ca have been reported in pigs, whereas values for both ATTD and standardized total tract digestibility (STTD) of P in feed ingredients have been reported. To be able to determine STTD values for Ca it is necessary to determine basal endogenous losses of Ca. Although most Ca is absorbed in the small intestine, there are indications that Ca may also be absorbed in the colon under some circumstances, but more research to verify the extent of Ca absorption in different parts of the intestinal tract is needed. Most P in plant ingredients is usually bound to phytate. Therefore, plant ingredients have low digestibility of P due to a lack of phytase secretion by pigs. During the last 2 decades, inclusion of microbial phytase in swine diets has improved P digestibility. However, it has been reported that a high inclusion of Ca reduces the efficacy of microbial phytase. It is possible that formation of insoluble calcium-phytate complexes, or Ca-P complexes, not only may affect the efficacy of phytase, but also the digestibility of P and Ca. Therefore, Ca, P, phytate, and phytase interactions are aspects that need to be considered in Ca digestibility studies.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.5
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• pp.614-621
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• 2010

Increasing accuracy of broiler diet formulation based on amino acid digestibility in comparison to application of total amino acids could lead to more feed efficiency and productivity. This experiment was conducted for determination of sampling site (excreta and ileum) and recognition of the effects of a commercial enzyme ($Grind^{(R)}$ Danisco, Finland) on metabolizable energy, protein and amino acid digestibility of barley. This study was modulated by a marker in 21-day old Arbor Acres chickens. Corn-soybean meal was used as a control diet and, in the other two treatments, barley (at a level of 40%) with and without enzyme as the test ingredient were supplemented to the basal diet. Chromic oxide was included in all diets (0.5%) as an indigestible marker. Apparent metabolizable energy (AME), corrected by nitrogen (AMEn) and apparent digestibility of aspartic acid, glutamic acid, serine, glycine, alanine, tyrosine, valine and methionine were significantly (p<0.05) higher in feces than ileum. Protein digestibility of diet and barley was significantly (p<0.05) higher in the ileum than in feces. Apparent digestibility of tryptophan, proline, methionine, phenylalanine and lysine was increased significantly (p<0.05) by enzyme supplementation. In contrast, no response was observed in AME, AMEn, and protein digestibility of the diet and barley by enzyme supplementation. The results of this study have shown that AME and amino acid digestibility were increased in feces, in contrast an adverse effect was observed for protein digestibility of the diet and barley.