Ileal Digestibility of Amino Acids in Meat Meal and Soybean Meal Fed to Growing Pigs

The objective of this experiment was to determine the concentration and digestibility of crude protein (CP) and amino acid (AA) in meat meal (MM), and to compare these values with the respective values in soybean meal (SBM). Six barrows (initial body weight = 66.9±3.8 kg) surgically fitted with a T-cannula at the distal ileum were allotted to a replicated 3×3 balanced Latin square design with 3 diets and 3 periods. Two experimental diets containing test ingredients as the sole source of AA were prepared to estimate the apparent ileal digestibility (AID) for CP and AA by the direct method. An N-free diet was also prepared to estimate basal endogenous losses of CP and AA. All experimental diets contained 5% chromic oxide as an indigestible index. Each period consisted of a 5-d adaptation period and a 2-d of ileal digesta collection period. Ileal digesta samples were collected from 0900 to 1700 on d 6 and 7 of each period. The concentrations of CP, Lys, Met, and Trp in MM and SBM were analyzed to be 64.1, 3.5, 1.1 and 0.6, and 45.6, 2.8, 0.8, and 0.3%, respectively. The AID of all AA except Gly in MM was less (p<0.05) than in SBM. The AID of Lys, Met, and Trp in MM was estimated to be 56.0, 71.7, and 47.1%, respectively. The SID of all AA in MM was less (p<0.05) than in SBM. The SID of Lys, Met, and Trp was 65.1, 79.2, and 78.5%, respectively. In conclusion, the CP and AA contents in MM were greater than those in SBM whereas the ileal digestibility of all AA in MM was less than in SBM

Ileal apparent and standardized amino acid digestibility of soybean and colza meal in diets for finishing pigs

Agri-food chains generate by-products such as soybean and colza meal for animal feed. Their nutritional value is variable and should be analysed for better quality control before their inclusion in balanced diets. The objective was to determine the content and ileal apparent and standardized digestibility of protein and amino acids (AA) of soybean (PS) and colza meal (PC) as a source of protein in diets for finishing pigs. The experimental units were arranged in a 3×3 Latin square design repeated. The treatments (T) were T1: PS+corn starch, T2: PC+corn starch, and T3: corn starch (Control), which were randomly assigned to six pigs cannulated in distal ileum (PV 75±1.2 kg). The variables were contents and apparent ileal and standardized ileal digestibility of amino acids in soybean and colza meal. To determine digestibility, chromic oxide was added to the diets. The protein and fat contents were higher in the soybean meal. Ash, crude fibre, neutral detergent fibre, acid detergent fibre, phosphorus and calcium contents were higher in the colza meal. Essential amino acid content was higher in soybean meal, but methionine was higher in colza meal. Apparent ileal digestibility (DIA) of total amino acids was similar (p > 0.05) among protein ingredients; but for lysine and threonine it was higher (p ≤ 0.05) in soybean meal, except methionine. Methionine DIA was 89.78 %, 3.88 % higher (p ≤ 0.05) in colza meal. Standardized ileal digestibility (DIE) of total amino acids was similar (p > 0.05) among ingredients, but lysine and threonine were higher (p ≤ 0.05) in soybean meal. DIE was different (p ≤ 0.05) among ingredients for all amino acids except methionine. Ileal and standardized digestibility of all amino acids were higher in soybean meal, except methionine, which was higher in colza meal. The DIA of total amino acids was similar in both protein ingredients, except lysine and threonine in soybean meal and methionine in colza meal

Basal endogenous losses of amino acids in protein nutrition research for swine and poultry

AbstractIn this review, the definition and terminology of amino acid (AA) digestibility and ileal endogenous losses of AA (IAAend) in poultry and swine nutrition are discussed. Compared with apparent (AID) and true (TID) ileal digestibility, standardised ileal digestibility (SID) of AA is recommended for the expression of digestible AA contents of feed ingredients and for describing nutritional requirements of poultry and swine. To determine the SID of AA, total ileal flow of AA should be corrected for basal IAAend. Therefore, the measurement of basal IAAend is of great importance for the accuracy of the SID estimation in feed ingredients. The techniques for measuring basal IAAend in poultry and swine include the use of a nitrogen-free diet (NFD), a highly digestible or enzyme hydrolyzed protein diet, and the regression method. The classic method for basal IAAend determination involves the feeding of a NFD to experimental animals and measuring the ileal AA flow. This IAAend output is considered as basal IAAend, and it is assumed that the excretion of basal IAAend depends only on DM intake, regardless of dietary composition. There are criticisms with the NFD method about the abnormal physiological state induced by severe AA deficiency. Although this AA deficiency may affect the estimate of basal IAAend for dispensable AA, especially proline and glycine because of the degradation of body protein, the NFD method is still the most widely used method for basal IAAend measurements. According to the definition of basal IAAend, the NFD should be the preferred methodology in SID determination, because the basal IAAend should be only related to dry matter intake. Additionally, the SID coefficients in feed ingredients generated by NFD method are considered to be additive in a complete diet. However, the results generated from NFD method can vary among studies due to the variance in the experimental animals and diet composition. To improve the accuracy of estimating the SID of AA in feed ingredients, it is suggested that a mandatory NFD be included in individual studies to generate basal IAAend for correcting total ileal amino acid flow in determining SID of AA. In addition, research is needed to investigate the standard diet formulation of NFD

The relationship between protein and phosphorus digestion and retention in growing pigs and broiler chickens

Xue, Pengcheng. Ph.D., Purdue University, December 2016. The Relationship between Protein and Phosphorus Digestion and Retention in Growing Pigs and Broiler Chickens. Major Professor: Dr. Layi Adeola. The objective of this study was to investigate the relationship between protein and P digestion and retention in growing pigs and broiler chickens. The methodology of determining the digestibility of AA and P and the effect of dietary N and P on the digestion and retention of these two nutrients were investigated. An experiment was conducted in growing pigs to investigate the additivity of AID or SID of CP and AA in mixed diets containing multiple protein sources. Using the determined AID or SID for CP and AA in corn, SBM, DDGS, and canola meal, the AID or SID for 4 mixed diets was predicted and compared with determined AID or SID, respectively. Eighteen growing pigs (initial BW = 61.3 ± 5.5 kg) with surgically fitted T-cannula were assigned to a duplicated 9 × 4 incomplete Latin square design with 9 diets and 4 periods. A nitrogen-free diet was included to estimate basal ileal endogenous loss of AA; 4 semi-purified diets to determine the AID and SID of CP and AA in the 4 ingredients; and 4 mixed diets to test the additivity of AID and SID. The results substantiate the notion that SID of AA are more accurate than AID for predicting ileal digestibility of AA in mixed diets containing multiple protein sources. To determine the TTTD of P in triticale DDGS for growing pigs with or without phytase using the regression method, six diets were formulated in a 3 × 2 factorial arrangement, including 3 levels of triticale DDGS (300, 400, or 500 g/kg) and phytase (0 or 500 FTU/kg of diet). A total of 48 barrows (initial BW 22.2 ± 1.3 kg) were assigned to the 6 diets in a randomized complete block design. There was a 5-d adjustment period followed by a 5-d total collection of feces. The results indicated that phytase improved ATTD of P in triticale DDGS (P \u3c 0.001). In diets without added phytase, the ATTD of P in triticale DDGS was 65.0, 67.7, and 63.2% for the diets with 300, 400, and 500 g/kg triticale DDGS, respectively; the corresponding values for diets with added phytase were 77.3, 76.3, and 75.7%.The TTTD of P was estimated at 75.4% for triticale DDGS or 81.1% with added phytase, respectively. The difference between the TTTD with or without phytase was not statistically significant. For triticale DDGS, the supplementation of 500 FTU/kg phytase in the diet could increase the ATTD of P (P \u3c 0.001), but not the TTTD of P. The effect of dietary CP concentrations on ileal P digestion in growing pigs was investigated in the third study. A total of 18 ileal-cannulated pigs (initial BW 44.2 ± 3.2 kg) were used in a duplicated 9 × 3 incomplete Latin Square design, with 9 treatments and three 7-d experimental periods giving 6 replicates per treatment. The 9 treatments consisted of 1 nitrogen-free diet to estimate basal endogenous loss of AA, and 8 corn-soybean meal-based diets in a 2 × 4 factorial arrangement, which included 2 CP concentrations (6.9 or 13.4%) and 4 ATTDP concentrations (0.09, 0.16, 0.24, or 0.32%). Low CP diets limited ileal digested P (g/kg•DMI) (P \u3c 0.05). The ileal digested P (g/kg•DMI) increased linearly (P \u3c 0.01) with increasing ATTDP concentrations in the low CP group, but the pattern was linear (P \u3c 0.01) and quadratic (P \u3c 0.01) in the high CP group. In the low and high CP diets, the determined true ileal digestibility of P in mono-calcium phosphate was 54.4% and 75.6%, respectively. In conclusion, this research indicated that the ileal digestion of P could be limited by protein deficiency. Thus dietary CP concentration should be considered in P digestibility related studies. The quantitative relationship between N and P digestion and retention in broiler chickens and growing pigs was determined in the last two studies. In the broiler chicken study, a total of 384 14-d-old male broiler chickens were used in a randomized complete block design with 8 treatments and 6 replicates per treatment in a 7-d experimental period. There were 8 corn-soybean meal-based diets in a 2 × 4 factorial arrangement, which included 2 CP concentrations (10.7 or 21.5%) and 4 ATTDP concentrations (0.18, 0.32, 0.45, or 0.59%). Results showed that low dietary CP concentration limited growth performance (P \u3c 0.01), pre-cecal digestion and total tract retention of P (P \u3c 0.01), and NaPi-IIb gene expression ( P \u3c 0.05). Pre-cecal digestion and total tract retention of P (g/kg DM intake) linearly increased (P \u3c 0.01) with increasing ATTDP concentrations in both low and high CP groups. In conclusion, this study suggests an interrelationship between N and P digestion such that CP deficiency decreased the growth performance of birds consequently reducing pre-cecal P digestion in broiler chickens. Total tract retention of CP and P are linked with each other and body tissue growth may be a driver of the deposition of these two nutrients. In the growing pig study, a total of 72 growing pigs (initial BW 20.9 ± 0.8 kg) were used in a randomized complete blocked design, with 9 treatments and four 10-d experimental periods giving 8 replicates per treatment. The pigs were blocked by BW and allotted to 9 treatments with a 3 × 3 factorial arrangement consisting of 3 CP concentrations (5.5, 9.7, or 13.9%) and 3 ATTDP concentrations (0.11, 0.19, or 0.27%). The determined TTTD of P in MCP for the 5.5, 9.7, and 13.9% CP diets were 80.5, 82.6, and 87.9%, respectively. There were no statistical differences among the three TTTD estimates. In the nitrogen utilization results, increasing dietary P level decreased the urine nitrogen output (P \u3c 0.05). In conclusion, the results indicated that dietary CP deficiency may limit total tract P digestion and retention. Yet the quantitative relationship between total tract N and P retention remains unclear. In summary, the SID of most AA in corn, SBM, canola meal, and DDGS, are additive in complete diets. The regression method can be used to determine the true P digestibility and retention in feed ingredients for growing pigs and broiler chickens. Dietary CP deficiency can limit ileal and total tract P digestion. In broiler chickens, the retention of P is correlated with the retention of N. Yet in growing pigs this relationship has not been observed. Body weight gain might be the driving factor for the correlation between N and P retention in growing pigs and broiler chickens

Oxidative Decolouring of Bloodmeal Using Peracetic Acid

Bloodmeal is an ancillary product of the agricultural industry, containing 80 – 100 % protein, and has been used to create a bio-based plastic called Novatein Thermoplastic Protein®, with a proprietary blend of sodium sulfite, sodium dodecyl sulfate (SDS), water and triethylene glycol (TEG). Recent investigation has shown that the colour and odour of bloodmeal based thermoplastic can be significantly improved through the pre-treatment of bloodmeal with equilibrium peracetic acid. The resulting decoloured bloodmeal (DBM) no longer relies on the addition of sodium sulfite to be processed in conventional thermoplastic equipment. The purpose of this study was to gain a comprehensive understanding of the role by which peracetic acid decolours bloodmeal and the consequences of oxidation on composition, physico-chemical properties, protein structure and interactions and final polymer mobility. Oxidative decolouring of haem is straightforward when the haem is freely accessible or in the form of oxyhaemoglobin and most common oxidants lead to cleavage of the porphyrin ring, resulting in a loss of colour saturation. However, after extensive thermal treatment during manufacture, the haem present in bloodmeal has migrated to inaccessible hydrophobic regions of the protein aggregates or has been oxidised to the form of methaemoglobin. Literature revealed that methaemoglobin catalytically removes hydrogen peroxide, lowering decolouring efficacy. Thus, peracetic acid is required when haem is present in the form of methaemoglobin, as is found in bloodmeal. Further, it was confirmed that a minimum of 3% w/w peracetic acid, in a 3:1 ratio to bloodmeal is required to obtain adequate decolouring (> 70% whiteness based on the RGB colour space). The role of each component in equilibrium peracetic acid was established; water and acetic acid resulted in protein swelling but were found unlikely to influence accessibility of the oxidants to the haem sites and both hydrogen peroxide and peracetic acid were consumed in oxidising reactions. Acidic conditions were found to reduce the consumption of hydrogen peroxide, possibly through the inhibition of hydroxyl radical formation, resulting in less effective decolouring. Acetic acid was observed to have a protective effect on protein recovery as well as the resulting iron content, molecular mass distribution and secondary structure of protein. Due to the large excess of peracetic acid solution required to facilitate diffusion and subsequent decolouring, a significant quantity remains unreacted in the recovered wastewater. Unreacted peracetic acid was shown to have potential for recycling, although in its immediate state it was insufficient to decolour fresh bloodmeal. The protein-rich decoloured bloodmeal recovered had undergone a change in secondary structure composition and was found to contain evidence of a diffusion front, consistent with the heterogeneous phase decolouring mechanism. Oxidation with peracetic acid was found to result in less β-sheet aggregation compared to hydrogen peroxide treatment, although all treatments resulted in an increase in the quantity of disordered structures. Oxidation was also found to result in a significantly lowered glass transition temperature and along with an increased enthalpy of relaxation, evidenced a large improvement in polymer chain mobility compared with untreated bloodmeal. DBM was found to be comprised of 90 – 99% w/w protein (1 – 10% w/w salt), with a significantly higher protein solubility and a similar volume weighted molecular mass compared with untreated bloodmeal. Further, DBM was found to have a greater composition of charged and polar amino acids, along with a large reduction in lysine and small reduction in aromatic and heterocyclic amino acids. Additionally, cystine crosslinks which stabilise bloodmeal were found to be partially oxidised to cysteine sulfonate compounds and cysteic acid (cleavage of the disulfide bond). Such a reduction in the quantity of amino acids which are capable of forming covalent networks (lysine, tyrosine and cysteine) support prior evidence that DBM no longer requires sodium sulfite to produce a thermoplastic. The influence of SDS and TEG on secondary structure and chain mobility at ambient and elevated temperatures were explored. It was found that heating DBM and DBM with SDS alone is incapable of providing sufficient energy to induce mobility and chain rearrangement. However, the addition of TEG was found to facilitate chain mobility, and beyond 55 oC significant changes to the secondary structure composition was observed, first through the formation of α-helices and finally through the aggregation of chains into β-sheets. Wide angle X-ray scattering confirmed that the changes in ordered structures composition were reversible in DBM which contained both SDS and TEG. The ability of TEG to plasticise DBM was more thoroughly explored, and it was found that prior to heating TEG was localised into regions either plasticiser-rich or -poor, and this resulted in the presence of two glass transition temperatures. After heating, the TEG was more homogeneously distributed, which resulted in the presence of one broad glass transition region