Determination of apparent ileal amino acid digestibility in rapeseed meal and cake processed at different temperatures using the direct and difference method with growing pigs

Determination and Prediction of Amino Acid Digestibility in Rapeseed Cake for Growing-Finishing Pigs

OBJECTIVE

The experiment was conducted to determine the apparent or standardized ileal digestibility (AID or SID) of crude protein (CP) and amino acids (AA) in 10 rapeseed cake samples fed to pigs, and to construct predictive models for the SID of CP and AA based on the chemical composition of rapeseed cakes.

METHODS

Twenty-two cannulated pigs (initial body weight: 39.8 ± 1.2 kg) were assigned to two 11 × 3 incomplete Latin square designs, including an N-free diet and 10 diets containing rapeseed cake. Each experimental period included 5 days of adaptation and 2 days of ileal digesta collection. Titanium dioxide (TiO2) was added at 0.3% to all the diets as an indigestible marker for calculating the ileal CP and AA digestibility.

RESULTS

The coefficients of variation (CV) of the content of crude fat (EE), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), and total glucosinolates (TGS) in 10 samples of rapeseed cake were greater than 10%. The standardized ileal digestibility (SID) of crude protein (CP), lysine (Lys), methionine (Met), threonine (Thr), and tryptophan (Trp) in rapeseed cake was 73.34% (61.49 to 81.12%), 63.01% (41.41 to 73.10%), 69.47% (50.55 to 88.16%), 79.61% (74.41 to 87.58%), and 94.43% (91.34 to 97.20%), respectively. The best prediction equations for SIDCP, SIDLys, and SIDVal were as follows: SIDCP = 90.124 - 0.54NDF (R2 = 0.58), SIDLys = 100.107 - 1.229NDF (R2 = 0.94), and SIDVal = 151.012 - 2.990TGS (R2 = 0.57).

CONCLUSION

Overall, great variation exists among the 10 rapeseed cakes, and the NDF, TGS, and heating temperature can be used as the key predictors for the SID of CP and AA.

Rapeseed meal as a feed component in monogastric animal nutrition – a review

Rapeseed is an important oil crop worldwide, with an annual production of more than 70 million tons. Rapeseed meal (RSM) is a by-product of rapeseed oil production and is second after soybean meal (SBM) in the world production of protein meal. Rapeseed meal derived from black-seeded winter oilseed rape (Brassica napus L.) usually contains between 35 and 40% of crude protein (CP), which is considered to be one of the more valuable plant proteins. It has a good balance of essential amino acids and a very high protein efficiency ratio (PER=3.29). However, full utilisation of this protein is difficult due to presence of the non-protein components of the seed which are associated with it. These are called antinutritional factors and they limit the utilisation of RSM in monogastric animal nutrition. The main antinutritional factors in RSM are dietary fibre, glucosinolates, phytic acid, and phenolic compounds (sinapine, tannins). For many years, research has been conducted in many centers around the world to improve the nutritional value of RSM, which will consequently increase its use in feeding monogastric animals. The attempts that have been undertaken include breeding strategy, optimisation, modernisation and better control of the oil extraction process, as well as technological treatments of seeds and meal. This review provides information on how RSM has evolved in recent years, as well as on its nutritive value, particularly protein, fibre and glucosinolate content. Techniques which have been used to improve the nutritional value of rapeseed products are also discussed. However, the used methods do not allow for full replacement soybean meal by RSM in monogastric animal nutrition.

Chemical composition, energy and amino acid digestibility in double-low rapeseed meal fed to growing pigs

Background

The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition. And a precise understanding of the nutritional value of an ingredient is beneficial for the accurate diet formulation and reduction of feed costs. This study was conducted to determine the chemical composition, digestible energy (DE) and metabolizable energy (ME) content, and apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) for growing pigs. Thirteen solvent-extracted double-low rapeseed meal (DLRSM) samples were obtained from the main double-low rapeseed producing areas in China.

Methods

The DE and ME contents of the 13 DLRSM samples were measured in growing pigs (six pigs per DLRSM sample, average initial body weight (BW) = 48.3 kg). The AID and SID of AA of 10 DLRSM samples were determined in 12 crossbred barrows (average initial BW = 35.3 kg) by using two 6 × 6 Latin square designs. Each Latin square comprised one N-free diet and 5 DLRSM test diets.

Results

The chemical composition of DLRSM varied among samples, and the coefficient of variation was greater than 10 % for ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium (Ca), and total glucosinolates. The AA content of DLRSM varied among samples especially for lysine (Lys) and methionine (Met). On a dry matter (DM) basis, the apparent total tract digestibility (ATTD) of gross energy (GE), the DE and ME and the ME:DE ratio of DLRSM averaged 62.39 %, 2862 kcal/kg and 2723 kcal/kg, and 94.95 %, respectively. The mean value of SID of Lys was 70.52 % which varied from 66.54–76.54 %. The SID of crude protein (CP), Met, and threonine (Thr) averaged 72.81 %, 82.41 %, and 69.76 %, respectively.

Conclusions

There was great variability in chemical composition especially in the concentration of EE, NDF and ADF, but no significant differences in energy content of the DLRSM samples were observed. In addition, the AID and SID of all AA were relatively similar among DLRSM samples except for that of Lys.

Comparative ileal amino acid digestibility and growth performance in growing pigs fed different level of canola meal

The digestibility of different vegetable protein sources were investigated and the effects of supplementing canola meal (CM) as partial inclusions were studied in growing pigs, to determine the performance parameters and its economic importance. In Exp. 1, four pigs (average initial BW = 15.4 ± 0.35 kg, 5 weeks of age) fitted with simple T-cannula at terminal ileum, were fed four diets following repeated 4 × 4 Latin square design having adoption period of 7 days. Diet 1 was Nitrogen free diet containing corn starch. Diets 2, 3, and 4 were the basal diet supplemented with soybean meal (SBM), rapeseed meal (RSM), and domestic CM respectively. The AID of crude protein was decrease in RSM in comparison to SBM supplementation. The AID of Dietary indispensable amino acids (DIAA) such as Lys, Meth, Pha, and dispensable amino acid Ala, Pro, Asp were decreased (P < 0.05) in RSM supplemented diets. The SID of DIAA does not differ but the SID of Asp was higher (P < 0.05) in RSM and CM diets while SID of Pro was lower (P < 0.05) in RSM in comparison to SBM supplemented diets. In Exp. 2, 192 growing pigs (average initial BW 24.76 ± 2.55 kg) were randomly allotted to four dietary treatments with increasing levels of CM i.e. 0, 3.75, 7.50, and 11.25 % respectively. Diets were fed in meal form for 35 days. Increasing CM levels in diets had no effects (P > 0.05) on growth performance and apparent total tract digestibility (ATTD) of nutrients and energy. Total weight gain, total feed intake, and feed cost per kg weight gain were not affected by increasing levels of CM in diets but total feed cost (TFC) per pigs was linearly reduced (26.463 to 25.674; P < 0.05). Broadly, the AID, and SID of amino acid was reduced in RSM but was not effected in CM in comparison to SBM supplemented pigs. Moreover, increasing levels of CM in pigs diet had no effect on the ATTD and performance but TFC per pig was reduced. Thus CM inclusion of up to 11.25 % in diets can be used for reducing the production cost in growing pigs without any negative effect.

Effectiveness of Rapeseed Press Cake (RPC) in Sow Feeding in Two Reproduction Cycles

The possibility of replacing soybean meal with rapeseed press cake (RPC) in feed was determined over two reproductive cycles in an experiment with 54 pregnant and lactating sows allocated to three groups with 18 gilts per group. Group I received the standard mixture, group II received RPC as the main protein source from insemination to 100 days of pregnancy, and the control diet during late pregnancy and lactation. In group III, RPC replaced all of soybean meal protein in early pregnancy and one-half of soybean meal protein during late pregnancy and lactation. Half of the sows in each group received a iodine supplement (1 mg/kg feed). Sows were weighed at mating, farrowing and weaning. Piglets were weighed at 1 and 28 days of age (weaning). Samples of milk were collected at 14 days postpartum to determine the content of protein, fat, lactose and iodine. After the first reproductive cycle sows were mated and allocated to the respective groups as in the first cycle. Neither RPC nor iodine had any effect on body weight of the sows. RPC had a beneficial effect on body weight of piglets at birth and weaning, which could be due to a higher content of fat and amino acids in sow RPC diets. RPC, especially when given throughout pregnancy and lactation significantly lowered iodine content in sow milk. Piglets grew significantly faster in the second compared to the first reproductive cycle (184 and 178 g per day, respectively). Iodine supplemented to sows reduced piglet daily weight gain from 185 to 177 g. It is concluded that rapeseed press cake can replace soybean meal in the diets for pregnant and lactating sows without a negative effect on their performance while improving piglet body weight.

Effect of dehulling of rapeseed on feed value and nutrient digestibility of rape products in pigs

In the presented study the influence of dehulling rapeseed on the composition of rapeseed meal (RM) and rapeseed cake (RC) and on its feed value for piglets and growing-finishing pigs was investigated. Before withdrawal of oil, rapeseed (variety Express) was dehulled applying a procedure developed by SKET GmbH Magdeburg and the Section Food-Technology of the University Essen. The steps of the dehulling procedure were described. For RM the oil was removed by the prepress-solvent procedure till a crude fat content of 2.1% in DM. RC was produced by pressing only resulting approximately 13% crude fat in DM. The RM and RC from not dehulled (ND) and dehulled (D) rapeseed were examined analytically. Crude nutrients, sugar and fibre substances, amino acids, some minerals and trace elements, fatty acids, glucosinolates and sinapine, and phytate were determined. By dehulling the seed the crude fibre content was decreased in RM and RC by approximately 40%. The ADF content declined by 35 and 39%, and the NDF content by 28% and 40% in RM and RC, respectively. The decrease in ADL content amounted to 50% and 65% for RM and RC, respectively. On the other hand, the CP content of RM and RC was increased by 7% and 13%, respectively, by dehulling the seed while the amino acid content of rape protein increased only slightly. The contents of glucosinolates and sinapine were also increased by dehulling, while the contents of phytate and phytate P were decreased. In digestibility and balance experiments with piglets and intact hybrid breeds of growing-finishing pigs, the digestibility of organic matter and of crude nutrients and the contents of digestible energy and metabolizable energy were estimated. Furthermore, the precaecal digestibility of crude nutrients and amino acids was determined with fistulated mini-pigs. By dehulling the seeds the digestibility of organic matter from RM and RC was improved in piglets and adult pigs by approximately 10%, and the ME contents increased by 13-15%. The precaecal digestibility of the sum of amino acids was increased by approximately 3 and 6 units in RM and RC, respectively. The precaecal digestibility of lysine in RM and RC reached that of soybean oil meal from not dehulled beans.