Data sheets: Animal plasma

Introduction

Animal plasma is a product obtained from the valorisation of the blood from slaughterhouses. It can be of multi-species origin (mixture of bovine and porcine plasmas) or of single species origin (only bovine or only porcine) according to the regional rules and regulations for use in animal feeding.

The plasma obtention process begins at the slaughterhouse with the collection of blood and the incorporation of salts with anticoagulant effects (trisodium citrate and sodium tripolyphosphate). Then the treated blood is processed to separate the plasma from the red blood cells, which comprise ¾ of the blood. After the filtration, the most commonly used separation methods today are reverse osmosis or nano or ultra filtration. Finally, the separated plasma is dried by an spray process to obtain a dry, stable, end product that is powdered and cream in color.

The separation process used is the main determining factor in the quality of the final product, varying basically in protein and salt content. The plasma obtained by reverse osmosis has a lower protein content and a higher salt concentration (±70% of CP and >15% ash) while filtration allows a higher concentration of protein (±78%) and a significant reduction of ash (5-6%). Globally, the tendency to use one quality of product over the other depends on the processing systems used regionally.

Plasma as an animal feed ingredient offers a high digestible and high quality protein and as it essentially contains plasma proteins (albumins and globulins). At the amino acid level, plasma is rich in lysine and threonine but poorer in sulphur animo acids and branched-chain amino acids, especially unbalanced in isoleucine. Due to its high cost, plasma has been used mainly in young piglet diets however, currently it is being considered as an ingredient in other phases due to its functionality.

Finally, it must be noted that in the EU since 2005, only the use of porcine plasma from authorized sources is allowed (Commission Regulation EC 1292/2005) in swine diets. This is why in the context of the EU pig sector, many times it is mentioned as porcine plasma instead of animal plasma.

Comparative study of nutritional values

The systems used in the comparison are: FEDNA (Spanish), CVB (Dutch), INRA (French), NRC (USA) and Brazil.

¹ The FEDNA evaluation system shows a range of values (minimum and maximum) which result from the integration of the two different classifications that this assessment system considers based on the protein content, which differs by process (reverse osmosis vs nano or ultra filtration).

² No data is shown for the INRA and CVB evaluation systems because neither considers animal plasma an ingredient.

It should be noted that two of the selected evaluation systems (INRA and CVB) do not consider animal plasma an animal feed ingredient, and therefore only FEDNA, NRC and BRASIL show nutritional evaluation data for this ingredient. In addition, FEDNA presents two qualities of animal plasma basically differentiated according to protein content (±70% and ±80%), values directly associated with the type of process used to obtain the product (by reverse osmosis or by nano/ultra filtration, respectively). The protein content evaluation for BRAZIL (±72%) and NRC (±78%) are coupled with the two qualities of protein differentiated by FEDNA, clearly corresponding to the most typical obtainment system of each production area and its evaluation system.

The dry matter range shown for the different assessment systems is very stable with very little variation between systems (91.5%±0.31).

The variation observed in the protein content associated with the obtainment process is consistent for the rest of the nutrients (mainly AA) as well as for the energy value, since the influence of the fat content (2%±0.6) does not explain any effect on the energy value prediction. If BRAZIL is not considered, which presents a relatively high NE value (2280 kcal/kg) with a lower protein content than NRC (for a NE 226 kcal/kg lower), a more linear response can be observed between the protein content and the NE value (r2 = 0.40).

In terms of total amino acids, using lysine as a reference, BRAZIL assesses a higher lysine content per protein unit than do NRC (+2.5%) and FEDNA (+4.3%). A similar trend can be observed for methionine, tryptophan and arginine, although for valine the differential of +4.3% is equal for NRC and FEDNA and in the case of treonine the relationship is inverted, +7.8% with respect to NRC and +4% with respect to FEDNA. Finally, it should be noted that FEDNA and NRC on average overestimate the isoleucine content per protein unit by >9% with respect to BRAZIL, an effect directly associated with the obtainment system in the case of this amino acid since the overestimation of FEDNA with respect to BRAZIL when considering the isoleucine content is >11% for plasma with 78% protein. A range is presented for the digestibility coefficient of protein and lysine between 81-90% and 87-95% respectively. As for the AA content, there is an overestimation of the digestibility coefficient proposed by BRAZIL with respect to NRC (+15% and +8%) and lesser so with respect to FEDNA (+7% and +3%).

It should be noted that the process to obtain it, has a very important impact on the final ash content of the product (ranging from 12-15%) obtained by concentration prior to atomization by reverse osmosis (FEDNA 70%CP and BRAZIL) with respect to the product obtained by nano or ultra filtration which shows lower mineral content. In this sense the response in high contents is similar for Na, Cl and K. In the case of sodium and chlorine, high contents are explained by the addition of anticoagulant salts (mostly trisodium citrate and sodium tripolyphosphate) during collection and processing. This is due to the reverse osmosis system only removing salts and therefore concentrating all solutes, while parts of those salts are lost during the nano or ultra filtration process. On the other hand, it is also important to point out that although the ultra filtration system allows a significant reduction of the accumulated mineral content, the total P and digestible P content is clearly higher for FEDNA 80% CP and NRC with values of 1.20%, which is explained by the fact that while ultra filtration eliminates salts, P is bound to the plasma fractions acting as a stabilizer.

Recent findings

1. Effects of a nursery feed regimen with spray-dried bovine plasma on performance and mortality of weaned pigs positive for porcine reproductive and respiratory syndrome virus.

The study was conducted to evaluate the effect of plasma supplementation in PRRSV positives piglets during the nursery period. Higher BW was observed for pigs fed spray dried plasma during the nursery period and cumulative ADG and ADFI were also higher. Moreover, a reduction of the mortality rate was also reported. It may be concluded that spray dried plasma supplementation of PRRSV challenged pigs during the nursery period may exert positive effects on performance and piglet loss reduction.

2. Spray dried plasma as an alternative to antibiotic in piglet feeds, mode of action and biosafety.

Spray dried plasma may represent an effective alternative to antibiotics for piglets, particularly during the first weeks post-weaning as better or equivalent efficacy on pig performance compared with antibiotics or other alternative antimicrobial products has been reported. The efficacy of SDP in animal feed appears to be related mainly to an improved barrier function of the gut mucosa and the modulation of the mucosal immune response. The available biosafety studies provide enough evidence to support that commercial SDPP is a safe product for pigs.

3. Influence of spray dried porcine plasma in starter diets associated with a conventional vaccination program on wean to finish performance.

Vaccination supported a long-term antibody response against PCV2 and a moderate but weaker antibody response against Mhyo for early finishing pigs challenged with PCV2. Using SDPP in the starter diet along with vaccination supported the best long-term beneficial effects on survival to market and carcass weight.

4. Effects of spray-dried porcine plasma on growth performance, immune response, total antioxidant capacity, and gut morphology of nursery pigs.

Dietary SDPP increased growth performance was observed during the nursery period. After 1 week post-weaning, pigs fed SDPP had greater ADG, ADFI and G:F compared with CTL pigs. On d 28, pigs fed SDPP had greater BW and tended to have greater ADG and ADFI compared with CTL pigs. Moreover, the positive effect on gut morphology may be explained via the increased proliferation of enterocytes.

5. Spray dried animal plasma as an alternative to antibiotics in weanling pigs – A review.

In weanling pigs, the use of porcine spray dried plasma has the highest efficacy, which is partly explained by the specificity of its IgG against porcine pathogens. It is established that after weaning, the optimal inclusion level may be between 4 and 8%. The improved feed efficiency may be explained by lower expenditure of energy and nutrients to build an immune response against the challenge. Finally, the IgG and other bioactive substances contained may help to reduce the incidence of diarrhea in post-weaned piglets feed plasma.

References

FEDNA: http://www.fundacionfedna.org/
NRC 1982. United States-Canadian Tables of Feed Composition: Nutritional Data for United States and Canadian Feeds, Third Revision.
Rostagno, H,S, 2017, Tablas Brasileñas para aves y cerdos, Composición de Alimentos y Requerimientos Nutricionales, 4° Ed