There is limited data published on the nutritional value of camelina co-products fed to pigs though. New research involving Dr Hans Stein, the University of Illinois, and Spain and Denmark based researchers has tried to plug such knowledge gaps.
Their paper was published in Animal Feed Science and Technology.
Camelina (Camelina sativa) is an oilseed crop of the Brassica family that is grown to obtain oil for biofuel production. Oil from camelina seeds can be mechanically expelled or solvent extracted resulting in production of co-products called camelina expellers (CAE) and camelina meal (CAM), respectively.
The authors said the nutritive value of camelina co-products for pigs varies depending on the method of oil extraction and the amount of heat used during production.
Both ingredients have high concentrations of crude protein (CP) and dietary fiber, according to the findings of earlier studies. However, the residual oil content in CAE (100–140 g/kg) is greater than in CAM (20–30 g/kg; Woyengo et al., 2016).
In addition, in the solvent extraction process used to obtain CAM, camelina is subjected to more heat during oil extraction than in the mechanical process to obtain CAE. The energy value of oilseed co-products for pigs is partially dependent on the amount of residual oil in the co-products and CAE is therefore expected to contain more energy than CAM.
The availability of AA and energy may be reduced by heat whereas the concentration of heat-labile antinutritional factors (ANF) such as trypsin inhibitors can be reduced when heat is applied to the ingredient, they added.
The researchers hypothesized that CAM has lower energy and amino acid digestibility than CAE because of the lower oil concentration and the higher processing temperatures used during production of CAM rather than CAE.
They said that the goal of their research was determining the digestible energy (DE) and the metabolizable energy (ME), as well as the coefficient of ileal standardized digestibility (CISD) of CP and AA of CAE and CAM when fed to growing pigs.
The team conducted two experiments.
In the first, the idea was to determine the coefficient of total tract apparent digestibility (CTTAD) of energy and the concentration of DE and ME in CAE and CAM when fed to growing pigs.
The researchers allotted 36 barrows six different diets: a basal corn-soybean meal diet and five diets in which a proportion of the corn and soybean meal in the basal diet was replaced by CAE (100, 200 or 300 g/kg) or CAM (100 or 200 g/kg).
The experiment lasted 15 days and, during the last five days, the total amount of feces and urine were collected to calculate the energy metabolizability of the diets.
In the second trial, they wanted to determine the coefficient of ileal apparent digestibility (CIAD) and the CISD of CP and AA in CAE and CAM. They gave 33 barrows three different diets: two corn starch-based diets containing 350 g/kg CAE or 300 g/kg CAM as the sole source of CP and AA and a N-free diet.
After seven days of feeding, animals were euthanized and ileal digesta were sampled.
The researchers saw that camelina meal has a lower fat and a greater protein content than camelina expellers, energy digestibility was similar in both camelina by-products.
Camelina expellers have a greater digestible and metabolizable energy content than camelina meal, while leucine and cysteine standardized ileal digestibility was greater in camelina meal compared with camelina expellers.
The authors suggest that the greater concentration of soluble dietary fiber negatively affected AA digestibility in camelina expellers.
“Compared with other common protein sources such as canola or soybean meal, the energy content of camelina by-products was also lower, but the digestibility of specific AA such as methionine, isoleucine, valine, and arginine can be comparable. Thus, more research is needed to elucidate the main factors affecting the nutritional value of camelina co-products fed to pigs,” they concluded.
Source: Animal Feed Science and Technology
Title: Nutritional value of Spanish Camelina sativa co-products for pigs
Authors: A Cerisuelo, P Ferrer, E Ángel Gómez, TA Woyengo, HH Stein, M Martínez, JL Cano, O Piquer