Analysis of Physical Parameters and Chemical Composition of Offal From Puławska Fattening Pigs Raised in Deep Litter and Slatted Floor Housing Systems

Abstract

The objective of this study was to comparatively analyse the physical parameters, basic chemical composition and the macro- and microelement content of offal obtained from fattening pigs raised in deep litter and slatted floor housing systems. The experiment involved a group of 80 Puławska fatteners, including 40 pigs kept in deep-litter pens (group I) and 40 pigs in slatted pens without bedding (group II). Offal (tongues, kidneys, hearts, lungs and livers) were evaluated for weight, physical characteristics (pH45, pH24, WHC), chemical composition (water, protein, fat) and the content of minerals: macro- (K, Na, Mg, Ca) and microelements (Zn, Fe, Mn, Cu). Based on the results obtained, associations were found between housing system and basic chemical composition of some offal, i.e. percentage of water (slatted floor<deep litter) and protein (slatted floor>deep litter) in lungs, content of protein (slatted floor>deep litter) and fat (slatted floor<deep litter) in liver, and content of fat in heart (slatted floor<deep litter). The amount of macro- and microelements was significantly differentiated by the housing system with regard to the kidneys: potassium, magnesium, calcium and manganese (slatted floor<deep litter), sodium (slatted floor>deep litter); lungs: sodium (slatted floor>deep litter), potassium (slatted floor<deep litter); and liver: iron (slatted floor>deep litter) and copper (slatted floor<deep litter). In general, the housing system of fattening pigs modified the physical parameters and chemical composition of the analysed offal.

Edible Offal as a Valuable Source of Nutrients in the Diet—A Review

“…Edible by-products constitute a significant portion of an animal’s total carcass weight, with offal yields ranging from 10% to 30% depending on various factors such as species, age, sex, live weight, fatness, living conditions, and other factors [ 3 , 13 , 19 , 24 , 64 , 65 , 66 , 67 , 68 ]. The quality of offal is influenced by both genetic [ 32 ] and environmental factors, including the animal’s housing system and nutrition [ 9 , 22 , 69 ].…”

“…In pigs, the liver typically weighs around 1.16–2.12 kg, making up 1.0–1.7 of the total slaughter weight, which averages about 100 kg [ 24 , 70 , 71 ]. Studies show that breed, rearing method, or genotype does not significantly influence the weight and percentage of offal [ 20 , 22 , 69 , 72 , 73 ], with the heart weighing approximately 0.4 kg (0.35%), the kidney 0.34–0.40 kg (0.3%), the tongue 0.25–0.30 kg (0.25%), the lungs 0.67–1.013 kg (0.53–0.77%). Similarly, research on wild animals such as zebras, donkeys, antelopes, wildebeests, and fallow deer indicates no significant seasonal effect on the weight and proportion of internal organs [ 39 , 74 , 75 , 76 , 77 ].…”

“…As with cattle [ 14 ], the mass proportion of internal organs (liver, kidney, and heart) of wild boars is determined by age and sexual dimorphism [ 78 ]. In addition, wild boars, unlike domestic pigs, are characterized by a higher mass proportion of by-products [ 20 , 22 , 59 , 69 , 79 ]. The crossbreeding of domestic pigs and wild boars also impacts the weight and proportion of offal [ 80 ].…”

“…Numerous studies [ 6 , 7 , 8 , 9 , 20 , 21 , 23 , 44 , 45 , 51 , 52 , 58 , 61 , 68 , 69 , 78 , 117 , 119 ] have shown that offal contains a significant amount of high-quality protein, minerals (including iron, phosphorus, copper, magnesium, iodine, calcium, potassium, sodium, selenium, zinc, and manganese), vitamins (such as B1, B2, B6, folic acid, B12, A, D, E, and K), and essential fatty acids, especially n -3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and have a favorable polyunsaturated fatty acid (PUFA) to saturated fatty acid (SFA) ratio. The chemical composition primarily determines the favorable taste and dietary qualities.…”

“…The chemical composition primarily determines the favorable taste and dietary qualities. Offal, except liver, contains few carbohydrates [ 56 , 69 ].…”