## 3 Results and Discussion
### Fatty Acid Profiles and Health Indexes of Groin, Jowl, and Trimming Shoulder Fats
Pancreatic lipase, taking part in fat digestion, is capable of detaching fatty acids located only in the external positions (_sn_-1,3) of triacylglycerol molecules, and after this process, monoacylglycerols with a fatty acid in the internal position (_sn_-2) are formed. Pork fat contains more saturated fatty acids in the _sn_-2 position than vegetable fats, in which this position is occupied mainly by unsaturated fatty acids. In lard, for example, the _sn_-2 position is mainly occupied by palmitic acid (C16:0). When saturated fatty acids are located in the _sn_-2 position, it has a positive effect on the fat absorption process. Saturated monoacylglycerols and polyunsaturated fatty acids and their salts obtained after hydrolysis have a high absorption rate. A large share of saturated fatty acids in the external positions (_sn_-1,3) of triacylglycerols has an adverse effect on fat digestibility. Saturated fatty acids present in these positions, detached from triacylglycerol molecules after the digestion process, tend to form poorly soluble calcium salts, which may result in calcium deficiencies in the body and significant deterioration of fat absorption [55]. Authors have reported many advantages of applying liquid feeding systems compared to dry feeding. These include improved nutrient utilization, the possibility of using liquid by-products, and improved animal performance [58; 59; 60]. Additionally, introducing liquid to a diet can help digestion by facilitating the breakdown of nutrients, which can further enhance feed conversion efficiency. Liquid feeding form can also enhance gut health, reduce the need for feed medications and improve animal well-being [60; 61]. Liquid feeding systems often improve the palatability of the feed, which can lead to increased feed intake. This increase in feed intake can often lead to improved growth rates, as the pigs are consuming more nutrients that are vital for their development. Notably, fat quality is influenced by physical and nutritive characteristics, which are both related to the fatty acid composition of the fat depots. The major issues related to fat quality are fat softness, oxidative rancidity, and the impact of the composition of pork fat on human health. The composition of dietary fat, used in liquid and dry feeding systems in this study (Table 1), could affect the quality of the fat deposits in pigs. [PERSON] et al. [61] reported that pigs' diets supplemented with soybean oil increased the amount of unsaturated fat deposited. Increasing the feeding duration of soybean oil increased C18:2 _n_-6, PUFA, UFA:SFA ratio, and PUFA:SFA ratio and decreased C18:1 _cis_-9, C16:0, SFA, and MUFA concentrationsin jowl fat and backfat. It should be highlighted that feeding ingredients with relatively high levels of unsaturated fatty acids increase the degree of unsaturation of the fat tissue, consequently decreasing fat firmness, and negatively impacting fat quality. The empirical results reported herein should be considered in the light of some limitations. The primary limitation to the generalization of these results is the size of the research group. More studies with larger sample sizes should be conducted to reconfirm the findings. The second limitation concerns the lack of previous research studies on the topic, so the possibility of comparing the results with those of other authors was limited. The third limitation is the lack of information about the content of each fatty acid contributed by the type of diet (in mg/100 g), so it is likely that the amounts are different in the liquid and dry formulations which could influence the results presented in the study. There is still a need for additional studies regarding the impact of the liquid and dry feeding systems on the quality of pork fat, including fatty acid profiles, their distribution between internal and external positions in triacylglycerol molecules, peroxide value, oxidative stability, and nutritional indexes.