Effect of different levels of organic zinc supplementation on pork quality

This study investigated the effect of two supplementation levels of zinc glycinate (ZnGly) on performance, carcass characteristics, and meat quality of growing-finishing pigs. Thirty pigs (bodyweight: 61 ± 4.0 kg) were assigned to three treatments and fed ad libitum for 56 days a diet supplemented with 0 (control), 45 (Zn45), or 100 mg/kg (Zn100) of ZnGly. The highest ZnGly supplementation lowered the average daily gain (P = 0.031); while, cold carcass weight did not differ between treatments. Both ZnGly levels reduced carcass chill loss (P < 0.001). Micromineral content, color stability, and fatty acid profile of meat were not altered by ZnGly. Superoxide dismutase activity was lowered by Zn45 compared to control (P = 0.007); while, catalase activity was enhanced by Zn100 (P = 0.003). Although ZnGly supplementation did not influence lipid oxidation in raw meat and in meat homogenates incubated with pro-oxidant catalysts, Zn45 limited lipid oxidation in cooked meat (P = 0.037). Our results demonstrated that supplementing pigs with 45 mg/kg of ZnGly could improve the oxidative stability of pork subjected to strong pro-oxidant conditions, but this effect needs to be further elucidated.

Do animal slaughter age and pre-cure freezing have a significant impact on the quality of Iberian dry-cured pork loin?

The influence of various animal slaughter age and of pre-cure freezing times on the quality traits of dry-cured loins from Iberian × Duroc (IBxD) crossbreed animals was assessed. Three animal batches (n = 15) were selected (IBxD8, IBxD10 and IBxD12) to be slaughtered at the age of 8, 10 and 12 months, respectively. Following slaughter, longissimus thoracis et lumborum muscles were extracted and submitted to curing (T0) or freezing storage during three (T3) or six (T6) months prior to curing. The dry-cured loins from IBxD12 yielded lower intramuscular fat and lightness, a less saturated fatty acid profile and the highest hardness and shear force (P ≤ 0.05). The pre-cure freezing process increased weight loss, saturated fatty acids, lipid oxidation, and most of the textural parameters (P ≤ 0.05). So, both slaughter age and pre-cure freezing should be taken into account in order to obtain quality and productive performance.

Effects of dietary fat saturation level on growth performance, carcass traits, blood lipid parameters, tissue fatty acid composition and meat quality of finishing pigs

Objective

The objective of this study was to investigate the effects of various dietary unsaturated to saturated fatty acids ratios (UFA to SFA ratios) on growth performance, carcass traits, blood lipid parameters, tissue fatty acid (FA) composition, and meat quality of finishing pigs.

Methods

A total of 45 crossbred pigs ([Duroc×Landrace]×Yorkshire), with an average initial body weight of 60.3±2.4 kg, were randomly allocated to three treatment groups of 1:1, 2:1, and 3:1 dietary UFA to SFA ratios.

Results

Both average daily gain and average daily feed intake of pigs were decreased linearly (p<0.05), whereas backfat thickness was decreased linearly (p<0.05) with increasing of dietary UFA to SFA ratio. Serum triglyceride and low density lipoprotein cholesterol were decreased quadratically or linearly (p<0.05) respectively, whereas high density lipoprotein cholesterol was increased quadratically (p<0.05) with increasing dietary UFA to SFA ratio. In M. longissimus thoracis, the proportion of C18:1 and monounsaturated FA was decreased linearly (p<0.05), whereas the proportion of C18:2n-6, C20:4n-6 and polyunsaturated FA (PUFA) were increased linearly (p<0.05) as dietary UFA to SFA ratio increased. In the subcutaneous adipose tissue, the proportion of SFA was decreased linearly (p<0.05), whereas the proportion of n-6 PUFA, n-3 PUFA, and the UFA to SFA ratios were increased linearly (p<0.05) with increasing of dietary UFA to SFA ratio. Meat color scores and shear force of pigs were decreased linearly (p<0.05), whereas drip loss and cooking loss were increased linearly (p<0.05) with increasing of dietary UFA to SFA ratio.

Conclusion

Appropriately boosted dietary UFA to SFA ratio could be conductive to optimize blood lipid parameters and tissue FA composition. However, when the ratio is too high or too low it tends to have negative effects on growth performance and meat quality.

Evaluation of the Physicochemical and Structural Properties and the Sensory Characteristics of Meat Analogues Prepared with Various Non-Animal Based Liquid Additives

This study investigates the effects of various non-animal-based liquid additives on the physicochemical, structural, and sensory properties of meat analogue. Meat analogue was prepared by blending together textured vegetable protein (TVP), soy protein isolate (SPI), and other liquid additives. Physicochemical (rheological properties, cooking loss (CL), water holding capacity (WHC), texture and color), structural (visible appearance and microstructure), and sensory properties were evaluated. Higher free water content of meat analogue due to water treatment resulted in a decrease in viscoelasticity, the highest CL value, the lowest WHC and hardness value, and a porous structure. Reversely, meat analogue with oil treatment had an increase in viscoelasticity, the lowest CL value, the highest WHC and hardness value, and a dense structure due to hydrophobic interactions. SPI had a positive effect on the gel network formation of TVP matrix, but lecithin had a negative effect resulting in a decrease in viscoelasticity, WHC, hardness value and an increase in CL value and pore size at microstructure. The results of sensory evaluation revealed that juiciness was more affected by water than oil. Oil treatment showed high intensity for texture parameters. On the other hand, emulsion treatment showed high preference scores for texture parameters and overall acceptance.

Effects of exogenous emulsifier supplementation on growth performance, energy digestibility, and meat quality in broilers

This experiment was conducted to investigate the effects of exogenous emulsifier supplementation on growth performance, energy digestibility, and meat quality in broilers. A total of 60 Ross 308 broilers were treated for two weeks. The three dietary treatments were: (CON) basal diet; (T1) basal diet + 0.1% exogenous emulsifier, and (T2) basal diet + 0.2% exogenous emulsifier. In Period 1 (0–7 days), broilers in the T2 group showed significantly higher body weight gain (BWG) (p < 0.05) and broilers in the T1 and T2 treatment groups had significantly lower feed conversion ratios (FCR) (p < 0.05). In Period 2 (8–14 days), broilers in the T2 treatment group had significantly higher feed intake (FI) (p < 0.05). Therefore, in this experiment (from days 0 to 19), BWG and FCR were affected (p < 0.05) by the T1 and T2 treatments. Additionally, the T1 and T2 treatments with added exogenous emulsifier in the broiler feed showed significantly higher energy digestibility (p < 0.05) than the CON treatment. Broilers fed the T2 diet had higher water-holding capacity (WHC) (p < 0.05) and cooking loss than the broilers fed the CON and T1 diets. Moreover, the shearing force in the meat was decreased (p < 0.05) in broilers fed the T2 diet. In conclusion, supplementation with exogenous emulsifier to broiler diets improved growth performance, energy digestibility, and meat quality. The optimal amount of exogenous emulsifier supplementation requires further investigation.

Dietary lecithin improves feed efficiency without impacting meat quality in immunocastrated male pigs and gilts fed a summer ration containing added fat

The aim of this study was to investigate the effects of sex and dietary lecithin on growth performance, meat quality, muscle collagen content and gene expression of key genes involved in collagen synthesis in finisher pigs. A total of 256 pigs (Large White × Landrace) were allotted to a 2 × 2 factorial arrangement involving sex (gilt or immunocastrated [IC] male) and dietary treatment (0 or 5 g/kg of dietary lecithin). All diets were formulated to contain 4.6% tallow with relatively high total fat of 6.3%. After 5 weeks of dietary treatment, pigs were slaughtered and Longissimus dorsi muscle was obtained for evaluation of meat quality and collagen content. Rectus abdominis muscle was analysed for gene expression of key genes involved in collagen synthesis namely, type I (α1) procollagen (COL1A1), type III (α1) procollagen (COL3A1), α-subunit of prolyl 4-hydroxylase (P4H), lysyl oxidase and metalloproteinase-1 (MMP-1). The results showed that lecithin improved feed efficiency of all pigs (P < 0.05) but it had no effect on feed intake, average daily gain and dressing percentage (P > 0.05). Lecithin also had no effect on meat compression, shear force, collagen content and gene expression (P > 0.05). Immunocastrated male had higher growth rate and increased COL1A1 expression than gilts. However, sex had no effect on fat depth at the P2 site (65 mm from the midline over the last rib), collagen content and expression of other genes (P > 0.05). In conclusion, lecithin improved feed efficiency in finishing pigs without impacting pork quality. Thus, inclusion of lecithin in diets containing high amount of tallow during the summer period could be beneficial.

Dietary Lecithin Supplementation Can Improve the Quality of the M. Longissimus thoracis

Simple Summary

Meat tenderness and texture can be influenced by the connective tissue content. Dietary lecithin offers a means of improving fat digestibility of pigs and reducing the connective tissue of pork. This feeding study confirmed that dietary lecithin decreased the chewiness and improved the fatty acid composition of pork without impacting on growth performance of pigs. Therefore, dietary lecithin supplementation has the potential to improve the quality attributes of pork.

Abstract

Forty crossbred (Large White × Landrace × Duroc) female pigs (16.4 kg ± 0.94 kg) were used to investigate the effect of dietary lecithin supplementation on growth performance and pork quality. Pigs were randomly allocated to a commercial diet containing either 0, 3, 15 or 75 g lecithin/kg of feed during the grower and finisher growth phase. Pork from pigs consuming the diets containing 15 g and 75 g lecithin/kg had lower hardness (P < 0.001) and chewiness (P < 0.01) values compared to the controls. Dietary lecithin supplementation at 75 g/kg significantly increased (P < 0.05) the linoleic acid and reduced (P < 0.05) the myristic acid levels of pork compared to the control and the 3 g/kg and 15 g/kg lecithin supplemented treatments. Pigs fed the 75 g/kg lecithin supplemented diet had lower plasma cholesterol (P < 0.05) at slaughter compared to pigs fed the control diet and the 3 g/kg and 15 g/kg lecithin supplemented treatments. These data indicate that dietary lecithin supplementation has the potential to improve the quality attributes of pork from female pigs.

Effects of dietary fat saturation on fatty acid composition and gene transcription in different tissues of Iberian pigs

The effect of two diets, respectively enriched with SFA (S) and PUFA (P), on FA tissue composition and gene expression was studied in fattened Iberian pigs. The FA composition of adipose, muscular and liver tissues was affected by dietary treatment. S group showed higher MUFA and MUFA/SFA ratio and lower PUFA and n-6/n-3 ratio than P group in all analyzed tissues. In muscle and liver the extracted lipids were separated into neutral lipids and polar lipid fractions which showed significantly different responses to the dietary treatment, especially in liver where no significant effect of diet was observed in NL fraction. The expression of six candidate genes related to lipogenesis and FA oxidation was analyzed by qPCR. In liver, stearoyl CoA desaturase (SCD), acetyl CoA carboxylase alpha (ACACA) and malic enzyme 1 (ME1) genes showed higher expression in S group. SCD, ACACA, ME1, and fatty acid synthase (FASN) gene expression levels showed a wide variation across the tested tissues, with much higher expression levels observed in adipose tissue than other tissues. Tissue FA profile and gene expression results support the deposition of dietary FA, the lipogenic effect of dietary saturated fat in liver and the employment of saturated dietary fat for endogenous synthesis of MUFA in all the analyzed tissues.

Dietary lecithin improves dressing percentage and decreases chewiness in the longissimus muscle in finisher gilts

The influence of dietary lecithin at doses of 0, 4, 20 or 80 g/kg fed to finisher gilts for six weeks prior to slaughter on growth performance, carcass quality and pork quality was investigated. M. longissimus lumborum (loin) was removed from 36 pig carcasses at 24h post-mortem for Warner-Bratzler shear force, compression, collagen content and colour analyses. Dietary lecithin increased dressing percentage (P=0.009). Pork chewiness and collagen content were decreased by dietary lecithin (P<0.05, respectively), suggesting that improved chewiness may be due to decreased collagen content. However, dietary lecithin had no effect on shear force, cohesiveness or hardness (P>0.05, respectively). Dietary lecithin reduced loin muscle L* values and increased a* values (P<0.05, respectively) but no changes on b* values (P=0.56). The data showed that dietary lecithin improved dressing percentage and resulted in less chewy and less pale pork.