No abstract

No abstract

Iberian (IB, n = 60) and crossbred Large White × Landrace (F1, n = 58) pigs were slaughtered at 160 kg, after finishing under intensive conditions or on pasture and acorns. The study was carried out as a factorial arrangement of treatments, and physicochemical properties and sensory attributes of meat were assessed in Longissimus thoracis samples. Physical characteristics included the assessment of drip loss, cooking loss, shear force, and color coordinates in meat samples processed at 2 and 9 d postmortem. The interactions of genetic group and finishing system were significant (P < 0.05) for cooking loss in meat aged for 9 d and for sensorial tenderness and global acceptability of meat, but none of the other physicochemical, color coordinates, and sensory variables analyzed showed a significant interaction. Genetic group was the main factor influencing the variables analyzed, with a major (P < 0.01) influence on all meat physicochemical characteristics and sensory attributes. Relative to F1 pigs, the IB produced meat with higher intramuscular fat content and marbling score, more appealing color coordinates, lower shear force, and higher sensorial tenderness. The finishing systems affected (P < 0.05) most physical characteristics, but not chemical composition of meat and their impact on sensory properties was small. The tenderness, juiciness, and global acceptability of meat were much higher in IB pigs, and flavor was also more desirable, but the difference was smaller. The differences in sensory properties between meats originating from the two genetic groups were largely explained by the higher fat deposition in IB pigs, such that a higher level of marbling was positively associated with all the sensory attributes evaluated. Ageing meat for up to 9 d postmortem benefited pork quality, improving meat tenderness, and color, particularly in crossbred pigs and those finished intensively.

The lower results in cryopreservation of in vitro-produced (IVP) sheep embryos, when compared to the in vivo derived, limits its use. Four groups of blastocyst (BL) were evaluated: fresh IVP (n = 3), fresh in vivo derived (n = 3), warmed IVP cryopreserved in open pulled straws (OPS, n = 3) and warmed in vivo derived cryopreserved in OPS (n = 3). Ultrastructural observation of processed fresh embryos showed a reduced number of microvilli and mitochondria in the IVP ones, as well as a lower number of mature mitochondria, that can be associated with deficient metabolism in IVP embryos, possibly involved in the lower resistance to cryopreservation. Both in vivo-derived and IVP embryos had a large number of vesicles, with light and dense content. In embryos vitrified by OPS, major changes were observed mainly in IVP embryos with small changes in grade 2 (fair) and high changes in grade 3 (bad) semithin scoring. The main changes associated with cryopreservation included disruption of cellular membranes and poor intracellular preservation, with loss of microvilli and the presence of cellular debris. In conclusion, ultrastructural evaluation of IVP blastocysts cryopreserved in OPS was herein described for the first time, reporting more severe cellular damage in these embryos when compared to those produced in vivo. This is probably associated with a lower cryotolerance that can be related to their lipid content and metabolism.

A factorial experiment was performed with 117 barrows belonging to the Iberian (IB) and crossbred F Large White × Landrace (F) genetic groups, either intensively finished (IN) or finished outdoors on pasture in an oak and cork tree forest (EX). Information was collected on carcass weight, yield, and dimensions; weight of organs, carcass cuts, and abdominal fat depots; backfat depth; measurements of the longissimus thoracis (LT); and yield of different leg tissues. For the 41 slaughter and carcass traits analyzed, the interaction between genetic group and finishing system was significant ( < 0.05) in 18 traits, and overall, there was a more pronounced influence of genetic group than of finishing system. In most variables, particularly those related with fat deposition, the interaction reflected mostly changes in mean differences among genetic groups rather than in their ranking, where IB pigs consistently produced fatter carcasses, regardless of the finishing system. Liver weight in IB-EX pigs was lower by nearly 8% when compared with F-EX or IB-IN pigs, but the opposite pattern was found in F pigs, where liver weight in F-EX pigs was higher by 16% relative to IB-EX pigs or to F-IN pigs. The deposition of adipose tissue was much larger ( < 0.05) in IB pigs compared with F pigs, with means for fat depots in IB pigs that were higher by about 25% in total abdominal fat, 94% in dorsal fat depth, 72% in intermuscular plus subcutaneous fat in the leg, and over 300% in intramuscular fat (IMF). The deposition of lean tissue was much lower in IB pigs ( < 0.05), with means for trimmed loin weight corresponding to about one-half of the means obtained in F pigs, whereas lean percentage in the leg of IB pigs was about two-thirds of the mean in F pigs and the mean area of the LT was nearly one-half of that observed in F pigs in the same finishing system ( < 0.05). A strong correlation was observed between the various fat depots when the full data set was considered (correlations of IMF with abdominal fat and backfat depth of 0.65 and 0.83, respectively; < 0.05), but the correlations were much smaller when they were estimated within breed, particularly for IB pigs (-0.10 and 0.20 for the correlations of IMF with abdominal fat and backfat depth, respectively; > 0.05), indicating that it is feasible to reduce subcutaneous and abdominal fat without compromising IMF and meat quality.