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The aims of this study were to estimate covariance components for BW at 270 d (BW270) and carcass and ham quality traits in heavy pigs using models accounting for social effects and to compare the ability of such models to fit the data relative to models ignoring social interactions. Phenotypic records were from 9,871 pigs sired by 293 purebred boars mated to 456 crossbred sows. Piglets were born and reared at the same farm and randomly assigned at 60 d of age to groups (6.1 pigs per group on average) housed in finishing pens, each having an area of 6 m(2). The average additive genetic relationship among group mates was 0.11. Pigs were slaughtered at 277 ± 3 d of age and 169.7 ± 13.9 kg BW in groups of nearly 70 animals each. Four univariate animal models were compared: a basic model (M1) including only direct additive genetic effects, a model (M2) with nonheritable social group (pen) effects in addition to effects in M1, a model (M3) accounting for litter effects in addition to M2, and a model (M4) accounting for social genetic effects in addition to effects in M3. Restricted maximum likelihood estimates of covariance components were obtained for BW270; carcass backfat depth; carcass lean meat content (CLM); iodine number (IOD); and linoleic acid content (LIA) of raw ham subcutaneous fat; subcutaneous fat depth in the proximity of semimembranosus muscle (SFD1) and quadriceps femoris muscle (SFD2); and linear scores for ham round shape (RS), subcutaneous fat (SF), and marbling. Likelihood ratio tests indicated that, for all traits, M2 fit the data better than M1 and that M3 was superior to M2 except for SFD1 and SFD2. Model M4 was significantly better than M3 for BW270 (P < 0.001) and CLM, IOD, RS, and SF (P < 0.05). The contribution of social genetic effects to the total heritable variance was large for CLM and BW270, ranging from 33.2 to 35%, whereas the one for ham quality traits ranged from 6.8 (RS) to 11.2% (SF). Direct and social genetic effects on BW270 were uncorrelated, whereas there was a negative genetic covariance between direct and social effects on CLM, IOD, RS, and SF, which reduced the total heritable variance. This variance, measured relative to phenotypic variance, ranged from 21 (CLM) to 54% (BW270). Results indicate that social genetic effects affect variation in traits relevant for heavy pigs used in dry-cured hams manufacturing. Such effects should be exploited and taken into account in design of breeding programs for heavy pigs.

Two independent trials were carried out to test the effectiveness of different environmental enrichments in improving Italian heavy pigs' welfare. Eighty undocked Landrace × Large White barrows (body weight range: 27.1–158.4 kg) were used. In Trial 1, group C1 received a metal chain and group WL wooden logs (placed inside a specifically designed metal rack). In trial two, the enrichments proposed were a hanging chain (C2), and a vegetal edible block (EB) inside the metal rack. General health, animal behaviour, hair cortisol, blood parameters and growth performance were recorded. In Trial 1, WL pigs interacted with the enrichment at a lower extent than C1 (p <.01) and walked less (p <.05). In Trial 2, EB pigs spent less time in lateral recumbency and rooting/exploring the pen floor (p <.05 and p <.01, respectively), and interacted more with the enrichment (p <.001) than C2. Motivation to explore both WL and EB was maintained over time, conversely to what happened to C1 and C2. No differences were observed in hair cortisol concentration, neutrophil/lymphocyte ratio, skin lesions and growth parameters. Tail lesions were higher in WL than in C1 (p <.05) Minor, transient differences were found in plasma biomarkers. Overall, WL had limited effect on behaviour, whereas EB might have reduced floor over-exploration when compared to the chains. It is concluded that, although from an animal behaviour standpoint EB might be promising, regardless of the device used (C, WL or EB), all experimental groups showed similar welfare parameters levels, stimulating the necessity for wider research on enrichment design and function. [ABSTRACT FROM AUTHOR]

To explore the influence of 4 feeding strategies on dry-cured ham quality, 336 barrows and gilts (3 batches, 112 pigs/batch) of 90 kg body weight (BW), were divided into 4 groups and housed in 8 pens with automated feeders. In the control group (C), the pigs were fed restrictively medium-protein feeds and slaughtered at 170 kg BW (SW) and 265 d of slaughter age (SA). With the older age (OA) treatment, the pigs were restrictively fed low protein feeds and slaughtered at 170 kg SW and 278 d SA. The other two groups were fed ad libitum high protein feeds, the younger age (YA) group was slaughtered at 170 kg SW and 237 d SA, the greater weight (GW) at 265 d of SA and 194 kg SW. The hams were dry-cured and seasoned for 607 d, weighed before and after seasoning and deboning. Sixty hams were sampled and sliced. The lean and the fat tissues were separated and analyzed for proximate composition and fatty acid profile. The model of analysis considered sex and treatment as fixed factors. With respect to C: i) OA lowered the ham weight, the lean protein content, increased marbling and decreased the PUFA proportion in intramuscular and subcutaneous fat; ii) YA hams had thicker fat cover with lower PUFA in intramuscular and subcutaneous fat; iii) GW increased the deboned ham weight, fat cover depth and marbling, reduced PUFA in intramuscular and subcutaneous fat, without alteration of the lean moisture content. Sex had a negligible impact. • The impact of four rearing strategies on the dry-cured ham quality was assessed; • Hams from older age pigs were lighter but more marbled than control (C); • Hams from younger age pigs had thicker fat cover with less PUFA than C; • Hams from heavier pigs had greater size, thicker fat cover and less PUFA than C; • Implications for the dry-cured ham industry are discussed. [ABSTRACT FROM AUTHOR]

This study investigated the effects of four dietary treatments characterized by 0 to 20% progressive reduction of the dietary crude protein (CP) and indispensable amino acid (AA) contents on carcass quality and uniformity of pigs fed restrictively and slaughtered around 165 kg body weight (BW). Carcass data from 233 pigs from a feeding study that involved 3 batches of 80 crossbred pigs each were used. Pigs, offspring of 12 boars, were assigned to 1 of 4 dietary treatments (10 pigs per pen, gilts and barrows, and 2 pens per treatment in each batch) with diets formulated to contain 146 to 117 and 133 to 108 g/kg of CP and 7.3 to 5.8 and 5.7 to 4.7 g/kg of total Lys in early (90 to 130 kg BW) and late (130 to 165 kg BW) finishing, respectively. After slaughter, the carcasses were processed and the weight of the commercial lean (neck, loin, shoulder, and ham) and fat cuts (backfat, belly, and jowl) was recorded. The coefficient of variation was used to describe uniformity of the most important carcass traits, and the corresponding confidence intervals were computed to make comparisons across dietary treatments. Carcass weight and midline backfat thickness averaged 137 kg and 31 mm, respectively, and were not affected by diets. Diets did not influence the weight of commercial cuts and their proportion on carcass weight, with the sole exception of loins. Pigs fed diets containing the 2 lowest CP content had a slight lower proportion of loins in the carcass compared with pigs fed the conventional CP diet ( P <0.05). Most carcass traits were affected by sex and by sire effects, but interactions between diet and sex or sire was only episodic. Uniformity of carcass weight, backfat thickness, and weight of loins and dressed hams was not influenced by the dietary treatments. In conclusion, the content of CP, Lys, and other indispensable AA of conventional diets for finishing heavy pigs may be reduced by 20% without impairing the weight of carcass and primal cuts and the yields of dressed hams. This feeding strategy will contribute to the heavy pig industry by reducing feed costs (i.e., decreasing the dietary provision of soybean meal and crystalline AA) and minimizing the nitrogen excretion, without affecting carcass quality. [ABSTRACT FROM AUTHOR]

Abstract: Italian heavy pigs, with an average slaughtering body weight of 150-170kg, are world-wide famous for its Parma ham production. Because the requirement of market diversity, producers are interested in ham production following the procedure of Italian pork industry. However, with ever growing public concern about nitrogen (N) pollution in the environment, it is necessary to determine a suitable method to measure N excretion from heavy pig production. The N retention was calculated by factorial method and compared with estimations of other methods available in literature. The results showed that the N percentage of heavy pigs is 2.43% ± 0.07% on body weight basis and the percentage of N excretion was approximately 69.62% ± 0.20 of N intake. Regarding the N excretion of estimation methods, the proposal of Xiccato et al. was closer to reality of the heavy pig production than other methods and could be used as a standard way to calculate the N excretion. Besides the overall standard, it is opportune to make a N balance sheet for every individual farm under specific conditions. Only in this way, the farmers can realize their deficiencies and will voluntarily follow the Good Management Practice (GMP) indications so as to guarantee a sustainable development of pig production. [Copyright &y& Elsevier]

Abstract: Polymorphisms MC4R c.1426A>G (p.Asp298Asn) and LEPR c.2002C>T (p.Leu663Phe) have been associated in pigs with feed intake, growth and fatness. Our aims were to analyze how these polymorphisms influence production and quality traits in Duroc×Iberian crossbred pigs, and moreover evaluate how the effects of gender and Duroc line were affecting these traits. Significant effects of gender, Duroc sire line and LEPR c.2002C>T mutation, were detected on the main traits. LEPR c.2002T allele increased body weight (2.5±0.7kg), backfat thickness (1.5±0.4mm), loin intramuscular fat (0.7±0.2 %), and lightness (1.0±0.3); however it was decreasing premium cuts yield (−0.9±0.2%). Allele c.2002T increased SFA (0.60±0.12 %), and decreased MUFA (−0.35±0.12%) and PUFA (−0.25 ± 0.06%). No significant effects of MC4R c.1426A>G SNP were identified. A genetic test based on the LEPR c.2002C>T SNP may be useful to select Duroc sires to reduce undesirable heterogeneity of carcasses and premium cuts of crossbred animals. [Copyright &y& Elsevier]

Simple Summary: The nutritional recommendations for pigs largely focus on pigs with lean genotypes fed ad libitum until reaching up to 140 kg in body weight (BW). Under different rearing conditions, it is still unclear whether existing recommendations apply to pigs that weigh more than 140 kg in BW, especially in heavy pig production systems. In the current study, pigs growing from 90 to 200 kg in BW were raised with different feeding strategies. We observed that energy restriction had a negligible effect on pigs' estimated metabolizable energy requirements at heavier BW under different feeding conditions. Under energy and protein restrictions, a value of 0.73 could be assumed as the maximum marginal efficiency of standardized ileal digestible lysine (SID lysine) utilization for protein deposition irrespective of BW, which corresponds to 9.8 g of SID lysine per 100 g of protein deposition as a minimum requirement. The current nutrient recommendations focus on pigs fed ad libitum up to 140 kg in body weight (BW). It remains unclear whether this applies to pigs weighing above 140 kg in BW under different rearing conditions. This study aimed to estimate protein (Pd) and lipid (Ld) depositions and the metabolizable energy (ME), standardized ileal digestible lysine (SID lysine) requirement and partitioning in 224 C21 Goland pigs (90–200 kg in BW). The control pigs (C) received diets limiting ME up to 170 kg in slaughter weight (SW) at 9 months of age (SA); older (OA) pigs had restricted diets limiting ME and SID lysine up to 170 kg in SW at >9 months SA; younger (YA) pigs were fed nonlimited amounts of ME and SID lysine up to 170 kg in SW at <9 months SA; and greater weight (GW) pigs were fed as the YA group, with 9 months SA at >170 kg in SW. The estimated MEm averaged 1.03 MJ/kg0.60. An 11% increase in MEm was observed in OA pigs compared to the controls. Energy restriction had negligible effects on the estimated MEm. The marginal efficiency of SID lysine utilization for Pd averaged 0.725, corresponding to a SID lysine requirement of 9.8 g/100 g Pd. [ABSTRACT FROM AUTHOR]

We investigated the in vivo effects of dietary conjugated linoleic acid (CLA) on subcutaneous adipose tissue from heavy pigs to clarify the involvement of possibly different causative effects in the established sntiadipogenic effect of CLA. Pigs [n = 36; initial body weight, 106 kg live weight (LW)] were assigned to 1 of 2 LW-matched groups supplemented with either 0 or 0.75% of a CLA preparation containing 50% CLA isomers. The pigs were slaughtered at 155 kg LW and adipose tissue analyzed. CLA supplementation affected ash content, and decreased iodine values (P < 0.01) and adipocyte size (P < 0.05). The fat content of adipose tissue was lower (P < 0.05) in females than castrated males, and females had smaller (P < 0.01) adipocytes than castrated males. Neither CLA nor sex influenced adipocyte lipid droplet diameter or the extent of lipid peroxidation as determined by quantitation of Schiff's histochemical reaction. NADPH-diaphorase was not influenced by CLA treatment. Presdipocyte proliferation rates were lower in pigs fed CLA (P < 0.05), whereas the number of adipocyte apoptotic nuclei was greater (P < 0.05). Preadipocyte proliferation was also greater (P < 0.05) in females than castrated males. Neuronal and endothelial nitric oxide synthase activities did not differ between groups in adipose tissue vessels, but inducible nitric oxide synthase expression in adipocytes was lower in pigs fed CLA (P = 0.05). These findings suggest that the antiadipogenic effect of CLA in heavy pigs is not a direct effect but may occur by downregulation of a NO-mediated lipolytic pathway. [ABSTRACT FROM AUTHOR]

Simple Summary: Italian heavy pigs production differs from pig farming in other countries of the world mainly due to the high body weight and age at slaughter of the animals. This implies that peculiar animal needs may be addressed to achieve a high level of animal welfare during the pre-slaughter phases. This narrative review aims to collect the available information on welfare issues of Italian heavy pigs in the pre-slaughter phases, and to highlight recent findings and knowledge gaps. This work provides a narrative review of the available information on the welfare of Italian heavy pigs in the pre-slaughter phase (transport, lairage, and stunning). The meat from these pigs is used for specific PDO (Protected Designation of Origin) products, and the production rules for these specialties require higher body weight (160–170 kg) and age (in general more than 9 months) at slaughter than in most other countries. This may lead to specific behavioral and physiological needs of pigs. The present paper summarizes the main research findings and knowledge gaps for each of the pre-slaughter phases. Studies are presented according to the four principles of the Welfare Quality assessment protocol (good feeding, good housing, good health, and appropriate behavior). The results of the literature review indicate a lack of knowledge on several aspects. Most of studies were carried out in a single slaughterhouse, making it difficult to identify risk factors and confounding effects. Moreover, animal-based measures were assessed using different protocols, reducing the possibility of comparison across studies. These findings may serve as a basis for the development of specific research studies and policies aimed at enhancing the animal welfare level and the ethical attributes of this renowned production, also in accordance with consumers' expectations. [ABSTRACT FROM AUTHOR]