Mangalica pigs are a popular niche breed given their reputation for superior pork quality. However, growth and carcass parameters for this breed are poorly documented. To better characterize optimal harvest weights for the Mangalica, a growth trial was conducted whereby pigs (n = 56) were randomly distributed across stratified harvest weights (50, 57, 68, 82, 93, 102, 127 kg) in a completely randomized design. Pigs were fed standard finisher rations with individual daily feed intakes and weekly body weights recorded for all animals. At 24 h postmortem, carcasses were split and ribbed with marbling and loin eye area (LEA) measured at the 10th rib. Primal cuts were fabricated and individually weighed. Fat back was separated from the loin and weighed. As expected, live weight significantly increased across the weight class (p < 0.0001). ADG was similar across classes up to 82 kg live weight, before steadily declining with increasing weight class (p < 0.0025). Likewise, feed efficiency did not differ between classes until weights heavier than 82 kg (p < 0.03). LEA significantly increased by class up to 82 kg and then plateaued as harvest weight increased further (p < 0.003). Marbling score significantly increased with increasing weight class up to 102 kg, where they then plateaued (p < 0.04). Fat back dramatically increased across all weight classes (p < 0.0001) despite negligible increases in LEA or marbling after 102 kg. Primal cut weights for the ham (p < 0.0001), loin (p < 0.0001), Boston butt (p < 0.0001), shoulder (p < 0.0001), and belly (p < 0.0001) all significantly increased with increasing live weight though significant fat deposition contributed to this gain. These data suggest an optimal harvest weight occurs between 82 to 102 kg, while offering little objective justification for harvesting Mangalica pigs at heavier live weights.

Relaxin (RLN) is best known as a reproductive hormone that remodels cervical connective tissue. However, porcine adipose tissue can secrete and respond to RLN, suggesting locally derived RLN could modulate adipose tissue development and function. To test this hypothesis, primary cultures of porcine subcutaneous adipose tissue stromal-vascular (AT-SV) cells and visceral adipose tissue explants were utilized as model systems to determine the effect of 100 ng/ml exogenous RLN on 1) preadipocyte proliferation and differentiation, 2) the mRNA expression of adipokine, extracellular matrix protein and fatty acid metabolism genes, and 3) lipolytic rate in porcine adipose tissue. AT-SV cells were harvested from 3-day-old neonatal pigs (n=6) and plated in vitro in growth medium containing either vehicle or RLN for cell number assays or were induced to differentiate by treatment with insulin, hydrocortisone, and rosiglitazone for 8 days in the presence or absence of RLN for adipogenesis assays. Total RNA was extracted from differentiating cultures on days 0 and 8 post-induction. Real-time PCR was then utilized to determine changes in mRNA expression for target genes. For lipolysis and cell signaling experiments, visceral adipose tissue was obtained from market weight pigs at harvest, minced into explants, and cultured in serum-free medium in the presence or absence of RLN and cAMP pathway modulators with differences in glycerol release determined following 2-hour treatment. Overall, RLN decreased preadipocyte number 1.27-fold under serum-free conditions (P &lt; 0.05), enhanced adipogenesis based upon 2.4-fold increase in GAPDH activity (P &lt; 0.05) and a 2.2-fold increase in ORO accumulation (P &lt; 0.05) while significantly increasing the mRNA expression of multiple metabolic, adipokine, and extracellular matrix component genes. RLN treatment stimulated glycerol release by 3-fold via the cAMP pathway (P &lt; 0.01). Collectively, these data support the hypothesis that RLN regulates adipose tissue development through stimulating adipogenesis and modulating adipocyte metabolism.

Mangalica pigs are a popular niche breed given their reputation for superior quality pork. However, growth and carcass parameters for this breed are poorly documented. Our objective was to better characterize optimal harvest weights for the Mangalica breed. To accomplish this, a growth trial was conducted whereby pigs (n = 56) were randomly distributed across stratified harvest weights (50, 57, 68, 82, 93, 102, 127 kg) in a completely randomized design. Pigs were fed standard finisher rations with individual daily feed intakes and weekly body weights recorded for all animals. At 24h postmortem, carcasses were split and ribbed with marbling and loin eye area (LEA) measured at the 10th rib. Primal cuts were fabricated and individually weighed. Fat back was separated from the loin and weighed. As expected, live weight significantly increased across weight class (P &lt; 0.0001). ADG was similar across classes up to 82 kg live weight before steadily declining with increasing weight class (P &lt; 0.0025). Likewise, feed efficiency did not differ between classes until weights heavier than 82 kg (P &lt; 0.03). LEA significantly increased by class up to 82 kg and then plateaued as harvest weight increased further (P &lt; 0.003). Marbling score significantly increased with increasing weight class up to 102 kg where they then plateaued (P &lt; 0.04). Fat back dramatically increased across all weight classes (P &lt; 0.0001) despite negligible increases in LEA or marbling after 102 kg. Primal cut weights for the ham (P &lt; 0.0001), loin (P &lt; 0.0001), Boston butt (P &lt; 0.0001), shoulder (P &lt; 0.0001), and belly (P &lt; 0.0001) all significantly increased with increasing live weight. These data suggest an optimal harvest weight occurs between 82 to 102 kg while offering little objective justification for the current practice of harvesting Mangalica pigs at much heavier live weights.

Mangalica pigs are a popular niche breed given their reputation for superior quality pork. However, growth and carcass parameters for this breed are poorly documented. Our objective was to better characterize optimal harvest weights for the Mangalica breed. To accomplish this, a growth trial was conducted whereby pigs (n=56) were randomly distributed across stratified harvest weights (50, 57, 68, 82, 93, 102, 127 kg) in a completely randomized design. Pigs were fed standard finisher rations with individual daily feed intakes and weekly body weights recorded for all animals. At 24h postmortem, carcasses were split and ribbed with marbling and loin eye area (LEA) measured at the 10th rib. Primal cuts were fabricated and individually weighed. Fat back was separated from the loin and weighed. As expected, live weight significantly increased across weight class (P &lt; 0.0001). ADG was similar across classes up to 82 kg live weight before steadily declining with increasing weight class (P &lt; 0.0025). Likewise, feed efficiency did not differ between classes until weights heavier than 82 kg (P &lt; 0.03). LEA significantly increased by class up to 82 kg and then plateaued as harvest weight increased further (P &lt; 0.003). Marbling score significantly increased with increasing weight class up to 102 kg where they then plateaued (p &lt; 0.04). Fat back dramatically increased across all weight classes (p &lt; 0.0001) despite negligible increases in LEA or marbling after 102 kg. Primal cut weights for the ham (P &lt; 0.0001), loin (P &lt; 0.0001), Boston butt (P &lt; 0.0001), shoulder (P &lt; 0.0001), and belly (P &lt; 0.0001) all significantly increased with increasing live weight. These data suggest an optimal harvest weight occurs between 82 to 102 kg while offering little objective justification for the current practice of harvesting Mangalica pigs at much heavier live weights.

Given adipose tissue is histologically classified as connective tissue, we hypothesized expression of extracellular matrix (ECM) components are significantly altered during adipogenesis. However, little is known about the regulation of the ECM during adipose tissue development in the pig. Therefore, the objective of this study was to characterize expression of ECM components during porcine adipogenesis. Primary cultures of adipose tissue stromal-vascular cells were harvested from 3-day-old neonatal pigs (n=6) and preadipocytes induced to differentiate in vitro for 8 days in the presence of insulin, hydrocortisone, and rosiglitazone. Total RNA was extracted from these cultures on days 0 and 8 post-induction. Real-time PCR was then utilized to determine changes in mRNA expression for collagen type I alpha 1 chain (COL1A), collagen type I alpha 2 chain (COL2A), collagen type I alpha 3 chain (COL3A), collagen type I alpha 4 chain (COL4A), collagen type I alpha 6 chain (COL6A), biglycan, fibronectin, laminin, nitogen-1 (NID1), matrix metallopeptidase 2 (MMP2), matrix metallopeptidase 9 (MMP9), metallopeptidase inhibitor 3 (TIMP3). The mRNA abundances of COL1A, COL3A and MMP2 were significantly downregulated 2.86-fold (P &lt; 0.05), 16.7-fold (P &lt; 0.01) and 3.1-fold (P &lt; 0.05) respectively in day 8 (differentiated) compared to day 0 (undifferentiated) cultures. Meanwhile, mRNA abundances were significantly upregulated during adipogenesis for the COL2A (2.82-fold; P &lt; 0.05), COL4A (2.01-fold; P &lt; 0.05), COL6A (2.8-fold; P &lt; 0.05), biglycan (49.9- fold; P &lt; 0.001), fibronectin (452-fold; P &lt; 0.001), laminin (6.1-fold; P &lt; 0.05), NID1(47.4-fold; P &lt; 0.01), MMP9 (76.8- fold; P &lt; 0.01), and TIMP3(3.04-fold; P &lt; 0.05) genes. These data support the hypothesis that significant changes in ECM components occur during porcine adipogenesis. Modulating adipose tissue ECM remodeling might be a novel strategy to manipulate adiposity in the pig.