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PubMed2026

Transmitochondrial pigs reveal causal effects of mitochondrial DNA on backfat thickness via nuclear epigenetic reprogramming.

Mitochondrial DNA (mtDNA) polymorphisms have been associated with production traits in farm animals, including backfat thickness in pigs, yet direct in vivo evidence establishing a causal link between specific mtDNA haplotypes and fat deposition remains limited. In this study, we generated transmitochondrial pigs (mitopigs) by combining the Dapulian nuclear genome with Wuzhishan mtDNA via somatic cell nuclear transfer, introducing 23 mtDNA mutations relative to controls. Mitopigs exhibited significantly increased backfat thickness at 5 months, a difference that persisted in their offspring, without significant differences in body weight, body size, or litter size. Fibroblasts derived from mitopigs exhibited reduced mtDNA copy numbers, decreased expression of mitochondrial biogenesis genes (PPARA, PPARGC1A, RRM2B, and LRPPRC), impaired mitochondrial respiration, elevated reactive oxygen species (ROS), and upregulated adipogenic transcription factors (CEBPA, CEBPB, and PPARG). Consistent with these fibroblast findings, backfat tissue of mitopigs showed corresponding upregulation of adipogenic transcription factors and downregulation of mitochondrial biogenesis genes. Integrated transcriptomic and whole-genome bisulfite sequencing (WGBS) analyses revealed nuclear transcriptional reprogramming that was closely associated with differential DNA methylation, predominantly affecting mitochondrial function and lipid metabolism pathways. Mitopig fibroblasts also showed a pro-inflammatory response to lipopolysaccharide stimulation, with elevated expression of IL-12, NOS2, RELA, and TNF-α. Our findings provide direct in vivo evidence that mtDNA variants regulate adiposity in pigs through mitochondrial dysfunction, oxidative stress, and nuclear epigenetic modulation, highlighting the potential for incorporating mtDNA haplotype information into pig breeding programs as a complementary strategy to nuclear genomic selection.

Adipogenesis↗

PubMed1992

Correlated responses in reproductive and carcass traits to selection for 200-day weight in Duroc swine.

Correlated responses in reproductive and carcass traits from a line of Duroc pigs selected for increased 200-d weight along with a randomly selected control line were studied in 189 litters (116 select, 73 control) and 191 pigs (106 select, 85 control), respectively. Reproductive and maternal traits studied included litter sizes born, born alive, and alive at 21 d and litter weight at birth and at 21 d. Carcass traits studied were carcass length, longissimus muscle area, average backfat thickness, 10th rib backfat thickness, specific gravity, weights of closely trimmed ham, loin, and shoulder, belly weight, subjective scoring of the longissimus muscle for color and marbling, estimated percentage of muscle and lean gain per day. Total weighted cumulative selection differential for 200-d weight was 81.7 kg. The realized heritability for 200-d weight was .18 +/- .08, and the change in 200-d weight was 2.5 +/- 1.2 kg per generation. The regression coefficient of litter size born on generation was -.29 +/- .12 (P less than .10) pigs per generation. None of the other regression coefficients for the reproductive traits differed from zero. Average backfat thickness, 10th rib backfat thickness, and belly weight increased by .093 +/- .016 cm, .122 +/- .029 cm, and .089 +/- .040 kg, respectively, per generation. Specific gravity, ham weight, shoulder weight, color score, and percentage of muscle decreased -.00086 +/- .00024, -.165 +/- .013 kg, -.104 +/- .011 kg, -.035 +/- .015 points, and -.47 +/- .12%, respectively, per generation in response to the selection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

PubMed1992

Correlated responses in reproductive and carcass traits to selection for 70-day weight in Landrace swine.

Correlated responses in reproductive and carcass traits were studied in 181 litters and 218 pigs from a line of Landrace pigs selected six generations for increased weight at 70 d of age and a contemporaneous, randomly selected control line. The reproductive and maternal traits studied included litter sizes born, born alive, and alive at 21 d and litter weight at birth and at 21 d. Carcass traits studied were carcass length, longissimus muscle area, average backfat thickness, 10th-rib backfat thickness, specific gravity, weights of closely trimmed ham, loin, and shoulder, belly weight, subjective scoring of the longissimus muscle for color and marbling, estimated percentage of muscle, and lean gain per day. Total weighted cumulative selection differential for 70-d weight was 30.2 kg. The realized heritability for 70-d weight was .13 +/- .06, and the change in 70-d weight was .65 +/- .29 kg per generation. The regression coefficient of litter size at 21 d on generation was .24 +/- .10 (P less than .10) pigs per generation. None of the other regression coefficients for the reproductive traits differed from zero. Carcass length, specific gravity, and ham weight decreased (P less than .10) -.075 +/- .036 cm, -.00054 +/- .00027, and -.102 +/- .048 kg, respectively, per generation. Color score and lean gain per day increased .046 +/- .021 points and .0032 +/- .0013 kg/d, respectively, each generation in response to the selection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1976

The effect of an anabolic agent on N deposition, growth, and slaughter quality in growing castrated male pigs.

The conversion of feed protein into body protein in growing pigs is rather unfavourable. With Dutch Landrace pigs only 30--40 percent of the digestible crude protein is converted into body protein. To study the influence of implanting 20 mg 17beta-estradiol + 140 mg trenbolone acetate per animal on this conversion ratio, three nitrogen-balance experiments were performed with castrated male pigs of 55--75 kg liveweight. In experiment 3 the energy balance was also measured. N-retention was significantly improved by the treatment. In none of the experiments the digestibility of the ration was influenced. With the pigs implanted at around 55 kg live weight, N-deposition during the period from 6--9 till 26--32 days after treatment was increased by on an average respectively of 24 percent (experiment 1), 60 percent (experiment 2) and 56 percent (experiment 3) as compared with a placebo. Where pigs of 75 kg were implanted, N-deposition was increased over the period from 2 till 28 days after implantation by 39 percent as compared with a placebo. In experiment 3 it was shown that the conversion of the metabolizable energy of the ration into energy deposited in the body (= protein + fat) was not considerably altered at 13--17 days after the treatment of pigs (weighing 55 kg) with anabolic agents. As compared with the placebo, N-deposition was increased by 40 percent and fat deposition was descreased by 15--20 percent. So the implantation with the anabolic agents has resulted in shift to a higher protein deposition and a lower fat deposition. The results of the balance determinations were confirmed in a comparative growth experiment, in which 14 castrated male Large Wht& x Landrace pigs of 56 kg weight (i.e. 69 days before slaughter at 90 kg live weight) were implanted with the aforementioned combination; 14 animals served as control. In the period from treatment till slaughter live weight gain was significantly improved by 6.5 kg; feed conversion was 0.3 units significantly lower than the control. Carcass weight was significantly higher for the treated group (difference compared with control 4.5 kg). Carcass quality was also improved; the carcasses of the treated pigs were longer and the thickness of the backfat was less. In a second comparative experiment on growth of castrated male pigs from 66 to 100 kg, the effect of the oral application of the combination ethinylestradiol (0.6 ppm, 1.2 ppm, and 2 ppm respectively in the feed) and trenbolone acetate (2 ppm in the feed) was studied. The three experimental groups and the control group consisted of 15 animals each. Live weight gain was significantly improved in the two groups with the higher levels of ethinyl estradiol (i.e. 4.4 kg and 6.9 kg respectively), feed conversion was significantly lower in all three anabolic agroups (i.e. 0.2, 0.3 and 0.4 respectively). Backfat thickness was less in all three anabolic groups and the carcasses were longer in the two higher dosage groups compared with the control group...

Anabolic Agents↗

PubMed1992

An embryo transfer study of reciprocal cross differences in growth and carcass traits of Duroc and Landrace pigs.

Reciprocal cross differences have been reported for growth rate and carcass traits in F1 pigs with the Duroc (D) as a parent breed. Such differences are synonymous with maternal effects if effects of sex linkage and genomic imprinting are negligible. In the present study, transfer of embryos (ET) to paternal breed recipients partitioned effects occurring at or before fertilization from postfertilization effects for growth and carcass traits in F1 D-Landrace (L) pigs. Fifteen boars sired 115 F1 litters, 49 produced by ET. Growth rate of 349 barrows and 361 gilts and carcass measurements on 256 barrows and 159 gilts were analyzed assuming mixed linear models with animal and litter as random effects. Contrasts among genotype (D x L, L x D)- treatment (ET, non-ET) means were tested. Reciprocal cross differences were not detected for growth rate or for carcass weight, length, average backfat thickness, estimated carcass lean, or lean per day of age. Reciprocal cross differences for 10th rib backfat thickness (BF) and longissimus muscle area (LMA) were detected only in barrows. The sexual dichotomy for reciprocal cross differences followed expectations for a Y-linked gene(s), consistent with the fact that reciprocal D-L crossbred barrows exhibited a paternal effect, with responses more like the sire breed than the dam breed. Barrows that were non-ET from D sires and L dams had 3.9 cm2 larger LMA and 5.8 mm less BF than barrows from L sires and D dams (P less than .001). Barrows from ET sired by D boars had 3.8 cm2 larger LMA than did barrows from ET sired by L boars (P less than .001), although no difference was detected for BF. Barrows sired by D boars reared in a D postfertilization environment (ET) had 6.2 cm2 greater LMA and 4.1 mm less BF (P less than .05) than barrows sired by L boars gestated and reared by D dams (non-ET). Barrows sired by D boars reared by L dams (non-ET) had 1.5 cm2 greater LMA and 2.3 mm less BF (P greater than .10) than barrows sired by L boars reared by L dams (ET). In conclusion, reciprocal cross differences detected for BF and LMA in barrows were established before or at fertilization and seemed to be Y-linked.

Adipose Tissue↗

PubMed1978

Body composition, in vitro lipid metabolism and skeletal muscle characteristics in fast-growing, lean and in slow-growing, obese pigs at equal age and weight.

Eight slow-growing feral, obese (Ossabaw) pigs were sacrificed at 45 kg live weight and an average age of 170 days and were compared with a group of fast-growing, lean (Yorkshire) pigs fed the same ration and sacrificed at either 45 kg (average age 130 days) or at 170 days (average live weight 90 kg). Body composition and various carcass measurements, in vitro adipose tissue metabolism and muscle composition were measured. At equal weight, the obese pig had a greater percent body fat (40 vs. 23%) and backfat thickness (3.3 vs. 2.0 cm) than the lean. At equal age, the difference in percent body fat was not as great (40 vs. 31%) while backfat thickness was equal. Percent body protein was greater in the lean pigs at either equal weight or equal age. In vitro lipolysis, per 100 mg adipose tissue, was lower in obese pigs than in lean pigs at equal weight. However, obese tissue exhibited a greater lipolytic reaponse to DBcAMP stimulation than adipose tissue from lean pigs at equal weight; basal lipolysis per total fat mass was similar. At equal age, no differences in lipolysis between lean and obese pigs were observed. When compared at either equal age or equal weight, weight of semitendinosus muscle, and measurements of muscle RNA and DNA were greater in lean compared to obese pigs. RNA/DNA ratios were similar at equal weight and age whereas the protein/DNA ratio was lower in lean muscle compared to obese at equal weight. The decreased protein deposition in the obese, slow-growing pigs appeared due to fewer muscle nuclei rather than a decreased cellular capacity for protein synthesis.

Animals↗

PubMed1976

The effect of grassmeal and alfalfa meal on daily gain, thickness of backfat and on the esophagogastric region in bacon pigs.

In pigs dietary factors often are involved as causes of lesions in pars esophagea of the stomach. In experiments the primary purpose of which was to clarify the effect of grassmeal or alfalfa meal on growth, feed efficiency and carcass quality in bacon pigs, an influence of these feedstuffs on the growth rate and degree of esophagogastric lesions was detected. Pigs with these lesions had as an average a lower daily gain and less backfat than pigs without lesions.

Animal Feed↗

PubMed1992

Relationship of mode of porcine somatotropin administration and dietary fat to the growth performance and carcass characteristics of finishing pigs.

Ninety-six pigs were used to investigate the relationship of diet (control vs fat-supplemented with equal energy:protein ratios), porcine somatotropin (pST) administration (non-treated; 2 mg/d, daily injection; and 2 mg/d, 6-wk implant), and sex (barrows and gilts) to performance and carcass characteristics. Diet and pST treatments were initiated at 87 kg of BW and continued for 38 d. Both the fat-supplemented diet (P less than .001) and pST treatment (P less than .0001) improved feed efficiency. The effects of diet were accounted for by differences in energy density of the diets. Across diets, pST improved gain:feed ratio by 29 and 16% in pigs treated by daily injection and the implant, respectively; the two modes of delivery resulted in different responses (P less than .01). Circulating insulin-like growth factor I (IGF-I) levels, determined from blood samples drawn on d 35, were increased 2.5-fold above those of controls in pigs treated by either daily injection or the implant. However, the elevation of glucose and decrease in blood urea nitrogen concentrations in response to pST were of a greater magnitude in pigs treated by daily injection. Similarly, reductions in backfat thickness and the rate of backfat accretion determined by ultrasound were greater in response to the daily injection of pST than in response to the implant. Lean meat ratio, calculated from measurements with a Fat-O-Meater probe, was increased by 6 and 13% by the implant and daily injection, respectively. It is concluded that although the use of an implant that delivers pST on a continuous basis was as effective as the same dose administered as a bolus injection for increasing IGF-I levels, it was less effective in improving feed efficiency and carcass quality.

Adipose Tissue↗

PubMed2026

Integrated Genome-Wide Association Studies and Selection Signature Analysis Reveal the Genetic Architecture of the Wattle Trait in Goats.

Wattles are finger-like appendages on the ventral neck of goats, serving as a distinctive morphological marker for breed identification that serves potential implications for production performance. However, their genetic basis remains incompletely characterized. Here, we integrated a genome-wide association study (GWAS) and selection signature analysis to identify candidate genes and genomic regions associated with the wattle trait in goats. Using a linear mixed model, GWAS on 463 goats (23 wattled and 440 non-wattled) identified 385 quantitative trait loci (QTLs) at a 5% false discovery rate, yielding 346 candidate genes. The most significant association signal was observed on chromosome 10 (72.61-73.48 Mb), where the lead SNP (rs636481767) is located within a region containing GJD2, GREM1, and FMN1, showing strong linkage disequilibrium (r2 > 0.6) with surrounding loci. Subsequent selection signature analysis (23 wattled and 23 non-wattled) identified 83 genomic regions harboring 119 candidate genes. The strongest signals were detected at MFSD14B on chromosome 8 (FST = 0.154, log2π-ratio = 2.611) and PDLIM7 on chromosome 7 (FST = 0.144, log2π-ratio = 0.806). KEGG pathway enrichment analysis revealed that GWAS-associated genes were involved in glycosylation and immune responses, whereas selection-signature genes were enriched in DNA repair and the Hippo, Notch, and Wnt pathways. Furthermore, cross-species PheWAS revealed that human FMN1 is associated with dermatological, skeletal, and metabolic phenotypes, while porcine FMN1 is associated with backfat thickness and loin muscle depth. Overall, this study provides molecular markers of potential value for goat breeding and pinpoints key candidate genes for future functional validation of wattle development.

Animals↗

PubMed2026

FOS Regulates Myogenic and Adipogenic Differentiation via Extracellular Matrix Signaling.

In the livestock industry, intramuscular fat deposition is a key factor influencing meat tenderness and flavor. Although FOS (Fos proto-oncogene, AP-1 transcription factor subunit) has been implicated in the regulation of cell proliferation and differentiation, its differential roles in myogenic and adipogenic regulation remain unclear. In this study, we revealed that FOS markedly enhanced myogenic differentiation while inhibiting adipogenic differentiation in muscle stem cells, indicating that it exerts distinct effects on muscle development and intramuscular fat deposition. Mechanistically, FOS modulated extracellular matrix signaling by regulating FAK and PXN phosphorylation, acting as a molecular regulator between the muscle and fat lineages. Furthermore, exon SNPs in FOS were associated with slaughter weight and backfat thickness, and the mutant genotypes weakened its antiadipogenic effect. Collectively, these findings suggest that FOS is an important regulator of myogenic and adipogenic differentiation and is a potential candidate gene for the genetic improvement of meat quality traits.

Animals↗

PubMed1979

The amino acid supplementation of barley for the growing pig. 2. Optimal additions of lysine and threonine for growth.

1. Thirty-three diets were made by adding to ground barley combinations of L-lysine (0--6.0 g/kg) and L-threonine (0--3.0 g/kg), together with vitamins and minerals. Each was given to two female and two castrated male pigs during their growth from 25 to 60 kg. 2. Growth rate increased from 0.36 kg/d to a maximum of 0.65 kg/d with additions of 3.8 g L-lysine/kg and 1.8 g L-threonine/kg; these values and the maximum gains achieved were slightly higher for castrates than for females. Minimum values for food conversion ratio of 2.84 for castrates and 3.06 for females were achieved with similar amino acid additions to those giving fastest growth. 3. Carcass fat, estimated by sepcific gravity, was least with the addition of 5.9 g L-lysine/kg, but continued to decrease up to the highest threonine concentrations. Backfat thickness was also reduced by amino acid additions but failed to reach a minimum.

Adipose Tissue↗

PubMed2026

Genome-wide association studies for feed efficiency, production and feeding behavior traits in Canadian purebred Duroc pigs.

This study aimed to identify potential genetic variants and candidate genes associated with feed efficiency (FE), production, and feeding behavior traits in Canadian purebred Duroc pigs. Genome-wide association studies (GWAS) were conducted using 8,861 individuals and an imputed Affymetrix PigGen Canada 50K panel v2.0 using a linear mixed model (LMM) and a Bayesian B model. This analysis used an adjusted P-value threshold (ranging from 6.6 × 10-5 to 1.3 × 10-4) using a false-discovery rate to determine significance. The number of significant SNPs identified for each trait was as follows: average daily gain (ADG, 48), daily feed intake (DFI, 85), feed conversion ratio (FCR, 101), residual feed intake (RFI, 37), residual gain (RG, 64), residual intake and gain (RIG, 55), backfat thickness (BF, 100), loin depth (LD, 6), Kleiber's ratio (KR, 0), total time spent eating per day (TPD, 7), and number of visits to the feeder per day (NVD, 6). Several traits (BF, DFI, FCR, RFI, RG, and RIG) showed strong overlapping signals on chromosomes 7 and 10 with 24 shared significant SNPs, indicating potential shared genetic mechanisms. These traits also had 71 overlapping candidate genes, such as PACSIN1, PTCH1, ADIPOR1, and ITPR3, associated with glucose, lipid, and cholesterol metabolism. Well-known candidate genes in literature associated with growth and fatness such as MC4R and CDH20 were also identified to be associated with ADG, BF, FCR, and DFI in this study. Gene ontology enrichment analysis revealed that a set of the candidate genes were involved in the gonadotropin-releasing hormone (GnRH) and the platelet-derived growth factor (PDGF) signaling pathways. Overall, this study contributed to understanding the genetic architecture and provided a biological foundation for improving FE, production, and feeding behavior traits in Canadian Duroc pigs, facilitating the selection of more efficient pigs.

Sus scrofa↗

PubMed1976

Metabolic clearance and secretion rates of porcine growth hormone in genetically lean and obese swine.

The metabolic clearance rate (MCR) and the secretion rate (SR) of porcine growth hormone (pGH) have been examined in swine rendered genetically either lean or obese after 18 generations of selection for or against backfat thickness. At 15 weeks of age (when the muscle:fat ratio was greater than 1) the mean half-life (t1/2), MCR, and SR, for the obese, control, and lean swine were: t1/2 = 7.4, 8.9, and 9.8 min; MCR = 341, 279, and 158 ml/min; SR = 907, 802, and 520 ng/min, respectively. At 90 kg body weight (when muscle:fat ratio was less than 1, and the age was about 30 weeks) the data for obese, control, and lean swine were: t1/2 = 11.3, 12.0, and 11.7 min; MCR =305, 280, and 336 ml/min; SR= 535, 626, and 932 ng/min, respectively. The t1/2, MCR, and SR were not significantly different among the obese, control, and lean swine at either 15 weeks or 90 kg body weight. Comparing the two stages of development, the younger swine (15 weeks of age) had a shorter t1/2 (P less than .01), and secreted and cleared more pGH on a per kg body weight basis (P less than .05) than the older swine (90 kg bodyweight, about 30 weeks of age). However, the results suggest that the selection of swine for either leanness or fatness for 18 generations did not alter the MCR and SR of pGH. In addition, the differences observed between the younger and older swine suggest that GH is cleared at a more rapid rate and more GH is available per unit of mass in the younger animals.

Age Factors↗

PubMed1991

The effect of ractopamine hydrochloride on the carcass cutting yields of finishing swine.

This study was designed to evaluate growth performance, carcass cutting yield, and processing characteristics of boneless hams and bellies from finishing pigs fed diets containing 0, 5, 10, or 20 ppm of the phenethanolamine ractopamine hydrochloride (RAC). Sixty pigs were blocked by starting weight and randomly assigned to pens (four pigs/pen) within each of three blocks. Treatments were then randomly assigned to the pens to total six pens of the 0-ppm level and three pens each at the 5-, 10-, and 20-ppm RAC levels. Weight gain and feed consumption were monitored and animals were slaughtered by weight block after approximately 48 d on trial. Slaughter weight, ADG, and feed/gain were improved (P less than .05) for RAC treatments. Dressing percentage was higher and increased linearly (P less than .05) for RAC treatments. Carcass weight, length, leaf fat weight, backfat thickness, loin eye area, and color, marbling, and firmness of the longissimus were evaluated. The RAC-treated carcasses were heavier (P less than .05) and loin eye area increased linearly (P less than .05). One side of each carcass was fabricated using National Association of Meat Purveyors specifications. Trimmed hams and loins from the RAC treatments were heavier (P less than .05) than those from control animals. No differences (P greater than .05) in carcass cutting yield (percentage of trimmed primal cuts) were observed between treatments. However, trimmed hams and loins from the 20-ppm RAC treatment represented a greater (P less than .05) percentage of carcass weight than did those from control animals. Ractopamine did not affect raw belly or bacon characteristics (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

PubMed1992

Effect of feed intake during late development on pubertal onset and resulting body composition in crossbred gilts.

A total of 105 nonboar-exposed, F2 ([Landrace x Yorkshire] x Duroc) gilts were used in two replicates of a randomized complete block experiment to evaluate the effect of dietary feed intake on pubertal onset and subsequent body composition. Feed intakes were established at 50% of ad libitum (AL-50), 75% of ad libitum (AL-75), or at ad libitum (AL-100) levels from 4.5 to 9 mo of age. A corn-soybean meal diet fed to all gilts was formulated to meet or exceed nutrient requirements except for energy. Puberty was measured by two methods: 1) monitored once daily by back pressure applied by the herdsman or 2) from elevated plasma progesterone concentrations. Body composition was evaluated by the deuterium oxide method after plasma progesterone concentrations were elevated. Daily feed intake for the experimental period averaged 1.6, 2.3, and 3.2 kg, and the BW of gilts at 8 mo of age were 111, 131, and 154 kg for the AL-50, AL-75, and AL-100 groups, respectively. Body weight, backfat thickness, and body fat content increased linearly (P < .01) as feed intake increased, but age at puberty was not severely influenced. A minimum body fat content or percentage did not seem to initiate pubertal onset. There was a trend for a lower percentage of the AL-50 gilts to ovulate (P = .08) than those fed the AL-75 and AL-100 intakes. An inverse relationship resulted between the percentage of gilts that ovulated to the percentage that showed behavioral estrus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

The repeatability and accuracy of ultrasound in measuring backfat of cattle.

Repeatability of ultrasound backfat measurements was determined on 217 cattle, and the association of ultrasound and carcass backfat measurements was evaluated with 580 animals. The correlation (repeatability) between consecutive ultrasound measurements was .975. Average difference between two ultrasound measures was .72 mm and error size was directly related (P less than .001) to the amount of backfat. Ultrasound measures averaged 8% (P less than .001) less than carcass measures. The average absolute difference between these two measures was 1.57 mm. Discrepancies were (P less than .001) larger when backfat was thicker; cattle with backfat measuring less than 10 mm averaged 1.43 mm absolute difference, whereas those with backfat greater than 10 mm averaged 1.89 mm. The variance of the discrepancies was partitioned into three components: ultrasound measurement error (14%), drift related to intercept and slope (15%), and residual (71%). The residual component may have represented errors in carcass measurement. In a subsequent trial with 175 cattle, average difference between ultrasound and carcass backfat measurements was reduced to 1.19 mm. Also, the slope and intercept virtually mimicked the isopach. Ultrasound measures can be more precise (minutely exact) and accurate (close to the true value) than carcass measures for assessing absolute backfat thickness in cattle. Elements of measurement protocol that may improve ultrasound technique are imparted in the manuscript.

Adipose Tissue↗

PubMed1992

Performance and carcass characteristics of swine when fed diets containing canola oil and added copper to alter the unsaturated:saturated ratio of pork fat.

A 3 x 2 trial was conducted to determine the effects of adding canola oil (0, 5, or 10%) and copper sulfate (0 or 250 ppm Cu) to diets of growing-finishing swine on performance, carcass characteristics, and carcass fat fatty acid composition. The trial used 180 pigs (27 kg). Grower diets (.80% lysine for 0% canola oil diet) were given from 27 to 57 kg of BW and finisher diets (.64% lysine) from 57 to 102 kg. Diets were formulated to constant ME:lysine ratio within the grower and finisher phases. Over the entire growing-finishing period, the addition of canola oil to the diets resulted in linear improvements in rate of gain (P less than .05) and feed efficiency (P less than .01). Dietary additions of canola oil had no effect (P greater than .10) on resulting backfat thickness or longissimus muscle area but resulted in reductions (P less than .01) in loin marbling and color and carcass fat firmness, mostly noted in pigs fed the diets with 10% canola oil. Canola oil additions at 5 and 10% levels, respectively, resulted in a 23 and 37% reduction (P less than .01) in saturated fatty acids, 3 and 8% increase (P less than .01) in monounsaturated fatty acids, and 37 and 77% increase (P less than .01) in polyunsaturated fatty acids in the carcass fat compared with the diets without canola oil. The addition of canola oil to diets of growing-finishing swine had a favorable influence on animal performance and on increasing the unsaturated:saturated ratio of the carcass fat.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

PubMed1992

Effects of Duroc, Meishan, Fengjing, and Minzhu boars on productivity of mates and growth of first-cross progeny.

Meishan, Fengjing, Minzhu, and Duroc boars were mated by AI to crossbred gilts to compare the sire breeds for effects on productivity of their mates and performance of their progeny. Gilts were derived from a four-way cross of Chester White, Landrace, Large White, and Yorkshire. At weaning, litters sired by Meishan boars averaged 1.69 and 1.32 more pigs than those sired by Duroc and Minzhu boars, respectively (P less than .05). Pigs sired by Meishan and Fengjing boars averaged 1.2 to 1.8 more nipples than pigs sired by Duroc and Minzhu boars (P less than .05). Minzhu-sired pigs had a lower (P less than .05) survival rate to 14 and 28 d of age than did those sired by Meishan, Fengjing, and Duroc. Fengjing-sired pigs were heavier than Minzhu-sired pigs at birth and heavier than Minzhu- and Duroc-sired pigs at 14, 28, and 56 d of age (P less than .05). At 70 d of age, Meishan-sired pigs were heaviest, followed in order by Fengjing-, Duroc-, and Minzhu-sired pigs. At 98 d of age, Meishan-sired pigs were significantly heavier than all other breed groups and Duroc-sired pigs were significantly heavier than Minzhu-sired pigs. At 126 and 154 d of age, Duroc-sired pigs were heaviest, followed in order by Meishan-, Fengjing-, and Minzhu-sired pigs; all differences were significant. Average backfat thickness of gilts at 99.7 kg was least for Duroc-sired gilts and highest for Meishan-sired gilts. Sire breed groups did not differ significantly in feed efficiency from 70 to 98 d of age. Duroc-sired pigs were the most efficient (P less than .05) from 98 to 126 and 126 to 154 d of age. Results indicate that use of these Chinese breeds in crossbreeding programs will decrease performance traits. This decrease would have to be offset by increases in reproductive efficiency of Chinese sows, use of repartitioning agents, or other management techniques if Chinese pigs are to improve overall production efficiency of a crossbreeding program.

Animals↗