Partition of minerals in body components from a high- and low-lean genetic line of barrows and gilts from 20 to 125 kilograms of body weight.

An experiment was conducted to determine if the macro- and micromineral contents of the ham and loin or the remaining body component differed by genetic line, sex, or BW. The experiment was a completely randomized design with a factorial arrangement (2 × 2 × 5) using barrows and gilts of 2 genetic lines at 5 BW intervals in 2 groups with 6 replicates (n = 120 pigs). Pigs were housed in groups of 5 per pen and removed when individual pigs reached their targeted BW. Twelve pigs (3 from each genetic line and sex) were killed at 23 kg of BW and at 25-kg intervals up to 125 kg of BW. After slaughter, loin and ham muscles were dissected and trimmed of fat, with the ham deboned. This muscle mass constituted the first body compartment. The trimming from these muscles, ham bones, the remaining body, internal tissues, skin, and head were combined and constituted the second body component. The data were analyzed by PROC MIXED using the animal as the experimental unit. Muscle weights and their protein contents differed (P < 0.01) between the high- and the low-lean pigs and barrows and gilts and also among 5 BW groups/intervals. Total macro- and micromineral contents in the loin and ham were greater (P < 0.01) in the high-lean genetic line and gilts and increased (P < 0.01) as BW increased. Genetic line × BW and sex × BW interactions (P < 0.01) occurred for the macrominerals and for Fe, Se, and Zn, with contents diverging, and were greater as BW increased in high-lean pigs and gilts. The weight and protein content of the remaining body component was greater (P < 0.01) in the high-lean genetic line but not for the 2 sexes. In this body component, macromineral contents were greater as BW increased (P < 0.01), as were the microminerals Fe, Se, and Zn (P < 0.01). When the minerals were expressed on a per kilogram of body component basis, the ham and loin mineral compositions were similar for both genetic lines and sexes, but Na and Cl declined (P < 0.01) as BW increased. Most microminerals showed a small increase with BW. In the remaining body component, Ca increased (P < 0.03) in the low-lean line, whereas K was greater (P < 0.01) in the high-lean genetic line. When expressed on a unit protein basis, the low-lean genetic line had more macrominerals in the loin and ham than the high-lean genetic line. These results indicate that high-lean genetic line pigs and gilts have greater total macro- and micromineral contents in the ham and loin than the low-lean pigs, thus indicating that their dietary mineral needs are greater during the latter part of the finisher period in heavier muscled pigs.

Effect of dietary organic and inorganic micromineral source and level on sow body, liver, colostrum, mature milk, and progeny mineral compositions over six parities.

A sow study evaluated the effects of 2 dietary micromineral sources (organic or inorganic) and 3 dietary mineral levels [NRC, industry (IND), and IND + Ca:P] with selected sows killed at parities 1, 2, 4, and 6. Three sows per treatment group were killed at weaning (total = 68), and their body and liver, 72 colostrum and milk samples (17 d), 69 full-term stillborn pigs and their livers, and 32 pigs at weaning were analyzed for minerals. Tissue and milk samples from the sows were analyzed as a 2 x 3 x 4 factorial arrangement of treatments in a completely randomized design (CRD) with 3 replicates per treatment. Full-term stillborn pig mineral compositions were determined at parities 1, 3, and 5 and evaluated as a 2 x 3 x 3 factorial arrangement of treatments in a CRD with 3 replicates per treatment. Weanling pigs from parity 6 sows were analyzed as a 2 x 3 factorial in a CRD. Sow and pig mineral compositions are reported on an equivalent empty BW and kilograms of liver weight basis. The results indicated that sow body macromineral contents were not affected by dietary micromineral source or level or when the diets contained added Ca and P. Sow body Se increased when dietary organic microminerals increased from the NRC to the IND level, resulting in a source x level interaction (P < 0.01), but there was no increase in those sows fed inorganic microminerals. There were increases in Cu (P < 0.05) and Se as levels increased from NRC to the IND, and there were increases (P < 0.05) in Cu and Zn when the IND + Ca:P diet was fed compared with feeding the IND diet. Increases (P < 0.01) in sow liver Cu, Se, and Zn occurred as microminerals increased from the NRC to the IND level. As parity advanced, there were cubic increases (P < 0.01) in sow body Cu, Fe, and Se, but a quadratic increase in Zn (P < 0.05). There was no clear effect of sow dietary treatments on full-term stillborn pig or liver micromineral contents, except Se (P < 0.01). There was a greater pig body Se content when sows were fed organic microminerals at the greater level, resulting in a source x level interaction (P < 0.01). Colostrum minerals were generally not affected by diet variables, except Se. Colostrum Se was greater when sows were fed the organic micromineral source than the inorganic source at the greater level, resulting in a source x level interaction (P < 0.05). Milk Cu (P < 0.01) and Zn (P < 0.01) increased as dietary level increased. Milk Se was increased when organic Se was fed (P < 0.05) and when the micromineral level was increased (P < 0.01). Weaned pig body Fe (P < 0.01) and Se (P < 0.01) were greater when organic microminerals were fed to the sow, whereas Mn (P < 0.01) and Zn (P < 0.05) increased when the IND level was fed. These results indicate that the dietary micromineral source and level had a minimal effect on sow body and liver mineral contents or in colostrum and pigs at birth, except Se, which was greater when the organic form was fed.

Mineral composition of two genetic lines of barrows and gilts from twenty to one hundred twenty-five kilograms of body weight.

Two genetic lines of barrows and gilt pigs with lean BW gain averages of 280 and 375 g/d were used to evaluate their macro- and micromineral contents at BW intervals from 20 to 125 kg of BW. The experiment was a 2 x 2 x 5 factorial arrangement of treatments (i.e., 2 sexes, 2 genetic lines, and 5 BW intervals) conducted in a completely randomized design in 6 replicates using a total of 120 pigs. Initially, 12 pigs (3 from each genetic line and sex) were killed, and then at approximately 25 kg of BW intervals to 125 kg. Pigs were fed vitamin and mineral fortified corn-soybean meal diets. At slaughter the total body (except digesta and blood) of each pig was ground and analyzed for their macro- and micromineral contents. The high-lean genetic line (P < 0.03) pigs and barrows (P < 0.01) reached their targeted BW an average 3 d earlier than the low-lean genetic line and gilts. Total macro- and micromineral contents increased as BW increased, generally in a linear or quadratic (P < 0.01) manner. There was an increasing difference between genetic lines in some minerals as BW increased. Total body Ca content was greater in the low-lean genetic line with increasing differences occurring as BW increased resulting in a BW x genetic line interaction (P < 0.05), whereas P was similar for both genetic lines. The quantity of K (P < 0.01) and S (P < 0.01) increased at a greater rate in the high-lean genetic line as BW increased, resulting in BW x genetic line interactions (P < 0.01). Body Cl (P < 0.01), Mg (P < 0.06), Mn (P < 0.05), Se (P < 0.01), and Zn (P < 0.01) were greater in the high-lean genetic. As BW increased, the Ca:P and the P:K ratios were increasingly greater (P < 0.01) in the low-lean genetic line, whereas the K:Na ratio was greater (P < 0.01) in high-lean genetic line. Although K and Fe were greater (P < 0.05) in gilts than in barrows, other mineral content differences were not significant. When minerals were expressed on a per kilogram of empty BW basis, the macro- and microminerals differed (P < 0.01) as BW increased indicating a response by body maturity. Genetic line had a greater effect on mineral content per kilogram of empty BW than sex. These results indicate that differences in mineral content are largely affected by BW or physiological age and by genetic line. Best-fitting equations were developed to determine macro- and micromineral contents of both genetic lines.

Growth of protein, moisture, lipid, and ash of two genetic lines of barrows and gilts from twenty to one hundred twenty-five kilograms of body weight.

Two genetic lines of barrows and gilts with different lean growth rates were used to determine the BW and chemical composition growth from 23 to 125 kg of BW. The experiment was a 2 x 2 x 5 factorial arrangement of treatments in a completely randomized design conducted in 2 replicates. Six pigs from each sex and genetic line were killed at approximately 25-kg intervals from 23 kg to 125 kg of BW. At slaughter, tissues were collected and weighed. All components were ground and frozen until analyzed for water, protein, lipid, and ash. Serial BW data were fitted to alternative functions of day of age. Based on Akaike's information criteria values, the random effects model, BW(i, t) = (1 + c(i))(b(0) + b(1)t + b(2)t(2)), was the best mixed model equation. The chemical component mass data were fitted to alternative functions of BW. The allometric function, chemical component mass = aBW(b), provided the best fit to the data. Daily deposition rates of each chemical component were predicted by using the derivatives of the 2 functions. The overall ADG of the 2 genetic lines were not different. Barrows had 0.052 kg/d greater (P = 0.03) ADG than gilts. Allometric growth coefficients for all 4 chemical components were different (P < 0.01) for each genetic line. Allometric coefficients and predicted relative growth (g/kg of BW gain) for protein and moisture mass were greater (P < 0.01) for the high lean-gain pigs than the low lean-gain pigs. Allometric coefficients for lipid mass were smaller (P = 0.001) for the high lean-gain pigs than the low lean-gain pigs overall. Allometric coefficients and predicted relative growth rates for lipid mass were greater (P < 0.01) and for moisture and protein mass were lesser (P < 0.002) than the gilts. Compared with low lean-gain pigs, high lean-gain pigs had (1) 32.8% lesser predicted daily rates of lipid deposition (200 vs. 305 +/- 80 g/d), with the difference increasing from 23 to 37% from 25 to 125 kg of BW; (2) 12.3% greater daily rates of protein deposition (118.7 vs. 106.0 +/- 3.3 g/d); and (3) 18.8% greater predicted daily moisture accretion rates (423 vs. 356 +/- 9 g/d). Overall, barrows had 21.3% greater lipid deposition (279 vs. 230 +/- 78.2 g/d) than gilts. In this study, barrows and gilts had similar predicted daily moisture, protein, and ash accretion rates.

Tissue weights and body composition of two genetic lines of barrows and gilts from twenty to one hundred twenty-five kilograms of body weight.

Barrows and gilts of 2 genetic lines with differing lean gain potentials (high-lean = 375 g of fat-free lean/d; low-lean = 280 g of fat-free lean/d) were used to determine tissue and organ weights and compositions from 20 to 125 kg of BW. The experiment was a 2 (genetic line) x 2 (sex) x 5 (BW) factorial arrangement of treatments in a completely randomized design conducted with 2 groups of pigs in 6 replicates (n = 120 pigs). Six pigs from each sex and genetic line were slaughtered at 20 kg of BW and at 25 kg of BW intervals to 125 kg of BW. At slaughter, the internal tissues and organs were weighed. Loin and ham muscles were dissected from the carcass and trimmed of skin and external fat, and the ham was deboned. Residuals from the loin and ham were combined with the remaining carcass. Body components were ground, and their compositions were determined. The results demonstrated that tissue weights increased (P < 0.01) as BW increased. Loin and ham muscle weights increased but at a greater rate in the high-lean line and in gilts resulting in genetic line x BW and sex x BW interactions (P < 0.01). Liver and heart expressed on a BW or a percentage of empty BW basis increased at a greater rate in the high-lean line resulting in a genetic line x BW interaction (P < 0.01). Liver and intestinal tract weights were heavier in barrows than in gilts, significant only at 45 (P < 0.05), 75 (P < 0.01), and 100 (P < 0.05) kg of BW. Loin and ham muscles from the high-lean genetic line and gilts had greater (P < 0.01) water, protein, and ash contents compared with the low-lean genetic line and barrows resulting in genetic line x BW and sex x BW interactions (P < 0.01). The remaining carcass (minus loin and ham muscles) had greater (P < 0.01) amounts of water and protein, and less (P < 0.01) fat in the high-lean genetic line and gilts. The high-lean genetic line and gilts had more total body water, protein, and ash, but less body fat, with these differences diverging as BW increased, resulting in a genetic line x BW interaction (P < 0.01). The results indicated that liver and heart weights were greater in high-lean pigs, reflecting the greater amino acid metabolism, whereas the liver and intestinal tract weights were greater in barrow than gilts, reflecting their greater feed intakes and metabolism of total nutrients consumed.

Phenotypic measurements and various indices of lean and fat tissue development in barrows and gilts of two genetic lines from twenty to one hundred twenty-five kilograms of body weight.

Two genetic lines with different lean gains were evaluated for various body measurements and indices of lean tissue in barrows and gilts from 20 to 125 kg of BW. One genetic line was identified as the low-lean line [280 g of fat-free lean (FFL)/d], and the second line was the high-lean line (375 FFL gained/d). The experiment was conducted as a completely randomized design using a 2 x 2 x 5 factorial arrangement of treatments in 6 replicates (n = 120 pigs). The 2 genetic lines and sexes were provided ad libitum access to cornsoybean mixtures that met or exceeded their required amino acid requirements for their respective lean gain potentials. Six pigs of each sex and genetic line were slaughtered initially and at 25-kg of BW intervals to 125 kg of BW. Pigs slaughtered were measured for height, width, and length using metal calipers. Backfat and LM area were measured using real-time ultrasound, with backfat depth also measured using A-mode ultrasound technology. Longissimus muscle area and back-fat thickness at the 10th rib were measured on the chilled carcass. Data was analyzed using the MIXED procedure of SAS, with the animal as the experimental unit. Shoulders (P < 0.05) and lumbars (P < 0.05) were wider in the low-lean genetic line and in barrows. Gilts and the high-lean genetic line had less backfat and greater LM areas than the low-lean genetic line. As BW increased, there was a greater increase in FFL tissue and lower backfat depths in the high-lean vs. the low-lean genetic line. This resulted in a greater divergence of measurement values as BW increased. Femur weight, length, and cortical wall thickness were greater in the high-lean genetic line, but the differences were not significant. The high-lean genetic line had a greater (P < 0.01) organic matrix content in the femur and less ash, resulting in a lower percentage of bone ash (P < 0.01). The results indicate that differences occurred phenotypically between pigs having more muscle (wider hams) or more fat (wider shoulder and lumbar). As BW increased, the high-lean pigs had an increase in lean tissue, particularly after 75 kg of BW, and less backfat and less bone mineralization, whereas the low-lean line pigs had increased backfat and greater bone mineralization. Real-time ultrasound measurements using various formulas to estimate lean tissue produced values close to those determined from carcass measurements at 100 and 125 kg of BW.

Evaluating the antioxidant status of weanling pigs fed dietary vitamins A and E.

Two experiments evaluated the relationship of vitamin E (source and level) and vitamin A (level) on the apparent absorption and retention of both vitamins in weaned pigs. Both experiments used a combined total of 460 crossbred pigs ([Yorkshire x Landrace] x Duroc), housed in elevated 1.2- x 1.2-m crates containing five pigs per pen. Experiment 1 was a 2 x 2 x 2 factorial arrangement of treatments in a randomized complete block design conducted in seven replicates. Levels of vitamin A (2,200 or 13,200 IU/kg), vitamin E (15 or 90 IU/kg), and two vitamin E sources (D-alpha-tocopheryl acetate [D-TAc] or DL-alpha-tocopheryl acetate [DL-TAc]) were evaluated over a 35-d period. Vitamin A or E levels and the two vitamin E sources did not affect pig performances to 20 kg BW. Serum retinol and alpha-tocopherol concentrations increased (P < 0.01) as the dietary level of each vitamin increased. Serum alpha-tocopherol declined as dietary vitamin E level increased when vitamin A level increased resulting in an interaction (P < 0.05). Serum alpha-tocopherol concentrations were higher (P < 0.05) at 35-d postweaning when D-TAc was the vitamin E source. Experiment 2 was a 3 x 2 factorial arrangement of treatments conducted in six replicates. Three levels of vitamin A (2,200, 13,200, or 26,400 IU/ kg) and two sources of vitamin E (D-TAc or DL-TAc) each provided at 40 IU/kg diet were evaluated over a 35-d period. Pig performances to 35-d postweaning were not affected by the dietary variables. Serum alpha-tocopherol (P < 0.01) and retinol (P < 0.05) concentrations increased as their respective vitamin level increased. Serum (P < 0.05) and liver (P < 0.01) alpha-tocopherol concentrations both declined as dietary vitamin A levels increased resulting in interaction responses. Serum alpha-tocopherol concentration was higher (P < 0.05) at 35-d postweaning when d-TAc was the vitamin E source. Dietary vitamin E sources had no effect on serum or liver retinol concentrations. These results demonstrated that both supplemental vitamin A and vitamin E increased in the blood as their dietary levels increased. However, as dietary vitamin A level increased, serum and liver alpha-tocopherol concentrations declined, suggesting a reduced absorption and retention of alpha-tocopherol when weaned pigs were fed high dietary vitamin A levels.