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PubMed1990

Effect of recombinant porcine somatotropin on growth and carcass quality in growing pigs: interactions with genotype, gender and slaughter weight.

Effects of recombinant porcine somatotropin (rpST) on growth, lean tissue growth, feed intake, feed conversion, lean tissue feed conversion, backfat thickness and lean percentage were examined in 96 growing pigs. The experiment used barrows and gilts from the genotypes Duroc, F1 (Dutch Yorkshire x Dutch Landrace) and Pietrain. Half the pigs received 14 mg rpST i.m. twice each week starting at 60 kg; others received a placebo. Pigs had ad libitum access to a diet containing 2,162 kcal net energy and 182 g crude protein per kilogram and were slaughtered at either 100 or 140 kg live weight. From 60 to 100 and from 100 to 140 kg, live weight responses to rpST averaged as follows: daily gain, +4.5 and +19.9%; feed intake, -4.4 and +3.5%; feed conversion, -8.4 and -13.9%; backfat thickness, -13.8 and -22.8%; lean percentage, +4.4 and +8.7%; lean tissue growth rate, +8.6 and +35.8%; and lean tissue feed conversion, -13.1 and -24.9%. No gender x rpST interaction was detected. However, a genotype x treatment interaction was significant for backfat thickness at both slaughter weights, showing a higher response to rpST in Duroc than in Pietrain and F1. Growth performance was improved more by rpST in F1 and Pietrain than in Duroc, especially at higher weights, but carcass traits were improved more by rpST in Duroc. The response to rpST in lean tissue growth rate from 60 to 100 kg was highest in fatter animals (Duroc, barrows), whereas from 100 to 140 kg, response in lean tissue growth rate to rpST was highest in leaner animals (Pietrain, F1, gilts).

Animals↗
PubMed1989

Bromocriptine alters hormone rhythms and lipid metabolism in swine.

Hormones, metabolites and activities involved in lipid synthesis were assayed in pigs made leaner by bromocriptine treatment. Market size female swine were allowed free access to food under natural lighting conditions and implanted with bromocriptine pellets designed to release 10 mg/pig/day for 28 days in an effort to inhibit prolactin secretion. Between the 2nd and 3rd week of treatment, plasma samples were obtained from each group at 4-hour intervals throughout the day for assays of prolactin, cortisol, insulin, triglyceride, cholesterol and glucose concentrations. Twenty-eight or thirty days after the implantations, all animals were sacrificed for determinations of backfat thickness and insulin binding in the liver. At sacrifice, bromocriptine treatment reduced backfat thickness by 14% and insulin binding to partially purified hepatic membranes by 39% compared with control values. At 14 days following implantations, there were dramatic daily variations in plasma cortisol and prolactin levels in the control pigs and these rhythms were markedly altered in phase and amplitude in the bromocriptine-treated pigs. Bromocriptine reduced by 45, 20 and 13% the high levels of triglyceride, glucose, and cholesterol, respectively, that were found in control pigs near sunset. Plasma insulin concentrations did not vary during the day in control pigs and bromocriptine did not influence the insulin levels. The findings support important roles for a temporal synergism of cortisol and prolactin rhythms in maintaining hepatic lipogenic responsiveness to insulin. Bromocriptine treatment alters these hormonal relations and reduces lipid synthesis.

Animals↗
PubMed1990

Bromocriptine-induced reduction of body fat in pigs.

An experiment was conducted with 36 crossbred finishing pigs (18 male castrates and 18 females) to evaluate the effect of bromocriptine implants on growth, feed intake, feed efficiency, plasma urea nitrogen (PUN) and carcass characteristics. Three levels of bromocriptine (0, 5 and 10 mg/[pig.d]) were administered, via implants at the base of the ear, to six (two replicates of three) male castrates or to six (two replicates of three) intact female pigs (2 x 3 factorial arrangement of treatments). Average initial weight of pigs at the time of implantation was 89.7 kg, and the implants remained in the pigs for 28 (replicate 1) or 30 (replicate 2) d prior to slaughter. Gain, feed intake and efficiency of feed utilization were not affected (P greater than .10) by bromocriptine. Plasma urea nitrogen was lower in female pigs administered 10 mg bromocriptine; bromocriptine did not affect PUN of male pigs (gender x bromocriptine, P less than .08). Tenth rib fat thickness and average backfat thickness were lower (P less than .06) and percentage of muscling was higher (P less than .06) in pigs implanted with bromocriptine. Female pigs had less 10th rib fat but larger loin eye areas and a greater percentage of muscling than male pigs.

Adipose Tissue↗
PubMed2000

A QTL on pig chromosome 4 affects fatty acid metabolism: evidence from an Iberian by Landrace intercross.

Three Iberian boars were bred to 31 Landrace sows to produce 79 F1 pigs. Six F1 boars were mated to 73 F1 sows. The F2 progeny from 33 full-sib families (250 individuals) were genotyped for seven microsatellites spanning the length of chromosome 4. Least squares procedures for interval mapping were used to detect quantitative trait loci (QTL). A permutation test was used to establish nominal significance levels associated with QTL effects, and resulting probability levels were corrected to a genomewide basis. Observed QTL effects were (genomewide significance, position of maximum significance in centimorgans): percentage of linoleic acid in subcutaneous adipose tissue (< 0.01, 81); backfat thickness (< 0.01, 83); backfat weight (< 0.01, 80); longissimus muscle area (0.02, 83); live weight (0.19, 88); and percentage of oleic acid in subcutaneous adipose tissue (0.25, 81). Gene action was primarily additive. The Iberian genotypes were fatter, slower growing, and had lower linoleic and higher oleic acid contents than Landrace genotypes. The interval from 80 to 83 cM contains the FAT1 and A-FABP loci that have been shown previously to affect fat deposition in pigs. This is the first report of a QTL affecting fatty acid composition of subcutaneous adipose tissue in pigs and provides a guide for the metabolic pathways affected by candidate genes described in this region of chromosome 4.

Adipose Tissue↗
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↗
PubMed1984

Factors affecting growth and survival of neonatal genetically obese and lean swine: cross fostering experiments.

Obese and lean lines of pigs were developed previously by genetic selection for thick and thin backfat thickness, respectively. A greater proportion of these obese than lean pigs survive to weaning. A cross-fostering experiment was designed to study neonatal piglet growth and to attempt to decipher some of the causes of the increased survival rate. At about 24 h postpartum, lean and obese sows were paired, the litters standardized to six pigs and three pigs from each sow transferred to a dam of opposite genetic line. The smaller birthweight of obese than lean piglets and the lesser growth of either obese or lean pigs raised on obese compared to lean sows were both observations that might support greater survival of lean rather than obese piglets. Positive factors that might contribute toward the greater survival of obese than lean piglets were the greater lipid content of milk from obese than from lean sows during the first 2 wk postpartum and possibly greater physiological maturity of obese than lean pigs at birth as reflected in greater hemoglobin, hematocrit, plasma protein and plasma albumin.

Animals↗
PubMed2001

Early postnatal plasma concentrations of testicular steroid hormones, pubertal development, and carcass leanness as potential indicators of boar taint in market weight intact male pigs.

Testicular steroid hormone concentrations in plasma of early postnatal male pigs were compared with plasma steroid hormone concentrations and androstenone concentrations in the fat of pigs at market weight. Positive correlations were found between the concentrations of fat androstenone at market weight and the concentrations of plasma androstenone (r = 0.46; P < 0.01), estrone sulfate (r = 0.42; P < 0.01), and testosterone (r = 0.26; P < 0.05) at market weight. These correlations were not found in animals that had reached an advanced state of pubertal development as judged by high estrone sulfate concentrations in plasma. Significant correlations were observed between plasma testosterone concentrations at market weight and plasma concentrations of androstenone (r = 0.57; P < 0.05), and estrone sulfate (r = 0.49; P < 0.05) in early postnatal animals. However, concentrations of androstenone in the fat of market weight animals were not correlated with plasma concentrations of estrone sulfate, androstenone, or testosterone in early postnatal animals. Plasma concentrations of steroid hormones in early postnatal animals cannot, therefore, be used to predict the potential for boar taint in the same animals at market weight. In market weight animals, there was a negative correlation (r = -0.57; P < 0.01) between backfat thickness and concentrations of androstenone in fat. Animals were subsequently sorted according to backfat thickness into lean and fat groups of animals. There was a strong, negative correlation between back-fat thickness and androstenone concentrations in fat (r = -0.80; P < 0.01), as well as a positive correlation between plasma androstenone and concentrations of androstenone in fat (r = 0.42; P < 0.05) among the lean group of animals. This was not seen in the fat group of animals. This suggests that the accumulation of androstenone from plasma into fat may be affected by the leanness of the pig.

Adipose Tissue↗
PubMed2005

Identification of carcass and meat quality quantitative trait loci in a Landrace pig population selected for growth and leanness.

The identification of QTL related to production traits that are relevant for the pig industry has been mostly performed by using divergent crosses. The main objective of the current study was to investigate whether these growth, fatness, and meat quality QTL, previously described in diverse experimental populations, were segregating in a Landrace commercial population selected for litter size, backfat thickness, and growth performance. We have found QTL for carcass weight (posterior P > 0.75), cutlet weight (posterior P > 0.99), weight of ham (posterior P > 0.75), shoulders weight (posterior probability > 0.99), and shear firm-ness (posterior P > 0.99) on pig Chromosome 2. Moreover, QTL with posterior P > 0.75 for fat thickness between the 3rd and 4th ribs (Chromosome 7), rib weights (Chromosome 8), backfat thickness (Chromosomes 8, 9, and 10), and b Minolta color component (Chromosome 7) were identified. These results indicate that commercial purebred populations retain a significant amount of genetic variation, even for traits that have been selected for many generations.

Adipose Tissue↗
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↗
PubMed1989

Effect of dietary folic acid supplementation on sow performance through two parities.

One hundred fifty-three gilts were maintained in three breeding groups and fed gestation-lactation diets supplemented with either 0 (control), 1.65 or 6.62 mg of supplemental folic acid/kg of diet for two consecutive parities. Serum folate concentrations of sows were linearly (P less than .05) increased by dietary additions of folic acid during both gestation and lactation, but serum glucose and urea concentrations were unaffected by treatment. Serum folate concentrations decreased from breeding to d 60 and 90 of gestation and then increased through lactation for all treatments. Number of pigs born and live pigs at birth, d 14 and d 21 were quadratically (P less than .05) increased by folic acid additions. Average pig weights were similar among treatments (P greater than .10) on both d 0 and 14 of lactation but were less (P less than .01) than the other treatment groups on d 21 for pigs from sows fed the 1.65 mg/kg treatment. Litter weights were quadratically (P less than .01) increased on d 0 and d 14 by folic acid supplementation. Sow weight gain and backfat thickness loss were unaffected by treatment during gestation (P greater than .06); sow weight loss and backfat thickness loss increased quadratically with increasing level of folic acid during lactation (P less than .06 and .05, respectively). More control sows exhibited estrus by d 7 postweaning than sows receiving folic acid supplementation in parity I (P less than .05); however, no differences (P greater than .10) were detected among treatments by d 14, nor were any differences observed by d 7 in parity II. Conception rate was unaffected by folic acid additions. Dietary folic acid supplementation improved sow reproductive performance by increasing the number of pigs born alive.

Administration, Oral↗
PubMed1993

Effects of nutrition on pregnant and lactating sows.

It has been suggested that the long-term reproduction of the sow is best served by minimizing weight and fat loss in lactation. Such a strategy would require only a minimal restoration of weight in the following pregnancy, which would be beneficial, since the greater feed intake and weight gain in pregnancy, the greater the weight loss in lactation. Feeding ad libitum should be practised during lactation while gestation feed intake must be held low. A relationship between feed intake and embryo survival has been demonstrated in several studies, but the data are sometimes difficult to interpret. High energy feeding during the premating period and during early pregnancy, however, are often associated with increased embryo mortality. A short-term starvation in lactation decreased prolactin to post-weaning concentrations, and insulin and glucose to very low concentrations. Prolactin increased very rapidly after refeeding indicating that a neural mechanism might be involved. The increasing levels of cholecystokinin after refeeding and the neural reflex triggered might be related to this increase in prolactin. No changes in LH release were observed during the periods of starvation or refeeding. The catabolic rate during the first week of lactation is higher in sows with higher backfat thickness than in late gestation. As lactation progresses a more balanced metabolism is achieved regardless of backfat thickness before parturition. High-weight-loss primiparous sows need a longer recovery period from their negative energy balance during lactation than do low-weight-loss primiparous sows or multiparous sows. Several investigations have demonstrated that sows losing excessive amounts of body weight have extended weaning to oestrous intervals and an increase in anoestrus. Sows with low body-weight loss during lactation have higher plasma insulin and lower cortisol around weaning than do sows with high body-weight loss. What remains undefined is the degree of weight or condition loss below which an extension in the remating interval will occur and the level of dietary energy intake required to prevent this extension.

Animal Nutritional Physiological Phenomena↗
PubMed1995

The effect of dietary lysine on growth, carcass composition, and lipid metabolism in high-lean growth gilts fed from 72 to 136 kilograms.

One hundred fourteen high-lean growth gilts (72.5 kg BW) were used to determine the apparent digestible lysine requirement for maximum growth performance and carcass protein deposition rate from 72.5 to 136 kg BW. The experiment was a randomized complete block design with initial BW used to establish blocks. Six dietary treatments were included, ranging from .44 to .94% (.10% increments) apparent digestible lysine (.62 to 1.13% total lysine) with six replicate pens per treatment and three pigs per pen. Pig weights and feed consumption were collected weekly to determine ADG, ADFI, and gain: feed ratio (G/F). Six gilts were slaughtered at 72.5 kg BW to determine initial carcass composition. When the mean weight of pigs in a pen reached 104 or 136 kg, one pig per pen was selected (closest to 104 or 136 kg, respectively) and slaughtered for determination of carcass measurements and composition. From 72.5 to 104 kg and from 104 to 136 kg, ADG and G/F increased (linear, P < .05; quadratic, P < .10, respectively) as apparent digestible lysine increased. From 72.5 to 136 kg, G/F increased (quadratic, P < .10) as apparent digestible lysine increased. Average backfat thickness and longissimus muscle area at 104 kg were not influenced (P > .10) by apparent digestible lysine. However, average backfat thickness increased (quadratic, P < .05) with increasing digestible lysine for gilts slaughtered at 136 kg. Carcass CP accretion was not influenced (P > .10) from 72.5 to 104 kg but tended to increase (linear, P < .10) from 72.5 to 136 kg as digestible lysine increased. Plasma and longissimus muscle cholesterol concentrations were unaffected (P > .10) by increasing digestible lysine. These results suggest that high-lean growth gilts require greater dietary lysine than current NRC (1988) estimates to maximize ADG, G/F, and carcass CP accretion from 72.5 to 104 and from 104 to 136 kg.

Animals↗
PubMed2001

Effects of betaine on growth, carcass characteristics, pork quality, and plasma metabolites of finishing pigs.

An experiment was conducted to determine the effect of dietary betaine (0, 0.125, 0.250, or 0.500%) on growth, carcass traits, pork quality, plasma metabolites, and tissue betaine concentrations of cross-bred finishing pigs. Four replications of three pigs (two barrows and one gilt) each were used for each treatment. The basal diet contained 0.85 (69 to 88 kg BW) or 0.65% Lys (88 to 115 kg BW). Overall ADG and gain:feed were not affected (P > 0.10) by betaine, but overall ADFI was decreased (quadratic, P < 0.05; 0 vs betaine, P < 0.01) by betaine; pigs fed 0.250% betaine had the lowest ADFI. Loin muscle area, average back-fat, dressing percentage, percentage lean, total fat, lean:fat, and leaf fat weight were not affected (P > 0.10) by betaine. Tenth-rib backfat thickness was decreased (quadratic, P < 0.05; 0 vs betaine, P < 0.05); pigs fed 0.250% betaine had the lowest 10th-rib backfat thickness. Carcass length was increased (linear, P < 0.05; 0 vs betaine, P < 0.10) as the level of betaine was increased. Fat-free lean, lean gain per day, ham weight, ham fat-free lean, and ham percentage lean were increased (quadratic, P < 0.10), but percentage fat, total ham fat, percentage ham fat, and butt-fat thickness were decreased (quadratic, P < 0.10); these traits were respectively highest or lowest in pigs fed 0.250% betaine. Thaw loss and 24-h pH were increased (quadratic, P < 0.10; 0 vs betaine, P < 0.05) and cook loss was decreased (linear, P < 0.05) in pigs fed betaine. The CIE L* value for the biceps femoris was decreased (quadratic, P < 0.10; 0 vs betaine, P < 0.10); pigs fed 0.250% betaine had the lowest CIE L* value. Subjective color, firmness-wetness, marbling, percentage moisture and bound water of the loin muscle, and shear force were not affected (P > 0.10) by betaine. Betaine was not detectable (< 0.07 mg/g) in the loin muscle of pigs fed 0% betaine, but betaine was detectable and relatively constant in pigs fed 0.125, 0.250, or 0.500% betaine (0.22, 0.17, and 0.21 mg/g, respectively). Plasma urea N, total protein, albumin, triglycerides, and HDL cholesterol concentrations were not affected (P > 0.10). Plasma total cholesterol (linear, P < 0.10) and NEFA (quadratic, P < 0.10) were increased in pigs fed betaine. Betaine improved carcass traits when provided at 0.250% of the diet and improved some aspects of pork quality.

Animal Feed↗
PubMed2003

Detection of QTL affecting fatty acid composition in the pig.

We present a QTL genome scan for fatty acid composition in pigs. An F2 cross between Iberian x Landrace pigs and a regression approach fitting the carcass weight as a covariate for QTL identification was used. Chromosomes (Chrs) 4, 6, 8, 10, and 12 showed highly significant effects. The Chr 4 QTL influenced the linoleic content and both the fatty acid double-bond index and peroxidability index. In Chr 6 we found significant associations with the double-bond index and the unsaturated index of fatty acids. Chr 8 showed clear effects on the percentages of palmitic and palmitoleic fatty acids as well as the average chain length of fatty acids. In Chr 10 we detected a significant QTL for the percentage of myristic fatty acid, with an F value that was slightly above the genomewide threshold. The percentage of linolenic fatty acid was affected by a region on Chr 12. A nearly significant QTL for the content of gadoleic fatty acid was also detected in Chr 12. We also analyzed the genomic QTL distribution by a regression model that fits the backfat thickness as a covariate. Some of the QTL that were detected in our analysis could not be detected when the data were corrected by backfat thickness. This work shows how critical the selection of a covariate can be in the interpretation of results. This is the first report of a genome scan detection of QTL directly affecting fatty acid composition in pigs.

Animals↗
PubMed1994

The effects of lysine:energy ratio on the performance of weanling pigs.

In five trials, 382 weaned pigs with an average BW of 9.1 +/- .07 kg were randomly allotted in groups of four to determine the optimum ratio of lysine:energy and the interrelationship between lysine and DE levels. Twelve dietary treatments, three levels of DE (13.3, 14.0, and 14.7 MJ of DE/kg), and four lysine:energy ratios (Lys:DE) of .7, .8, .9, and 1.0 g of lysine/MJ of DE were used in a 3 x 4 factorial arrangement. All diets were formulated to have similar CP levels (19.5%) and were based on wheat, barley, and soybean meal. There was a linear decrease (P < .05) in feed intake as the energy in the diet increased. Feed intake was not affected by Lys:DE. A positive linear effect (P < .001) of Lys:DE on ADG was observed. Also, ADG increased linearly (P < .05) with an increase in DE level. Increases in DE level and Lys:DE resulted in linear (P < .001) improvements in gain to feed. Plasma urea nitrogen (PUN) concentrations decreased (linear, P < .001; quadratic, P < .007) as Lys:DE increased up to .9 g of lysine/MJ of DE. As the level of DE increased, there was a linear decrease in PUN concentration (P < .001). Backfat thickness of pigs increased linearly (P < .003) with an increase in DE level. Ratio of lysine:DE had a quadratic (P < .002) effect on backfat thickness, with an increase up to .9 g of lysine/MJ of DE and a decrease thereafter. The combination of DE level and Lys:DE, based on response surface analysis, that produced maximization of weight gain (612 g/d) was 14.13 MJ of DE/kg and .95 g of lysine/MJ of DE for pigs from 9.1 to 25.7 kg of BW.

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↗
PubMed1983

Ultrasonic equipment for the measurement of backfat on unshorn live sheep.

Because of the ease of application to the animal's exposed skin, the measurement by A-scan ultrasonics of backfat on pigs is an established technique; but difficulties are experienced with unshorn sheep because the fleece presents an obstacle, as a parting of the wool offers only a limited aperture for insonification of the subcutaneous tissues. Also, movement of the typical nervous sheep usually provides somewhat intermittent return echo signals, rendering difficult an otherwise simple measurement. The present instrument has overcome these problems by an accumulator-averaging technique, implemented by a microprocessor, allowing estimation of live backfat thickness to the nearest 0.5 mm. This paper describes the instrument function, and presents results of a series of experiments which examined the correlation with the carcass backfat thickness.

Adipose Tissue↗
PubMed1993

The effects of porcine somatotropin and dietary lysine on growth performance and carcass characteristics of finishing swine fed to 105 or 127 kilograms.

One hundred twenty barrows (initially 59 kg) were used to determine the effects of dietary lysine and porcine somatotropin (pST) on growth performance and carcass characteristics of finishing pigs fed to heavy market weights (127 kg). Pigs were injected daily with either 4 mg of pST or a placebo and fed diets containing either .8, 1.0, 1.2, or 1.4% lysine in a 2 x 4 factorial arrangement. Performance data were collected and evaluated for the weight ranges: 59 to 105, 105 to 127, and 59 to 127 kg. In addition, daily accretion rates of protein (DPA), lipid (DLA), moisture, and ash were determined by slaughtering six randomly selected pigs at the start of the experiment, then one pig per pen when pigs reached mean weights of 105 and 127 kg. Pigs injected with pST had greater (P < .05) ADG than control pigs at all weight ranges. Increased dietary lysine had no effect (P > .20) on ADG during the entire trial (59 to 127 kg). Although control pigs showed no increase in ADG with increasing lysine, ADG of pST-treated pigs tended to increase. This resulted in a pST x lysine interaction (P < .07) for ADG from 59 to 127 kg. Feed consumption decreased (P < .05) in pigs from 59 to 105 kg and 59 to 127 kg with pST treatment and with increasing dietary lysine. Feed conversion (G/F) was improved (P < .01) by pST administration and a tendency for a pST x lysine interaction (P < .12) was observed. At 105 kg, average backfat thickness, kidney fat, longissimus muscle area, and DPA were unaffected by dietary lysine but were improved by pST treatment (P < .01). At a slaughter weight of 127 kg, average backfat thickness decreased and DPA increased (linear, P < .05) with increasing dietary lysine and pST treatment (P < .01). Longissimus muscle area was increased and DLA was decreased (P < .01) by injections of pST but both were unchanged by dietary lysine. These data indicate that growth performance and carcass characteristics at 105 and 127 kg were improved by daily administration of 4 mg of pST. At both slaughter weights, increasing dietary lysine resulted in increased carcass leanness (increased carcass protein and decreased carcass lipid). Although increasing lysine did not improve overall (59 to 127 kg) ADG and feed efficiency, pST-treated pigs showed a greater response to increasing dietary lysine. The data indicate that pST-treated pigs (4 mg/d) require approximately 28 g/d of lysine.

Adipose Tissue↗