Biomedical subjects

C A Baile

Publications and source records attributed to C A Baile.

At least 37 records · Page 2Linked to original sources

PubMed1998

Down-regulation of CCAAT/enhancer binding proteins alpha, beta and delta in adipose tissue by intracerebroventricular leptin in rats.

In our previous report, intracerebroventricular (i.c.v.) administration of leptin caused fat depletion by an induced adipocyte apoptosis in addition to influencing lipid metabolism. To uncover the biochemical mechanisms that mediate this response, the present study was designed to determine whether CCAAT/enhancer binding proteins (C/EBP)alpha, -beta and -delta play a role in the leptin-induced fat depletion. Expressions of C/EBPalpha, -beta and -delta in epididymal fat tissues were examined by Western immunoblot and in situ immunocytochemical analysis after 5 days of i.c.v. treatment. Young and old rats (3 and 8 months old) were treated with or without 5 micrograms/day leptin. The expression of C/EBPalpha, -beta and -delta was decreased by i.c.v. leptin treatment in young rats as compared with controls (P<0.05). However, leptin did not influence the expression of C/EBPalpha, -beta and -delta in adipose tissues of 8-month-old rats. The basal level of expression of C/EBPbeta was greater in 8-month-old rats than in 3-month-old rats, (P<0.05) whereas the basal expression of C/EBPalpha and -delta was not different between age groups. These results were confirmed by in situ immunocytochemical analysis. The present study suggests that leptin-induced down-regulation of C/EBPalpha, -beta and -delta might influence adipocyte differentiation and growth in a number of ways.

Adipose Tissue↗

PubMed1998

Leptin regulation of peroxisome proliferator-activated receptor-gamma, tumor necrosis factor, and uncoupling protein-2 expression in adipose tissues.

It has previously been reported that intracerebroventricular (i.c.v.) administration of leptin induced adipose tissue apoptosis in addition to influencing lipid metabolism. The objective of the present study was to determine if the expressions of peroxisome proliferator-activated receptor-gamma (PPAR gamma), uncoupling protein-2 (UCP2), and tumor necrosis factor (TNF alpha) were influenced by in vivo leptin treatment. Expression of PPAR gamma, UCP2, and TNF alpha in epididymal fat tissue was examined by Western immunoblot and in situ immunocytochemical analysis after 5 days of i.c.v. leptin treatment. Young and old rats (3 and 8 months old) were treated with or without 5 micrograms/d leptin. Leptin treatment increased PPAR gamma expression by 70-80% (P < 0.01) in both age groups. Leptin treatment decreased the expression of UCP2 (P < 0.01) in young rats, whereas it increased UCP2 expression (P < 0.01) in old rats. Leptin treatment also decreased TNF alpha expression by 40% (P < 0.01) in young rats but did not influence its expression in old rats. The basal level of expression of PPAR gamma was greater in 3-month-old rats than in 8-month-old rats. The basal level of UCP2 and TNF alpha expression was not different between the two age groups. These immunoblotting data were further confirmed by in situ immunocytochemical analysis. The present study suggests that expression of PPAR gamma may be directly involved in the leptin-induced adipocyte apoptosis signal pathway, whereas UCP2 and TNF alpha may play roles in the leptin-induced lipolysis process.

Adipose Tissue↗

PubMed1998

Brain administration of leptin causes deletion of adipocytes by apoptosis.

Leptin, produced in adipocytes, works through the central nervous system (CNS) to modulate food intake and energy expenditure, resulting in rapid loss of body fat depots. It is now shown that this process includes adipocyte apoptosis. Adipocyte deletion by apoptosis occurred after intracerebroventricular (i.c.v.) administration of leptin in rats. Adipose tissue of leptin-treated rats demonstrated characteristic features of apoptosis, including internucleosomal fragmentation of genomic DNA, elevated levels of DNA strand breaks and a reduction in total DNA content and cellular volume. These apoptotic features were absent in control and pair-fed rats and in other tissues of leptin-treated rats.

Adipocytes↗

PubMed1998

The biology of leptin: a review.

Leptin, a 16-kDa protein secreted from white adipocytes, has been implicated in the regulation of food intake, energy expenditure, and whole-body energy balance in rodents and humans. The gene encoding leptin was identified by positional cloning and is the mutation leading to the profound obese phenotype of the ob/ob mouse. Exogenous administration of leptin to ob/ob mice leads to a significant improvement in reproductive and endocrine status as well as reduced food intake and weight loss. The expression and secretion of leptin is highly correlated with body fat mass and adipocyte size. Cortisol and insulin are potent stimulators of leptin expression, and expression is attenuated by beta-adrenergic agonists, cAMP, and thiazolidinediones. The role of other hormones and growth factors in the regulation of leptin expression and secretion is emerging. Leptin circulates specifically bound to proteins in serum, which may regulate its half-life and biological activity. Isoforms of the leptin receptor, members of the interleukin-6 cytokine family of receptors, are found in multiple tissues, including the brain. Many of leptin's effects on food intake and energy expenditure are thought to be mediated centrally via neurotransmitters such as neuropeptide Y. Multiple peripheral effects of leptin have also been recently described, including the regulation of insulin secretion by pancreatic beta cells and regulation of insulin action and energy metabolism in adipocytes and skeletal muscle. Leptin is thought to be a metabolic signal that regulates nutritional status effects on reproductive function. Leptin also plays a major role in hematopoeisis and in the anorexia accompanying an acute cytokine challenge. The profound effects of leptin on regulating body energy balance make it a prime candidate for drug therapies for humans and animals.

Animal Husbandry↗

PubMed1998

Glucagon-like peptide-1 (7-36) amide administered into the third cerebroventricle inhibits water intake in rats.

Intracerebroventricular (icv) injection of glucagon-like peptide-1 (7-36) amide (GLP-1) has been shown to reduce food intake in rats. In these studies, we confirmed that injection of 10 microg of GLP-1 into the third cerebroventricle suppressed food intake. Moreover, we observed a reduction in water intake associated with the decreased food intake. We further examined whether GLP-1 injected icv in rats has a specific inhibitory effect on water intake. It was found that GLP-1 reduced water deprivation-induced drinking. Furthermore, the same dose of GLP-1 (10 microg) was sufficient to condition taste aversion. Finally, when 2 microg of GLP-1 were injected into the third ventricle, it only suppressed water deprivation-induced water intake and failed to influence spontaneous food and water intakes or induce conditioned taste aversion. These observations indicate that GLP-1 is a potent inhibitor of water intake in the rat and may play a role in the control of fluid homeostasis.

Animals↗

PubMed1998

Increased leptin resistance as rats grow to maturity.

Three or eight-month-old Sprague-Dawley rats were treated intracerebroventricularly (ICV) with 5 microg of rat leptin/d for 5 days to determine the effect of age on leptin's actions in ingestive behavior, adipose tissue cellularity, organ weights, body composition, and blood metabolite profile. Effects of leptin on food intake were greater in young immature rats (22.0 vs. 5.7 g/d) than in mature rats (17.4 vs. 9.3 g/d) with a leptin x age interaction (P< 0.01). Leptin results in body weight loss (P < 0.001) by 19% and 9% in young and mature rats, respectively. Water intake was reduced by leptin treatment only in young animals (P< 0.001). The decrease in carcass weight by leptin treatment (P < 0.001) was observed in both young (22%) and mature rats (9%). Leptin treatment greatly reduced retroperitoneal (0.82 vs. 0.11 g, P < 0.05) and epididymal fat weight (1.90 vs. 0.48 g, P < 0.003), associated with a reduction in total adipocyte cell number, DNA content, and cellular volume in young rats; however, there were no effects of leptin in the mature rats. In addition, young rats also displayed a 60% loss of carcass lipid content. An increase in serum fatty acid levels by leptin treatment was observed also only in young rats (P< 0.001). An interaction of leptin by age that was observed for the reduction of serum glucose levels by leptin treatment (P < 0.04) further indicated that mature rats showed a leptin insensitivity compared to young rats. In summary, the data suggest that normal rats become resistant to leptin as they age.

Adipose Tissue↗

PubMed1997

Growth performance, endocrine, and metabolite responses of finishing hogs to porcine prolactin.

Prolactin, a member of the somatotropin-prolactin-placental lactogen gene family, increases feed intake and rate of weight gain in several species. To determine whether prolactin affects growth performance and carcass composition in swine, recombinant porcine prolactin (rpPRL) was administered to finishing hogs. Doses of 0, 2, 4, 8, and 16 mg of rpPRL/d and 4 mg of recombinant porcine somatotropin (rpST)/d were administered to groups of seven barrows and seven gilts initially weighing 75.0 +/- .2 kg for a 28-d period. Recombinant pPRL did not alter feed intake or growth rate or affect carcass composition. In addition, most growth-related blood variables did not change, although plasma IGF-I was increased in the 8 and 16 mg of rpPRL treatment groups. At slaughter, mammary development was apparent in rpPRL-treated gilts and was characterized by distended alveolar and ductal lumina and presence of secretory material. In rPST-treated hogs, feed intake was decreased 28% (P < .01), gain/feed was increased more in barrows than in gilts (59 vs 39%, treatment x sex interaction, P = .035), and growth rate was increased 22%, but in barrows only (treatment x sex interaction P = .005). Compared with those in control hogs, circulating concentrations of IGF-I, insulin, and glucose were 175, 311, and 22% higher, respectively, and of blood urea nitrogen were 62% lower in rpST-treated hogs (P < .05). These results suggest that rpPRL, at the doses administered, does not increase feed intake in finishing hogs in contrast to rats and other species.

Analysis of Variance↗

PubMed1996

Effect of bovine somatotropin administered to periparturient dairy cows on the incidence of metabolic disease.

Thirty-eight dry, pregnant Jersey cows were assigned to diet and bST treatment in a 2 x 2 factorial design. During the dry period, half of the cows were fed a normal TMR (0.4% Ca; 0.3 to 0.4% P), and half of the cows were fed a high Ca TMR (1.5 to 1.6% Ca; 0.4 to 0.7% P). The high Ca diets were designed to induce milk fever and were relatively cationic (194 to 293 meq/kg) compared with the normal diets (-131 to 30 meq/kg). A standard dairy diet was fed to all cows postcalving. Cows received subcutaneous injections of either an oil-based excipient or 500 mg of bST in an oil-based excipient every 14 d from 28 d before expected calving until approximately 14 d postcalving. Peripartal bST treatment decreased the incidence of clinical mastitis, did not affect incidence of milk fever, and increased the duration, but not the incidence, of ketosis in mature Jersey cows. Blood data confirmed the clinical responses and indicated that treated cows mobilized more bone Ca than did controls, as was evidenced by increased hydroxyproline concentrations. Treatment with bST did not affect blood concentrations of 1,25-dihydroxyvitamin D, Ca, or Mg. High Ca diets increased the incidence of milk fever and downer cow syndrome compared with normal diets. The effect of bST on mastitis and milk production must be considered as preliminary given the small size of the study. Although bST treatment increased Ca mobilization, the effect was insufficient to prevent milk fever in this model.

Animals↗

PubMed1995

Growth performance, carcass characteristics, and sensory attributes of boars administered porcine somatotropin by sustained-release implant for different lengths of time.

We investigated the effect of sustained-release implant administration of porcine somatotropin (pST) (4 mg/d) to male pigs for different lengths of time before slaughter. Crossbred white boars were assigned to six groups (n = 10/ group); B0, non-implanted boars; B6, boars implanted from 22 to 28 wk of age; B12, boars implanted from 16 to 28 wk of age; B18, boars implanted from 10 to 28 wk of age;C0, non-implanted castrates; and C18, castrates implanted from 10 to 28 wk of age. Castration was at 65 d of age. All pigs were slaughtered at 28 wk of age, and measures of offal and carcass components were recorded. Loin chops were collected for sensory evaluation. During the trial the pigs were maintained in individual pens with ad libitum access to water and a 19% CP corn-soybean meal diet containing 1.08% calculated lysine. Although pST reduced feed intake in castrates (P < .01), the effect in boars was nonsignificant. Slaughter weight was increased in a linear (P < .04) manner with length of pST treatment of boars, and slaughter weights of castrates given pST were greater (P < .01) than those of control castrates. The product of the changes in feed intake and gain resulted in greater efficiency of gain in pST-treated pigs than in control pigs (P < .01). A linear effect (P < .06) of length of pST treatment on trimmed lean cut weights of boars was noted. The weights of trimmed lean cuts produced by castrates treated for 18 wk with pST and boars treated for 12 or 18 wk were similar. Boars given pST for 18 wk had improved (P < .10) boar taint scores compared with untreated boars. Boars and castrates given pST for 18 wk had a similar rates of gain and weights of trimmed lean cuts. Efficiencies of gain were greater in pST-treated boars and castrates than in untreated boars, which were superior to untreated castrates in efficiency of gain.

Analysis of Variance↗

PubMed1995

Comparative effectiveness of somatotropin and anabolic steroids in feedlot steers.

Crossbred steers (n = 252, BW = 379 +/- 28 kg) were allotted to 42 pens in a 2 x 3 factorial arrangement of treatments: control or steroid implant (STR; estradiol benzoate+progesterone [three lighter blocks reimplanted on d 84] and trenbolone acetate [reimplanted on d 63]), and either 0, 80, or 160 mg/wk of recombinant bovine somatotropin (bST). Steers were adapted to the finishing diet (12% roughage equivalent, 13% CP) before the start of the experiment and fed for 84 or 119 d. Blood samples were taken on d 0, 14, 28, 56, and 84 for plasma urea N (PUN), serum somatotropin (ST), plasma insulin-like growth factor I (IGF-I), and plasma amino acid assay. Few interactions were noted (P > .1). Gain was increased by both treatments: 1.30 vs 1.66 kg/d for control vs. STR (P < .001) and 1.44, 1.49, and 1.51 kg/d (linear, P = .07) for 0, 80, and 160 mg of bST/wk, respectively. Gain efficiency was also improved: 169 vs 205 g/kg (P < .001) and 177, 189, and 195 g/kg (linear, P < .001), respectively. Average PUN was decreased (P < .001) 29% by STR and decreased 17 and 29% by 80 and 160 mg of bST/wk, respectively (linear, P < .001). Somatotropin decreased mean serum ST compared with controls; STR increased ST 36% compared with controls. Average plasma IGF-I was increased (P < .001) 12% by STR and 13 and 19% (linear, P < .001) by 80 and 160 mg of bST/wk, respectively. Both STR and bST influenced (P < .05) plasma amino acid profiles. Indicators of carcass fatness were decreased linearly (P < .05) by bST; STR implant tended to decrease carcass fatness and increase longissimus muscle area, which was related to carcass weight. The anabolic effects of STR and bST were found to be additive and possibly independent in feedlot steers.

Amino Acids↗

PubMed1994

Performance, clinical chemistry, and carcass responses of finishing lambs to formulated sometribove (methionyl bovine somatotropin).

Formulated zinc methionyl bST (sometribove, 50, 100, or 150 mg) was administered as a single treatment once every 2 wk or as two equal treatments once/week to evaluate the efficacy of prolonged release delivery of bovine somatotropin (bST) in finishing lambs. Feed conversion during the 6-wk treatment period was improved 9 and 19% in lambs that received treatments once and twice/2 wk, respectively (P < .05), and the responses to differing doses were similar within a dosing frequency (P > .05). Carcass muscle:fat ratio indicators generally were affected in a dose-related manner and were independent of frequency of administration. For example, fat thickness was 17, 30, and 42% lower than control in lambs that received 50, 100, and 150 mg of formulated sometribove/2 wk, respectively (P < .05). Percentages of muscle were higher and of fat were lower with increasing dose of formulated sometribove, but weight of only fat was significantly affected (P < .05). Clinical chemistry indices of metabolic effects of bST (e.g., circulating bST, IGF-I, insulin, glucose, and urinary nitrogen concentrations) were affected in directions similar to those observed with bST administered by daily injection. The results of this study demonstrate the growth performance and carcass composition advantages of a formulation designed to deliver bST over a 2-wk period.

Adipose Tissue↗

PubMed1994

Reduction of feed intake in sheep by enterostatin, the procolipase activation peptide.

Enterostatin, a peptide formed during the activation of pancreatic procolipase in the duodenum, is likely a mediator of satiety in the rat. The objective of this research was to determine whether administration of enterostatin into the lateral cerebral ventricle of sheep unfed for 2 h resulted in reduced feed intake. Bolus doses of 2 micrograms did reduce (P < .03) feed intake during the hour after injection by one- to two-thirds of control. Doses 20 micrograms or greater were not effective, and .2 microgram also did not have any statistically significant effect. This range of effective doses was similar to that observed in the rat, and the effective dose of 2 micrograms was approximately 10-fold greater on a per-animal basis, but less on a brain-size basis, than the amount needed to achieve a similar response in the rat. Therefore, enterostatin can reduce feed intake and thus may also be involved in satiety in sheep.

Amino Acid Sequence↗

PubMed1993

Adipsin expression and growth in rats as influenced by insulin and somatotropin.

Adipsin is a molecular marker of obesity in rodents. Content of adipsin protein in blood and mRNA in adipocytes is significantly reduced in several genetic and experimentally induced obese models. It has been suggested that this reduction in adipsin is causative to obesity development. Insulin reduces adipsin expression in vitro and is negatively correlated with adipsin expression in vivo. Because bovine somatotropin (bST) opposes many actions of insulin and can reduce body fat content, we tested the hypothesis that bST enhances adipsin expression. In two experiments using 210 rats, bST and a similar hormone, bovine placental lactogen (bPL), both caused a small (14 to 27%) but statistically significant reduction in circulating adipsin protein. Because exogenous bST can increase circulating insulin we next used a diabetic model to test the bST effect on adipsin. In rats treated with streptozotocin and injected daily with insulin (STZ+I), bST had no effect on circulating adipsin. Additional variables related to growth were influenced differently by bST in normal vs. STZ+I animals. In conclusion, the drop in circulating adipsin following bST administration in normal rats is dependent upon the animals' ability to secrete insulin.

Adipose Tissue↗

PubMed1993

Performance, clinical chemistry, and carcass responses of finishing lambs to recombinant bovine somatotropin and bovine placental lactogen.

Bovine placental lactogen (PL) is a partial somatotropin agonist in the cow and decreases urea nitrogen, indicating increased nitrogen retention. In the present study, the somatogenic effects of bovine PL (bPL; 4 and 8 mg/d) were compared with those of bovine somatotropin (bST; 4 and 8 mg/d) in finishing lambs. Measures of comparison included growth performance, carcass composition, and growth-related clinical chemistry traits. Although feed efficiency during the first 3 wk of treatment with bPL was improved by 14% (P < .05), feed efficiency for the full 6-wk treatment period did not differ from that of control lambs. Responsiveness to bPL may have been attenuated by high titer antibodies present after 2 wk of treatment. However, bPL also did not influence growth-related clinical chemistry traits during short-term (7 d) treatment, strongly suggesting that bPL was ineffective in finishing lambs at the doses tested. In contrast, bST improved 6-wk feed efficiency by an average of 17% (P < .05) and decreased feed intake by an average of 12% (P < .05). In addition, measures of carcass composition including longissimus muscle area, specific gravity of the rack, kidney and pelvic fat, and fat thickness demonstrated that bST, but not bPL, treatment decreased carcass fatness and increased carcass leanness. Treatment with bST, but not with bPL, affected IGF-I, insulin, glucose, and urea nitrogen in a dose-related manner. Thus, daily injections of bPL did not affect either performance or carcass quality, whereas performance and carcass responses of finishing lambs to bST were consistent with those reported by others.

Adipose Tissue↗

PubMed1993

Comparison of the growth-promoting properties of daily versus continuous administration of somatotropin in female rats with intact pituitaries.

The effect of dose and mode of delivery of recombinant bovine (rbST) or porcine somatotropin (rpST) on the growth rate of female rats with intact pituitaries was investigated in a series of experiments. The overall objective of these studies was to compare the relationship of dose and mode of delivery on the growth response to somatotropin. The equivalence of rbST and rpST in stimulation of growth was demonstrated. In an initial study, treatment of rats with 0, .67 (3 mg/kg), or 2.0 mg/d (9 mg/kg) of rbST for 28 d resulted in ADG of .8, 2.6, and 3.8 g/d (P < .0001, SEM .1 g). A log-linear dose response to rbST in the range of .07 to 32 mg/d (.3 to 145 mg/kg) for the stimulation of gain was observed. Continuous delivery of rpST in bicarbonate buffer was achieved using osmotic pumps. Sustained, log-linear growth for doses of 0, .5, 1, 2, and 4 mg of rpST/d for 28 d was demonstrated. In a direct comparison of bolus injection and continuous delivery at doses of 0, .22, .67, 2.0, and 6.0 mg of rpST/d, a significant difference in slope (P < .0001) of the modes of delivery was observed; continuous delivery had a greater slope. Depending on the dose administered, bolus injection was either more (< .67 mg/d) or less efficacious (> .67 mg/d) than continuous delivery in its ability to stimulate growth in female rats with intact pituitaries. It is hypothesized that the difference in the slope of the dose-response curves can be accounted for by the animal's ability to utilize the hormone effectively.

Animals↗

PubMed1993

Comparison of performance, clinical chemistry, and carcass characteristics of finishing lambs treated with recombinant ovine or bovine somatotropins.

The variation in growth and carcass composition responses of lambs to somatotropin (ST) treatment may depend on the source of ST used as well as on other experimental conditions. In the present experiment, growth, carcass composition, and clinical chemistry responses to recombinantly produced ovine ST (oST) and two bovine ST (N-methionyl-bST[M-bST] and N-alanyl-bST[A-bST] were compared. Lambs weighing 42 kg were assigned to treatment groups of control (no injection) or 4 mg/d of M-bST, A-bST, or oST administered by s.c. injection for 6 wk. Growth rate was increased by an average of 30% and feed efficiency was improved by an average of 22% by ST treatment compared with control, and responses did not differ among ST. The IGF-I, insulin, and glucose concentrations were increased by 107, 700, and 53% compared with control, respectively, and did not differ among ST treatment groups. Urea nitrogen responses to A-bST and oST were transiently greater than those to M-bST. Although quality grade was not affected by treatment, an average .8-kg increase in weight of retail cuts was calculated from yield grade. Carcasses of ST-treated lambs were calculated to have 1.3 kg more muscle and 1.9 kg less fat. Although fat and muscle were affected more by oST than by M-bST on a percentage basis, they did not differ among treatment groups on a total weight basis. Thus, both bST variants and oST improved growth performance and carcass leanness. Decreased responses of some carcass variables to M-bST treatment may have been related to the presence of antibodies that were indicated by an increased number of positive responders in a relative bST binding assay.

Adipose Tissue↗

PubMed1993

Effects of a porcine somatotropin implant on tissue mineral status of finishing pigs exposed to a thermoneutral or cold environment.

An experiment was conducted with 24 crossbred (Landrace x Yorkshire x Duroc) finishing pigs (mean BW 85 kg) to study the effects of a single 100-mg recombinant porcine somatotropin (rpST) implant on the tissue mineral status of pigs exposed to either a thermoneutral (TN; 18 to 21 degrees C, 50 to 55% RH) or cold (C; 5 to 15 degrees C, 50 to 70% RH) environment until BW averaged 110 kg. The implants used in this study delivered an average 2.4 to 2.5 mg of rpST/d during the course of the study. Control pigs were implanted with a placebo. All diets were supplemented with minerals at levels that either met or exceeded the requirements of an 85-kg pig. At slaughter (mean BW 110 kg), tissues were collected and analyzed for selected macro- and microminerals. Pigs treated with rpST had higher (P < .05) Ca concentrations and total Ca in liver and kidney and higher (P < .05) Ca concentrations in muscle. Total P, Mg, Na, and K were all higher (P < .05) in the liver and kidneys of rpST-treated pigs. In general, rpST had little influence on Cu, Zn, and Fe in tissues. No consistent trend was evident in the response of tissue minerals to environmental temperature. Results indicated that pigs treated with rpST and supplemented with adequate minerals accumulated more minerals in certain tissues than did pigs not given rpST.

Animals↗

PubMed1993

Performance, carcass composition, and blood hormones and metabolites of finishing pigs treated with porcine somatotropin in hot and cold environments.

Two experiments were conducted to assess the ability for recombinant porcine somatotropin (rpST)-treated pigs to perform and cope with the demands of hot and cold environments. In the first experiment, finishing pigs were exposed to either a thermoneutral (TN; 18 to 21 degrees C) or a hot environment (H; 27 to 35 degrees C) for 35 d. In the second experiment, pigs were exposed to a TN or cold environment (C; 5 to 15 degrees C). The rpST delivered by a 6-wk prolonged-release system had no effect on ADG, whereas both H and C reduced ADG by 29.4 and 11.8%, respectively. In the first experiment, rpST-treated pigs consumed 17.6% less feed than control pigs, whereas rpST-treated pigs in H consumed 24.4% less feed than rpST-treated pigs in TN. Overall feed/gain ratios through the first 4 wk of both studies were improved by 21.8 and 14%, respectively, by rpST (P < .05) and were 24.3% poorer in C (P < .05) than in H. The changes in blood concentrations of pST, IGF-I, and IGF-II associated with rpST were not influenced by the different environments. Total body composition of rpST-treated pigs had increased amounts of protein (P < .05) and decreased amounts of fat (P < .05); H further reduced fat (P < .05). The C resulted in reduced protein content (P < .05). No evidence of thermal imbalance due to rpST was found as assessed by rectal temperature, respiration rate, and heat production estimated by indirect calorimetry and chemical analysis.

Adipose Tissue↗