Daily Protein Accretion Research Articles

Exigência de energia metabolizável de codornas de corte no período de 1 a 14 dias de idade

Este experimento foi realizado para estimar a exigência de energia metabolizável (EM) para codornas de corte de 1 a 14 dias de idade. Foram utilizadas 1.140 aves com 1 dia de idade, distribuídas em delineamento inteiramente casualizado, com cinco tratamentos (2.750; 2.850; 2.950; 3.050 e 3.150 kcal de EM/kg de ração), seis repetições e 38 aves por unidade experimental. Observou-se redução linear dos níveis de energia no peso corporal, consumo de ração e ganho de peso das aves. A conversão alimentar foi influenciada de forma quadrática, com melhor estimativa obtida com 2.997 kcal de EM/kg de ração. Enquanto o teor de proteína bruta não sofreu diferença, o teor de água diminuiu e o de extrato etéreo aumentou de forma linear com os níveis crescentes de EM. Os níveis de EM tiveram efeito quadrático sobre a taxa de deposição de proteína e eficiência de deposição de proteína nos cortes. A exigência de EM de codornas de corte na fase inicial de crescimento é de 2.997 kcal de EM/kg, que corresponde à relação energia metabolizável:proteína bruta de 108,9.

Decreased Protein Accretion in Pigs with Viral and Bacterial Pneumonia Is Associated with Increased Myostatin Expression in Muscle

Chronic respiratory infections reduce growth in pigs but protein accretion (PA) during an ongoing multifactorial respiratory infection has not been determined, and the mechanisms underlying growth inhibition are largely unknown. The objectives of this study were to determine whether viral and bacterial pneumonia in young pigs decrease PA, increase serum IL-1beta and IL-6, and increase myostatin (MSTN) mRNA in biceps femoris and triceps muscles. Mycoplasma hyopneumoniae (Mh) or medium was given intratracheally at 4 wk of age, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) or medium was given intranasally at 6 wk of age, and pigs were killed 7 or 14 d after PRRSV inoculation for body composition analysis. PRRSV but not Mh induced a marked increase (P < 0.01) in IL-1beta, IL-6, and MSTN mRNA and a decrease (P < 0.01) in food intake, daily weight gain, PA, and lipid accretion. PRRSV also reduced (P < 0.01) myofiber area in the biceps femoris. Food intake, weight gain, PA, and weight of biceps femoris and triceps muscles were negatively correlated (r = -0.4 to -0.8, P < 0.05) with serum IL-1beta and IL-6 and with MSTN mRNA in muscle. These results suggest that the magnitude of increases in inflammatory cytokines during a respiratory infection may be predictive of decreases in PA and growth. They further suggest that during infection growth of skeletal muscle is limited in part by myostatin.

Development of a model to describe the compositional growth and dietary lysine requirements of pigs fed ractopamine.

The objective of this research was to use recent ractopamine research data to develop an updated mathematical model to describe the daily compositional growth of pigs fed ractopamine. Mean increases of 18.2, 23.1, and 25.0% for daily protein accretion were assumed for 5, 10, and 20 ppm of ractopamine for an overall gain of 40 kg of BW gain during the feeding period. The relative effect of ractopamine described the rapid increase and subsequent decrease in the effect of ractopamine as a function of BW gain or days on test and ractopamine concentration (RC, ppm). The reduction in ME intake produced by ractopamine was described as 0.036 x (RC/20)(0.7) multiplied by the ME intake for the first 20 kg of BW gain, and then increasing to 0.078 x (RC/20)(0.7) at 40 kg of BW gain feeding period. The ratio of fat-free muscle gain to protein accretion increased by 14 to 16% with the feeding of ractopamine, depending on the dietary lysine/essential AA levels. The ratio of carcass fat gain to empty body lipid gain was increased when lysine and essential AA requirements were met. Daily protein accretion and fat-free lean growth were described as functions of dietary lysine/essential AA intakes. The percentage of lysine in protein accretion increased with the feeding of ractopamine from 6.80 to 7.15%, depending on ractopamine concentration. Equations predicting carcass measurements, such as fat and longissimus muscle depths from carcass weight and composition, were modified to incorporate prediction biases produced by ractopamine. For the four concentrations of ractopamine (0, 5, 10, and 20 ppm, respectively) during a 78 to 110 kg of BW feeding period, the model predicted performance levels for ADG (1.03, 1.15, 1.16, and 1.16 kg/d), gain:feed (kg of ADG/kg of ADFI; 0.360, 0.401, 0.412, and 0.425), dressing percentage (75.1, 76.0, 76.3, and 76.4), percentage fat-free lean (48.7, 51.0, 51.5, and 52.2), longissimus muscle area (38.8,41.8,42.5, and 43.5 cm2), 10th-rib fat depth (22.1, 19.8, 19.3, and 18.7 mm), and fat-free lean gain (321, 446, 467, and 495 g/d), comparable to recent research data. The model allows the effect of ractopamine to be added to farm specific pig growth curves. It can be used to evaluate ways to optimize the use of ractopamine, including duration of ractopamine feeding, concentration of ractopamine, and dietary lysine concentration.

Effect of dietary L-carnitine on growth performance and body composition in nursery and growing-finishing pigs.

Two experiments were conducted to determine the effect of dietary L-carnitine on growth performance and carcass composition of nursery and growing-finishing pigs. In Exp. 1,216 weanling pigs (initially 4.9 kg and 19 to 23 d of age) were used in a 35-d growth trial. Pigs were blocked by weight in a randomized complete block design (six pigs per pen and six pens per treatment). Four barrows and four gilts were used to determine initial carcass composition. L-Carnitine replaced ground corn in the control diets to provide 250, 500, 750, 1,000, or 1,250 ppm. On d 35, three barrows and three gilts per treatment (one pig/block) were killed to provide carcass compositions. L-Carnitine had no effect (P > 0.10) on growth, percentages of carcass CP and lipid, or daily protein accretion. However, daily lipid accretion tended to decrease and then return to values similar to those for control pigs (quadratic P < 0.10) with increasing dietary L-carnitine. In Exp. 2, 96 crossbred pigs (initially 34.0 kg BW) were used to investigate the effect of increasing dietary L-carnitine in growing-finishing pigs. Pigs (48 barrows and 48 gilts) were blocked by weight and sex in a randomized complete block design (two pigs/pen and eight pens/treatment). Dietary L-carnitine replaced cornstarch in the control diet to provide 25, 50, 75, 100, and 125 ppm in grower (34 to 56.7 kg; 1.0% lysine) and finisher (56.7 to 103 kg; 0.80% lysine) diets. At 103 kg, one pig/pen was slaughtered, and standard carcass measurements were obtained. Dietary L-carnitine did not influence growth performance (P > 0.10). However, increasing dietary carnitine decreased average and tenth-rib back-fat (quadratic, P < 0.10 and 0.05), and increased percentage lean and daily CP accretion rate (quadratic, P < 0.05). Break point analysis projected the optimal dosage to be between 49 and 64 ppm of L-carnitine for these carcass traits. It is concluded that dietary carnitine fed during the nursery or growing-finishing phase had no effect on growth performance; however, feeding 49 to 64 ppm of L-carnitine during the growing-finishing phase increased CP accretion and decreased tenth-rib backfat.

Anabolic implant effects on visceral organ mass, chemical body composition, and estimated energetic efficiency in cloned (genetically identical) beef steers.

Six sets of four genetically identical Brangus steers (n = 24; X BW 409 kg) were used to determine the effect of different anabolic implants on visceral organ mass, chemical body composition, estimated tissue deposition, and energetic efficiency. Steers within a clone set were randomly assigned to one of the following implant treatments: C, no implant; E, estrogenic; A, androgenic, or AE, androgenic + estrogenic. Steers were slaughtered 112 d after implanting; visceral organs were weighed and final body composition determined by mechanical grinding and chemical analysis of the empty body. Mass of the empty gastrointestinal tract (GIT) was reduced approximately 9% (P < .10) in steers implanted with estrogen alone or in combination with an androgen. Liver mass was increased (P < .10) from 6 to 14% by implants. Steers implanted with the AE combination had greater (P < .10) daily protein accretion (163.4 g/d) than either E (128.8 g/d) or A (137.1 g/d), and, because the combination improved gain above C (101.1 g/d), this demonstrates the additive effects of a combination implant on protein deposition. Anabolic implants did not alter (P > .10) the efficiency of ME utilization. In general, estrogenic implants decreased GIT, androgenic implants increased liver, and all implants increased hide mass. Steers implanted with an AE combination had additive effects on protein deposition compared with either implant alone. The NEg requirements for body gain are estimated to be reduced 19% by estrogenic or combination implants.

Characterization of growth parameters needed as inputs for pig growth models.

Swine growth models have the potential to evaluate alternative management decisions and optimize production systems. However, the lack of economical, yet accurate methods to obtain the growth parameters required to characterize pig genotypes, and which are required by growth models, limits their widespread implementation. The four primary parameters required are 1) daily whole-body protein accretion potential, 2) partitioning of energy, intake over maintenance between protein and lipid accretion, 3) maintenance requirements for energy, and 4) daily feed intake. Estimation of daily protein accretion rates requires that serial estimates of composition and growth be fitted to flexible nonlinear functions. Serial dissection and chemical analysis are too expensive to be routinely conducted on an adequate number of pigs for precise daily protein accretion rates at different live weights. Three alternate methods include 1) serial slaughter and double sampling; 2) use of serial live measurements to estimate composition, i.e., serial ultrasonic measurements; and 3) use of generalized functions that estimate daily protein accretion as a function of mean daily fat-free lean gain over a specified weight interval. The energy partitioning between lipid and protein accretion can be expressed as two interchangeable measurements, either as the slope of protein accretion or the change in the lipid: protein gain ratio as a function of energy intake at each live weight. Both methods require serial estimates of composition and scale feeding of pigs to specified energy intake levels. Maintenance requirements for energy are better expressed as a function of protein mass than body weight. However, differences in body protein mass do not fully explain difference in maintenance requirements between various pig genotypes. Daily feed intakes at each live weight can be estimated by accurately collecting feed intake data at least three live weight ranges and fitting the data to nonlinear functions. An alternative method to estimate daily feed intake is to develop daily lipid and protein accretion curves. On the basis of their energetic costs of lipid and protein deposition and assumed maintenance requirements, daily energy intakes can be estimated. Genetic selection changes the underlying growth parameters. The selection criteria and testing environment direct the relative genetic change for each growth parameter. The different sexes may also be affected differently by selection. For this reason, each closed uniformly selected population must be evaluated for each parameter for each sex.

Prediction of daily protein accretion rates of pigs from estimates of fat-free lean gain between 20 and 120 kilograms live weight.

The objective of this study was to evaluate a method for predicting daily protein accretion rates of various genotypes of pigs reared in different environmental conditions using easily obtained mean daily fat-free growth rates. Data were obtained for seven genotype-environment groups of gilts and nine groups of barrows. Daily empty body protein accretion rates were estimated at 1.0-kg intervals between 20 and 120 kg live weight. The estimates were fitted to a generalized exponential function, PA = A e(B x WT + C/WT + D x WT2), where WT is kilograms of live weight and A, B, C, and D are estimated parameters for each sex. Nonlinear least squares methods were used to estimate the intercept and regression coefficients expressing each parameter estimate (A, B, C, and D) as a linear function of the mean fat-free lean gain for each sex-genotype-environment group. The mean percentage absolute errors were 3.5% for gilts and 6.1% for barrows. The largest errors occurred between 110 and 120 kg live weight. From 20 to 110 kg, mean percentage errors averaged 2.7% for gilts vs 4.8% for barrows. These results offer encouraging evidence that a generalized equation can be used to predict daily protein accretion rates from mean fat-free lean growth data. Further research, with additional genotype-environment populations, is needed to increase accuracy of the generalized growth functions.

The responses of growing pigs, of different sex and genotype, to dietary energy and protein

AbstractIntact male pigs from two nucleus breeding herds (one predominantly Duroc, DM; the other purebred Large Wliite, LM) together with intact male (RM), castrated male (RC) and female (RF) commercial hybrid pigs were given one of two diets, with the same balanced protein (180 or 240 g/kg) at three daily rates, the highest being ‘to appetite‘. Six replicates of 30 pigs were allocated to these regimes at 40 kg: one replicate was slaughtered immediately to determine initial carcass composition; the remaining pigs were slaughtered at 85 kg when carcass fat and specific gravity (SG) were measured. For two replicates this was followed by dissection and chemical analysis: daily gains of carcass lipid and protein were estimated directly for these two replicates and predicted from carcass weight and SG for the other three. Fed ‘to appetite’, castrated males and females ate more than males; LM pigs ate least. All males grew faster than females or castrated males, the DM pigs the fastest, these rankings being relatively insensitive to feeding level. However, both in daily weight gain and daily protein accretion only the males responded to additional dietary protein. Daily body protein accretion of DM pigs increased linearly with intake on both diets whereas LM pigs showed little response to the highest level of feeding. At the same daily protein intake all pigs had higher rates of body protein accretion on the low protein diet, showing that they were sensitive to additional dietary energy. Results indicate that an animal's superiority may result from a greater efficiency of protein utilization or a higher lean growth potential but that these two characteristics are not simply related.

Effects of porcine somatotropin administration and its duration on growth performance and carcass characteristics of finishing swine fed to 280 lb (1991)

One hundred eight barrows with an initial weight of 120 lb were utilized to determine the effects of porcine somatotropin (PST) administration period and duration on growth performance and carcass characteristics of finishing swine fed to 280 lb. Pigs were injected daily in the extensor muscle of the neck with either a placebo or 4 mg pST. Treatments included: (A) placebo injection from 120 to 280 lb; (B) pST injection from 120 to 280 lb; (C) pST injection from 120 to 230 lb and then placebo injection from 230 to 280 lb; (D) placebo injection from 120 to 230 lb and then pST injection from 230 to 280 lb; (E) placebo injection from 120 to 170 lb, pST injection from 170 to 230 lb, and then placebo injection from 230 to 280 lb; and (F) placebo injection from 120 to 250 lb and then pST injection from 250 to 280 lb. All pigs were fed a corn-soybean meal diet containing 1.2% lysine. Performance data were collected and evaluated for three weight ranges: 120 to 230 Ib, 230 to 280 lb, and 120 to 280 lb. Two pigs from each pen were slaughtered to determine carcass characteristics. The first pig was slaughtered at 230 lb and the second pig at 280 Ib . Average daily gain (ADG), average daily feed intake (ADFI), and feed conversion (F/G) were all optimized when pigs were treated with pST for the entire time from 120 to 230 lb and from 120 to 280 lb. Longissimus muscle area (LEA), backfat thickness, percentage carcass muscle, and kidney fat were all improved at 230 lb when pigs were injected with pST. There was no difference in these carcass traits when pigs were injected with pST from 120 to 230 lb compared to pigs treated with pST from 170 to 230 lb. These same carcass characteristics measured in pigs slaughtered at 280 lb showed significant improvement with pST treatment compared to the control. However, when pST treatment lasted the entire trial (120 to 280 lb), there was significant improvement in carcass characteristics over pST treatments of shorter duration. Whole ham weight was unaffected by pST treatment at either slaughter weight, but trimmed ham weight was improved by pST treatment at 230 lb. Daily protein accretion rate (DPA) and daily fat accretion rate (DFA) were optimized at both slaughter weights by pST treatment that lasted for the duration of the trial. Organ weights were increased by pST treatment but were unaffected by administration period or duration of pST treatment. These data indicate that growth performance and carcass characteristics were maximized when pST was administered continually from 120 to 280 lb.; Swine Day, Manhattan, KS, November 21. 1991

Effects of porcine somatotropin administration and its duration on growth performance and carcass characteristics of finishing swine fed to 280 lb (1991)

One hundred eight barrows with an initial weight of 120 lb were utilized to determine the effects of porcine somatotropin (PST) administration period and duration on growth performance and carcass characteristics of finishing swine fed to 280 lb. Pigs were injected daily in the extensor muscle of the neck with either a placebo or 4 mg pST. Treatments included: (A) placebo injection from 120 to 280 lb; (B) pST injection from 120 to 280 lb; (C) pST injection from 120 to 230 lb and then placebo injection from 230 to 280 lb; (D) placebo injection from 120 to 230 lb and then pST injection from 230 to 280 lb; (E) placebo injection from 120 to 170 lb, pST injection from 170 to 230 lb, and then placebo injection from 230 to 280 lb; and (F) placebo injection from 120 to 250 lb and then pST injection from 250 to 280 lb. All pigs were fed a corn-soybean meal diet containing 1.2% lysine. Performance data were collected and evaluated for three weight ranges: 120 to 230 Ib, 230 to 280 lb, and 120 to 280 lb. Two pigs from each pen were slaughtered to determine carcass characteristics. The first pig was slaughtered at 230 lb and the second pig at 280 lb . Average daily gain (ADG), average daily feed intake (ADFI), and feed conversion (F/G) were all optimized when pigs were treated with pST for the entire time from 120 to 230 lb and from 120 to 280 lb. Longissimus muscle area (LEA), backfat thickness, percentage carcass muscle, and kidney fat were all improved at 230 lb when pigs were injected with pST. There was no difference in these carcass traits when pigs were injected with pST from 120 to 230 lb compared to pigs treated with pST from 170 to 230 lb. These same carcass characteristics measured in pigs slaughtered at 280 lb showed significant improvement with pST treatment compared to the control. However, when pST treatment lasted the entire trial (120 to 280 lb), there was significant improvement in carcass characteristics over pST treatments of shorter duration. Whole ham weight was unaffected by pST treatment at either slaughter weight, but trimmed ham weight was improved by pST treatment at 230 lb. Daily protein accretion rate (DPA) and daily fat accretion rate (DFA) were optimized at both slaughter weights by pST treatment that lasted for the duration of the trial. Organ weights were increased by pST treatment but were unaffected by administration period or duration of pST treatment. These data indicate that growth performance and carcass characteristics were maximized when pST was administered continually from 120 to 280 lb.; Swine Day, Manhattan, KS, November 21, 1991

Fixation de protéines chez les ruminants : évolution en fonction du poids des animaux et variations selon la race, le sexe ou le niveau des apports alimentaires

Using a great amount of published and unpublished data, this paper analyzes changes in the protein content of the empty body of growing cattle and sheep (appendices 1, 2). Protein content (p. 100 of empty body weight) usually increased from 6-7 p. 100 to 18-20 p. 100 in cattle and to 14-18 p. 100 in sheep during foetal life. After birth, it decreased slowly, reaching 13-15 p. 100 in 70 p. 100 mature-weight animals. Changes in water and lipid content were analyzed in relation to protein content (fig. 1). Protein content (p. 100 of fresh weight) varied between 10 and 14 p. 100 in the adipose tissues, 15 and 16 p. 100 in the offals, 19 and 20 p. 100 in the muscles and skeleton and 28 and 30 p. 100 in the hide. Muscle protein amounted to 48 to 53 p. 100 of whole body protein. Mean daily protein accretion increased in cattle from 100 g after birth to a maximum of 160-200 g/day at 200-300 kg of body weight and decreased afterwards (fig. 3). From 20 g/day in very young lambs, it reached 30-40 g/day at 20-30 kg of body weight. Daily protein accretion in g per kg of metabolic weight (W0.75) was similar in the two species (5.5 g at birth, 2.8 g at 30 p. 100 mature body weight and 1.2 g at 60 p. 100 mature body weight). The lipid deposition was greater than protein accretion after 10 p. 100 mature body weight in sheep, but only after 20 p. 100 mature body weight in cattle. The ratio between lipid deposition and protein accretion was greater in sheep than in cattle. Daily protein accretion, which varied according to sex and genotype, ranged between 150-235 g/day in cattle and between 32-54 g/day in sheep. The protein content of sheep and cattle gain dropped when the feeding level increased. Simultaneously, the lipid content of gain increased and the animals were fatter at slaughter. However, it appears that the composition of sheep gain was less sensitive to feeding level than that of cattle.

Protein turnover in growing pigs. Effects of age and food intake.

1. Measurements were made of the nitrogen and energy balances of pigs of 30, 60 and 90 kg given a conventional diet at various daily rates. 2. Body protein synthesis was estimated from the irreversible loss of leucine from the blood following the infusion of [1-14C]leucine, and from the oxidation of the labelled amino acid. 3. Protein synthesis (g/d) increased by 2.17 for each 1 g increase in daily protein accretion and by 1.55 for each 1 g increase in daily protein intake. 4. At 30 kg, pigs close to energy equilibrium synthesized 270 g protein daily compared with 406 g and 512 g when their ration supplied twice and three times their maintenance requirement. 5. There was a close correlation between the daily urinary excretion of urea + ammonia and total amino acid catabolism estimated from the catabolism of leucine, but the latter underestimated the observed excretion by 2.5 g N/d. 6. The results imply that protein turnover accounts for only a proportion of the heat production associated with protein deposition.