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1.
To quantify the utilization of ME by growing pigs, a factorial analysis method is often used in which the ME intake is regressed on protein (PD) and lipid deposition (LD) rates. The approach has been criticized because there often is a strong correlation between PD and LD, which makes accurate estimation of model parameters difficult. The current study describes a nonlinear multivariate analysis procedure in which PD and LD are the result of variation in ME intake. The approach requires a hypothesis concerning the partitioning of ME intake above maintenance between PD and LD. The method was evaluated using data for growing pigs of different genotypes and sex and weighing between 20 and 107 kg that were offered a diet close to ad libitum. Energy, nitrogen, and fat balances were determined at regular intervals over the growing period. The maintenance energy requirement was expressed as a function of BW (with group-specific parameters) or as a function of muscle and visceral mass. The maintenance energy requirements ranged from 913 to 1,070 kJ ME/((kg BW).60.d) for obese castrates and boars of a synthetic line, respectively. Viscera contributed 1,558 kJ ME/ ((kg tissue).70.d) to the maintenance energy requirement, whereas muscle contributed only 555 kJ ME/ ((kg tissue).70.d). It was assumed that the proportion of ME intake (above maintenance) designated for PD declined linearly with increasing BW. At 20 kg of BW, 49% of ME intake above maintenance was designated for PD in lean genotypes, whereas this was only 34% in obese genotypes. In general, with increasing BW, less energy was designated for PD, but this relationship depended on genotype and sex. Extremely lean male genotypes maintained a constant partitioning of energy between PD and LD for all BW. The energetic efficiencies varied (depending on the model used to express the maintenance requirement) between .58 and .60 for PD and .77 and .82 for LD. Extrapolation of results suggested that animals fed at maintenance energy level would still deposit protein at the expense of body lipid. It is argued that this finding requires nonbiological efficiencies of lipid catabolism and protein synthesis and illustrates the limitation of the maintenance concept for growing animals. The multivariate analysis method proposed here circumvents many of the problems associated with the factorial regression analysis of ME intake on PD and LD. The method can be used to further refine nutritional models describing growth in pigs. 相似文献
2.
Fifty-eight purebred castrated male Iberian (IB) piglets (initial BW 9.9 ± 0.1 kg) were used in an experiment to determine the effect of dietary protein content (PC) and feeding level (FL) on the rates of BW gain, whole body protein deposition (PD), and energy utilization between 10 and 25 kg of BW using the serial slaughter method. Treatments followed a 4 × 2 factorial arrangement with 4 PC (201, 176, 149, and 123 g of CP/kg of DM) and 2 FL (0.95 and 0.70 × ad libitum) and 6 or 7 piglets per combination of treatments. All diets were formulated to have an optimal AA pattern. Six piglets were slaughtered at the start of the trial to estimate initial body composition. The experimental pigs were individually housed in an environmentally controlled room (27 ± 2°C) until they reached 25 kg of BW, when they were slaughtered and analyzed for body composition. Positive linear effects of dietary PC on ADG, G:F, and gain:ME intake were observed (P < 0.001). Piglets fed at the highest FL showed greater ADG, G:F, and gain:ME intake (P < 0.001). An average increase was estimated to be 38.0 g of gain/MJ of ME intake. Protein deposition increased linearly from 35.6 to 50.9 g/d with increasing dietary PC (P < 0.001). A daily increase was estimated to be 0.35 g of PD/g of CP intake. Although the maximal genetic potential for PD of the IB piglet was not attained, a maximal value of 59.9 g/d for whole-body PD was achieved when the diet provided 201 g of CP/kg of DM and was fed at 0.95 × ad libitum. Piglets on the highest FL deposited on average 39% more body protein (P < 0.001) than restricted piglets. An average value of 4.39 g increase in PD/MJ of ME intake was obtained for diets containing 201 and 176 g of CP/kg of DM. Maintenance energy requirements and net efficiency of utilization of ME for growth, calculated by linear regression of ME intake on body retained energy, were 427 kJ/kg of BW(0.75)·d(-1) and 0.552, respectively. The corresponding partial efficiencies of utilization of ME for protein and fat deposition were 0.378 and 0.672, respectively, considerably less than the accepted values for conventional pig breeds. Practical diets of the young IB piglet should contain at least 201 g of ideal CP/kg of DM. 相似文献
3.
Twenty-four beef steers (predominantly Angus x Hereford, 14 to 18 mo of age, 403 +/- 3 kg of BW), were housed and fed in individual pens for about 122 d. Twelve steers came from a herd that had been selected for growth (high growth; HG) and the other 12 from a herd with no selection program (low growth; LG). Another 6 steers (3 from each group) were slaughtered at the beginning to obtain the initial composition. All steers were fed the same corn-based diet (3.06 Mcal of ME/kg of DM, 13.6% CP) on an ad libitum basis. Two weeks before slaughter, total urine was collected for 5 d for estimation of 3-methylhistidine excretion and myofibrillar protein breakdown rates. Compared with LG steers, HG steers had less initial BW but greater final BW, DMI (7.52 vs. 6.37 kg/d), ADG (1.33 vs. 0.853 kg/d), G:F (0.176 vs. 0.133 kg/kg), ME intake (0.233 vs. 0.201 Mcal x kg of BW(0.75) x d(-1)), and retained energy (RE; 0.0711 vs. 0.0558 Mcal x kg of BW(0.75) x d(-1)); gained more fat (676 vs. 475 g/d); and tended to gain more whole body protein (100 vs. 72 g/d), with no difference in residual feed intake (RFI). Estimated net energetic efficiency of gain (k(g)) and ME for maintenance (ME(m)) did not differ between the 2 groups, averaging 0.62 and 0.114, respectively. The HG steers had greater HCW (350 vs. 329 kg), backfat (16.1 vs. 11.6 mm), and yield grades (3.53 vs. 2.80), with a similar dressing percent, KPH fat, LM area, and marbling score. Skeletal muscle protein gain (70.2 vs. 57.6 g/d) and fractional protein accretion rate (0.242 vs. 0.197%/d) tended to be greater in HG than in LG steers. Steers were classified into low (-0.367 kg/d) and high (0.380 kg/d) RFI classes. Compared with the high RFI steers, low RFI steers consumed less DM (6.61 vs. 7.52 kg/d) and ME (0.206 vs. 0.234 Mcal x kg of BW(0.75) x d(-1)) and tended to gain less fat (494 vs. 719 g/d), but were similar for initial and final BW, ADG, G:F, protein gain, HCW, dressing percent, backfat, KPH fat, LM area, marbling score, and yield grade, as well as for all observations related to myofibrillar protein metabolism. Residual feed intake may be positively [corrected] correlated with ME for maintenance. The maintenance energy requirement increased by 0.0166 Mcal x kg(-0.75) x d(-1) for each percentage increase in fractional protein degradation rate, confirming the importance of this process in the energy economy of the animal. 相似文献
4.
Two experiments were conducted to determine the optimal apparent ileal digestible lysine:ME (Lys:ME) ratio and the effects of lysine and ME levels on N balance (Exp. 1) and growth performance (Exp. 2) in growing pigs. Diets were designed to contain Lys:ME ratios of 0.6, 0.7, 0.8, and 0.9 g/MJ at 13.5 and 14.5 MJ of ME/kg of diet in a 4 x 2 factorial arrangement. In Exp. 1, conventional N balances were determined on 48 crossbred barrows (synthetic line 990, initial BW = 13.1 +/- 0.7 kg) at approximately 15, 20, and 25 kg of BW with six pigs per diet. At 15 kg of BW, an energy density x Lys:ME ratio interaction on daily N retention was observed (P < 0.05). At each BW, N retention improved with an increase in N intake associated with increasing ME concentration. In 15-kg BW pigs, increasing the Lys:ME ratio increased daily N retention at the 13.5 (linear, P < 0.001) and 14.5 MJ of ME level (linear, P < 0.01; quadratic, P < 0.05). In 20-kg BW pigs, N retention (g/d) increased (linear, P < 0.001; quadratic, P < 0.01) and N retention (percentage) increased (linear, P < 0.001) as the Lys:ME ratio increased. At 25 kg of BW, N retention (g/d) increased quadratically (P < 0.05) with an increase in Lys:ME ratio. The Lys:ME ratios that maximized daily N retention at 15 kg of BW were 0.88 and 0.85 g/MJ at the 13.5 and 14.5 MJ of ME levels, respectively and 0.81 and 0.77 g/MJ (for both ME levels) at 20 and 25 kg of BW, respectively. Over the 28-d trial, an energy density x Lys:ME ratio interaction on ADG was observed (P < 0.05). Increasing energy density increased growth performance, whereas increasing the Lys:ME ratio in high-energy diets increased ADG (linear, P < 0.05; quadratic, P < 0.01) and gain:feed ratio (G/F) quadratically (P < 0.01). Average daily gain and G/F ratio were greatest in pigs fed the 14.5 MJ of ME diet and the Lys:ME ratio of 0.82 g/MJ. In Exp. 2, 128 individually housed crossbred barrows and gilts (initial BW = 12.8 +/- 1.6 kg) were used to determine the effect of diets used in Exp. 1 on growth performance in a 4 x 2 x 2 factorial arrangement. The ME level increased ADG and G/F from d 0 to 14 and from d 0 to 28. Increasing the Lys:ME ratio increased ADG from d 0 to 14, whereas growth performance was maximized in pigs fed Lys:ME ratio of 0.82 g/MJ. These results suggest that pigs from 13 to 20 and from 20 to 30 kg of BW fed diets containing 14.5 MJ of ME/kg had maximum N retention and ADG at 0.85 and 0.77 g of apparent ileal digestible lysine/MJ of ME, respectively. 相似文献
5.
Much of our understanding of energy metabolism in the pig has been derived from studies in which the energy supply was controlled through regulated feed intake. In commercial situations, where ad libitum feeding is practiced, dietary energy concentration, but not daily feed intake, is under producer control. This study evaluated the interactive effects of dietary energy concentration and feeding level (FL) on growth, body composition, and nutrient deposition rates. Individually penned PIC barrows, with an initial BW of 9.5 +/- 1.0 kg, were allotted to 1 of 9 treatments in a 3 x 3 factorial arrangement plus an initial slaughter group (n = 6) that was slaughtered at the beginning of the trial. Three NE concentrations (low, 2.15; medium, 2.26; and high, 2.37 Mcal of NE/kg) and 3 feeding levels (FL: 100, 80, or 70% of ad libitum access to feed) were investigated. Daily feed allowance for the restricted-fed pigs was adjusted twice per week on a BW basis until completion of the experiment at 25 +/- 1 kg of BW. Average daily gain, ADFI, and G:F were unaffected by NE (mean = 572 g, 781 g, and 0.732 g/g, respectively). Average daily gain and ADFI, but not G:F, increased (P < 0.05) with FL. Empty body lipid concentration increased with dietary NE concentration and with FL; a significant (P < 0.01) interaction revealed that empty body lipid concentration increased most rapidly as ADFI increased on the highest energy diet. Empty body lipid concentration was greatest in pigs with ad libitum access to the high-NE diet. Empty body protein concentration decreased with increasing NE (P < 0.05) but was not affected by FL. Empty body protein deposition (PD) increased with increasing FL (P < 0.001), but not with NE. Empty body lipid deposition (LD) and the LD:PD ratio increased (P < 0.01) in pigs with ad libitum access to the high-NE diet. In conclusion, NE did not interact with FL on growth, body protein concentration, or PD, suggesting that the conclusions regarding energy utilization obtained from experiments using restricted feed intake may not easily be applied to pigs fed under ad libitum conditions. The interactive effects of NE and FL on body lipid concentration, LD, and the LD:PD ratio indicate that changes in dietary energy concentration alter the composition of gain without necessarily changing overall BW gain. Consequently, the composition of gain is an important outcome in studies on energy utilization. 相似文献
6.
Efficiency of utilisation of energy from maize- and broken rice-based diets in old White Leghorn and Rhode Island Red laying hens. 总被引：1，自引：0，他引：1
1. The efficiency of utilisation of metabolisable energy (ME) for maintenance (k(m)) from diets containing maize and broken rice (BR) at 500 g/kg was studied in old White Leghorn (WL) and Rhode Island Red (RIR) laying hens using the respiration calorimetry technique. The maize-based diet contained 180.8 g crude protein (CP)/kg and 16.4 MJ gross energy (GE)/kg while the BR-based diet contained 173.2 g CP/kg and 16.3 MJ GE/kg. Diets were fed for 10 d, while an energy and nitrogen metabolism study was conducted during 3 d on an ad libitum-fed diet followed by another 3 d on two-thirds of the ad libitum-fed quantity. 2. ME values for the maize- and BR-based diets for WL hens were 73.3% and 77.6% of the GE, whereas for the RIR hens these were 77.7% and 80.0%, respectively. 3. Fasting heat productions, determined at the end of 24 h fast for WL and RIR hens were 473.2 and 366.1 kJ/kg W0.75/d, respectively. During fasting WL and RIR hens utilised body energy reserves with efficiencies of 84.9% and 73.7%, respectively. 4. The k(m) of maize- and BR-based diets for the WL hens were 81.6% and 79.6%, whereas for the RIR hens these were 74.2% and 76.0%, respectively. 5. ME for maintenance of WL and RIR hens were 589 and 499.6 kJ/kg W0.75/d, respectively. 6. It is concluded that although WL and RIR hens differ significantly in energy metabolism, their efficiency of utilisation of energy from maize- and BR-based diets are similar. 相似文献
7.
Van Kessel JS Nedoluha PC Williams-Campbell A Baldwin RL McLeod KR 《Journal of animal science》2002,80(11):3027-3034
Forty crossbred steers were used to determine the effects of carbohydrate supply site on the indigenous bacteria of the gastrointestinal tract. Steers were fitted with ruminal and abomasal infusion catheters and assigned randomly to one of eight groups in a complete randomized block design. The experimental period was 36 d. Treatments included: 1) a pelleted basal diet fed at 0.163 Mcal ME x (kg BW(0.75)) x 1 x d(-1) (LE); 2) the basal diet fed at 0.215 Mcal ME x (kg BW(0.75)) (-1) x d(-1) (HE); 3) the basal diet fed at 0.163 Mcal ME x (kg BW(0.75))(-1) x d(-1) with ruminal infusion of starch hydrolysate (SH) (RSH); 4) the basal diet fed at 0.163 Mcal ME x (kg BW(0.75))(-1) x d(-1) with abomasal infusion of SH (ASH); and 5) the basal diet fed at 0.163 Mcal ME x (kg BW(0.75))(-1) x d(-1) with abomasal infusion of glucose (AG). The total volume ofinfusate (5 kg x site(-1) x d(-1)) was equalized across treatments and infusion sites by infusion of water. Glucose and SH were infused at rates of 14.35 and 12.64 g x (kg BW(0.75)) x d(-1), respectively. Ruminal, cecal, and fecal samples were obtained on d 36. Ruminal pH was low (5.79) in LE steers and unaffected (P > 0.10) by increased energy intake or carbohydrate infusion. Cecal and fecal pH were 6.93 and 7.00, respectively, for LE steers. Increasing energy intake (P < 0.10) and the rate of carbohydrate infusion (P < 0.01) significantly decreased cecal and fecal pH compared with LE. Ruminal counts of anaerobic bacteria in LE steers were 8.99 log10 cells/g and abomasal carbohydrate infusion had no affect (P > 0.10) on these numbers. However, ASH and AG steers had approximately 1.5 log10 cells/g more (P < 0.01) cecal and fecal anaerobic populations. Ruminal, cecal, and fecal aerobic bacterial counts were 40, 22, and 23%, respectively, lower than anaerobic counts. Generally, aerobic counts responded similarly to the anaerobic counts. Less than 1% of the anaerobic bacteria enumerated in the rumen, cecum, and feces were coliforms, and 97% of the coliforms were Escherichia coli. Carbohydrate infusions resulted in only numerical increases in fecal coliform and E. coli concentrations (P > 0.10). Fecal E. coli were highly acid sensitive in all steers, with less than 1% surviving a 1-h exposure to low pH (2.0). This suggests that cecal or fecal pH is not a good indicator of acid resistance, and it supports the concept that there are other factors that may induce acid resistance. 相似文献
8.
Twelve mature Angora does were used in a replicated 3 × 3 Latin square to determine effects of feeding level on energy utilization. Fiber growth and change in tissue (nonfiber) mass were determined in the first 4 wk of 6-wk periods, preceded by 14 or 18 d of adaptation. Determination of ME intake and gas exchange measures occurred in wk 4, followed by feeding near maintenance, then fasting in wk 5 and 6 to determine the ME requirement for maintenance (ME(m)). A 60% concentrate diet was fed at levels to approximate 100, 125, and 150% of assumed ME(m) [low, medium (med), and high, respectively]. Digestibilities and diet ME/GE were not affected by treatment with different amounts of feed offered and subsequent intake near ME(m). Heat energy during fasting (261, 241, and 259 kJ/kg of BW(0.75); SEM = 8.7) and efficiency of ME used for maintenance (71.6, 69.6, and 69.2%; SEM = 2.29) were similar among treatments, although ME(m) differed (P < 0.04) between med and high (365, 344, and 377 kJ/kg of BW(0.75) for low, med, and high, respectively; SEM = 10.3). Tissue gain was less (P < 0.01) for low than for the mean of med and high (MH; -0.6, 23.7, and 29.8 g/d), although clean fiber growth only tended (P < 0.09) to differ between low and MH (5.60, 6.57, and 7.36 g/d for low, med, and high, respectively; SEM = 0.621). Intake of ME was greater (P < 0.01) for MH than for low (6.87, 8.22, and 8.41 MJ/d for low, med, and high, respectively). Total heat energy was less (P < 0.02) for low vs. MH and tended (P < 0.07) to be greater for high than for med (6.03, 6.31, and 6.77 MJ/d); mobilized tissue energy was low but greater (P < 0.02) for low vs. MH (0.16, 0.01, and 0.04 MJ/d for low, med, and high, respectively). Efficiency of ME use for fiber growth was similar among treatments (17.2, 16.3, and 17.7% for low, med, and high, respectively; SEM = 1.61). In conclusion, efficiency of ME use for fiber growth was similar to the NRC recommendation regardless of feeding level, although ME(m) was decreased perhaps because of experimental conditions used. Energy appeared partitioned to fiber growth, but preferential usage was not complete possibly because energy metabolism for tissue accretion reached a plateau with the greatest feeding level. 相似文献
9.
1. The data compiled by Marsden and Morris (1987) to examine the relationships between environmental temperature and the long-term, adapted responses of laying pullets were divided at random into two subsets of 99 and 113 observations. The first subset was used to estimate regression coefficients for an econometric model, and the second subset to validate the model. 2. Equations to predict inputs (costs) and outputs (returns) were estimated with a three-stage least-squares regression model. Three stage least-squares estimation is a technique which corrects for the simultaneity of variables within the model and correlation across equations of the model. This results in more efficient estimates of the regression coefficients. 3. The final output and output equations were: MEI = 253.86-190.31EM+5.766EM2-0.546EM3 + 0.7034T-0.004388T3 + 695.08BW-120.23BW2 + 397.37ME-13.132ME2-1.06MEXT; R2 = 0.86; EO = 119 + 0.025MEI -0.0000045MEI2-1.462T-0.0791T2-135.3BW + 38.31BW2-1.483T X BW + 0.0288T2 X BW + 0.673 delta BW; R2 = 0.59 where MEI = daily metabolisable energy intake (kJ/bird d), T = environmental temperature (degree C), EO = egg output (g/bird d), BW = body weight, and ME = metabolisable energy concentration (kJ/g). The values for R2 indicate very good fits considering that the data were recorded over a 26-year period in 14 different laboratories. 4. This statistical model can serve as the basis for an econometric model of egg production to determine the environmental temperature that maximises profits from laying pullets of different body weights. 相似文献
10.
Energy metabolism in lactating beef heifers 总被引：1，自引：0，他引：1
To obtain measurements of energy balance in lactating beef cows, respiration calorimetry and digestion trials were conducted using seven lactating (613 kg BW) and three nonlactating (598 kg BW) Hereford x Angus heifers fed a pelleted 75% alfalfa:25% concentrate diet. Five measurements of energy balance were obtained at 6- to 7-wk intervals beginning 6 to 10 wk postpartum in lactating heifers and at 6-wk intervals in nonlactating heifers. Milk yield was measured using a combination of weigh-suckle-weigh and machine milking to adapt heifers to milking by machine without the use of oxytocin. Heifers were milked only by machine during measurements of energy balance. Weekly milk yield averages ranged from 8.2 kg/d at wk 5 postpartum to 3.2 kg/d at wk 32 postpartum. When scaled to BW(.75), the regression of NE1 on ME intake and the regression of ME intake on NE1 were remarkably similar to previously published regressions for measurements obtained from lactating Holstein-Friesian cows. The average daily maintenance energy requirement from these regressions was 503 kJ ME/kg BW(.75), a value similar to the average value reported previously for lactating Holstein-Friesian cows (488 kJ/kg (BW.75)). This is in contrast to numerous published comparisons of the maintenance requirements of cattle breed types in the nonlactating state and current NRC standards for estimating maintenance energy requirements of beef and dairy cattle. The results of the present study suggest that when expressed on the basis of BW(.75) the efficiency of utilization of incremental ME above maintenance for milk and tissue energy (i.e., NE1) is similar among lactating Hereford x Angus heifers and lactating Holstein-Friesian cows. The breeds differ in terms of their propensity for milk yield and the resulting partition of ME between milk synthesis and tissue energy retention. 相似文献
11.
Gottlob RO DeRouchey JM Tokach MD Goodband RD Dritz SS Nelssen JL Hastad CW Knabe DA 《Journal of animal science》2006,84(6):1396-1402
Two experiments were conducted to determine the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA and DE, and to estimate ME and NE of rice protein concentrate, salmon protein hydrolysate, whey protein concentrate, and spray-dried plasma protein. In Exp. 1, 6 barrows (initially 29.5 +/- 2.5 kg of BW) were fitted with ileal T-cannulas and fed each of 5 cornstarch-based diets in a balanced crossover design over 35 d. During a given week, there were either 1 or 2 replications of each treatment, resulting in 6 total replications over 5 wk. The 4 test diets (fed from d 0 to 28) were formulated to contain 12.5% CP by using analyzed nutrient compositions of rice protein concentrate, salmon protein hydrolysate, whey protein concentrate, or spray-dried plasma protein. The fifth (N-free) diet was fed from d 28 to 35 to estimate basal endogenous losses of CP and AA, which were used to calculate SID. Ileal digesta were collected and analyzed, and AID and SID values were calculated. Apparent ileal digestible Lys, Met, and Thr values were 80.0 +/- 3.3, 65.6 +/- 3.1, and 68.4 +/- 4.5% for rice protein concentrate; 85.6 +/- 4.8, 85.5 +/- 4.3, and 69.8 +/- 8.5% for salmon protein hydrolysate; 93.3 +/- 1.4, 89.9 +/- 5.8, and 83.6 +/- 5.3% for whey protein concentrate; and 92.8 +/- 0.9, 85.7 +/- 2.1, 86.5 +/- 2.3% for spray-dried plasma protein, respectively. In Exp. 2, 6 barrows (initially 37.6 +/- 1.7 kg of BW) were fed each of 5 corn-based diets in a balanced crossover design over 35 d. During a given week, there were either 1 or 2 replications of each treatment, resulting in 6 total replications over 5 wk. The 4 diets containing the test ingredients were formulated to contain approximately 20% CP by using their analyzed nutrient compositions. The fifth (corn control) diet containing 8.2% CP was also used to calculate energy values by difference. Feces were collected to determine DE. The ME and NE contents were estimated using published regression equations. The DE, ME, and NE (as-fed) values were 4,724 +/- 461, 4,226 +/- 437, and 3,235 +/- 380 kcal/kg for rice protein concentrate; 4,173 +/- 1,052, 3,523 +/- 1,002, and 2,623 +/- 872 kcal/kg for salmon protein hydrolysate; 4,949 +/- 1,002, 4,352 +/- 955, and 3,344 +/- 831 kcal/kg for whey protein concentrate; and 4,546 +/- 673, 3,979 +/- 652, and 3,020 +/- 567 kcal/kg for spray-dried plasma protein, respectively. The excellent AA digestibility and relatively high DE, ME, and NE values indicate that these protein sources warrant further investigation as ingredients for growing pig diets. 相似文献
12.
Wichert B Müller L Gebert S Wenk C Wanner M 《Journal of animal physiology and animal nutrition》2007,91(5-6):278-281
Measurements of nitrogen, carbon and energy balances were done on eight female adult cats aged approximately 1.5 years with the help of respiration chambers. The cats were fed with a marked dry food for kittens (Biomill kitten). Faeces and urine samples were collected with the help of a special cat toilet that allows the single collection of both materials. The calculated energy requirement of these eight female cats was 239.6 kJ ME/kg BW/day (R(2) = 0.98). Including the data, on 12 young male adult cats, of L?uger, (2001), an energy requirement of 238 kJ ME/kg BW/day (R(2) = 0.95) could be calculated. From these data, it can be followed that the energy requirements of young, active cats are higher than that of the older cats. The method of indirect calorimetry does not necessarily lead to lower energy requirements. 相似文献
13.
Interspecies scaling of pharmacokinetic (PK) parameters is commonplace in drug development. However, information about proportionality of pharmacodynamic (PD) parameters in different species is scarce. We investigated the feasibility of allometric scaling of PK and PD parameters of s(+)-ketoprofen (sKTP) using the literature data from several animal species. Two different indirect response models were proposed to characterize sKTP inhibitory effects on synthesis of thromboxane B(2) (TXB(2)) and prostaglandin E(2) (PGE(2)). Using the traditional allometric approach, the obtained PK and PD parameters were plotted against body weights (BW) on a log-log scale. For all species, values of systemic clearance (Cl), distribution clearance (Cl(D)), central volume of distribution (V(c)), and volume of distribution at steady-state (V(ss)) were highly correlated (r(2) = 0.89-0.99) with BW. The PD parameters for inhibition of TXB(2) synthesis were poorly correlated with BW (r(2) = 0.25-0.54) while most of the parameters for inhibition of PGE(2) synthesis lacked any correlation (r(2) approximately 0.05). In conclusion, indirect response models adequately described the time course of sKTP inhibitory effects on synthesis of TXB(2) and PGE(2). Allometrical scaling showed PK parameters to change proportionally to BW, whereas PD parameters had limited ranges and were essentially weight independent. 相似文献
14.
Young MG Tokach MD Noblet J Aherne FX Dritz SS Goodband RD Nelssen JL van Milgen J Woodworth JC 《Journal of animal science》2004,82(7):2013-2022
Twelve multiparous sows with an average initial weight of 182 kg were used in a randomized complete block design to determine the effects of feeding Carnichrome (50 mg of carnitine and 200 microg of chromium picolinate per kilogram of feed, as fed) on energy and nitrogen utilization in early, mid-, and late gestation. All sows were fed a diet with or without Carnichrome for the preceding 28-d lactation, the weaning-to-estrus period, and for the duration of gestation. Daily feeding allowances over pregnancy were based on calculated energy and nutrient requirements to achieve a target sow maternal weight gain of 20 kg and remained constant throughout gestation. Heat production (HP) and its partitioning (activity, thermic effect of feeding short term [TEFst], basal) were determined in early (wk 5 or 6), mid- (wk 9 or 10), and late (wk 14 or 15) pregnancy using indirect calorimetry. Net maternal weight gain and total number of fetuses averaged 21.6 kg and 16.4, respectively. Organic matter and energy digestibility for the Carnichrome diet was greater (P < 0.05), which resulted in greater DE and ME contents (0.6%, P < 0.05) compared with the control diet. The digestibility coefficient of energy in the current experiment for a typical corn and soybean meal diet (92%) was greater than that predicted from DE values of corn and soybean meal in feeding tables (88%). Carnichrome had no effect on total HP, energy retained as protein or lipid, and maternal energy retention in early, mid-, or late gestation. Heat production in late gestation increased linearly (4.0 kJ/[kg BW0.75 x d]) for each additional day from d 90 to 110, despite the reduction of ME intake per unit of BW0.75. Metabolizable energy requirement for maintenance was 405 kJ/(kg BW0.75 x d). On average, activity HP was 116 kJ/(kg BW0.75 x d), which was equivalent to 20% of ME intake; however, this value ranged from 11 to 37% between sows, which corresponds to duration of standing ranging from 210 to 490 min/d. Energy cost of standing activity averaged 0.30 kJ/(kg BW0.75 x min). In conclusion, Carnichrome had no effect on the components of heat production and maternal weight gain during gestation, although it improved energy and organic matter digestibility of the diet. 相似文献
15.
Influence of abomasal carbohydrates on small intestinal sodium-dependent glucose cotransporter activity and abundance in steers 总被引：1，自引：0，他引：1
Rodriguez SM Guimaraes KC Matthews JC McLeod KR Baldwin RL Harmon DL 《Journal of animal science》2004,82(10):3015-3023
Most animals adapt readily to increased supplies of carbohydrate in the intestinal lumen by increasing enzymes for degradation and increasing glucose transporter activity. However, the extent of upregulation of Na+-dependent glucose cotransporter 1 (SGLT1) activity and content in response to increased delivery of carbohydrate to the small intestinal lumen of ruminants is unclear. Therefore, an experiment was conducted to determine the effect of glucose and starch hydrolysate on the activity and abundance of SGLT1 in the small intestine of steers. In a randomized complete block design, 40 crossbred beef steers (243+/-2 kg BW) were fed 0.163 Mcal of ME/(kg BW0.75(d; W), 0.215 Mcal of ME/(kg BW0.75 x d; 2M), or 0.163 Mcal ME/(kg BW0.75 x d) and infused for 35 d into the rumen (R) or abomasum (A) with 12.6 g/(kg BW0.75 x d) of starch hydrolysate (S) or into the abomasum with 14.4 g/(kg BW0.75 x d) of glucose (G). Steers were slaughtered, and brush-border membrane vesicles were prepared from the small intestinal samples obtained from five equidistant sites along the intestine. Maltase activity in vesicles and homogenates differed with intestinal sampling site (quadratic, P < 0.001). Steers on the AG treatment yielded a greater intestinal maltase activity (38 nmol glucose x mg protein(-1) x min(-1)) compared with the AS, RS, W, or 2M treatments (34, 26, 23, and 23 nmol glucose x mg protein(-1) x min(-1) respectively [SEM = 3; P = 0.02]). Sodium-dependent glucose uptake averaged 18.4+/-3.94 pmol glucose/(mg protein x s) and was not affected by treatment, but uptake decreased distally along the intestine (P < 0.001). There was no effect of treatment on SGLT1 protein abundance, but SGLT1 protein abundance increased linearly from the duodenum to the ileum (P = 0.05). The inverse relationship between glucose uptake and SGLT1 abundance suggests that the regulation of brush border Na+-dependent glucose transport capacity is complex, involving factors other than the presence of luminal carbohydrate. 相似文献
16.
1. Experiments were conducted to determine the nitrogen (N) requirement for maintenance (N(m)) in Yangzhou goslings. 2. At 56 d old, 18 birds were divided into three equal groups and fed on diets with equal metabolisable energy (ME) and different contents of crude protein (CP; low, medium and high) in an N balance test. N(m) was estimated from the relationship between N output (N(E)) and N intake (N(I)). Following the above N balance test, 16 goslings at the same age were used in a N balance test with an N-free diet. The birds were divided into 4 equal groups and offered an N-free diet at intakes of 90, 70, 50 and 0 g per d, respectively. 3. The estimated N(m) was 240 mg/kg BW(0.75) per d in the N balance test. The result from the N-free diet trial gave a value of 244 mg/kg BW(0.75) per d, confirming the result of the N balance test. The lower intake of N-free diet resulted in more N(E), suggesting that protein catabolism may occur in the body of birds to meet N(m) when dietary N(I) was very low. 4. It was concluded that the N(m) of Yangzhou goslings was about 240 mg/kg BW(0.75). 相似文献
17.
Effects of diet forage:concentrate ratio and metabolizable energy intake on isolated rumen epithelial cell metabolism in vitro 总被引：2，自引：0，他引：2
Crossbred wether lambs were used to assess the effect of altered forage:concentrate ratio and metabolizable energy intake on metabolism of substrates by ruminal epithelium using an isolated cell system. Lambs (n = 28; 20.1 +/- 3 kg BW) were assigned randomly to a factorial arrangement of dietary treatments consisting of either 75% forage or 75% concentrate fed once daily at either .099 or .181 Mcal ME x(kg BW(.75))(-1) x d(-1) for 52 d. After a 52-d feeding period, isolated rumen epithelial cells (IREC) were incubated in the presence of an oxidizable substrate with a single 14C label (acetate, propionate, butyrate, glucose, glutamate, and glutamine) at concentrations ranging from .1 to 50 mM, and substrate oxidation to 14CO2 or metabolism to beta-hydroxybutyrate (beta-HBA), acetoacetate, pyruvate, and lactate was determined. For all substrates, oxidation to CO2 was concentration-dependent and saturable within the physiological range. Differences in substrate oxidation to CO2 by IREC at specific substrate concentrations did not affect Vmax (maximal rate of substrate oxidation, nmol oxidized to CO2 x 1 x 10(6) cells(-1) x 90 min(-1)) and K(ox) (concentration of substrate at which half Vmax oxidation rate is achieved, mmoles/L) estimates for the dietary treatments. Production of beta-HBA from butyrate by IREC from the lambs fed 75% forage was not affected by ME intake; however, production was elevated by high ME intake of the 75% concentrate diet (diet x intake interaction; P < .02). Acetoacetate production from butyrate by IREC from lambs fed at high ME intake was greater (P = .001) than from those fed at low ME intake. Lactate and pyruvate production from glucose, glutamate, and propionate were generally unaffected by dietary treatment; however, rate of glutamine metabolism to lactate and pyruvate by IREC was increased with increased ME intake. The observed changes in metabolite production rates across groups did not affect the predicted Vmax and K(ox) parameter estimates. The estimated K(ox) values corroborate that VFA are the primary oxidizable fuels used by ruminal epithelial cells while illustrating that other substrates such as glucose, glutamate, and glutamine would not be expected to be oxidized extensively in vivo due to the high K(ox) relative to substrate concentrations in vivo. In conclusion, the capacity of isolated ruminal epithelial cells to oxidize substrates was largely unaffected by ME intake or dietary forage:concentrate ratio of the diet. 相似文献
18.
Bell KM Rutherfurd SM Morton RH 《Journal of animal physiology and animal nutrition》2012,96(2):182-190
Growth rate is an important factor in neonatal survival. The aim of this study was to determine growth rates in hand-reared cheetah cubs in South Africa fed a prescribed energy intake, calculated for growth in the domestic cat. Growth was then compared with previously published data from hand-reared cubs in North America and the relationship between growth and energy intake explored. Daily body weight (BW) gain, feed and energy intake data was collected from 18 hand-reared cheetah cubs up to 120 days of age. The average pre-weaning growth rate was 32 g/day, which is lower than reported in mother-reared cubs and hand-reared cubs in North American facilities. However, post-weaning growth increased to an average of 55 g/day. Growth was approximately linear prior to weaning, but over the entire age range it exhibited a sigmoidal shape with an asymptotic plateau averaging 57 kg. Energy intake associated with pre-weaning growth was 481 kJ ME/kg BW(0.75). Regression analysis described the relationship between metabolic BW, metabolisable energy (ME) intake, and hence daily weight gain. This relationship may be useful in predicting energy intake required to achieve growth rates in hand-reared cheetah cubs similar to those observed for their mother-reared counterparts. 相似文献
19.
《Journal of aquatic animal health》2013,25(3):236-240
Abstract Infectious salmon anemia (ISA) is a viral disease of Atlantic salmon Salmo salar that have been exposed to seawater in fish farms or hatcheries. This disease was previously believed to be exclusively one of salmon. However, it has been shown that anadromous brown trout Salmo trutta may carry the ISA virus (ISAV). Propagation of the ISAV in brown trout without the trout's showing any gross clinical signs of disease could be a result of a longstanding host-pathogen relationship between the virus and brown trout. A brown trout population isolated from the sea during the last 5,000 years and expected to be naive to the virus was challenged. These fish did not develop any gross signs of disease, but a few ISAVs were present as late as 46 d postchallenge. It was also shown that the ISA virus was present in brown trout as late as 7 months after challenge. 相似文献
20.
1. This study was conducted to determine the effects of starter and grower diets with differing crude protein (CP) and metabolisable energy (ME) concentrations on the body weight (BW), live weight gain (LWG), feed consumption (FC), feed conversion ratio (FCR), and carcase, breast+back, rump, wing, neck and abdominal fat weights of chukar partridge raised in captivity. 2. Chukar partridges were fed on starter diets containing 4 concentrations of CP (160, 200, 240, 280 g/kg) and 4 concentrations of ME (10.9, 11.7, 12.6, 13.4 MJ/kg) from hatch to 8 weeks of age; they were fed on grower diets containing 4 concentrations of CP (150, 175, 200, 225 g/kg) and 4 concentrations of ME (11.9, 12.6, 13.2, 13.8 MJ/kg) from 9 to 16 weeks of age. All diets contained at least 5.5 g/kg methionine, 15 g/kg lysine and 10 g/kg methionine+cystine. Sixteen starter and 16 grower diets were arranged in a 4 x 4 factorial design with 4 levels of CP and 4 levels of ME. Each treatment was replicated three times with each replicate consisting of 5 males and 5 females. 3. Partridges fed on a starter diet containing 160 g CP/kg were significantly lighter at 8 weeks of age than those in groups given diets containing a higher CP. However, at 16 weeks of age, the differences in BW among treatments had disappeared. Throughout, there were no significant effects of ME concentration on BW and LWG. 4. The daily mean FC for the 0 to 8 week and 0 to 16 week periods was not affected by dietary CP concentration. For the 9 to 16 week period, the partridges fed on a grower diet containing 225 g CP/kg consumed more feed than those given a diet containing 175 g CP/kg. 5. The highest FCR for the 0 to 8 week period was in partridges fed on a starter diet containing 160 g CP/kg. For the 9 to 16 week period, the lowest FCR was in partridges fed on a grower diet containing 150 g CP/kg. For the 0 to 16 week period, there was not a significant effect of dietary CP concentration on FCR. The daily mean FC and the FCR for the 0 to 8, 9 to 16 and 0 to 16 week periods decreased when the ME concentration of the starter and grower diets increased. 6. The carcase, rump and breast+back weights of the male partridges increased when the ME content of the diets increased. Weights of all carcase components of the male partridges were significantly greater than those of the carcase components of the females. 7. There were no significant interactions between CP and ME concentrations on BW, LWG, FC, FCR and carcase characteristics. 8. We conclude that the starter diet for chukar partridges raised for meat production should contain at least 200 g CP/kg, 11.7 MJ ME/kg, and the grower diet should contain 150 g CP/kg, 12.6 MJ ME/kg. 相似文献