scholarly journals Evaluation of nutritional strategies to slow growth rate then induce compensatory growth in 90-kg finishing pigs

Author(s):  
Zhong-Xing Rao ◽  
Mike D Tokach ◽  
Jason C Woodworth ◽  
Joel M DeRouchey ◽  
Robert D Goodband ◽  
...  

Abstract Two 44-d experiments were conducted to evaluate nutritional strategies with different concentrations of dietary lysine (and other amino acids) on growth rate and subsequent compensatory gain of 90-kg finishing pigs. Three diets were formulated to contain 0.70 (control), 0.50 and 0.18% standardized ileal digestible (SID) Lys. In Exp. 1, 356 pigs (Line 241 × 600, DNA; initially 89.0 ± 1.10 kg) were used with 4 treatments. From d 0 to 28, pigs received either the control or the 0.50%-Lys diet. On d 28, pigs either remained on these diets or were switched the 0.18%-Lys diet until d 44. There were 18 pens per treatment from d 0 to 28 and 9 pens per treatment from d 28 to 44. From d 0 to 28, pigs fed the 0.50%-Lys diet had decreased (P < 0.001) ADG and G:F compared to those fed the control diet. From d 28 to 44, pigs switched to the 0.18%-Lys diet had decreased (P < 0.05) ADG and G:F compared to pigs that remained on the control or 0.50%-Lys diets. From d 0 to 44, pigs fed 0.50%-Lys diet for 44-d had decreased (P < 0.05) ADG, G:F, and percentage carcass lean compared to pigs fed the control diet. Pigs fed the 0.50%-Lys diet then the 0.18%-Lys diet had decreased (P < 0.05) ADG and G:F compared to other treatments. Pigs fed the 0.50%-Lys diet for 44-d and pigs fed the control diet then 0.18%-Lys diet had decreased (P < 0.05) ADG, G:F, and percentage carcass lean compared to control pigs. In Exp. 2, 346 pigs (Line 241 × 600, DNA; initially 88.6 ± 1.05 kg) were used to evaluate compensatory growth after varying durations of dietary lysine restriction. A total of four treatments were used including pigs fed the control diet for 44-d or fed the 0.18%-Lys diet for 14, 21, or 28-d and then fed the control diet until the conclusion of the experiment on d 44. There were 9 pens per treatment. On average, pigs fed the 0.18%-Lys diet grew 49% slower than the control. Compared to the control, ADG of pigs previously fed the 0.18%-Lys diet increased (P < 0.05) 28% during the first week after switching to the control diet and 12% for the rest of the trial. Despite this improvement, overall ADG, G;F, final BW, and percentage carcass lean decreased (linear, P < 0.05) as the duration of Lys restriction increased. In summary, feeding Lys-restricted diets reduced the ADG and G:F of finishing pigs. Compensatory growth can be induced in Lys-restricted finishing pigs, but the duration of restriction and recovery influences the magnitude of compensatory growth.

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 183-184
Author(s):  
Zhong-Xing Rao ◽  
Jordan T Gebhardt ◽  
Mike D Tokach ◽  
Jason C Woodworth ◽  
Joel M DeRouchey ◽  
...  

Abstract A total of 356 pigs (241×600; DNA; Columbus, NE; initially 89.0 kg) were used in a 44-d trial to evaluate nutritional strategies to reduce growth rate. Three diets [control, Lys-deficient, and corn (98% corn and 2% vitamins and minerals)] were arranged into 4 nutritional strategies. The three diets contained 0.70, 0.50, and 0.18% standardized ileal digestible (SID) Lys, respectively, with all nutrients other than amino acids above requirement estimates. From d 0 to 28, pens received one of two diets (control or Lys-deficient). On d 28, pens either remained on their previous treatment or were fed the corn diet from d 28 to 44. Pens were assigned to nutritional strategies in a randomized complete block design based on initial body weight (BW) with 18 pens/treatment from d 0 to 28 and 9 pens/treatment from d 28 to 44. From d 0 to 28, pigs fed the Lys-deficient diet had decreased (P< 0.001) ADG, G:F, and d 28 BW compared to pigs fed the control diet. From d 28 to 44, pigs fed the corn diet had decreased (P< 0.05) ADG and G:F compared to pigs fed the control or Lys-deficient diets. Pigs fed the Lys-deficient diet for 44 days had decreased (P< 0.05) ADG and G:F compared to pigs fed the control diet for 44 days. From d 0 to 44, pigs fed the Lys-deficient diet then corn diet had decreased (P< 0.05) ADG, final BW, and G:F compared to all other treatments. Pigs fed the Lys-deficient diet for 44-d and pigs fed the control diet then corn diet had decreased (P< 0.05) ADG, G:F, and final BW compared to pigs fed the control diet for 44-d. In summary, feeding strategies with lysine deficient diets allow producers to slow growth rate of finishing pigs; however, feed efficiency is also impaired.


2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 32-33
Author(s):  
Zhong-Xing Rao ◽  
Mike D Tokach ◽  
Jordan T Gebhardt ◽  
Jason C Woodworth ◽  
Joel M DeRouchey ◽  
...  

Abstract A total of 346 pigs (241×600, DNA, Columbus, NE; initially 88.6 kg) were used in a 44-day trial to evaluate compensatory growth of pigs previously fed very low lysine diets. Two diets [control and corn (98% corn and 2% vitamins and minerals)] were arranged into 4 nutritional strategies. One group of pigs (control) was fed the control diet from d 0 to 44. The other three groups of pigs were fed the corn diet for 14, 21, or 28-d and then fed the control diet until day 44. The control and corn diets contained 0.70 and 0.18% standardized ileal digestible Lys, respectively. Pens were assigned to nutritional strategies in a randomized complete block design based on initial BW with 9 pens per treatment. On average, pigs fed the corn diet grew 49% slower than the control. Pigs previously fed the corn diet had 28% increased (P < 0.05) ADG during the first week of switching to the control diet and 12% faster (P < 0.05) ADG than the control for the rest of the trial. Despite this increase in ADG, final BW on d 44 was lower (P < 0.05) compared to the control for pigs fed the corn diet for 21 or 28-d. From d 0 to 44, control pigs and pigs fed the corn diet for only 14-d had increased (P < 0.05) ADG compared to pigs fed the corn diet for 21 and 28-d. Feed efficiency was decreased (P < 0.05) when the corn diet was fed and increased (P < 0.05) during the period of compensatory growth; however, overall G:F decreased (P < 0.05) as pigs were fed the corn diet longer. The data suggest that compensatory growth was observed when pigs fed the corn diet for 21 or 28-d followed by the control diet within a 6-week-period, but overall growth performance was still reduced compared to the control.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 117-118
Author(s):  
Michael S Edmonds ◽  
James W Smith

Abstract Limitations in harvest facility capacity can necessitate feeding programs to slow growth rate in late-finishing pigs. In Trial 1, six dietary regimens were used with 423 pigs (initial weight, 109 kg) randomly allotted in a 35 d study. The regimens consisted of: 1) Con (11.7% CP diet), 2) Low Protein (LP 8.8% CP), 3) Methionine (Met) 1% (LP plus 1% added Met for 35 d), 4) Met 1–1.8% (LP plus 1, 1.2, 1.4, 1.6 and 1.8% added Met for d 0–7, 7–14, 14–21, 21–28 and 28–35 d, respectively), 5) Met 2% (LP plus 2% added Met for 35 d) and 6) Met 1.5–2.3% (LP plus 1.5, 1.7, 1.9, 2.1 and 2.3%, added Met for d 0–7, 7–14, 14–21, 21–28 and 28–35 d, respectively). Pigs on Met 1% had reduced overall ADG and ADFI (P < 0.05) with similar G:F vs. pigs on LP. Compared to pigs on Met 1%, pigs on Met 1–1.8%, Met 2%, and Met 1.5–2.3% had reduced (P < 0.05) ADG of 28, 54 and 53%, respectively; and decreased (P < 0.05) ADFI of 12, 26 and 26%, respectively. In Trial 2, three regimens were used with 393 pigs (initial weight, 109 kg) in a 35 d study. The regimens consisted of 1) Met 2%, 2) Met 1.5–2.3% and 3) Met 2.0–2.8% (LP plus 2.0, 2.2, 2.4, 2.6 and 2.8% added Met for d 0–7, 7–14, 14–21, 21–28 and 28–35 d, respectively). Regimens 1 and 2 were identical to Trial 1. Overall, pigs on Met 1.5–2.3% had ADG and ADFI which were greater (P < 0.001) compared to pigs on Met 2%. Pigs on Met 2–2.8% had an overall ADG and ADFI which were less (P < 0.05) than those pigs on Met 2%. These data suggest that growth can be manipulated with excess Met.


1986 ◽  
Vol 34 (3) ◽  
pp. 351 ◽  
Author(s):  
A Lill

Estimated expenditures on brood-care by unassisted female superb lyrebirds, obtained through time-energy budgeting, were compared with published values for other bird species. With the exception of nestbuilding, estimated daily expenditures were relatively low, due mainly to the small brood size and low level of parental attentiveness. It is suggested that the traits which reduce daily brood-care expenditures, particularly the small brood size and extremely slow growth rate, may have evolved as adaptations which enabled deserted females operating close to maximal capacity to cope with single-parenting. Male parental involvement could probably increase the growth rate of the young, but not brood size; moreover, egg- laying was sufficiently asynchronous to afford multiple mating opportunities to parentally emancipated males. However, the slow growth rate of the young results in relatively large overall brood-care expenditures for females. Investments by males of up to 50% of daylight hours and 45% of BMR on singing at the height of the mating season were comparable with those of partially emancipated, polygynous males of other species. They probably reflect the high level of competition to control good display areas and to advertise status and quality to widely spaced females.


1990 ◽  
Vol 38 (3B) ◽  
pp. 609-622
Author(s):  
N.P. Lenis ◽  
J.T.M. van Diepen

Individual and group housed crossbred pigs 45 to 105 kg and 65 to 95 kg in experiments 1 and 2, respectively, were given basal diets with L-threonine 0.6, 1.2 and 1.8 g/kg. Positive and negative control diets contained total threonine 5.7 and 4.5 g/kg, respectively. To prevent other amino acids being limiting, the negative control diet was supplemented with lysine, methionine, tryptophan, isoleucine, histidine and valine. The positive control diet was supplemented with lysine and methionine. The requirement for total threonine of growing-finishing pigs for maximum growth performance was about 5.6 g/kg in a diet containing net energy 9.4 MJ/kg. This figure corresponds with about 4.7 g/kg apparent faecal digestible threonine and 4.3 apparent ileal digestible threonine. There was no difference between the growing and the finishing pigs. The requirement for ileal digestible threonine, relative to ileal digestible lysine requirement, was about 64%. It is concluded that dietary protein can be reduced by 2 percentage units without any adverse effect on growth performance, if limiting amino acids are sufficiently supplemented. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1970 ◽  
pp. 01-07
Author(s):  
Saumitro Das ◽  
L.K. Jha

The natural population of Taxus baccata L. (Himalayan Yew) throughout the Indian Himalayan Region is greatly reduced due to its extensive and reckless exploitation for “Taxol” an anticancer drug. The effects of overexploitation are exacerbated by the species poor regeneration process, slow growth rate and prolonged seed dormancy. Therefore vegetative propagation by branch cuttings seems to be only practical solution for its large scale multiplication. A study was conducted on six candidate trees (CTs) to examine the effect genotype, physiological age of stem, IBA treatment on rooting of Taxus baccata cuttings. Results revealed that rooting behaviour of cuttings was significantly affected by all the factors under study. Among the six CTs studied, CT 2 (from BSI, Shillong) had given the highest rooting response (46.28%). The juvenile cuttings have the higher rooting capacity; however the callusing was more prominent in mature cutting. The influence of IBA treatment was also significant for rooting where 1000 was most effective for stimulating rooting juvenile cuttings and 2000 ppm in mature cuttings.


2019 ◽  
Vol 63 (12) ◽  
Author(s):  
Charlotte L. Hendon-Dunn ◽  
Henry Pertinez ◽  
Alice A. N. Marriott ◽  
Kim A. Hatch ◽  
Jon C. Allnutt ◽  
...  

ABSTRACT Modulation of the growth rate in Mycobacterium tuberculosis is key to its survival in the host, particularly with regard to its adaptation during chronic infection, when the growth rate is very slow. The resulting physiological changes influence the way in which this pathogen interacts with the host and responds to antibiotics. Therefore, it is important that we understand how the growth rate impacts antibiotic efficacy, particularly with respect to recovery/relapse. This is the first study that has asked how growth rates influence the mycobacterial responses to combinations of the frontline antimycobacterials, isoniazid (INH), rifampin (RIF), and pyrazinamide (PZA), using continuous cultures. The time course profiles of log-transformed total viable counts for cultures, controlled at either a fast growth rate (mean generation time [MGT], 23.1 h) or a slow growth rate (MGT, 69.3 h), were analyzed by the fitting of a mathematical model by nonlinear regression that accounted for the dilution rate in the chemostat and profiled the kill rates and recovery in culture. Using this approach, we show that populations growing more slowly were generally less susceptible to all treatments. We observed a faster kill rate associated with INH than with RIF or PZA and the appearance of regrowth. In line with this observation, regrowth was not observed with RIF exposure, which provided a slower bactericidal response. The sequential additions of RIF and PZA did not eliminate regrowth. We consider here that faster, early bactericidal activity is not what is required for the successful sterilization of M. tuberculosis, but instead, slower elimination of the bacilli followed by reduced recovery of the bacterial population is required.


1989 ◽  
Vol 257 (4) ◽  
pp. E554-E560
Author(s):  
S. A. Norton ◽  
M. T. Zavy ◽  
C. V. Maxwell ◽  
D. S. Buchanan ◽  
J. E. Breazile

Twelve-hour plasma profiles of growth hormone (GH), insulin, glucose, and nonesterified free fatty acids (NEFA), as well as GH, insulin, and glucose responses to saline, glucose, arginine, and human pancreatic growth hormone-releasing factor (GRF) infusion were examined in 15 crossbred gilts, selected for rapid vs. slow growth. For experiment 1 GH and insulin patterns differed (P less than 0.05) between the rapid growth line (RGL) and slow growth line (SGL). Mean GH concentrations in SGL and RGL gilts were 4.1 and 3.2 ng/ml, respectively (P less than 0.05). Plasma GH profile area was greater (P less than 0.08) for SGL than RGL gilts. Glucose level, glucose area, and insulin level were higher (P less than 0.05) for RGL than SGL gilts. Plasma NEFA levels and area were greater (P less than 0.05) for SGL gilts. In experiment 2 responses of GH, insulin, and glucose to saline, glucose, arginine, and GRF infusions varied (P less than 0.05) between and within lines relative to control values. These results indicate that selection for growth rate results in concomitant changes in endocrine and metabolic status.


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