Level of alimentation and line of breeding on oxygen uptake by ovine jejunal mucosa

1987 ◽  
Vol 252 (2) ◽  
pp. R398-R401
Author(s):  
R. E. Rompala ◽  
D. E. Johnson ◽  
W. V. Rumpler ◽  
H. W. Phetteplace ◽  
C. F. Parker

Targhee rams from a selected and control line of breeding were provided with the same diet at either 100 or 40% of ad libitum feed intake levels for 28 days. The rams were killed in a serial fashion over a 35-day period. A sample of the jejunum mucosa was taken, and O2 consumption rates with and without ouabain were measured. Total O2 consumption and ouabain-sensitive respiration rates of the jejunal mucosa taken from rams of the select line were greater than for samples taken from the control rams. Line of breeding did not influence the percent of the total O2 consumption that was ouabain sensitive and the proportion of the jejunum that was mucosa. Differences in rates of total and ouabain-sensitive O2 consumption attributed to level of feed intake were not detected as significant. Both the percentage of the total respiration rates that was ouabain sensitive and the proportion of the jejunum that was mucosa were greater for rams fed at high intake levels compared with rams fed at low intake levels. Thus both breeding sheep on the basis of improved growth potential and level of alimentation influenced aspects of jejunal mucosa respiration that was Na+-K+-adenosinetriphosphatase dependent.

1981 ◽  
Vol 23 (3) ◽  
pp. 545-555 ◽  
Author(s):  
E. A. Dunnington ◽  
J. M. White ◽  
W. E. Vinson

Randomly bred ICR mice were selected for five generations for high and low serum cholesterol (SC), voluntary physical activity, 56-day body weight and feed intake. An unselected, randomly bred control line was maintained with each pair of selection lines. Significant increases in mature body weight occurred in males of high weight and high intake lines and in females of high SC, high weight and high intake lines. Significant decreases in mature body weights occurred in males of low weight line and in females of low SC and low weight lines. Both high and low selected SC lines had greater (P<0.05) activity scores and consumed more feed than the SC control. Mice selected for high activity consumed more (P<0.05) feed than mice selected for low activity. Mice selected for high 56-day body weight consumed more (P<0.05) feed and had higher SC than mice selected for low 56-day body weight. Mice selected for high feed intake were heavier (P<0.05) and more active (P<0.05) than low feed intake mice but had significantly lower SC levels.


1987 ◽  
Vol 252 (1) ◽  
pp. E21-E26 ◽  
Author(s):  
M. S. Bolze ◽  
R. D. Reeves ◽  
F. E. Lindbeck ◽  
M. J. Elders

Weanling male rats were fed control ad libitum, zinc-deficient (ZD, 1 ppm zinc) or pair-fed (PF) control diets for 13 days. Rats subsequently were refed control diets for up to 8 days and serially killed. ZD and PF diets significantly decreased growth rate, feed intake, and feed efficiency compared to controls. Body weight and feed efficiency, but not feed intake, were significantly less in ZD compared to PF. Bone zinc was 315, 286, and 109 micrograms/g (p less than 0.0001) for control, PF, and ZD at the end of depletion. 35SO4 uptake by glycosaminoglycans (GAG) was significantly less in ZD compared to either control ad libitum or PF rats. Xylosyltransferase activity was decreased significantly below PF and control by ZD, suggesting depressed enzyme activity and/or decreased GAG acceptor sites. Bioassayable somatomedin (Sm) activity was 0.81, 0.42 and 0.33 +/- 0.09 relative activity for control, PF and ZD at the end of depletion. Sm was statistically less in ZD compared to PF at day 2 and 5 of refeeding, but not at the end of depletion. Sm activity and GAG metabolism returned to normal after refeeding for 2–5 days in PF and for 5-8 days in ZD rats. Serum insulin but not glucose was significantly depressed by ZD and PF diets. Thus, zinc deficiency depressed growth and cartilage metabolism and was associated with decreased Sm activity and insulin levels. Some of these changes could be attributed to decreased feed intake as a result of ZD.


1988 ◽  
Vol 47 (1) ◽  
pp. 149-156 ◽  
Author(s):  
C. P. McPhee ◽  
G. A. Rathmell ◽  
L. J. Daniels ◽  
N. D. Cameron

AbstractSelection was carried out in a line of pigs for increased growth rate of lean tissue. The selection criterion was weight of lean in the ham predicted from live backfat and weight measurements after a 12-week performance test commencing at 25 kg live weight. All pigs were given the same total amount of food over the test period. The scale was set to about proportionately 0·85 of predicted ad libitum intake. Boars selected with an intensity of 1/12 were used for 6 months and sows selected with an intensity of 1/4 were kept for two farrowings. An unselected control line was maintained concurrently.After five generations, performances of selected and control line pigs were compared on ad libitum and scale feeding as they grew to 85 kg. Responses in the selected line on scale feeding were +51 g/day for growth rate (GR), −0·16 for food conversion ratio (FCR), −2·2 mm for backfat (F) and +0·47 kg for ham lean (HL). On ad libitum feeding, responses were much higher in the selected line, giving rise to line × food interactions. Responses were +128 g/day for GR, −0·27 for FCR, −2·3 mm for F, +1·01 kg for HL and +0·15 kg/day for food intake (FI). Estimates of the heritability of HL from variance components were 0·43 (s.e. 0·15) on scale feeding and 0·28 (s.e. 0·19) on ad libitum feeding. The realized heritability of HL on scale feeding was 0·29 (s.e. 0·04) and its co-heritabilities with the other traits on both feeding levels were of similar magnitude to its heritability. Scale feeding exposed genetic variation in the partitioning of food between lean and fat deposition and appeared to be a suitable selection regimen for performance on ad libitum feeding.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 393-394
Author(s):  
Camila D A Batalha ◽  
Fabiana L De Araújo ◽  
Renata H Branco ◽  
Luis O Tedeschi ◽  
Sarah F Bonilha

Abstract Retained energy (RE) and energetic efficiency index were measured in Nellore bulls from divergent classes of residual feed intake (RFI). Thirty-four Nellore bulls (15 low RFI-LRFI and 19 high RFI-HRFI) were feedlot finished and slaughtered with 385 ± 40 kg of body weight (BW) and 520 ± 26.2 days of age. At the beginning of the experiment, five LRFI and three HRFI were slaughtered and used as base line. Individual dry matter intake was recorded daily; initial and final BW were recorded after 16 h of fasting. Eight bulls, four LRFI and four HRFI, were fed at maintenance, receiving 65 g of DM/kg0.75 BW, and 18 bulls (10 LRFI and eight HRFI) were fed ad libitum. Diet had 19:81 roughage:concentrate, 88% of DM and 15% of crude protein. Ultrasound measurements on the Longissimus muscle were performed at intervals of 28 days. When two ad libitum bulls reached 4 mm of subcutaneous fat thickness, one maintenance bull was randomly chosen and slaughtered on the same day. After slaughter, the centesimal composition of the empty body and carcass was measured. Data were analyzed using a random coefficients model, and RFI class was included as a fixed effect. Least-square means were used to compare the means, and significance was declared for P ≤ 0.05. The LRFI had greater protein retention than HRFI (248 vs. 142 g/d; P = 0.009), and same fat and energy retention (313 g/d and 4.12 Mcal/d, respectively). The energy efficiency indexes, heat production per metabolic energy intake (Mcal/Mcal) and gain-to-feed (kg/kg) ratio, did not differ between RFI classes. Though LRFI had the same energy efficiency index, they were leaner. These results indicated an association of RFI and maturity patterns. Further research is needed to estimate the net energy requirements of Nellore bulls classified according to RFI. Acknowledgments: FAPESP Processes 2017/06709-2, 2018/20080–2 and 2019/17714-2.


1986 ◽  
Vol 61 (2) ◽  
pp. 449-455 ◽  
Author(s):  
W. Mueller-Klieser ◽  
R. Zander ◽  
P. Vaupel

A new technique is described for measuring O2 consumption rates and O2 concentrations in suspensions of respiring cells. Aliquots of a cell suspension kept in a special thermostated precision syringe are injected into the measuring system in defined time intervals. The O2 content of these samples is determined photometrically, as reported previously. The O2 consumption per cellular wet weight and/or per single cell can be calculated from the cell volume fraction, the physical density, the cell concentration in the suspension, and the time-dependent decline of the O2 concentration in the precision syringe. The minimum detectable amount of O2 is 0.1 microliter O2, which corresponds to 0.001 (vol/vol) of O2 if a 100-microliters sample of suspended cells is analyzed. Reproducibility of the O2 consumption measurement is 9% of the measured value. The advantages offered by this method are the straightforward calibration in absolute terms, the short time required for one analysis (2–6 min), a high sensitivity, the simultaneous determination of overall O2 concentration and O2 consumption rates in cell suspensions, and the great variability in the application.


1994 ◽  
Vol 59 (2) ◽  
pp. 263-269 ◽  
Author(s):  
N. D. Cameron ◽  
M. K. Curran

AbstractResponses to divergent selection for lean growth rate with ad-libitum feeding (LGA), for lean food conversion (LFC) and for daily food intake (DFI) in Landrace pigs were studied. Selection was practised for four generations with a generation interval ofl year. A total of 2642 pigs were performance tested in the high, low and control lines, with an average of 37 boars and 39 gilts performance tested per selection line in each generation. The average within-line inbreeding coefficient at generation four was equal to 0·04. There was one control line for the DFI and LFC selection groups and another control line for the LGA selection group. Animals were performance tested in individual pens with mean starting and finishing weights of 30 kg and 85 kg respectively with ad-libitum feeding. The selection criteria had phenotypic s.d. of 32, 29 and 274 units, for LGA, LFC and DFI, respectively, and results are presented in phenotypic s.d.Cumulative selection differentials (CSD) were 5·1, 4·5 and 5·5 phenotypic s.d. for LGA, LFC and DFI, respectively. Direct responses to selection were 1·4,1·1 and 0·9 (s.e. 0·20) for LGA, LFC and DFI. In each of the three selection groups, the CSD and direct responses to selection were symmetric about the control lines. The correlated response in LFC (1·1, s.e. 0·19) with selection on LGA was equal to the direct response in LFC. In contrast, the direct response in LGA was greater than the correlated response (0·7, s.e. 0·18) with selection on LFC. There was a negative correlated response in DFI (-0·6, s.e. 0·18) with selection on LFC, but the response with selection on LGA was not significant (0·2, s.e. 0·16).Heritabilities for LGA, LFC and DFI ivere 0·25, 0·25 and 0·18 (s.e. 0·03), when estimated by residual maximum likelihood, with common environmental effects of 0·12 (s.e. 0·02). Genetic correlations for LFC with LGA and DFI were respectively positive (0·87, s.e. 0·02) and negative (-0·36, s.e. 0·09), while the genetic correlation between DFI and LGA was not statistically different from zero, 0·13 (s.e. 0·10). Selection on components of efficient lean growth has identified LGA as an effective selection objective for improving both LGA and LFC, without a reduction in DFI.


2014 ◽  
Vol 54 (3) ◽  
pp. 319 ◽  
Author(s):  
Ronald E. Newman ◽  
Jeffery A. Downing ◽  
Peter C. Thomson ◽  
Cherie L. Collins ◽  
David J. Henman ◽  
...  

Three studies investigated the effect of feeding strategy on production performance and endocrine status of growing pigs. For Experiment 1, 20 entire male pigs (70.0 ± 4.6 kg) were allocated randomly to individual pens in one of four climate-controlled rooms. Pigs were fed for 23 days either ad libitum or entrained to feed bi-phasically for two 90-min periods. For Experiment 2, 20 entire male pigs (41.2 ± 3.5 kg) were housed as per Experiment 1. Pigs were fed for 49 days either ad libitum or fed bi-phasically for two 60-min periods. For Experiment 3, 100 female pigs (66.1 ± 3.5 kg) were randomly allocated to individual pens within a commercial piggery and fed for 42 days either ad libitum or bi-phasically for two 60-min periods. Ear vein catheters were inserted into 10 pigs from each group and hourly blood samples were collected for 24 h in Experiments 1 and 2 and for 11 h in Experiment 3. Plasma insulin, non-esterified fatty acid and glucose concentrations were determined in Experiments 1 and 2, and glucose and insulin concentrations in Experiment 3. Feed intake and performance were recorded in all experiments and carcass composition was assessed by computed tomography for Experiment 2. There were no differences in final liveweight between the two treatment groups for all experiments. Pigs fed for two 90-min periods (Experiment 1) showed no difference in feed intake when compared with feeding ad libitum. Pigs in Experiment 2 fed for two 60-min intervals consumed 2.49 kg/pig.day compared with those fed ad libitum that consumed 2.68 kg/day (P = 0.057). In Experiment 3, pigs fed twice daily consumed 2.82 kg/pig.day compared with 2.91 kg/pig.day in ad libitum-fed pigs (P = 0.051). Bi-phasic fed pigs in Experiment 2 had improved (P < 0.05) feed conversion efficiency compared with pigs fed ad libitum. For all experiments, there was no difference in plasma glucose concentrations between the two treatments. In all three experiments, the circulating insulin concentrations for pigs fed ad libitum remained at a constant level throughout the sampling period. However, plasma insulin concentrations for the bi-phasic fed pigs significantly increased ~1 h after both feeding periods during all three experiments. Insulin secretion of pigs fed for two 90-min periods differed from that of pigs fed for two 60-min periods. Plasma insulin concentration increased five-fold following feeding for 60 min, compared with that in pigs fed for 90 min, which increased two-fold. Bi-phasic-fed pigs from Experiment 2 had reduced (P < 0.05) total carcass fat and significantly increased muscle when compared with pigs fed ad libitum. The data showed that feeding pigs at two succinct periods aligned insulin secretion to the time of feeding. Pigs fed for 60 min, unlike those fed for 90-min intervals, had reduced feed intake in comparison to those fed ad libitum. This may suggest that the duration of the feeding bout is important for this response and this may in turn influence both energy balance and the way energy is partitioned.


1986 ◽  
Vol 26 (6) ◽  
pp. 647
Author(s):  
RT Norris ◽  
CL McDonald ◽  
JB Rowe

The accuracy with which monensin could control feed intake was studied in 200 3-4-year-old Merino wethers by measuring their intake of pelleted diets containing 5 levels of monensin: 0, 33, 66, 132 or 264 mg/kg of feed. The feed was offered ad libitum for 25 days except for the highest level of monensin where treatment was ended after 12 days.Mean daily intakes (g/sheep) of diets containing monensin at 0, 33, 66, 132 or 264 mg/kg feed were 1304, 959, 793, 403 and 137 respectively. Mean daily feed intake (Y, g) was negatively and linearly related to concentration of monensin (X, mg/kg feed) Y = 1244 - 6.57X (r2=0.98; P<0.05) Similarly there was a close negative relationship between the concentration of monensin (X, mg/kg feed) and daily liveweight change (Z, g/sheep) during the trial Z = 217 - 2.61X (r2=0.99; P< 0.01) From this relationship, maintenance of liveweight would have been achieved with a diet containing monensin at about 80 mg/kg feed. Signs of toxicity including deaths occurred in sheep receiving diets containing monensin at 66, 132 and 264 mg/kg feed. It was concluded that monensin could be used to restrict feed intake but further research is necessary to determine safe levels.


2021 ◽  
Vol 1 (2) ◽  
pp. 6-10
Author(s):  
M. Ya. Ibragimova ◽  
◽  
S. Yu. Zaytsev ◽  
V. V. Semenov ◽  
◽  
...  

The aim of the study was to evaluate the genetic activity of erythrocytes in peripheral on the model of peripheral blood erythrocytes in mice. The studies were carried out on mice (males) of the C 57B4/6 line weighing 20 g (1,5–2 months of age). For each experimental and control variant, six males were taken. The animals were kept in vivarium conditions according to international criteria for rinofix bedding, food and water ad libitum. When determining the genetic effects, the adrenergic receptor ligand was injected subcutaneously once. After 8 hours, a mutation inducer, an alkylating drug, cyclophosphamide, was injected intraperitoneally at a dose of 30 mg/kg. Before the end of the experiment in 2,5 hour, mice were injected intraperitoneally with 2.5 mg/kg of colchicine. 24 hours after injection, the animals were euthanized by delongation. The number of erythrocytes with micronuclei was counted from 2000 analyzed cells. The greatest antimutagenic effect (87,5%) of epinephrine hydrotartrate, a stimulator of α- and β-adrenergic receptors, was found at doses of 5 and 0,5 mg/kg.


1993 ◽  
Vol 73 (1) ◽  
pp. 159-167 ◽  
Author(s):  
F. E. Robinson ◽  
M. W. Yu ◽  
M. E. Lupicki ◽  
R. T. Hardin

The immediate effects of a sudden increase in feed allowance on selected morphological and reproductive traits were investigated in broiler breeder hens at 44 wk of age. Fifty Indian River hens were individually caged at 40 wk of age. Prior to 40 wk of age the birds had been feed restricted in accordance with the breeder's recommended feeding program. Five treatment groups (T1, T2, T3, T4 and T5) of 10 birds each were formed based on level of feeding and duration of exposure to such feeding. T1, T2 and T3 birds were feed restricted (128 g of daily feed bird−1) from 40 to 44, 40 to 45 and 40 to 46 wk of age, respectively. T4 and T5 birds were also feed restricted at the same level as the other groups to 44 wk of age and then were full fed from 44 to 45 and 44 to 46 wk of age, respectively. To facilitate study of follicular recruitment and yolk deposition, hens were fed 10 g of oil-soluble red and black dyes, daily, on alternate days, beginning at 42 wk of age. Birds were killed on day 0 (44 wk; T1), day 7 (45 wk; T2, T4), or day 14 (46 wk; T3, T5). Full-fed hens consumed approximately 100 g more feed per day than did feed-restricted hens, with marked increases in feed intake on the first day of full feeding. After 7 d of ad libitum feeding, significant increases were seen in body weight, liver weight, percent liver fat, plasma lipid concentration, ovary weight, and the incidence of a double hierarchy (simultaneous development) of large follicles. After 14 d of ad libitum feeding, significant increases were also observed in absolute fat-pad weight, individual weights of the four largest preovulatory follicles and number of large preovulatory follicles. The increased number of large follicles in the ovary was not associated with any change in egg production. It is apparent that the morphological disruptions associated with overfeeding broiler breeder hens can be identified within 7 d of full feeding, while any effects on egg production are not seen within the first 14 d of ad libitum feeding. Key words: Broiler breeder, feed intake, yolk deposition, ovarian morphology, egg production


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