Short- and long-term effects of eating on blood composition in free-feeding goats

1981 ◽  
Vol 96 (3) ◽  
pp. 659-668 ◽  
Author(s):  
A. de Jong

SUMMARYAdult goats provided with permanent jugular and portal vein catheters were used to study the relation between spontaneous meals and blood composition in free-feeding goats in order to determine which constituents might fulfil a feedback signal function in the control of feed intake. Animals were fed ad libitum concentrates, supplemented with a small amount of hay. Blood samples were collected before, during and after spontaneous meals by means of a remote sampling system and were analysed for volatile fatty acids, glucose, insulin, glucagon and growth hormone.In a preliminary experiment the relationship between body weight, voluntary feed intake, blood glucose and plasma insulin was examined in goats fed ad libitum concentrates and hay for 18 weeks. The data indicate a regulation of energy balance through control of feed intake. Since an increased glucose and insulin concentration was observed concomitantly with a decline in feed intake, glucose and/or insulin may fulfil a signal function in the control of energy balance.Spontaneous meals were not preceded by a systematic change of any of the above blood constituents. Therefore, it is unlikely that meal initiation is governed by one of those. In contrast, spontaneous meals resulted in a rapid increase of insulin during eating (P < 0·025) whereas no clear changes were observed for the other substances. Thus, insulin might be a candidate for a feedback function in the control of meal duration.

1966 ◽  
Vol 17 (5) ◽  
pp. 741 ◽  
Author(s):  
AR Egan

Results of experiments with infusions of volatile fatty acids into the rumen reveal that the induced changes in voluntary intake of roughages are not immediate, and vary in extent between animals. Single infusions resulted in subsequent depressions of feed intake, these being only partly related to the amount of energy of the infused volatile fatty acids. When longer-term infusions were made, acetic acid in small quantities depressed feed intake more than did propionic, and propionic acid modified the effect of acetic when the two were given together. Also recorded is an observation that animals receiving a casein-supplemented roughage diet reduced their feed intake when casein was infused per duodenum over 14-day periods. Results are discussed in relation to an hypothesis of an indirect mechanism attempting to maintain or restore the original energy balance, but showing considerable delay or inertia and imprecision when observed on a day to day basis.


1974 ◽  
Vol 18 (1) ◽  
pp. 105-108 ◽  
Author(s):  
J. Fordyce ◽  
M. Kay

SUMMARYExperiments were carried out to determine the effects of giving 1·36 kg of ‘RuffTabs’, polythene particles of dimension 1·27 × 0·63 × 0·95 cm3 (RT) to castrated male cattle (steers) given an all-concentrate diet, on the outflow of fluid from the rumen, on rumination and on the molar proportions of volatile fatty acids produced in the rumen.RT reduced the flow of fluid from the rumen of steers, given a restricted amount of an all-concentrate diet, from 4·65 to 2·75% rumen volume/hr. RT had no effect on the total time spent daily in ruminating and eating. The molar proportions of volatile fatty acids were unaffected by RT in steers which were given the diet ad libitum but when RT was given to steers offered a restricted allowance of feed there was a highly significant (P < 0·001) reduction in acetic and an increase in butyric, valeric and caproic acids.The feed intake of the steers was unaffected by RT.


1972 ◽  
Vol 52 (2) ◽  
pp. 207-239 ◽  
Author(s):  
G. M. JONES

The subject is reviewed with respect to the role of nutrient metabolism upon the regulation of ruminant feed intake. Chemical factors associated with changes in dietary or nutrient composition and their metabolism within the reticulorumen or animal body, or both, are emphasized. The importance of physical, physiological or metabolic, and sensory regulatory mechanisms are discussed in relation to their effects upon the formation of various metabolites known to be related to feeding. These include volatile fatty acids, amino acids, and blood glucose. Various tissues are discussed in relation to their relative importance for activation of a feedback signal associated with satiety. A general hypothesis is postulated for the integration of various factors, known to influence feed intake regulation, into a complex system.


1989 ◽  
Vol 29 (3) ◽  
pp. 327 ◽  
Author(s):  
EM Aitchison ◽  
K Tanaka ◽  
JB Rowe

The feed additives flavomycin, a glycolipid antibiotic, and tetronasin, an ionophore, were evaluated for their ability to improve wool growth and liveweight gains in Merino sheep. Each was included in 2 diets: one was a pelleted mixture of (g/kg) lucerne (590), lupins (250) and barley (1 50); the other diet was wheaten chaff. Flavomycin was included in each diet at 10 and 20 mg/kg feed; tetronasin at 5 and 10 mg/kg feed. During an 8-week experimental period, the diets were fed ad libitum to weaner Merino wethers, with 15 sheep receiving each treatment diet at each level of additive inclusion, and 30 sheep receiving each diet without additives. Liveweight changes, feed intake and wool growth were measured over 2 consecutive 4-week periods, and rumen fluid samples were taken from all sheep after 6 weeks. Feed intake, liveweight gain and wool growth rate were all higher for animals eating the pelleted diets compared with those eating chaff. Rumen volatile fatty acids (VFA) and ammonia (NH3) concentrations were also higher with the pelleted diet. On the pelleted diet, flavomycin and tetronasin inclusion significantly increased liveweight gains during the second 4-week period (296, 277, 231 g/sheep.day for flavomycin, tetronasin and controls respectively, P<0.001), but neither additive had any significant effect on feed intake. The amount of clean wool grown during both measurement periods was greater for animals receiving flavomycin or tetronasin with the pelleted diet compared with control animals. Neither additive had any significant effect on liveweight gains or wool growth of sheep eating chaff. Fibre diameter (FD) was measured on wool clipped in the second period, and was not significantly altered by either additive: mean FDs for animal receiving pellets were 25.1 �m, compared with 18.5 �m for animals receiving chaff. Total rumen VFA concentrations were lower with flavomycin or tetronasin treatments on both diets, and ammonia concentrations were lower with both additives on the pelleted diet and with tetronasin on the chaff diet. It is concluded that both flavomycin and tetronasin were able to increase liveweight gains and wool growth in rapidly growing sheep eating a high-protein diet, but had little or no consistent effects with animals eating a lower quality, low-protein diet.


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.


1971 ◽  
Vol 51 (3) ◽  
pp. 721-727 ◽  
Author(s):  
L. J. FISHER ◽  
J. D. ERFLE ◽  
F. D. SAUER

Glutamate, succinate, propylene glycol, or glycerol were added to a basic concentrate at 3.3% of air-dry feed. Each concentrate was fed both ad libitum and in restricted amounts to four cows in early lactation. Dietary intake, milk yield and composition, molar proportions of rumen volatile fatty acids and blood glucose, ketones and plasma free fatty acids were used as criteria of effect of these supplements. Propylene glycol in the diet resulted in a lower intake of concentrate compared with glycerol (11.44 versus 14.30 kg/day) and significantly decreased (P < 0.05) rumen butyrate and plasma beta-hydroxybutyrate. Glutamate supplementation prevented the fall in milk fat content which occurred when the other three supplemented concentrates were fed ad libitum, and this effect may have been related to the constancy in the ratio of acetate to propionate in the rumen fluid.


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.


Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Aline M De Souza ◽  
Jonathas Almeida ◽  
Nataliia Shults ◽  
Hong Ji ◽  
Kathryn Sandberg

Severe caloric restriction (sCR) increases the risk for acute cardiovascular disease. Less understood are the long-term effects on cardiovascular disease risk after the sCR period has ended. We investigated the effects of sCR on heart structure and function months after refeeding (sCR-Refed). Female Fischer rats (3-months-old) were maintained on (CT) ad libitum or a 60% caloric restricted diet for 2 weeks. Thereafter, all rats received ad libitum chow for 3 months and they were analyzed by precision ultrasound to assess their heart function. After imaging, the animals were sacrificed and the hearts were subjected to ischemia-reperfusion (I/R) using a Langendorff preparation. After 2 weeks of sCR, rats lost 15% of their initial body weight (BW) [% (100*(Final-Initial/Initial)): CT, 1.5±0.8 vs sCR, -15.4±1.1; p<0.001;n=8]. After 3 months of refeeding, there was no detectable difference in BW between CT and sFR-Refed groups. Isolated hearts from the sCR-Refed rats exhibited worse myocardial pathology after I/R compared to CT rats. The parallel orientation of myofibers and striations normally present in cardiomyocytes was lost in sCR-Refed rats. Further analysis revealed uneven blood-filling of the microcirculatory vessels and prominent interstitial edema of the myocardium. Hearts from sCR-Refed rats had more atrophied cardiomyocytes than CT [Atrophied/Total (%): CT, 0.2±0.1 vs sCR-Refed, 50.6±1.1; p<0.001; n=5]. The number of arrhythmic events during a 30 min ischemic interval in isolated hearts doubled after 2 weeks on the sCR diet ( data not shown ) and remained doubled 3 months later [Arrhythmias (% of time): CT, 34±8 vs sCR-Refed, 68±9; p=0.02; n=8]. Ultrasound imaging showed no difference in stroke volume, coronary perfusion pressure and left ventricular mass. However, the thickness of the left ventricular posterior wall was significantly reduced in sCR-Refed rats [(mm): CT, 2.55 ±0.03 vs sCR-Refed, 2.10±0.04; p=0.002; n=4]. These findings indicate heart structure and function remained damaged months after the sCR period ended and BW was restored. These studies have adverse cardiovascular risk implications for who are subjected either voluntarily (crash diets) or involuntarily (very low food security) to periods of inadequate caloric intake.


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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