Restricted Feeding Treatments Research Articles

A 3-week post-weaning restricted feeding as alternative to an ad libitum antibiotic-medicated feed: Effects on growth, carcass and meat of rabbits differing in genotype and slaughter age

In this investigation, the impact of a 3-week post-weaning restricted feeding (RF) using an antibiotic-free feed, applied to rabbits from 36 to 56 days of age to preserve their health status as alternative to an ad libitum medicated feed with antibiotics (AMF), was verify in relation to rabbit genotype and slaughter age (SA). The RF and AMF treatments were compared evaluating their effects on feed intake, growth, mortality, carcass and meat quality of rabbits of two genotypes, Italian White purebred (IWP) and hybrid Hycole×IWP crossbred (HIWC), slaughtered at 78 or 92 days of age to obtain light or heavy carcasses. At 36 days of age, 256 weaned rabbits of both sexes were divided into 4 homogeneous groups based on feeding treatment (FT) and genotype: RF-IWP, RF-HIWC, AMF-IWP and AMF-HIWC. The RF treatment was performed offering to each rabbit 70, 80 and 90 g/day of feed in the 1st, 2nd and 3rd week. After the 3-week RF and AMF treatments, all rabbits received the same ad libitum antibiotic-free feeds until their slaughter. For each group, 24 rabbits were slaughtered, 12 at 78 days and 12 at 92 days. On the whole feed intake with RF was equal to 63% of that with AMF. Regardless of genotype, RF was associated with a lower feed intake until 78 days and a compensatory growth from 58 to 78 day, whereas from 79 to 92 days intake was not affected by FT and genotype. Despite the compensatory growth, the lower intake of restricted rabbits resulted in lower live weight at 78 and 92 days, but in more favourable feed conversion than with AMF. The growth potential allowed the crossbred rabbits to reach higher body and carcass weights with more efficient feed utilization. Mortality for enteropathies occurred mainly during the post-weaning phase from 36 to 56 days of age, with no difference due to FT, whereas HIWC rabbits showed a lower resistance to enteropathies. Heavier and fatter carcasses were obtained from AMF rabbits, at both SA, whereas the heavier HIWC carcasses showed a lower fat content than IWP ones. Carcass yield was influenced by FT and SA, being lower in RF rabbits and at earlier age. The restriction affected some colour indexes of meat and induced lower adiposity. Collagen was higher in meat of 92-day rabbits and in males, with no relationship to shear force. No particular effect of genotype emerged for meat quality. On the whole a 3-week post-weaning RF with antibiotic-free feed is confirmed to be a suitable method to replace an ad libitum feed containing antibiotics. In addition, RF appeared more suitable for rabbits of high-growth genotype slaughtered at 92 days which were more effective to recover the growth slowing due to the post-weaning feed restriction.

Effects of restricted nutrition and flushing on reproductive performance and metabolic profiles in sheep

The aim of this study was to assess the impact of dietary restriction during the lactation period on flushing performance and metabolic profiles in sheep. The treatments were performed in a 2 × 2 factorial arrangement with (i) adequate and restricted feeding treatment during lactation and (ii) flushing and control feeding treatment during mating season. Eighty-four Karacabey Merino ewes were divided into two groups for adequate energy (100%) and restricted (70%) at energy requirements for three months of lactation. Each group was also divided into two sub-groups based on flushing diet (AL-F, RL-F; 150%) or control diet (AL-C, RL-C; 100%) during the mating season. Live weight (LW), body condition score (BCS), serum metabolites and hormone concentrations, ovulation rate, estrus performance and lambing performance of ewes were observed. Data from this study showed that average difference (P < 0.001) of LW and BCS between groups were 5.45 kg and 0.54 respectively at the end of lactation. No significant effects of nutritional treatments (P > 0.05) were observed; the average fecundity, litter size and ovulation rates of ewes were 1.30±0.07, 1.44±0.06 and 1.53±0.07 respectively. The onset of estrus was earlier (P = 0.021) in RL-F ewes (7.0 d) than for AL-F, AL-C and RL-C ewes (11.0, 12.2 and 10.9 d respectively). Mean PRG concentration of ewes was lower (P = 0.011) in RL-C group than ewes in AL-C group (1.859±0.266 and 3.143±0.272 ng/ml respectively) at the ram introduction day. Serum biochemical variables blood urea nitrogen (BUN), glucose (GLUC), triglycerides (TGL) and very low density lipoprotein cholesterol (VLDL-CHOL) concentrations- decreased (P < 0.05), while non-esterified fatty acid (NEFA), cholesterol (CHOL), high density lipoprotein cholesterol (HDL-CHOL) and low density lipoprotein cholesterol (LDL-CHOL) concentrations increased (P < 0.05) in the restricted ewes compared with adequate ewes in the different months. In conclusion, in addition to BCS, blood total protein, BUN, GLUC, NEFA and CHOL can be recommended for testing flock metabolic profiles as specific blood metabolites. Flushing did not cause significant differences in reproductive parameters including the ovulation rate. However, the time required for onset of estrus was found to be significantly shorter after the flushing treatment in restricted group of animals.

Time-restricted feeding improves blood glucose and insulin sensitivity in overweight patients with type 2 diabetes: a randomised controlled trial

BackgroundTime-restricted feeding is an emerging dietary intervention that is becoming increasingly popular. There are, however, no randomised clinical trials of time-restricted feeding in overweight patients with type 2 diabetes. Here, we explored the effects of time-restricted feeding on glycaemic regulation and weight changes in overweight patients with type 2 diabetes over 12 weeks.MethodsOverweight adults with type 2 diabetes (n = 120) were randomised 1:1 to two diet groups: time-restricted feeding (n = 60) or control (n = 60). Sixty patients participated in a 10-h restricted feeding treatment program (ad libitum feeding from 8:00 to 18:00 h; fasting between 18:00 and 8:00 h) for 12 weeks.ResultsHaemoglobin A1c and body weight decreased in the time-restricted feeding group (− 1.54% ± 0.19 and − 2.98 ± 0.43 kg, respectively) relative to the control group over 12 weeks (p < 0.001). Homeostatic model assessment of β-cell function and insulin resistance changed in the time-restricted feeding group (0.73 ± 0.21, p = 0.005; − 0.51 ± 0.08, p = 0.02, respectively) compared with the control group. The medication effect score, SF-12 score, and the levels of triglycerides, total cholesterol and low-density lipoprotein cholesterol were improved in the time-restricted feeding group (− 0.66 ± 0.17, p = 0.006; 5.92 ± 1.38, p < 0.001; − 0.23 ± 0.08 mmol/L, p = 0.03; − 0.32 ± 0.07 mmol/L, p = 0.01; − 0.42 ± 0.13 mmol/L, p = 0.02, respectively) relative to the control group. High-density lipoprotein cholesterol was not significantly different between the two groups.ConclusionThese results suggest that 10-h restricted feeding improves blood glucose and insulin sensitivity, results in weight loss, reduces the necessary dosage of hypoglycaemic drugs and enhances quality of life. It can also offer cardiovascular benefits by reducing atherosclerotic lipid levels.Trial registration: This study was registered with the Chinese Clinical Trial Registry (ChiCTR-IPR-15006371).

Respon Produksi Telur Puyuh (Coturnix Coturnix Japonica) dengan Pembatasan Pakan secara Kualitatif dan Kuantitatif pada Saat Pertumbuhan

Production responses of laying quails fed with restricted feeding during rearing were measured in four trials. The research was an experimental observation applying Nested Complete Randomized Design. An experiment using 300 fourteen days old quails. The quails maintained under two feeding restriction programs feeding allotted to 2 dietary regimes, qualitative restricted feeding are Metabolize Energy (ME) R1= 2900 kcal/kg; R2 = 2800 kcal/kg and quantitative restricted feeding; P0 = 100% of ad libitum; P1 = 90% of ad libitum and P2 = 80% of ad libitum (n= 300). Each group (n= 50) has five replicates containing 10 birds each. Restricted feeding treatment is done for fourteen days old quail until its sexual maturity. After its sexual maturity, the feeding is given in ad libitum. Observation is conducted for the feed energy and protein consumption, and performance of egg production. The results of experiment indicate that the restricted feeding consequently significant influenced (P&lt;0.01) on the protein and energy feed consumption. Restricted feeding until 90% ad libitum showed similar egg production with ad libitum treatment and decrease in feed conversion at the early production. Metabolize energy of ration does not have a significant effect to egg production with the result that a feed restriction of 90% ad libitum and EM feed of 2900 Kcal / kg can be applied during the starter period.

Growth performance and whole-body composition of yellow catfish (Pelteobagrus fulvidracoRichardson) under feeding restriction

Fish growth is an important index in aquaculture practice. However, the effect of growth under restricted feeding on quality of fish grown to the same size remains poorly unknown. In this study, yellow catfish were reared by feeding them at three different feeding rates such as low (FR-L group), medium (FR-M group) and high (apparent satiation) ration levels for 82, 58 and 34 days to reach the same size, respectively. After this period, the growth performance, whole-body amino acid composition and fatty acid profile of the fish were evaluated. Feeding restriction led to significant decreases in specific growth rate and feed conversion efficiency. Significant increases in dry matter, protein and energy contents were observed in fish under both restricted feeding treatments. FR-L-treated fish had significantly lower whole-body essential amino acid contents, and significantly higher Ala and non-essential amino acid contents compared to fish fed to satiation. Fish in restricted feeding treatments had significantly higher n-3 PUFA and n-3/n-6 ratio compared to the fish fed to satiation. The present results indicate that from a quality perspective, there are certain advantages in improvement of whole-body composition and enrichment of n-3 PUFA associated with the restricted feeding of yellow catfish at slow growth rate.

To what extent is cannibalism genetically controlled in fish? A case study in juvenile hybrid catfish Silurus meridionalis–asotus and the progenitors

Abstract The occurrence of cannibalism in teleosts is well documented, yet the role and extent of genotype in determining this behavior have not been determined clearly. We investigated sibling cannibalism among juvenile hybrids of southern catfish (Silurus meridionalis) ♀ × Chinese catfish (Silurus asotus) ♂ and within the two parental species, under varying levels of (i) food availability (satiated with 200% body mass versus restricted feeding with 10% body mass) and (ii) size distribution (homogeneity in experiment 1 versus heterogeneity in experiment 2). Two types of cannibalism were documented during the experiments: type I (incomplete predation), and type II (complete swallow). For the hybrids, cannibalism rates in the satiated and restricted feeding treatments were 5.6 ± 4.2% and 15.6 ± 6.3%, respectively. Both measures were intermediate between those for the pure progenitors (0% and 13.4 ± 4.7% in S. meridionalis; 58.9 ± 12.3% and 72.5 ± 3.7% in S. asotus) in trials with uniformly-sized conspecifics (experiment 1). In contrast, cannibalism rates of hybrids with heterogeneous size distributions (experiment 2) in the satiated and restricted feeding treatments were 12.2 ± 11.9% and 86.7 ± 8.2% respectively, both of which were significantly higher than those in the two pure species (p

Photic and non‐photic entrainment on daily rhythm of locomotor activity in goats

We studied the photic (L/D cycle) and non-photic (restricted feeding) entrainment on the patterns of daily rhythm of total locomotor activity in goats. Six female Maltese goats were subjected to three different artificial L/D cycles: 12/12 L/D, 12/12 D/L and constant light. During the 12/12 L/D and 12/12 D/L, food and water were available ad libitum. During constant light, animals were subjected to a restricted feeding treatment. Total activity was recorded by means of an actigraphy-based data logger (Actiwatch-Mini). Our results showed that goats exhibited clear daily rhythms of activity in 12/12 L/D cycle, 12/12 D/L cycle and constant light, although they showed FAA prior the feeding time during the restricted feeding treatment. Goats were diurnal, with activity consistently beginning promptly following the onset of light. Even when the L/D cycle was delayed by 12 h on some days, to the daily rhythm was re-established. During the constant light period, the onset of activity was linked to the time of food administration. Our study evidences two factors for the rhythm of total locomotor activity in goats: light stimuli (photic) and food access (non photic), strongly coupled to permit organisms the adaptive temporal coordination of behaviour with stable and unstable environmental periodicities.

Effects of restricted feeding on circadian activity rhythms of sheep—A brief report

The purpose of the present experiment was to investigate the impact of timed restricted feeding on the behavioural circadian organization of sheep. For this purpose, total activities of sheep subjected both to 12-h light:12-h dark (12:12 LD) cycle and to periodic food-availability during the dark phase were recorded. When food was available ad libitum, sheep activity was entrained to the 12:12 LD cycle. During the restricted feeding treatment, most activity occurred in the dark. Activity in the dark was confined to the food restriction time and a food anticipatory activity was clearly present. Restricted feeding-entrained activity demonstrated the existence of both food entrainable and food anticipatory activities in sheep, a diurnal mammalian species. Our results represent the first study on the feeding entrainment of behaviour in a ruminant farm species. Furthermore, they allow to plan a deeper analysis concerning the synchronization of circadian oscillators by periodic food access in non-rodent mammals.

The effect of restricted feeding on growth hormone (GH) secretory patterns in genetically lean and fat wether lambs

AbstractThe aim of this work was to determine whether developmental changes in growth hormone (GH) secretory patterns and carcass composition were influenced by nutrition and genotype in sheep. Four-month-old wether lambs from lean (low backfat), fat (high backfat) and control selection lines were nutritionally restricted to maintain a 28 kg live weight or given food ad libitum for 24 weeks. Plasma concentrations of GH and insulin-like growth factor 1 (IGF-1) were measured at predetermined times and carcass composition of the animals determined at the end of the trial.From week 3 on, restrictions in dry matter (DM) intake were observed as the ad libitum treatment group had a significantly greater intake than the restricted treatment group (7·70 v. 5·80 kg DM per week, s.e.d. = 0·81). Differences in live weight between the feeding treatments were significant (P &lt; 0·05) at week 9. The restricted feeding regime was associated with significant reductions in plasma levels of IGF-1 but had no effect (P &gt; 0·05) on carcass weight-adjusted carcass fat proportion at the close of the trial. The effect of food restriction on GH secretory patterns was variable. Although there was initially a suppression in mean plasma GH, there was subsequently significantly higher mean plasma GH in the restricted feeding treatment. Periodogram analysis indicated that both the absolute levels of GH and the GH secretory pattern were altered by restricted feeding. In all animals, mean and basal GH concentrations, as well as the frequency and amplitude of pulses, declined from February to March and then increased from May to July (P &lt; 0·001).DM intake and live weight did not differ (P &gt; 0·05) between genotypes, however the fat genotype had greater carcass fatness than lean or control genotypes (P &lt; 0·01). There were no consistent differences between genotypes in plasma IGF-1 concentrations. In the ad libitum treatment, the lean and control genotypes had higher plasma GH levels than the f at genotype but the pattern of GH release did not vary. Under restricted feeding, both the pattern and the level of plasma GH varied between genotypes.It is concluded that the developmental change in GH secretory patterns is affected by nutrition but not in a consistent manner. Although restricted feeding resulted in higher mean plasma GH concentrations later in the trial, this did not result in a change in carcass composition. The biological cues which lead to increased fat deposition in older lambs need further study but plasma GH levels may not he an important mechanism in this process.

Validation of a growth simulation model for catfish

Computer simulations can help in understanding how a fish population responds to a series of decision variables and external factors, thus contributing to better control of the production system. This paper describes a model which has been expanded to deal more explicitly with the effects of water quality and stocking density. The purpose of this paper is to compare simulated model results with actual pond trial results to determine the accuracy of the simulation and to assess the need and ability to make adjustments to the model. Data from a pond experiment using satiation and restricted feeding regimes at 26, 32, and 38% feed protein level were used to validate and adjust the parameters of the simulation model. Actual feeding, temperature, and dissolved oxygen (DO) were incorporated into the simulation, and feed consumption and final weight were compared to simulated feed consumption and final weight. After adjustments for water quality, stocking density, and growth parameters, simulated results ranged from 0 to 9% of pond experiment results. Simulated results of restricted feeding treatments were within 5% of pond results.

The performance of weaned lambs offered diets containing different proportions of fresh perennial ryegrass and white clover

ABSTRACTSix weaned lambs were allocated to each of eight restricted feeding treatments with 1·00, 0·85, 0·71, 0·57, 0·43, 0·29, 0·15 or 0 of the diet as perennial ryegrass and the remainder as white clover, and to one ad libitum treatment with perennial ryegrass offered alone. A further six lambs were offered white clover ad libitum starting on day 15. Lambs on the restricted treatments received the same daily allowance of dry matter relative to live weight, adjusted at weekly intervals to allow the greatest possible intake without any rejection of herbage. Fresh cut herbage was offered daily and measurements were made over 69 days. Twelve additional lambs were slaughtered at the beginning of the experiment, and all lambs on restricted treatments were slaughtered at the end.Increasing the proportion of clover in the diet increased the intake of nitrogen, empty-body-weight gain, carcass weight gain and nitrogen retention. When herbage was offered ad libitum, lambs ate significantly more clover than ryegrass and gained weight faster.The weight of gut contents decreased as the proportion of clover in the diet increased. The digestibility of the organic matter, energy and nitrogen of the mixed diets simply reflected the digestibilities of the two herbages and their proportions in the mixture.

The performance of lactating ewes offered diets containing different proportions of fresh perennial ryegrass and white clover

ABSTRACTSix ewes with twin lambs were allocated to each of six restricted feeding treatments with 10, 0·8, 0·6, 0·4, 0·2 or 0 of the diet as perennial ryegrass and the remainder as white clover, and to two treatments with either perennial ryegrass or white clover offered alone ad libitum. Fresh herbage was offered and measurements were made over 8 weeks, with the exception of the ad libitum clover treatment which was terminated after 5 weeks. All lambs were allowed access to clover from 14 days of age. Digestibilities of the herbages were measured during four periods in the experiment.Increasing the proportion of clover in the diet significantly increased the intake of nitrogen by the ewes and the growth rate of their lambs, but had no effect on the live-weight changes of ewes on the restricted treatments. When there was no restriction of intake, ewes ate slightly more clover than ryegrass and lost less weight, but mean daily live-weight gains of their lambs over the first 5 weeks did not differ significantly (0·30 and 0·34 kg for ryegrass and clover, respectively).When ryegrass and clover were eaten alone or together their organic matter digestibilities (OMD) did not change, although OMD declined with increasing level of intake.Initial body condition of the ewes had a significant effect on the decline of ewe live weight and body condition during lactation, and on lamb live-weight gain

The influence of dietary protein and level of feeding on the growth performance and carcass characteristics of entire and castrated male pigs

ABSTRACT1. Three isocaloric diets containing 170, 210 or 231 g crude protein per kg were given at two levels, and offered ad libitum to entire and castrated male pigs growing from 20 to 70 kg live weight.2. Between 20 and 45 kg, growth rate improved with each increase in level of feeding (P &lt; 005) and, on the ad libitum treatment the food intake and growth performance of both entire and castrated pigs were similar. On the restricted feeding treatments the growth performance of entire, but not of castrated pigs, improved when dietary protein was raised from 170 to 210g/kg (P &lt; 005).3. During the live-weight periods 45 to 70 and 20 to 70kg, raising food intake improved growth rate (P &lt; 005) but increased the food conversion ratio and carcass fat measurements at 70 kg (P &lt; 0·05). However, food conversion ratio and the majority of carcass characteristics of entire pigs fed ad libitum were equivalent to those of castrated pigs fed at the lowest level.4. Dietary protein level had no significant effect on growth performance from 20 to 70 kg or on carcass fat measurements at the latter weight. However, each increase in dietary protein in the live-weight period 45 to 70 kg depressed the performance of castrated pigs (P &lt; 0·05) while that of entire pigs was reduced when the protein level of the diet was raised from 210 to 231 g/kg.

Performance of Red × Rock Sex-Linked Hens Subjected to Restricted Feeding During the Laying Period

Two trials were conducted to compare the influence of various levels of feed during the laying period on the performance of the layers. Four feeding levels were utilized in each trial. One group served as the full-fed control and the other three groups were limited to 95, 90 or 85 percent of the amount consumed by the control group the previous week. The restricted feeding treatments were initiated at 22 and 32 weeks of age in Trials 1 and 2, respectively. At 22 weeks the birds were just beginning to lay while at 32 weeks they had reached peak production.A linear and significant decrease in egg production occurred with the feed restriction practiced, but the reduced feed consumption of the groups was sufficient to compensate for the reduced egg production since the feed efficiency of these groups was numerically superior in Trial 1 and significantly superior to the full-fed group in the second trial.The feed restriction utilized in this study reduced average body and egg weights, but treatment differences were not detected in shell thickness or Haugh units.