Severity Of Feed Restriction Research Articles

Effects of quantitative feed restriction on the performance of broiler chickens

A study was conducted to evaluate the effect of quantitative feed restriction on the performance and the production cost of broiler chickens. A total of 120, Indian River, day-old broiler chicks were randomly allocated into four dietary treatment groups such as 100% diet as control treatment and 90%, 80% and 70% diets, in floor pens. All treatments were replicated thrice with 10 birds each in a Completely Randomized Design. Broiler chickens were fed broiler starter diet from day 1 to day 21 and broiler finisher diet from day 22 to day 42. The results revealed that the body weight gain in the birds fed with 90% diet was significantly higher than those of control diet during finisher and overall phases and vice-versa during starter period. The feed intakes of birds were significantly decreased with the severity of feed restriction during all periods. However, significantly the lowest overall feed conversion ratio was reported in the birds fed with 70% diet. Furthermore, higher relative liver and lung weights were observed in the control treatment while they had lower relative heart weight. The spleen was significantly increased in the birds fed with 90% diet. It could be concluded that giving 90% of the recommended diet to the broiler chickens increases growth, immunity and income.

The effect of different degrees of feed restriction on heat shock protein 70, acute phase proteins, and other blood parameters in female broiler breeders

The aim of the current study was to determine the physiological response to feed restriction in female broiler breeders using a range of conventional and novel indicators. One hundred female breeders were subjected to one of five feeding regimens from d 28 to 42 as follows (i) ad libitum feeding (AL), (ii-v) 75, 60, 45, and 30% of ad libitum feed intake. Blood heterophil to lymphocyte ratio (HLR), and plasma circulating corticosterone (CORT), ghrelin (GHR), serotonin (5-HT), and dopamine (DA) and serum acute phase proteins (APP) concentrations together with brain heat shock protein (HSP) 70 level were measured. The results showed a significant effect of feed restriction on blood HLR and plasma CORT, GHR, 5-HT, DA, and brain HSP 70 levels. However, feed restriction had no effect on serum levels of APP of alpha-1 acid glycoprotein, ovotransferin, and ceruloplasmin. Serum levels of 5-HT and GHR varied curvilinearly with the feed restriction level. The relationship between brain HSP 70 and level of feed restriction was negligible. However, significant linear relationships between HLR, CORT, DA, and the level of feed restriction were noted. Thus, these 3 parameters appear to represent a straight forward relation with severity of feed restriction.

Effects of Feed Restriction on the Nucleolar Structure and Function in Lymphocytes

Since malnutrition leads to adverse effects of several drugs on haemopoiesis and blood morphology, we tested if malnutrition itself could affect the nucleolar structure and function in rat lymphocytes. We report changes in the proportion of different nucleolar types that were dependent on the severity of feed restriction. The observed changes resemble those seen with cytostatics suggesting a possible link between feed restriction and haemotoxicity.

The effect of the length and severity of feed restriction on weight, carcass measurements and body composition of goats

SUMMARYTwo experiments were done in Mexico (1992–93) to determine the response of goats to different periods of feed restriction on liveweight, organ weights and tissue composition. In each, the weight, body condition and daily dry matter intake (DM1) of two groups of 12 female, adult, non-lactating, non-pregnant, Nubian crossbred goats were recorded for 7 weeks (stabilization period; SP), to allow the animals to reach and maintain their liveweight and body condition. At the end of the SP the animals in Expt 1 (RP1) were feed restricted for 18 weeks and for 36 weeks in Expt 2 (RP2). Animals were divided into three groups receiving either 100 (FL1), 80 (FL2) or 60% (FL3) of the levels of DM1 previously observed. At the end of each experimental period all animals were slaughtered, carcass weights were recorded and viscerae were weighed.A sample of the soft tissues was chemically analysed. There were no significant changes in body condition in either experiment (P > 0·05). None of the feeding levels had an effect on carcass weight or the chemical composition of soft tissues (P > 0·05). Liver weights (as a proportion of slaughter weight) were significantly different among goats fed at different feeding levels in both experiments. The results of this study show the adaptation capacity of adult goats to medium and long term malnutrition, and the importance of the liver as a source for the generation of energy and for sustaining protein turnover. This could be especially important for goats grazing in arid and semiarid zones where dry periods can last for months and feed availability is therefore sometimes limited.

Effects of Different Methods and Severity of Growing Period Feed Restriction on Growth and Laying Performance of White Leghorns

Two experiments were conducted to study the effects of different methods of feed restriction and severity of feed restriction during the growing period on pullet growth and laying performance of White Leghorns. In Experiment 1, ad libitum feeding of the low protein diet (supplemented with amino acids) was the only treatment among four feed restriction treatments that did not significantly (P>.05) influence growing period feed consumption and body weight gain. The smallest body weight gain was obtained among birds subjected to the daily restrictive feeding (DRF) treatment. Ad libitum feeding of the low energy diet resulted in a significantly (P<.05) poorer growing period feed efficiency than any other treatment. Both energy and protein utilization efficiencies for body weight gain were significantly (P<.05) hindered by the skip feeding treatment. Although DRF birds consistently had higher egg production from 36 to 76 weeks of age than birds in any other group, overall average percent hen-day egg production from 20 to 76 weeks of age was not significantly (P>.05) improved by the DRF treatment. Also, in Experiment 2, various levels of DRF during the growing period did not significantly (P>.05) improve average percent hen-day egg production. Laying house mortality, feed efficiency, and egg weight were not significantly (P>.05) different among treatments (Experiments 1 and 2). Results of these experiments indicate that DRF was the most effective method of controlling growth rate and that neither method of feed restriction nor severity of feed restriction during the growing period significantly (P>.05) improved laying performance.

Effect of Duration of Feed Restriction on the Laying House Performance of Confinement Reared Pullets

INTRODUCTIONRESTRICTING the feed intake of growing pullets reduces body weight and delays sexual maturity (Gowe et al., 1960). The degree to which this occurs depends on the length and severity of feed restriction. There is little evidence of the age at which restriction should be started or stopped, or the length of time growing chickens should be restricted to give the maximum response. Fuller and Dunahoo (1962) restricted the feed intake of growing chickens from 6–12, 6–18, 6–24, and 12–24 weeks of age, and Gardiner and MacIntyre (1962) restricted the feed intake from 5, 9, 13, and 17 weeks of age up to 22 weeks in one experiment and from 9–17, 13–17, 13–21, and 17–21 weeks of age in another experiment. In all cases there were direct relationships between duration or degree of restriction and body weight at the end of…