An experiment was conducted to investigate the effect of different feed Restriction on broiler performance and carcass quality during second/third week of life. A 2´3´2 factorial experiment added a control was used, that the strain of broilers, severity and duration of feed restriction were considered as the main effects. Every treatment had three replicate. Totally in this experiment were considered 840 broilers unsexing Arian and Ross broilers (420 chicks of every strains). The feed restriction with 0, 30, 40 and 50% severities was begun at 8d of age, and depending on restriction duration (7 or 14d) continued until 14 or 21d of age. Then broilers fed to 56d of age ad-libitum.The varied feeding restrictions, had no effect on final body weight Arian broilers, but in Ross broilers with 30% less of ad-libitum in 7 or 14 days Resulted in a increasing body weight (P<0.05) comparation of the control Ross broilers. The varied treatments of feeding restriction had no effect on feed conversation ratio in two strains. Carcass characteristics in two strains were similar to control chicks. Abdominal fat percent decreased in the treatment of 30% feed restriction for 14d in the Ross broilers (P<0.05), and in the other treatments didn't change.

In a factorial experiment the effect of physical feed restriction on two commercial breeds of broiler (Ross vs Arian), two sexes, two initial body weights and three level of feed restriction (0, 15, 30%) were investigated. The restricted period was from 7 to 14 days of Wage. There was no significant difference in total body weight between two commercial breeds in any of treatments (0, 15, 30% restriction). feed restriction did not change body weight in Arian chicks, whereas in Ross chicks total body weight of 30% restriction treatment were. Significantly less than 0% restriction chicks (p<0.05). Feed conversion did not show any significant difference between two commercial breeds in total period after restriction the response birds to Feed restriction was better than those of female. The comparison of the performance of heavy and light weight groups in the response of feed restriction showed that the total body weight of heavy birds in two level of restriction (15, 30%) had no significant difference with the control birds, wherease light weight group birds in two level of restriction (15, 30%) were not able to show) compensatory growth until 56 days of age.

Eighteen crossbred Swifter (Flemish ♀ X Texel ♂) male lambs, born in March 1997 and weaned at the age of approximately 3 months, were used to quantify effects of feed quality restriction and realimentation on changes in energy and nitrogen metabolism. The ration consisted of grass straw (17 MJ of GE and 46 g CP per kg DM) on an ad libitum basis and 35 g.kg-75d-1 mixed concentrates (16.5 MJ of GE and 173 g CP per kg DM). At the age of approximately 3.5 months, the animals were randomly divided into six blocks, based on live weight, according to a randomized complete block design. Within each block, the animals were randomly assigned to two restricted treatments (R1 and R2) and a control treatment. Treatments R1 and R2 were subjected to feed quality restriction by withholding concentrate for 3 and 4.5 months, respectively. A modified linear model was developed to study the effects of restriction and realimentation. The comparison between treatments was made by analyzing the data of R1 and R2 animals as deviations from the control animal in each block. During the restriction period, restricted animals lost weight and showed a negative EB and NB, whereas their intake from low-quality roughage significantly (P < 0.001) increased. After realimentation, the R1 and R2 animals grew significantly (P < 0.001) faster than the C animals. The realimented animals persisted in ingesting more (P < 0.001) low-quality roughage and their EB and NB were greater (P < 0.001) than those of C animals. The R2 animals needed a longer period of realimentation because of a longer period of restriction. The expression of compensatory growth was mainly related to a sustained higher (P < 0.001) grass straw (low-quality roughage) intake during realimentation periods, and greater (P < 0.001) efficiency of metabolizable energy intake. The maintenance requirement of realimented animals was lower (P < 0.001) only during the initial stages of realimentation compared with controls.

Forty eight 8-month-old male goats were divided into three groups. In each group, eight goats were feed restricted for 45, 60 or 75 days, and eight goats served as the control. Restricted groups were fed with a maintenance ration, and the control goats were fed with a ration supporting 50 g of daily weight gain. At the end of restriction period, the restricted goats were offered the same ration as the control goats. When the average weight of the 75-day restricted goats approached that of the control, the goats were slaughtered. The carcass, several organs, carcass cuts and dissectible (trimmed) fat were weighed, and the chemical composition of the meat was determined. Feed restriction decreased the proportion in live weight of the dissectible fat, internal fat, liver and testis weight, meat dry matter and fat content, but the proportion of intestinal and splenic weights, and meat protein content were increased. Re-alimentation after 75 days of restriction was associated with a greater daily gain and less internal fat. Other measurements were not different from the control. Data showed that 8-month-old native kids are capable of considerable compensatory growth after 75 days of feed restriction without any deleterious effect on carcass co mposition.

This research is conducted to study effect of three feed restriction levels on growth and performance of production trails of Arian parent stock. The feeding level recommended in the Arian management guide considered as the standard treatment, and three, six, and nine percent less than the management guide levels were as three other experimental treatments. The live weight at 20 and 60 weeks and amount of feed consumed per egg produced by the birds of three restriction treatments were less than the standard level. The difference of egg production to 60 weeks of age and hatchability in four treatments was small and statistically not significant (p>0.05).

This experiment was carried out to evaluate the effect of Probiotic supplementation and feed restriction on growth response in broiler chickens. For this purpose, 336 male broiler chickens of Ross 308 were used. After housing, broilers allocated to experimental pens in a completely randomized design with factorial 2×3 arrangement. First and second groups considered as positive control group with supplemented probiotic or negative control group without supplemented probiotic, respectively, that birds in these groups had free access to feed. Four other groups used a diet same as control groups, but from 7 to 35 days of age subjected to 4 or 8 hours feed restriction. Four replicates of 14 birds were allocated to each experimental group. Results of the experiment indicated the birds subjected to feed restriction had significantly lower feed intake and body weight gain during the first week of rearing compared to those fed ad-libitum. There was no significant difference between experimental treatments for feed intake. In the group of without probiotic, feed restriction for 8 hours led to reduce weight gain and carcass weight compare to those fed ad-libitum. But when use probiotic, weight gain and carcass weight was similar to those birds were fed ad-libitum. The results of this experiment showed that the use of probiotic can improve the performance of broilers under severe feed restriction.

An experiment was conducted to determine growth and carcass characteristics of male broilers subjected to early feed restriction. Restricted birds were fed equivalent to 1/5*BW 0.67  Kcal/day/bird between days7 and 14.Ondays0to 7 and 14 to 56, all chickens received feed ad-libitum. Diets of feed-restricted birds were supplemented with 15%higher methionin and cystine recommended by NRC (1994) during refeeding in starter and grower periods.No significant differences were observed for liver, breast, heart, carcass and liver fat between early restricted birds and ad-libitum control at 56 days of age. Body weight for restricted broilers were significantly (P<0.05) lower than that of controls in 56 days. However, restricted broilers had significantly lower total-feed to gain ratio than the unrestricted control. Restricted broilers that received diets high in total sulfur amino acids in starter and grower periods had significantly lower abdominal fat pad than control birds.