Effect Of Quantitative Feed Restriction Research Articles

A comparative study on the effect of quantitative feed restriction in males and females of broiler chickens, rabbits and nutrias. II. Meat quality

The objective of the study was to evaluate the effects of feed restriction and sex on the physical, chemical and histochemical parameters of meat quality in chickens, rabbits and nutrias. Feed restriction was applied at a rate of 70% ad libitum from 14 to 21 days of age in chickens, 70% ad libitum from 42 to 49 days of age in rabbits, and 70% ad libitum from 12 to 15 weeks of age in nutrias. Animals were fed ad libitum prior to and following restriction. The results showed stronger effects of feed restriction, sex, and their interaction on the meat quality of broiler chickens than in rabbits and nutrias. The effect of feed restriction, sex and their interaction were mainly observed in the nutritional value of meat, while physical measurements of meat were negligibly affected. The interaction between feed restriction and sex affected the cross-sectional area of muscle fibre only in rabbits and nutrias. The data indicated the relationships between compensatory growth, muscle fibre distribution, and nutritional value of meat.

A comparative study on the effect of quantitative feed restriction in males and females of broiler chickens, rabbits and nutrias. I. Performance and carcass composition

The aim of the study was to compare the effects of feed restriction on the growth performance and carcass composition of chicken, rabbit and nutria males and females. Feed restriction was applied at a rate of 70% ad libitum from 14 to 21 days of age in chickens, 70% ad libitum from 42 to 49 days of age in rabbits, and 70% ad libitum from 12 to 15 weeks of age in nutrias. Animals were fed ad libitum prior to and following restriction. Carcass composition was evaluated at common slaughter ages, i.e., 31 days in chickens, 70 days in rabbits, and eight months in nutrias. The results showed stronger effects of feed restriction, sex, and their interaction in broiler chickens than in rabbits and nutrias. In chickens, feed restriction increased the sex differences in final body weight, which were associated with interaction of feed restriction and sex (P = 0.009). Feed restriction as a fixed factor significantly affected growth and feed conversion in chickens and it was with no effect in rabbits and nutrias. The effect of feed restriction on carcass composition was negligible in all selected species. With respect to sex, significant differences were observed in chickens in final body weight, daily weight gain, dressing out percentage and breast percentage, in rabbits in loin percentage, and in nutrias in growth and perirenal fat percentage. Results of the study indicated that interactions of feed restriction and sex in growth might be associated with a short realimentation period.

Effect of quantitative feed restriction on the performance, organ development and cecal activity of growing nutrias (Myocastor coypus)

Feed restriction in young growing animals has been used to improve the performance of chickens, rabbits, turkeys, pigs and lambs. However, no study has been published on nutrias. The aim of this study is focused on assessing the effect of quantitative feed restriction on the fattening results of male and female nutrias and their internal organ development and cecal fermentation parameters up to 32 weeks of age. In the first experiment, feed restriction was applied for 14 days from 11th to 12th week of age and nutrias received 75% of ad libitum feeding (AL). A 4-week restriction, from 13th to 16th week of age, was used in the second experiment; males received 75 g of feed daily, and females received 72 g. In both experiments, restricted nutrias compensated for growth and reached a final weight similar to that of the ad libitum fed animals. In the second experiment, 4 weeks of feed restriction significantly increased the length of the small intestine and the length of the cecum, with a higher effect in the males than in the females. The dry matter of the cecum (P < 0.001), and butyrate (P < 0.001) were lower, whereas propionate (P = 0.003) was higher in the restricted animals. Regarding sex, propionate (P = 0.025) was higher and butyrate (P = 0.021 was lower in the males. The results of the present study indicate moderate effect of short feed restriction on performance and morphological changes in the gastrointestinal tract. The 4 weeks restriction, in males, impaired growth; however, compensatory growth occurred in the second half of fattening period, which indicates that males need longer time for live weight compensation. More research is required to elucidate the effect of feeding regime on the performance, digestive morphology and physiology of nutrias.

The effect of feed restriction, sex and age on the carcass composition and meat quality of nutrias (Myocastor coypus)

The objective of the study was to evaluate the effect of quantitative feed restriction on the carcass composition and physical, chemical, histochemical and sensory properties of meat from male and female nutria at the end of the feed restriction and fattening period. In the experiment, from two to eight months of age, males and females were divided into two groups: one group was fed ad libitum throughout the experiment, and the second group was restricted to two weeks (from 11 to 12 weeks of age). The restricted nutrias received 75% ad libitum feeding. The significant interaction among feed restriction, sex and age was revealed only in the cross-sectional area of all muscle fiber types. Age was the main factor affecting carcass composition and meat quality characteristics. Sex-related differences in carcass composition and some sensory attributes and feed restriction-related differences in carcass composition were observed.

EFFECT OF FEED RESTRICTION ON BOILER PERFORMANCE: CONFORMATION TRAITS AND ISOMETRY OF GROWN

The effect of quantitative feed restriction on broiler conformation traits, namely breast width, keel length, thigh width and shank length, and on growth of these linear body structures relative to overall body growth was investigated using two hundred and forty Cobb broiler chicks. Three levels of restriction, namely 5, 10 and 15% of ad libitum intake, were randomly imposed on different groups. Birds restricted-fed in the starter phase of growth were full-fed in the finisher phase, and vice versa. Conformation traits, particularly breast width, keel length- and thigh diameter, were generally more adversely affected by feed restriction in the starter than in the finisher phase. However, there was evidence of compensatory growth for all parameters, except the breast. Feed restriction did not significantly affect the relative growth pattern of the breast, keel and thigh, which was positively allometric, Relative growth of the shank was, however, affected by different levels of restriction.

Research Note: The effects of genotype, sex, and feeding regime on performance, carcasses characteristic, and microbiota in chickens

The aim of the present study was to evaluate the effects of quantitative feed restriction (FR) in fast-, medium-, and slow-growing meat-type male and female chickens on their growth, feed consumption, economic efficiency, carcass composition, and gastrointestinal microbiota. In the experiment, fast-growing Ross 308, medium-growing Hubbard JA 757 and slow-growing ISA Dual chickens of both sexes were exposed to quantitative FR between 14 and 21 d of age. During the FR, restricted chickens received 70% of the amount of feed consumed by the ad libitum (AL) group. Live weight at the end of the experiment was affected by genotype (P < 0.001), sex (P < 0.001), feeding regime (P < 0.001), and their interaction (P < 0.001). The highest final weight was in AL and FR ISA Dual males and the lowest was in AL and FR females of the same genotype. A similar tendency was observed in daily weight gain and feed intake. Carcass traits were predominantly affected by genotype. However, interactions of genotype, sex, and feeding regime were observed in thigh (P < 0.001) and abdominal fat (P < 0.001) proportions. Concerning gastrointestinal microbiota, only Escherichia coli was affected by genotype. Feed restriction in slow-growing dual-purpose chickens might improve economic potential; however, further research is needed to reveal the involvement of variable processes, which are unclear and affect production.

Impact of restricting feed and probiotic supplementation on growth performance, mortality and carcass traits of meat-type quails.

The objective of this study was to evaluate the effects of quantitative feed restriction, along with dietary supplementation with a probiotic blend (Protexin) as a natural growth promoter, on the performance, water consumption, mortality rate and carcass traits of meat-type quails. A total of 250 1-day unsexed quails were randomly allocated to five equal groups in a completely randomized design. The first group (A) fed a basal diet without any restriction (24hr/day); the second group (B1) fed the basal diet for 20hr/day; the third group (B2) fed the basal diet enriched with probiotic (0.1g/kg diet) for 20hr/day; the fourth group (C1) fed the basal diet for 16hr/day; and the fifth group (C2) fed the basal diet enriched with probiotic (0.1g/kg diet) for 16hr/day. Birds were fed ad-libitum from 0-14days of age, and then the feed restriction regimes started from 14 till 28days of age. Results showed that quails in the control-group consumed more feed and water than the other treatment groups (p<.01), however their body weights did not differ (p>.05) compared with the other treated groups. The best feed conversion values were achieved in quails supplemented with probiotic blend (B2 and C2) in comparison with the other groups (p<.01). Feeding probiotic had a positive effect on bird health which reduced the mortality rate. Further, mortality rate was significantly reduced (p<.05) by feed restriction, with or without probiotic supplementation. No carcass parameters were significantly affected (p>.05) by treatments. Our results show that quail could be reared under a feed restriction system, for 4-8hr daily, along with dietary supplementation of probiotic as growth promoter for better growth performance.

Nutritional efficiency of feed-restricted F1 Holstein/Zebu cows in early lactation

The quantitative feed restriction of lactating cows has been used in intensive production systems as a strategy to reduce production costs. However, the effects of this restriction in F1 Holstein/Zebu cows are unclear. The objective of this work was to evaluate the effect of quantitative feed restriction on nutrient intake and digestibility, nitrogen balance, feed efficiency, feed behavior, and productive performance in F1 Holstein/Zebu cows during early lactation. Sixty F1 Holstein × Zebu cows were used at the stage of initial lactation (50 ± 13days of lactation), and they had an initial body weight (BW) of 482 ± 43kg. The experimental arrangement adopted was a completely randomized design, with five feed restriction levels (3.39, 2.75, 2.50, 2.25, and 2.00% of BW) and 12 cows in each treatment group. In the short term (63days), there were reductions of 45.9% and 47.2% in dry matter intake (P < 0.01) and crude protein (P < 0.01), respectively, when the diet supply was limited from 3.39% BW to 2.00% of BW. There were declines in intake of ether extract (P < 0.01) and nonfibrous carbohydrates (P < 0.01), but there was no change in daily milk production (P = 0.44) nor the daily milk production corrected to 3.5% fat (P = 0.12); the averages were 14.01kg/day and 13.25kg/day, respectively. Considering the lower body weight loss, feed restriction is recommended up to 2.5% of the BW.

Effect of quantitative feed restriction and realimentation on growth, carcass traits and economics in stallfed Barbari kids

Four months old 24 Barbari kids were allotted randomly to ad lib. feeding up to 12 months age, 20% (mild) and 40% (moderate) feed restriction at 5th and 6th months (MMFR) and 20, 40, 60% (severe) feed restriction (MMSFR) each of 20 days duration during 5th and 6th months followed by realimentation up to 12 months age. At the end of realimentation, 4 kids from three groups were slaughtered and carcass traits evaluated along with its economics. The kids did not differ significantly in growth and carcass traits. Body weight change indicated that the occurrence of compensatory growth in feed restricted kids proportional to body weight loss occurred during restriction. The feed cost/kg gain was lowest in MMSFR kids followed by ad lib. fed and MMFR kids. Therefore, stallfed Barbari kids shall easily be maintained up to 60% lower feed for 60 days thereby increasing the profit of stallfed kid rearing.

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.

Effects of quantitative feed restriction and sex on carcass traits, meat quality and meat lipid profile of Morada Nova lambs

BackgroundAn experiment was conducted to evaluate the effects of feed restriction (FR) and sex on the quantitative and qualitative carcass traits of Morada Nova lambs. Thirty-five animals with an initial body weight of 14.5 ± 0.89 kg and age of 120 d were used in a completely randomized study with a 3 × 3 factorial scheme consisting of three sexes (11 entire males, 12 castrated males and 12 females) and three levels of feeding (ad libitum – AL and 30% and 60% FR).ResultsEntire males presented greater hot and cold carcass weights (P < 0.05), followed by castrated males and females. However, the hot carcass yield was higher for females and castrated males than for entire males. Luminosity values were influenced (P < 0.05) by sex, with entire males presenting higher values than castrated males and females. Females showed higher (P < 0.05) concentrations of linoleic acid and arachidonic acid in the meat of the longissimus thoracis muscle. The meat of animals submitted to AL intake and 30% FR showed similar (P > 0.05) concentrations, and the concentrations of palmitic acid, palmitoleic acid, stearic acid, oleic acid and conjugated linoleic acid were higher (P < 0.05) than those of animals with 60% FR. The meat of females had a higher ω6/ω3 ratio and lower h/H ratio, and females had greater levels of feeding. The meat of animals on the 60% FR diet had a greater ω6/ω3 ratio, lower h/H ratio and lower concentration of desirable fatty acids in addition to a greater atherogenicity index (AI) and thrombogenicity index (TI).ConclusionLambs of different sexes had carcasses with different quantitative traits without total influence on the chemical and physical meat characteristics. The lipid profile of the meat was less favorable to consumer health when the animals were female or submitted to 60% feed restriction.

The effect of quantitative feed restriction on allometric growth in broilers

Feed restriction in broilers is aimed at preventing metabolic disorders, increasing feed efficiency, or manipulating carcass conformation. The purpose of the current study was to investigate the effects of modest graded levels feed restriction during the second and third wk of life. Mixed-sex chickens were raised in pens with 4 replications per treatment to 35 d of age. Chickens were fed ad libitum throughout the trial, or 90, 80, or 70% of expected ad libitum feed intake during the second wk of life, or 95, 90, 85, or 80% of expected ad libitum feed intake during the third wk of life. Feed intake, BW, ADG, and feed conversion ratio (FCR) were measured and weekly dissections were conducted to characterize allometric growth of the breast muscle, legs, abdominal fat pad, liver, gastro-intestinal tract (GIT), and heart. Feeding 70% of ad libitum during wk 2 and 80% during wk 3 reduced ADG during the restriction period and reduced BW at the end of the restriction period, but chickens exhibited complete compensatory growth within one wk after the restriction period. No significant effects of restriction treatment were found on BW, FCR, fat pad, empty GIT, breast muscle, heart, legs, and liver weight at d 35, but allometric growth curve for breast muscle was lower in birds fed 80 and 85% of ad libitum during wk 3, and for birds fed 70% of ad libitum in wk 2. Allometric growth curves for all body parts were different between males and females, except for the liver. Females had higher relative fat pad, breast muscle, and liver weight and a lower GIT and heart and leg weight compared with males at d 35. Feed restriction could differentially affect males and females. This study showed that feeding 70% of ad libitum in wk 2 might be beneficial to reduce fat pad, but later feed restriction in wk 3 may reduce breast muscle weight at broiler processing age.

Effect of Quantitative Feed Restriction on Some Physiological Parameters of Japanese Quails

The aim of this study to evaluate the effect of quantitative feed restriction on some physiological parameters of Japanese Quail. A total of 160 unsexed Japanese Quail aged 21 days were used for this study, divided randomly to four groups, each has four replicates as follows; control group (T1) feed ad libitum, treatment (T2), treatment (T3) and treatment (T4), 10%, 20% and 30% feed restriction of the control group value respectively for two weeks. On day 35 all the groups returned to the free feed ad libitum till the end of the treatment.Variables measured includes; productive, hematological and biochemical parameters.The results shows significant (p≤0.05) effect of feed restriction as the body weight decreased in the 4th, 5th and 6th week, on the other hand the weekly body weight increase, decreased significantly (p≤0.05) in the 4th week and increased significantly (p≤0.05) in the 6th week. The amount of feed taken in 4th, 5th decrease significantly (p≤0.05) and increased significantly (p≤0.05) at the 6th week, but the feed conversion ratio increased significantly (p≤0.05) in the 4th week and decreased (p≤0.05) in the 5th and 6th week, with significant (p≤0.05) increase in the relative growth rate in the 5th and 6th week in T4 . Cholesterol increased while triglycerides decrease significantly (p≤0.05). Hb and PCV decrease significantly (p≤0.05) compared to the control. We can conclude from the results that quantitative feed restriction programs may have some economic benefits with some health hazard through rising cholesterol levels, decreasing Hb and PCV values according to the intensity of feed restriction regimen.

Effect of intensity and duration of quantitative feed restriction on broiler caecum microbiota

This study evaluated the effects of quantitative feed restriction with different intensity and duration on broiler intestinal microbial flora. Using a completely randomized design, Ross 308 male broiler chicks (115; 3 replications/ treatment; 10 chicks/replication) were assigned to 5 experimental treatments. These included quantitative feed limitations in 50% (T2,T3) and 25% (T4,T5) lower than the recommended by the Ross 308 broiler catalogue in 2 periods of 7 (T2, T4) and 14 days (T3, T5), with one control treatment (T1; feed intake as ad lib.). All chicks were fed ad lib. before and after the limitation period, until slaughter (day 42). The results showed that quantitative feed restriction had significant effects on microbiota of ceca in broilers except for lactic acid bacteria. A feed restriction of 25% during 7 days (T4) resulted in the highest mean value for coliforms and Escherichia coli; in contrast, a feed restriction of 25% during 14 days (T5) resulted in the highest mean value for lactobacilli and enterobacteria. A feed restriction of 50% during 7 days did not affect microbial count when compared with the control group. The number of total bacteria was higher in T4 although the difference had not been statistically significant from T2 and T3. Major alterations occurred for E. coli and coliforms in T4, lactobacilli and enterobacteriaceae in T5 and enterecoccus in both T3 and T4. It is concluded that a feed restriction of 25% during 7 days (T4) gave rise to the growth of other species than those analyzed in this study whereas a feed restriction of 25% during 14 days increased lactobacilli and enterobacteriaceae.

The Effect of Quantitative Feed Restriction During the Starter Period on Compensatory Growth and Carcass Characteristics of Broiler Chickens

The Effect of Quantitative Feed Restriction During the Starter Period on Compensatory Growth and Carcass Characteristics of Broiler Chickens

The Effect of Quantitative Feed Restriction During the Starter Period on Compensatory Growth and Carcass Characteristics of Broiler Chickens

The Effect of Quantitative Feed Restriction During the Starter Period on Compensatory Growth and Carcass Characteristics of Broiler Chickens

Effect of quantitative feed restriction on pullet development and subsequent egg production

The effect of quantitative feed restriction during rearing on mature body weight and subsequent egg production of pullets was investigated in two experiments. All the birds in the two experiments were fed ad libitum on 20% crude protein and! 649kcal/kg ME diet from 0-8 weeks of age. From 9-20 weeks, feed was denied the birds for a day after one or two days of ad lib feeding, or restricted to 75% of ad lib intake by the control birds. Results of these two studies showed that with restriction, a significant decrease in growth rate was obtained at 20 weeks and 36 weeks. However, the feed regimen imposed on the birds during the growing period did not have any significant effect on sexual maturity nor peak production levels. Hen-day and hen-housed production levels as well as cost of feed per unit weight or dozen eggs, were not significantly affected by the treatments. These studies showed that when growing birds are restricted in quantity of feed fed, they respond with a reduction in mature weight, but the laying phase is unaffected. Key words: Feed restriction, pullet, egg production

Effect of quantitative feed restriction o the performance, carcass, organ weight s and meat quality of broiler finisher birds

Effect of quantitative feed restriction o the performance, carcass, organ weight s and meat quality of broiler finisher birds

Effect of quantitative feed restriction on broiler performance

The objective of the current study was to determine the effect of quantitative feed restriction on the performance of broilers. A total of 270 unsexed broilers were randomly allocated to three treatments: with no feed restriction (T1), one week (T2) and two (T3) weeks of feed restriction from 22 days of age and then fed ad libitum until the age of 42 days. Treatments were replicated three times with 30 birds per replicate. Birds were fed with starter, grower and finisher diets. The feed consumed and body weights were recorded every week from the third to the sixth week. The average daily gain (ADG), average daily feed intake (ADFI) and the feed conversion ratio (FCR) were computed for each week. At Week 6, body weights of T3 birds were similar (P>0.05) to those of T1 and T2 birds. There were also no treatment effects on the ADG at Week 6. In addition, no treatment effects (P>0.05) were observed on ADFI at each stage of growth. Since ADFI and FCR were similar among the three groups, it was concluded that feed restriction by limiting the time to eat was not successful. There was also no evidence of compensatory growth in the restricted groups.

The Effects of Quantitative Feed Restriction and the Protein and L-carnitine Density of Diets on the Performance of Broiler Chickens

The Effects of Quantitative Feed Restriction and the Protein and L-carnitine Density of Diets on the Performance of Broiler Chickens