Influence of Early Skip-A-Day Feed Removal on Live Performance and Carcass Yield of Broilers of Different Sexes and Strain Sources

Transcription

1 2003 Poultry Science Association, Inc. Influence of Early Skip-A-Day Feed Removal on Live Performance and Carcass Yield of Broilers of Different Sexes and Strain Sources W. A. Dozier, III,*,1 R. J. Lien, J. B. Hess, and S. F. Bilgili *Department of Poultry Science, Rural Development Center, P.O. Box 1209, University of Georgia, Tifton, Georgia 31793; and Department of Poultry Science and Alabama Agricultural Experiment Station, Auburn University, Alabama Primary Audience: Live Production and Complex Managers SUMMARY Feed restriction programs reduce early growth and decrease mortality in broilers. Observations of subsequent compensatory growth are conflicting and may be influenced by sex and strain. This study examined effects of sex, strain, and early skip-a-day feed removal on broiler performance and meat yield. In experiment 1, males and females were fed ad libitum to 54 d or subjected to 24-h feed removal periods at 8, 10, 12, 14, and 16 d. On d 16, BW was suppressed 44%. Although some compensatory growth occurred and feed conversion was improved, early feed removal adversely affected final BW and meat recovery. Mortality was unaffected by skip-a-day feed removal program. Sex did not affect responses to early feed removal; however, males had greater BW, feed consumption, and weights of all carcass parts. In experiment 2, males from 2 diverse strains were fed ad libitum to 54 d or subjected to 24-h feed removal periods at 9, 11, 13, 15, and 17 d. Body weight was suppressed 44% at the end of feed removal. The reduction of early growth of broilers did not allow for complete recovery of final BW and carcass parts. However, feed conversion was improved by early feed removal. Strain source did not influence responses to early feed removal; the yield strain had superior live performance and meat yield. These data indicate broilers subjected to 5 d of feed removal in a skip-a-day program do not attain equivalent final BW and meat recovery, and although feed conversion was improved, responses were not affected by sex or strain. Key words: broiler, feed restriction, live performance, carcass yield 2003 J. Appl. Poult. Res. 12: DESCRIPTION OF PROBLEM The efficiency and rate of growth of broiler chickens have dramatically improved over the last few decades. Genetic selection has been primarily responsible for the improvements in broiler performance and meat yield. The acceler- ated growth associated with contemporary high performance broilers has led to an increase in metabolic mortality and skeletal disorders [1]. Quantitative and qualitative feed restriction programs have been successful in reducing rapid early growth and decreasing the incidence of metabolic mortality and improving nutrient utili- 1 To whom correspondence should be addressed: bdozier@uga.edu.

2 440 JAPR: Research Report TABLE 1. Composition of feeds provided to broilers during 54 d of production (experiments 1 and 2) Starter Grower Finisher Item (1 to 22 d) (23 to 43 d) (44 to 54 d) Ingredient, % Corn Soybean meal (48% CP) Poultry oil Poultry by-product meal Dicalcium phosphate Limestone Sodium chloride Vitamin premix A Trace-mineral premix B Coccidiostat C BMD-50 D DL-Methionine L-Lysine HCl 0.10 Total Calculated analyses Crude protein, % ME,kcal/lb 1,463 1,473 1,485 Methionine, % Methionine + cystine, % Lysine, % Available phosphorus, % Calcium, % A Supplied per pound of diet: vitamin A, 7,356 IU; vitamin D 3, 2,205 IU; vitamin E, 8 IU; vitamin B 12, 0.02 mg; riboflavin, 5.5 mg; niacin, 36 mg; D-pantothenic acid, 13.0 mg; choline, 501 mg; menadione, 2.2 mg; folic acid, 0.5 mg; pyridoxine, 2 mg; thiamine, 1 mg. B Supplied (mg/lb of diet): manganese, 65; zinc, 55; iron, 6; copper, 6; iodine, 1; selenium, 0.3. C Coban, 60% monensin sodium premix, Elanco Products, Inc., Indianapolis, IN. D Bacitracin Methylene Disalicylate, (50 g/lb), A. L. Laboratories, Inc., Ft. Lee, NJ. TABLE 2. Live production measurements of male and female broilers at 54 d of age when subjected to ad libitum feeding or skip-a-day feed removal from 8 to 16 d of age A (experiment 1) Mortality (%) Treatment BW (lb) FC B (lb) F/G C Uniformity D (%) Metabolic E Nonmetabolic F Total Ad libitum G Removed 5 d H Male Female SEM Source of variation I Feeding program * *** ** NS NS NS NS Sex *** *** NS ** NS NS NS A Values are least-squares means of 32 pens with each pen having 50 birds at placement. B Feed consumption per bird. C Feed consumed per BW gained on a per-bird basis. D Values were calculated based on individual BW recorded at 50 d and represent percentages of birds within 15% of mean BW. E Values represent the combined occurrence of sudden death syndrome, ascities, and skeletal abnormalities. F Values represent mortality due to undetermined factors or factors other than those listed in E above. G Feed continuously provided ad libitum. H Feed provided ad libitum except for 24-h removal periods at 8, 10, 12, 14, and 16 d of age. I No significant interaction effects were found (P < 0.05). *P < 0.05; **P < 0.01; ***P <

3 DOZIER, III ET AL.: SKIP-A-DAY FEED REMOVAL 441 TABLE 3. Subsequent growth rates of male and female broilers subjected to ad libitum or skip-a-day feeding program from 8 to 16 d of age A (experiment 1) Growth rate (lb/d) Treatment 22 to 43 d 44 to 54 d Ad libitum B Removal 5 d C Male Female SEM Source of variation D Feeding program NS ** Sex *** *** A Values are least-squares means of 32 pens with each pen having 50 birds at placement. B Feed continuously provided ab libitum. C Feed provided ad libitum except for 24-h removal periods at 8, 10, 12, 14, and 16 d of age. D No significant interaction effects were found (P < 0.05). **P < 0.01; ***P < zation with compensatory growth [2, 3, 4, 5, 6]. Most research reported has used male broilers or straight-run broilers. The justification for using a predominantly male population is that the incidence of metabolic mortality and skeletal disorders are more pronounced with male broilers [7]. Thus, feed restriction research is limited with female broilers. Plavink and Hurwitz [8] determined that initiating feed restriction at 5 d of age until 13 d adversely affected final BW of 42-d-old female broilers, whereas male broilers subjected to early feed restriction for 7 d resulted in equivalent BW at 42 d when compared with birds fed ad libitum. Deaton et al. [9] provided female broilers 90, 75, or 60% of the daily feed consumption of birds fed ad libitum fed from 7 to 13 d of age from the previous 24-h period. The birds limited to 75 and 60% of the feed consumption of birds fed ad libitum had lower 42 d BW. A review by Yu et al. [1] suggested that strain source affects compensatory growth of broilers subjected to restricted feeding. Cherry et al. [10] found that slower-growing broilers had greater compensatory growth than fastgrowing broilers after subjection to feed restriction. Feed restriction programs reduce early growth but have been inconsistent in obtaining compensatory growth compared with fed birds fed ad libitum [2, 3, 4, 5, 6, 9, 11]. Some variation in achieving compensatory growth may be related to differences in strain sources used in feed restriction research. Dozier et al. [12] evaluated skip-a-day feed removal as a technique to reduce early growth of broilers. Removing feed for four 24-h periods during the starter period reduced early-rapid growth without compromising broiler performance and meat yield. Skip-a-day feed removal has been reported in other research to decrease early growth and reduce the incidence of ascites without affecting final BW [11, 13]. This study examined responses of broilers differing in sex and strain source subjected to ad libitum feeding or skip-a-day feed removal. Measurements included live production variables and carcass yield characteristics. TABLE 4. Preslaughter shrink and chilled carcass characteristics of male and female broilers subjected to ad libitum feeding or skip-a-day feed removal from 8 to 16 d of age A (experiment 1) Prewithdrawal Postwithdrawal Withdrawal Chilled Chilled Abdominal Treatment BW (lb) BW (lb) shrink (%) carcass B (lb) carcass (% of BW) fat (%) Ad libitum C Removed 5 d D Male Female SEM Source of variation E Feeding program ** ** NS ** NS NS Sex *** *** NS *** NS *** A Values are least-squares means of 32 pens each contributing 10 carcasses. B Carcasses without necks and giblets after 4hofstatic chilling and removal of abdominal fat. C Feed continuously provided ad libitum. D Feed provided ad libitum except for 24-h removal periods at 8, 10, 12, 14, and 16 d of age. E No significant interaction effects were found (P < 0.05). **P < 0.01; ***P <

4 442 JAPR: Research Report TABLE 5. Carcass parts of male and female broilers subjected to ad libitum feeding or skip-a-day feed removal from 8 to 16 d of age A (experiment 1) Wing Drumstick Thigh Fillet Tender Treatment Weight (lb) % B Weight (lb) % B Weight (lb) % B Weight (lb) % B Weight (lb) % B Ad libitum C Removal 5 d D Male Female SEM Source of variation E Feeding program *** NS NS NS ** NS ** NS *** * Sex *** * *** *** *** *** *** * *** NS A Values are least-squares means of 32 pens each contributing 10 carcasses. B Yield data were calculated as a percentage of live body weight. C Feed continuously provided ad libitum. D Feed provided ad libitum except for 24-h removal periods at 8, 10, 12, 14, and 16 d of age. E No significant interaction effects were found (P < 0.05). *P < 0.05; **P < 0.01; ***P <

5 DOZIER, III ET AL.: SKIP-A-DAY FEED REMOVAL 443 TABLE 6. Live production measurements of male broilers from two diverse strain sources at 54 d of age after being subjected to ad libitum feeding or skip-a-day feed removal from 9 to 17 d of age A (experiment 2) Mortality (%) Treatment BW (lb) FC B (lb) F/G Uniformity C (%) Metabolic D Nonmetabolic E Total Ad libitum F Removed 5 d G Fast food strain Yield strain SEM Source of variation H Feeding program *** *** *** NS NS NS NS Strain source *** * NS 0.06 NS NS NS A Values are least-squares means of 32 pens with each pen having 50 birds at replacement. B FC = feed consumption per bird, F/G = feed consumed per BW gained on a per-bird basis. C Values were calculated based on individual body weights recorded at 50 d and represent percentages of birds within 15% of mean BW. D Values represent the combined occurrence of sudden death syndrome, ascities and skeletal abnormalities. E Values represent mortality due to underdetermined factors or factors other than those listed in D above. F Feed continuously provided ad libitum. G Feed provided ad libitum except for 24-h removal periods at 9, 11, 13, 15, and 17 d of age. H No significant interaction effects were found (P < 0.05). *P < 0.05; ***P < MATERIALS AND METHODS General Procedures In both experiments, 1,600 broiler chicks (1 d old) were distributed into 32 floor pens in a curtain-sided facility with minimum ventilation fans and forced-air furnaces. Environmental temperature was set at 90 F at placement and was reduced by 5 F increments weekly until 35 d of age. All chicks were vaccinated at the hatchery for Marek s disease, Newcastle disease, and infectious bronchitis and then 14 d later for infectious bursal disease. Birds were provided a 3-phase feeding program (Table 1). Mortalities that occurred during experimentation were gross necropsied and identified as metabolic (sudden death syndrome, ascites, and skeletal disorders) or nonmetabolic (other reasons). Body weight and feed usage were measured at 22, 43, and 54 d of age. At 50 d of age, birds were individually weighed, and uniformity was calculated (the percentage of birds within 15% of average BW). At 54 d of age, 10 birds from each pen were processed online in a pilot plant. TABLE 7. Chilled carcass characteristics of male broilers at 54 d of age from 2 diverse strain sources subjected to ad libitum feeding or skip-a-day feed removal from 9 to 17 d of age A (experiment 2) Preslaughter Chilled Chilled Abdominal Treatment live weight (lb) carcass B (lb) carcass (% of BW) fat (%) Ad libitum C Removed 5 d D Fast food strain Yield strain SEM Source of variation E Feeding program *** *** *** NS Strain source *** *** *** * A Values are least-squares means of eight pens per treatment each contributing 10 carcasses. B Carcasses without necks and giblets after 4hofstatic chilling and removal of abdominal fat. C Feed continuously provided ad libitum. D Feed provided ad libitum except for 24-h removal periods at 9, 11, 13, 15, and 17 d of age. E No significant interaction effects were found (P < 0.05). *P < 0.05; ***P <

6 444 JAPR: Research Report TABLE 8. Carcass parts yields of male broilers of 2 diverse strain sources subjected to ad libitum feeding or skip-a-day feed removal from 9 to 17 d of age A (experiment 2). Wing Drumstick Thigh Fillet Tender Treatment Weight (lb) % B Weight (lb) % B Weight (lb) % B Weight (lb) % B Weight (lb) % B Ad libitum C Removed 5 d D Fast food strain Yield strain SEM Source of variation E Feeding program *** NS *** NS *** NS *** NS 0.06 NS Strain source NS *** NS NS ** NS *** *** *** *** A Values are least-squares means of 8 pens per treatment each pen contributing 10 carcasses. B Yield data were calculated as a percentage of live body weight. C Feed continuously provided ad libitum. D Feed provided ad libitum except for 24-h removal periods at 9, 11, 13, 15, and 17 d of age. E No significant interaction effects were found (P < 0.05). **P < 0.01; ***P <

7 DOZIER, III ET AL.: SKIP-A-DAY FEED REMOVAL 445 Carcasses were placed in slush ice for 2 h and then allowed to drain for approximately 3 min before weighing the carcass and removing abdominal fat. Fillets, tenders, wings, drumsticks, and thighs were removed from each carcass and weighed, and yields were determined. Experiment 1 The daily photoperiods were 23L:1D from 1 to 22 d, 18L:6D from 23 to 43 d, and 23L:1D from 44 to 54 d. Treatments consisted of providing male or female Ross Ross 308 broilers feed ad libitum or skip-a-day feed removal program. Feed was removed for 24 h on d 8, 10, 12, 14, and 16. Experiment 2 A 23L:1D lighting program was provided throughout experimentation. Body weights were determined at the end of the last feed removal period. Treatments consisted of 2 strains of broilers (high yield and fast food) provided a feed ad libitum program or skip-a-day feed removal on d 9, 11, 13, 15, and 17. Statistical Analysis All data were evaluated by the ANOVA procedure of SAS software [14] in a completely randomized design. All statements of significance were based upon P < The model included feed removal, sex, feed removal sex, and error in experiment 1 and feed removal, strain, feed removal strain, and error in experiment 2. Experiment 1 RESULTS Feeding program and sex influenced live performance responses of broilers during the 54-d production period (Table 2). Broilers subjected to early skip-a-day feed removal had decreased final live weight and feed consumption and improved feed conversion ratio compared with birds fed ad libitum. Skip-a-day feed removal did not alter the incidence of metabolic disorders, occurrence of total mortality, or body weight uniformity. As expected, males had greater final live weight and cumulative feed consumption; however, no differences in feed conversion ratio or incidence of mortality occurred between sexes. Females had improved BW uniformity compared with males. Both feeding program and sex effects altered growth rate of broilers from 22 to 54 d of age (Table 3). In comparison with birds fed ad libitum, early skip-a-day feed removal suppressed BW at the end of the last feed removal period by 46% for males and 43% for females. From 22 to 43 d (under 18L:6D), birds subjected to early feed removal did not grow at a greater rate than those fed ad libitum. However, male broilers grew faster than females. Conversely from 44 to 54 d (under 23L:1D), broilers subjected to early feed removal had accelerated growth compared with birds fed ad libitum, regardless of sex. As demonstrated in the previous period, male broilers had a pronounced advantage compared with females for growth rate. Subjecting broilers to early skip-a-day feeding did not affect percentage yield of the whole carcass or abdominal fat (Table 4). Neither skipa-day feeding nor sex influenced withdrawal shrinkage. Consistent with live weight measurements, carcass weight responses of broilers on skip-a-day feed removal were decreased compared with birds fed ad libitum. Male broilers had heavier carcass weights than female broilers on an absolute basis but not when expressed as a proportion to live weight. Females had greater percentages of abdominal fat than males. Both feed removal and gender influenced the weight and percentage yield of carcass parts (Table 5). Skip-a-day feed removal for broilers resulted in decreased amounts of wings, thighs, fillets, and tenders on an absolute basis, but when expressed as a proportion of the whole carcass, only tenders were reduced. Males had higher absolute and percentage weights of carcass parts than females, with the exception of relative (percentage) weight of tenders. Experiment 2 Male broilers from 2 strains on skip-a-day feed removal or ad libitum feeding had altered live performance responses (Table 6). Implementation of skip-a-day feeding from 9 to 17 d of age suppressed final BW and total feed consumption but improved cumulative feed conversion when compared with that of birds fed ad libitum. Skip-a-day feed removal did not af-

8 446 JAPR: Research Report FIGURE 1. Growth rates from 17 to 54 d of age of male broilers from 2 strains after being subjected to ad libitum feeding or skip-a-day feed removal from 9 to 17 d of age (experiment 2). fect the incidence of mortality. The high yielding strain had higher final BW and total feed consumption over the fast-food strain. Neither cumulative feed conversion nor incidence of mortality was affected by strain. The variation of BW at 50 d of age was less with the fast food strain than the high yielding strain as measured by percentage of uniformity. Growth rate from 17 to 54 d was influenced by feeding regimen and strain source (Figure 1). Skip-a-day feeding suppressed BW at the end of the last feed removal period by 44% for fast food and 43% for the high yielding strain compared with the birds fed ad libitum. Broilers subjected to skip-a-day feed removal had increased growth rate compared with the ad libitum group from the resumption of ad libitum feeding to the end of the experiment. However, this increase in growth rate did not allow for complete recovery of BW at 54 d of age. As expected, the high yielding strain grew faster than the fast-food strain. After being processed, differences were apparent in the amounts of chilled carcass and abdominal fat due to feeding program and strain source (Table 7). Subjection of male broilers to skip-a-day feeding decreased chilled carcass weight but did not alter abdominal fat yield compared with feeding ad libitum. The high yielding strain had heavier carcasses on absolute and relative bases and had less carcass fat than the fastfood strain. The weights and percentage yields of various body parts are shown in Table 8. The weights of wings, drums, thighs, and fillets were decreased in broilers on skip-a-day feed removal compared with birds fed ad libitum, but these differences were not observed when the parts were expressed as percentage of the chilled carcass. The accelerated growth of the high yielding strain led to heavier weights of thighs, fillets, and tenders and decreased the relative yield of wings, whereas relative yields of thighs, fillets, and tenders were increased. DISCUSSION In the present research, early feed removal for 5 d in a skip-a-day program did not allow for complete recovery of BW by 54 d. Implementation of a skip-a-day feed removal program for 5 d might have been too restrictive. Skip-aday feeding suppressed BW at the end of the last feed removal period by approximately 44% in both experiments. Dozier et al. [12] reported that birds subjected to 4 d of feed removal in a skip-a-day program had 35% lower BW at the end of the last feed removal period, but final BW were the same as those of birds fed ad libitum. However, BW was suppressed by 41% at the end of the last feed removal period after

9 DOZIER, III ET AL.: SKIP-A-DAY FEED REMOVAL 447 broilers had 6 d of feed removal in a skip-a-day program that led to reduced final live weight and decreased yield of carcass parts. A pronounced improvement in feed conversion occurred with birds subjected to skip-aday feed removal compared with birds fed ad libitum. Differences in feed conversion are partially explained by differences in BW. Other research has demonstrated that early feed removal initiated at 7 or 8 d of age for 3 or 4 d does not alter final BW [11, 13], but final BW generally was reduced, and cumulative feed conversion was improved with extension of feed removal to 6 d [11]. The incidence of metabolic mortality attributable to ascites, sudden death syndrome, or skeletal disorders was relatively low in both experiments reported herein, and early skip-a-day feed removal had minimal impact on altering livability. This finding has also been documented with previous research from this laboratory [12]. In contrast, Acre et al. [11] demonstrated that early skip-a-day feed removal is an effective method to reduce the occurrence of ascites with straight-run broilers. The overall incidence of late mortality was more pronounced than the results reported with the present re- CONCLUSIONS AND APPLICATIONS 1. Five days of feed removal in a skip-a-day program did not allow for complete compensatory growth by 54 d but did improve feed conversion. Feed removal for 3 or 4 d in this type program will likely restrict early growth to a degree that allows full BW recovery. 2. Broilers subjected to skip-a-day feed removal had 0.35% less breast fillet yield than birds fed ad libitum. 3. Sex and strain did not alter responses to early skip-day feed removal; the incidence of mortality was not significantly affected. 1. Yu, M. W., F. E. Robinson, M. T. Clandinin, and L. Bodnar Growth and body composition of broiler chickens in response to different regimes of feed restriction. Poult. Sci. 69: Su, G., P. Sorensen, and S. C. Kestin Meal feeding is more effective than early feed restriction at reducing the prevalence of leg weakness in broiler chickens. Poult. Sci. 78: Urdaneta-Rincon, M., and S. Lesson Quantitative and qualitative feed restriction on growth characteristics of male broiler chickens. Poult. Sci. 81: Zubair, A. K., and S. Lesson Effect of varying periods of early nutrient restriction on growth compensation and carcass characteristics of male broilers. Poult. Sci. 73: REFERENCES AND NOTES search. Their research was conducted in Mexico at higher elevations. Subjection of broilers to skip-a-day feeding reduced weights of carcass parts. Broilers on skip-a-day feeding had reduced breast fillet weights of 6.5 and 7.4% in experiments 1 and 2, respectively, compared with birds fed ad libitum. Dozier et al. [12] reported that carcass yields of 56-d-old broilers are generally lower with 6 d of early skip-a-day feed removal, but 4 d of skipa-day feeding does not alter meat yield. Ballay et al. [13] reported similar findings with 39-dold male broilers; implementation of skip-a-day feed removal from d 7 to 11 did not alter fillet yield compared with control birds fed ad libitum, but skip-a-day feed removal from 7 to 17 d reduced breast meat yield. Neither sex nor strain source interacted with early skip-a-day feed removal to influence live performance or carcass measurements. Conversely, Plavnik and Hurwitz [8] determined that subjection of female broilers to early skip-aday feed removal for 9 d suppressed 56-d BW; however, use of early skip-a-day feeding for 11 d did not alter 56-d BW of male broilers. Cherry et al. [10] reported over 20 yr ago that slower growing broilers are more able to achieve complete compensatory growth than fast growing broilers. 5. Fontana, E. A., W. D. Weaver, Jr., B. A. Watkins, and D. M. Denbow Effect of early feed restriction on growth, feed conversion, and mortality in broiler chickens. Poult. Sci. 71: Lee, K. H., and S. Lesson Performance of broilers fed limited quantities of feed or nutrients during seven to fourteen days of age. Poult. Sci. 80: Gardiner, E. E., J. R. Hunt, R. C. Newberry, and J. W. Hall Relationships between age, body weight, and the incidence of sudden death syndrome in male chickens. Poult. Sci. 67:

10 448 JAPR: Research Report 8. Plavink, I., and S. Hurwitz Early feed restriction in chicks: Effect of age, duration, and sex. Poult. Sci. 67: Deaton, J. W The effect of early feed restriction on broiler performance. Poult. Sci. 74: Cherry, J. A., P. B. Siegel, and W. L. Beane Geneticnutritional relationships in growth and carcass characteristics of broiler chickens. Poult. Sci. 57: Arce, J., M. Berger, and C. L. Coello Control of ascites syndrome by feed restriction techniques. J. Appl. Poult. Res. 1: Dozier, W. A., III, R. J. Lien, J. B. Hess, S. F. Bilgili, R. W. Gordon, C. P. Laster, and S. L. Vieira Effects of early skip-a-day feed removal on broiler live performance and carcass yield. J. Appl. Poult. Res. 11: Ballay, M., E. A. Dunnington, W. B. Gross, and P. B. Siegel Restricted feeding and broiler performance:age at interaction and length of restriction. Poult. Sci. 71: SAS Institute SAS Users Guide: Statistics. SAS Institute Inc., Cary, NC.