Response of growing turkeys to dietary energy levels

Effect of diet and population density on male turkeys under various environmental conditions. 1. Turkey growth and health performance

The performance of 1,312 male market turkeys (Large White, Nicholas strain) from 0 to 20 wk of age fed diets varying in feed form and energy level was measured under two stocking densities (.21 or .46 m2 per bird) and four lighting and temperature programs. The four diets were 1) corn and soybean meal with 1% supplemental fat, mash (CSM); 2) as 1, pelleted (CSP); 3) as Diet 1 but with 1, 2, 4, 6, and 8% supplemental fat during 0 to 4, 4 to 8, 8 to 12, 12 to 16, and 16 to 20 wk of age, respectively (CSF); and 4) as Diet 1 but with barely included at 0, 20, 35, 50, and 65% during the respective 4-wk age periods (CSB). The four light and temperature programs were 1) Environment A with intermittent light [4 [2 h light (L):4 h dark (D)]] in combination with cycling temperature at 7 and 21 C during light and dark photoperiod, respectively; Environment B with intermittent light, 21 C; Environment C with continuous light (18L:6D) and cycling temperature of 7 to 21 C; and Environment D with intermittent light, 7 C. Lighting and temperature programs started at 1 and 4 wk of age, respectively. Body weights at 20 wk of age decreased (P less than .05) with increasing temperature (13.86 versus 12.26 kg for Environments D and B, respectively) with cycling temperature intermediate (13.51 kg for Environment A). Intermittent light (P less than .05) improved BW and feed conversion by 3.4 and 2.0%, respectively, compared with continuous light. Rearing males at .21 m2 per bird versus .46 m2 per bird decreased weight (P less than .05) by 5.5%. Twenty-week BW of males fed the CSP (13.52 kg) and CSF (13.58 kg) diets were greater (P less than .05) than those fed CSM (12.90 kg) and CSB (12.69 kg) diets. Significant (P less than .05) interactions between diet, environment, and density were not detected for most performance characteristics. Environmental measurements indicated higher dust and ammonia levels in the warm environment (B). Isolates of aspergillus and incidence of airsacculitis at time of processing were greatest in Environment B.

Effects of different coccidiostats on performance of large white turkeys

Two trials were conducted to evaluate the effects of feeding various anticoccidial products to turkeys to 8 wk and then growing to market age (16 wk for hens and 20 wk for toms). Anticoccidials evaluated in the first trial included amprolium at 187.5 mg/kg for 0 to 4 wk and 125 mg/kg for 4 to 8 wk; butynorate at 375 mg/kg for 0 to 8 wk; monensin at both 60 (MON-60) and 100 mg/kg for 0 to 8 wk; zoalene at 187.5 mg/kg for 0 to 4 wk and 125 mg/kg for 4 to 8 wk; and halofuginone at 3 mg/kg for 0 to 8 wk. In the second trial, MON-60 was replaced by a combination of sulfadimethoxine (62.5 mg/kg) plus ormetoprim (37.5 mg/kg) for 0 to 8 wk. In each trial each treatment was fed to four pens of 16 hens and four pens of 12 toms. Several of the anticoccidials significantly influenced the weight of both hens and toms by producing lower weights at the end of the 8-wk feeding period than birds in other treatments. However, after removal of the anticoccidials, compensatory gains were observed in almost every instance. Significant effects of previous anticoccidial feeding were noted on body weight of hens at 16 wk but not on weights of toms at 20 wk.

Effects of dietary protein and added fat on turkeys varying in strain, sex, and age. 1. Live characteristics

An experiment was conducted to determine the effects of dietary protein and added fat on body weight, feed consumption, and feed efficiency of male and female Nicholas Large White (N), Jaindl Large White (JL), and Jaindl Medium White (JM) turkeys at various ages. At 8 wk of age, 162 males and 288 females from each strain were divided equally into six pens of males and six pens of females per strain. Each of 6 pelleted diets containing standard or high protein and 0, 5, or 10% added fat was fed to one pen of each sex and strain of turkeys. At 20 wk of age, N, JL, and JM males weighed 14.77, 11.56, and 9.00 kg, respectively, and females weighed 8.97, 7.49, and 5.75 kg, respectively. At 28 wk of age, N, JL, and JM males weighed 18.32, 15.10, and 11.65 kg, respectively, and females weighed 10.35, 9.12, and 7.04 kg, respectively. The feeding of diets containing 10% rather than 0% added fat from 8 to 20 wk of age decreased feed consumption 11.1 and 13.1% and increased feed efficiency 16.3 and 16.4% in males and females, respectively. Feeding high protein diets significantly increased body weight gains. The apparent smaller increase than previously experienced in feed efficiency from dietary added fat may be associated with the use of pelleted feed in this experiment.

Response of growing turkeys to dietary fat

Growth, feed efficiency, and carcass fat were evaluated in turkeys fed diets in which added fat varied, holding energy or the calories:protein ratio constant. In the 1 to 3-wk-old turkey, growth and feed efficiency increased with dietary energy, but did not change significantly when fat was added isocalorically. The 12 to 14-wk-old turkey responded with improved growth and feed efficiency when dietary fat was added either isocalorically or with increasing energy density. However, the response to the isocaloric fat addition was smaller in magnitude than the response when fat was added without calorie adjustment. No difference could be detected in 12 to 15-wk-old turkeys in the performance response to tallow and soybean oil. Carcass fat deposition generally increased with dietary fat supplementation, regardless of the caloric change. The results suggest that in the midterm of development of the growing turkey, dietary fat per se affects growth, feed efficiency, and carcass fat. Growth and feed efficiency responses to nutrient density occur in both young and older birds.

Differential responses to dietary carbohydrates and fat of turkeys kept at various environmental temperatures

Interactions between environmental temperature and dietary energy sources were evaluated in 6 to 9-wk and 9 to 12-wk-old turkeys using weight gain, feed efficiency, and carcass fat as response criteria. The dietary variables (soybean oil or glucose) were added in five or six increments at the expense of each other or of the fiber supplements, keeping the minima for protein and amino acid/energy constant. The resulting diets were fed to birds kept at 10 and 27 C. Duplicate experiments were conducted for each mode of dietary variable addition. Parallel increases in body weight gain and feed efficiency were obtained at the two temperatures when fat replaced carbohydrates or fiber, thereby raising dietary energy density. Some responses of weight gain and feed efficiency at the two temperatures were obtained also with a graded isocaloric addition of fat but the response was significant only at 27 C and not at 10 C. A greater response of gain and feed efficiency to energy supplied by dietary glucose was obtained at 10 C as compared with 27 C. Dietary fat supplementation resulted in increased deposition of carcass fat when given together with energy or isocalorically regardless of environmental temperature. Carcass fat was increased by glucose-energy at the low temperature only.

The effect of graded levels of corn oil and different fats on the performance of white pekin ducklings

One-hundred-eighty male and female ducklings (90 of each sex) were fed isocaloric and isonitrogenous diets formulated to contain 0, 2, 4, 6, 8, or 10% corn oil in the starter (0 to 14 days), grower (14 to 35 days), and finisher (35 to 49 days) periods. Body weights of the ducklings were not different among treatments; however, feed consumption decreased significantly between 0 and 49 days of age (10.22, 9.78, 9.18, 9.00, 8.54, and 8.96 kg) as the level of dietary corn oil increased (0, 2, 4, 6, 8, and 10%, respectively). Regression analysis indicated a linear decrease in feed/gain (F/G) as corn oil increased in the diet. F/G (0 to 49 days) = 3.48 - .06 (% corn oil); r2 = .92. In a second experiment, isocaloric and isonitrogenous diets were formulated to contain 0% added fat (NF) or 4% corn oil (CO), peanut oil (PO), vegetable shortening (VS), lard (LD), or tallow (TL). The body weights of the ducklings were the same across treatments throughout the 49-day experiment. Ducklings fed 4% TL consumed significantly (P less than .05) less feed than those ducklings fed NF, PO, VS, or LD. Feed efficiency was not statistically different among the ducklings fed the six different diets.

Independent effects of dietary metabolizable energy and protein concentrations on performance and carcass characteristics of Tom turkeys

An experiment was conducted to determine the independent and interaction effects of dietary metabolizable energy (ME) and protein concentrations on performance of Large White toms from 9 to 20 weeks of age. Diet treatments consisted of a complete factorial arrangement of three ME concentrations and three protein concentrations within each age interval (9 to 12, 12 to 16, and 16 to 20 weeks). The different ME concentrations were obtained by using an animal-vegetable fat blend at 0, 4, or 8% of the diets. Dietary protein levels tested provided approximately 88, 97, or 107% of those recommended by National Research Council (1977) for each age interval. The ME concentrations represented 95, 100, or 105% of those used most frequently in commercial feeding programs in the central United States. Dietary ME and protein concentrations had significant (P less than .03) independent effects on turkey performance. As each diet variable was increased, gain in body weight and feed efficiency were improved. Increasing dietary ME reduced the amount of protein consumed per kilogram of gain but not the ME consumed per kilogram of gain. Protein consumed per kilogram gain increased as dietary protein increased, while ME intake per kilogram gain decreased. Carcass composition and parts yield of the carcass were affected only slightly by dietary ME and protein concentration. No significant (P greater than .10) interaction effects of dietary ME and protein were detected, except in the instance of absolute quantity of carcass protein (P less than .07).(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of feeding supplemental fat by age sequence on the performance of growing turkeys

Large White toms were used in an experiment to determine the response of turkeys to feeding supplemental fat by age sequence. The eight treatments tested consisted of a factorial arrangement of dietary animal-vegetable fat blend (A-V fat) at 0 and 4% and four age periods (0 to 20, 6 to 20, 9 to 20, and 12 to 20 weeks). The concentrations of nutrients were kept constant within an age period, irrespective of level of dietary fat. On an age-period basis, improvements in feed efficiency resulting from supplemental fat increased with increasing age. During the 0- to 6-week period, feed efficiency was improved 1.6% per 1% added fat, while during the 12- to 20-week period, feed efficiency of toms previously fed no added fat was improved 3.6% for 1% added fat. Improvements in weight gains through 12 weeks of age followed a similar pattern but of lesser magnitude. The overall data through 20 weeks of age demonstrated that nearly all of the increases in weight gain and much of the improvements in feed efficiency obtained by feeding supplemental fat from 0 to 6, 0 to 9, and 0 to 12 weeks of age were lost after these treatment groups were fed a diet with no added fat for the rest of the growing period. Conversely, 20-week feed efficiencies and efficiencies of metabolizable energy and protein utilization were similar for all treatment groups that received no supplemental fat from 0 to 6, 0 to 9, or 0 to 12 weeks of age but were then fed 4% supplemental fat thereafter. A small numerical advantage in 20-week body weights was observed for toms fed supplemental fat from 0 or 6 to 20 weeks of age as compared with those fed fat-supplemented diets from 9 or 12 to 20 weeks of age.

The response of growing turkeys to dietary nutrient density

The response to diets of different nutrient densities was evaluated in male turkeys. In 2-week experiments with 1-week-old and 14-week-old turkeys the growth response to nutrient density appeared to be biphasic with an accelerated response at the lower and a much smaller response at the upper range of nutrient density. Results suggest that the upper limit of nutrient density for obtaining the accelerated growth response was higher for older (14-week-old) than for younger (1-week-old) birds. In two additional experiments, the growth response at the upper energy range was estimated at 1 to 2% per 100 kcal. In 14-week-old turkeys, abdominal fat did not change with nutrient density.