A 42-day experiment was conducted with 625 1-day-old male Hubbard chickens to evaluate the performance, carcass traits, nitrogen retention and economics of broiler chickens fed low protein and amino acid diets supplemented with different protease sources. Treatments included positive (PC) and negative (NC) controls (PC at 19.3% protein vs NC at 18.8% protein), with NC containing 7% less digestible amino acids. The other three treatment groups were based on the NC diet supplemented with 0.05% Cibenza® DP100 (CB), 0.02% Ronozyme® (RZ) or 0.02% Winzyme pro plus (WZ). Birds fed the PC, CB and WZ diets achieved the heaviest bodyweight compared with those fed the NC diet at end of the experiment. Total feed intake of birds fed the PC diet was higher (P < 0.05) than that of birds fed the NC diet. Feed conversion ratio was numerically significantly (P = 0.005) improved with all tested groups in comparison with NC throughout the experiment. European production index was similar (P > 0.05) among birds fed the PC, NC, RZ or WZ diets. All carcass parameters studied, including dressing, heart, gizzard, giblets, chest meat, thigh meat and abdominal fat percentages, were not significantly (P > 0.05) affected by feeding on the different sources of protease. Broilers fed the PC diet or diets formulated with all protease sources had higher (P < 0.05) nitrogen retention than did birds fed the NC diet. The supplementation of protease to low-protein and low-amino acid diets resulted in higher profit margin in broilers. It is concluded that supplementing exogenous protease to broiler diets containing low protein and amino acids improved the growth performance, feed utilisation, carcass traits, nitrogen retention and net returns of broiler chickens.
Floor type management is an important factor in turkey production in hot climates exceeding 30°C. In this study, a total of 360 turkeys aged 4 wk were randomly distributed to investigate growth performance, carcass characteristics, certain health aspects (breast blisters score, footpad burns, hock discoloration, and plumage condition), and airborne conditions. Birds in the first group were raised on a littered floor (control; C), whereas birds in the other groups (T1, T2, T3, T4, and T5) were raised on cement, wire net, rubber mat, plastic and wooden slatted floors, respectively. The results indicated that growth performance and meat quality were improved, with increases in body weight, daily body weight gain, feed conversion ratio, and tenderness and juiciness values, when plastic and wooden slatted floors were used. Moreover, the use of plastic and wooden slatted floors attenuated body temperature, airborne dust particulates, and ammonia concentrations. In conclusion, placing plastic, wooden slatted, or wire floors reduced the incidence of health disorders and alleviated heat stress effects by decreasing body temperature and the heterophil to lymphocyte ratio. Thus, plastic and wooden slatted floors are suitable for growing turkeys under the conditions of this study.
This investigation studied the effects of different feed withdrawal times, water temperatures, and their interaction on growth performance, carcass traits, blood parameters, and health aspects of native turkeys (Egyptian local breed). We distributed native turkey poults (n = 180; 4 wk old) into 3 groups according to feed withdrawal time (ad libitum; feed withdrawal from 800 to 1,400 h, FW8 to 14; and feed withdrawal from 1,400 to 2,000 h, FW14 to 20). Each group was further divided into 2 subgroups corresponding to water temperature (ordinary and chilled water). Our results indicated that birds of FW14 to 20 exhibited the highest (P = 0.0001) body weight (BW) and average daily gain (ADG), whereas turkeys that drank chilled water displayed a higher BW than those that drank ordinary water. Turkeys that were kept under FW8 to 14 and drank chilled water displayed the highest BW at marketing and ADG from 4 to 16 wk of age. The lowest feed conversion ratio (FCR) was exhibited in turkeys kept off feed under the FW14 to 20 regime. Birds that were kept under FW14 to 20 and received chilled water showed the lowest FCR. The meat color scores of the birds that drank chilled water were higher than those that drank ordinary water, whereas birds kept off feed under the FW14 to 20 regime displayed the highest tenderness and juiciness, followed by those fed ad libitum. Turkeys reared under FW14 to 20 exhibited the highest albumin/globulin ratio and glucose content but the lowest globulin and aspartate transaminase (AST) values. Birds that were kept under FW14 to 20 and drank chilled water displayed the lowest corticosterone concentration. Turkeys reared under FW14 to 20 presented the lowest body temperature. Birds that drank chilled water exhibited a lower body temperature than those that drank ordinary water. Turkeys that were fed ad libitum and drank chilled water displayed the lowest body temperature. Conclusively, applying feed withdrawal and cold water had benefits in turkeys during heat stress. Applying these treatments as managerial alternatives for raising native turkeys during the summer season is highly recommended.
This experiment was conducted to observe the effects of varying swimming times (ST) of Muscovy ducks, raised in an open-sided house, in alleviating the deleterious effects of high temperature in hotter times of the day in the summer season on growth performance (body weight, average daily gain, feed consumption, and feed conversion ratio), carcass characteristics, body temperature, and some health aspects. We hypothesized that swimming times during the hottest periods of the day would show different performances. To test this hypothesis a total of 180 Muscovy ducklings were randomly distributed into 4 equal groups in a completely randomized design experiment. All groups were raised under similar housing conditions. Birds of the first group (C) were raised in the indoor system and had no access to a swimming pond. While all birds of the second, third, and fourth groups (T1, T2, and T3) had access to a swimming pond during 10:00 to 12:00 h, 12:00 to 14:00 h, and 14:00 to 16:00 h, respectively. The swimming pond (dimensions of 30 m length × 10 m width × 3 m depth with cement floor) was located in the front of the house. Vaccination and medical programs were undertaken according to the different ages under supervision of a licensed veterinarian. The obtained results indicated that swimming during 12:00 to 14:00 h improved (P < 0.05) growth performance, dressed carcass, meat tenderness, lymphocyte, heterophils/lymphocytes ratio, body temperature, and mortality rate of Muscovy ducks. However, bone measurement, plumage conditions, foot pad dermatitis, hock discoloration, breast blisters score, and blood hematocrit values were insignificantly better in the group with access to the swimming pond during 12:00 to 14:00 h. In conclusion, raising ducks during hot conditions in an open-sided house with access to a swimming pond at 12:00 to 14:00 h is highly recommended due to the high BW, better immunity, decreased mortality rate, and low body temperature of ducks which was positively reflected in the health condition.
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