The effects of hen's age and egg storage time on the frequency of occurrence of physical defects in turkey poults

The aim of this study was to determine the effect of the interaction between hen's age and egg storage time on the frequency of occurrence and type of physical defects in turkey poults. The experimental materials comprised 6,048 eggs laid by BUT 6 turkey hens at 32, 38, 46, and 51 wk of age (1,512 eggs per week), which were randomly divided into 4 groups (378 eggs per group) and stored for different periods of time, i.e., 7, 10, 13, and 17 D. After incubation, poults were evaluated individually. Egg weight and the hatch-weight of poults increased with hen's age (P < 0.001). The relative body weight of poults, expressed as a percentage of egg weight, was highest in the group of the youngest hens (70.6%). Prolonged egg storage before incubation contributed to an increase in the percentage of poults with physical abnormalities (P < 0.001). Umbilical abnormalities were most common regardless of the week of the laying season and egg storage time.

Metabolic parameters in young turkeys fed diets with different inclusion levels of copper nanoparticles

The aim of this study was to verify the hypothesis postulating that the supplementation of turkey diets with Cu nanoparticles can lower dietary inclusion levels of Cu without compromising the growth rate and antioxidant status of turkeys. The experiment was carried out on 648 one-day-old Hybrid Converter turkeys divided into 6 groups with 6 replicates per group, in a two-factorial design with 3 dietary inclusion levels of Cu (20, 10 and 2 mg/kg) and 2 dietary sources of Cu - copper sulfate (Cu-SUL) and Cu nanoparticles (Cu-NP). At 42 days of age, blood samples were collected from 2 birds per replicate (12 birds per group), after slaughter livers were collected for analyses. Blood and liver samples were assayed for: Cu, Zn, Ca, P, Mg, GLU, TP, ALB, UREA, TAG, TC, UA, ALT, AST, ALT, GGT, ALP, SOD, GPx, CAT, VIT C, FRAP, GSH+GSSG, LOOH, MDA. The results of this experiment demonstrate that a decrease in the dietary inclusion levels of Cu from 10 mg/kg to 2 mg/kg does not compromise the growth performance of turkeys, but weakens antioxidant defense mechanisms. A Cu dose of 20 mg/kg induces oxidation reactions and has a much more inhibitory effect on the antioxidant defense system than dietary Cu content of 2 mg/kg. In turkeys, dietary supplementation with Cu-NP has a more beneficial effect on carbohydrate metabolism and antioxidant status compared with Cu-SUL. The results of analyses examining the antioxidant and metabolic status of young turkeys indicate that 10 mg/kg is the optimal dietary inclusion level of Cu.

Effect of hen age and storage time on egg weight loss and hatchability results in turkeys

The aim of this study was to determine the effect of egg water loss during storage and incubation on hatch rates in heavy-type broad-breasted white BUT Big 6 turkeys. Turkey hens started laying eggs at 30 weeks of age. In weeks 2, 8, 16 and 21 of the laying season, 1512 eggs were selected randomly and divided into 4 groups of 378 eggs each. The groups of eggs were stored for 7, 10, 13 or 17 days before incubation. At the beginning and end of the storage period and on days 9, 15, 21 and 24 of incubation, eggs were weighed to determine the percent water loss relative to the egg’s weight. Four incubation cycles of 378 eggs each were performed for each storage period. A total of 16 incubation cycles were carried out (4 weeks of the laying season × 4 egg storage periods) and the following parameters were determined (%): egg fertilization, dead embryos, unhatched eggs and hatchability results from fertilized eggs. The percentages of dead embryos and unhatched poults with physical defects and abnormal position were determined in hatchery waste from each incubation cycle. Egg water loss varied throughout storage and reached 0.57% of total egg weight after 7 days, 0.79% after 10 days, 0.87% after 13 days and 1.28% after 17 days (P≤0.05). After 7 days of storage, egg water loss during a 15-day and 21-day incubation period reached 5.76% and 8.72%, and lower values were noted after 17 days of storage (P≤0.05). Egg water loss of 1.28% during storage resulted in a high rate of early embryonic mortality (14.81%) and a low hatch rate (72.12%) (P≤0.05). High water loss in stored eggs contributed to a higher percentage of congested embryos. During storage, egg water loss reached 0.72% in week 2 of the laying season, 0.78% in week 8 and ≥1% in weeks 16 and 21 of the laying season (P≤0.05). Egg water loss during a 21-day incubation period was similar in weeks 2, 8 and 16 of the laying season, and lower in week 21 (P≤0.05). The hatchability of turkey eggs was lowest in weeks 16 and 21 of the laying season (P≤0.05). Low water loss during incubation contributed to a high rate of late embryonic mortality (13.2%). High water loss during egg storage is accompanied by lower water loss during incubation. Water loss should be monitored after storage and on days 15 and 21 of incubation to evaluate water metabolism in hatching eggs.