Effects of dietary metabolizable energy levels and beak trimming on the performance, egg quality, and economic viability of layers

Effect of different energy, protein levels and their interaction on productive performance, egg quality, digestibility coefficient of laying Japanese quails

For the evaluation of the effects of various quantities of crude protein (CP) and metabolizable energy (ME) (kcal/kg diet) in Japanese quail lay chicken meals on performance, digestion coefficients, and nutritional value. An experiment was undertaken in the summer season; 216 eight-wk-old Japanese quail laying hens were allocated at random to 1 of 9 groups in a factorial design (3 × 3) experiment involving 3 levels of CP (18, 20, and 22%) plus 3 levels of ME (2,800, 2,900, or 3,000 kcal/kg ME diet). The testing period lasted from 8 to 20 wk. The findings demonstrated that the relationship between protein and energy levels significantly impacted all productive outcomes except the feed conversion ratio (P < 0.01). Throughout the overall period 8 to 20 wk of age, the greatest measurements of egg weight (11.9 g) and egg mass (8.33 g) occurred in hens fed 20% CP with 2,900 kcal/kg diet, yet the lowest values of egg weight (11.2 g) and egg mass (6.72 g) were noticed in hens fed 22% CP with 2,900 kcal/kg diet. The data showed that the combination of dietary energy and protein levels had a substantial (P < 0.05 and P < 0.01) effect on all egg quality trials evaluated. The results indicated that the interaction between dietary energy and protein concentrations substantially impacted DM and EE digestion ratios (P < 0.01). Finally, when feeding layer Japanese quail between the ages of 8 and 20 wk during the summer, a dietary energy content of 2,900 kcal ME/kg with 20% CP is recommended.

Dietary metabolizable energy and crude protein levels affect the performance, egg quality and biochemical parameters of a dual-purpose chicken

Effects of dietary metabolizable energy (ME) and crude protein (CP) level on performance, egg quality and biochemical parameters were studied in a dual-purpose chicken-Beijing You Chicken (BYC) at peak laying period. A 3 × 3 factorial experiment was arranged, including 3 levels of dietary ME (11.31, 11.51, 11.71 MJ/kg) and 3 levels of dietary CP (14%, 15%, 16%). The results showed that dietary CP level alone and the interaction of ME by CP affected the total feed intake (TFI) during 27-30 wks, dietary ME level affected the mortality rate of 27-34 wks of age (p = 0.018), with the highest mortality rate found in 11.31 MJ/kg group (3.10%). The albumen height (AH), Haugh unit (HU) and egg grade (EG) of 16% group was higher than those in 14% and 15% groups (p < 0.05). Serum immunoglobulin G content in 11.31 MJ/kg group was lower than in 11.51 MJ/kg and 11.71 MJ/kg groups (p = 0.037). The present study suggested that dietary levels of 11.51 MJ/kg ME and 16.0% CP are enough to maintain the performance and egg quality of BYC at peak laying period. 11.31 MJ/kg ME increased the mortality of the chicken, which may be related to the decrease of the humoral immune function and antioxidative capability.

High dietary energy decreased reproductive performance through increasing lipid deposition in Yangzhou geese at late laying stage

Dietary metabolizable energy (ME) level could offer a well production performance through maintaining lipid homeostasis in poultry. In this study, a total of 540 geese (450 females and 90 males) at 64 wk of age with similar body weight (4,600 ± 382) were randomly divided into 5 groups with 3 replicates in each group and 30 females and 6 males (1♂:5♀) in each replicate. After 2 wk adaptation, the 5 groups were designed to provide diet with ME intakes of 9.65, 10.05, 10.70, 11.45, and 11.75 MJ/kg, respectively, according to production requirement. Body weight, egg production, hatchability, blood lipid, and fat deposition were recorded after 6 wk feeding. The expression of lipid synthesis-related genes, lipoprotein lipase (LPL) and fatty acid synthase (FASN), were determined by quantitative real-time PCR. Geese fed with high ME diet of 11.75 MJ/kg caused an increased liver and abdominal fat weight and low hatchability of set eggs. The ovarian weight and oviduct length were higher in geese fed dietary energy of 10.7 MJ/kg as compared to the 9.65 MJ/kg groups, whereas no significant difference was observed in geese fed dietary energy of 10.05 MJ/kg. Dietary energy level did not change the concentration of serum lipids at the late egg laying stage. The LPL expression exhibited linear and quadratic effect in response to dietary ME. The FASN expression showed quadratic effect and a relatively higher expression was exhibited in 10.05 and 11.45 MJ/kg than that of the 9.65 and 10.70 MJ/kg ME groups. According to the productivity, reproductive performance, and fat deposition, dietary ME of 10.13 to 10.28 MJ/kg could be suggested for breeding geese at their late laying stage.