Modulation of energy and protein supplies in sequential feeding in laying hens

Using low-protein diet in egg production for win-win of productivity and environmental benefits should be prudent: Evidence from pilot test

A shortage of feed protein resources restricts poultry productivity. Key strategies to alleviate this problem include improvements to the structure of the gut microbiota by the appropriate intake of high-quality protein, improvements to the comprehensive protein utilization rate, and reducing the consumption of protein raw materials. In addition, damage to the environment caused by nitrogen emissions needs to be reduced. The aim of the study was to evaluate the effects of dietary protein levels on laying performance, host metabolism, ovarian health, nitrogen emissions, and the gut microbial structure and function of laying hens. In total, 360 hens at the age of 38 weeks were randomly allotted four treatments. Each of the groups consisted of nine replicates, with 10 birds per replicate, used for 12 weeks of study. Dietary protein levels of the four groups were 13.85 %, 14.41 %, 15.63 %, and 16.30 %. Results revealed that, compared with the 13.85 % crude protein (CP) group, the 15.63 % CP group experienced significantly enhanced final body weight, average daily gain, egg production, and egg mass. Compared with the 16.30 % CP group, the other groups' serum concentrations of immunoglobulin G (IgG) and immunoglobulin M (IgM) were significantly reduced. Compared with the 16.30 % CP group, the 13.85 % and 15.63 % groups had increased CP utilization rates but reduced nitrogen emission rate, and daily per egg and per kilogram egg nitrogen emissions rose with increased dietary protein levels. Compared to the 13.85 % and 14.41 % CP groups, the 16.30 % CP group exhibited a significant increase in the expression of genes related to amino acids and carbohydrate metabolic pathways. According to the linear discriminant analysis effect size diagram, the predominant bacteria in the 15.63 % CP group (e.g., Subdoligranulum, and Ruminococcaceae_UCG-013) were significantly related to CP utilization. The results of this study emphasize that production performance is significantly reduced when protein levels are too low, whereas too high protein levels lead to gut microbiota imbalance and a reduction in the utilization efficiency of nutrients. Therefore, on the premise of ensuring the health of hens, the structure of the gut microbiota can be improved by appropriately reducing protein levels, which helps to balance the relationships among host health, productivity, resources, and the environment.

The influence of whole-corn feeding method during the finishing stage on the performance of overfed mule ducks

The aim of this trial was to compare 2 feeding systems based on whole corn, a loose-mix and a free-choice feeding system, during the finishing stage on the performance of ducks. Five hundred sixteen day-old male mule ducks (Muscovy drake × Pekin duck) were divided into 3 groups that differed in the presentation of the diet they received between 58 and 88 d of age: a complete pelleted diet (Control (CON) group; AMEn 12.1 MJ/kg, CP 15.0%) containing 500 g of corn per kg; or whole corn (AMEn 13.9 MJ/kg, CP 7.3%) and protein-rich pellets (AMEn 10.3 MJ/kg, CP 22.7%) in equal quantities mixed in the same feeders (loose-mix feeding [LMF] group) or in 2 separate feeders (free-choice feeding [FCF] group). From 89 to 99 d, 72 birds/group were overfed with a mixture containing mainly corn and water and then slaughtered to determine the weight and commercial value of the fatty liver. Feed intake was measured daily. Body weight (BW) was measured at 58, 88, and 99 d of age. From 58 to 88 d, total feed intake of the FCF group was +7% and +9% (+558 g and +672 g) higher than in the groups CON and LMF, respectively (P = 0.005). At 88 d, the BW was higher in the CON group than in the FCF group (4,959 vs. 4,778 g, P < 0.001), the LMF group being intermediate (4,874 g). During the experimental stage, the feed conversion ratio was higher in the FCF group than in the 2 others (+32%, P = 0.024), but the energy intake was similar between the 3 groups (92.6 MJ/duck, P = 0.353).After overfeeding (99 d), the BW (6,593 g), weight (642 g), and commercial grading of fatty liver were similar (P > 0.05) in the 3 groups. The present results suggest that loose-mix feeding during the finishing stage using whole corn is a solution for reducing feed cost.

Increasing persistency in lay and stabilising egg quality in longer laying cycles. What are the challenges?

In the past 50 years, selection starting initially at the breed level and then using quantitative genetics coupled with a sophisticated breeding pyramid, has resulted in a very productive hybrid for a variety of traits associated with egg production. One major trait currently being developed further is persistency of lay and the concept of the "long life" layer. Persistency in lay however cannot be achieved without due consideration of how to sustain egg quality and the health and welfare of the birds in longer laying cycles. These multiple goals require knowledge and consideration of the bird's physiology, nutritional requirements, which vary depending on age and management system, reproductive status and choice of the selection criteria applied. The recent advent of molecular genetics offers considerable hope that these multiple elements can be balanced for the good of all in the industry including the hens. The "long life" layer, which will be capable of producing 500 eggs in a laying cycle of 100 weeks, is therefore on the horizon, bringing with it the benefits of a more efficient utilisation of diminishing resources, including land, water, raw materials for feed as well as a reduction in waste, and an overall reduced carbon footprint.