Gandarillas Mónica, Elizalde Raimundo, Irazábal Sebastián, Calvache Iván, Keim Juan Pablo, Balocchi Oscar
Instituto de Producción Animal, Facultad de Ciencias Agrarias y Alimentarias, Universidad Austral de Chile, Independencia 631, Valdivia, Chile 5110566.
Instituto de Producción Animal, Facultad de Ciencias Agrarias y Alimentarias, Universidad Austral de Chile, Independencia 631, Valdivia, Chile 5110566.
Poult Sci. 2025 Apr 19;104(7):105188. doi: 10.1016/j.psj.2025.105188.
The aim of this study was to assess pasture growth, changes in botanical composition (BC), and the effects of pasture consumption on laying performance and egg quality in Isa Brown (IB) and White Leghorn (WL) hens. A total of thirty 18-week-old hens: 15 IB and 15 WL were used in this experiment which began after a two-week adaptation period. The hens were randomly assigned to three field replicates, each consisting of a 20 m² pasture plot with 5 hens per plot. Each hen was fed a balanced concentrate diet providing 120 g per hen per day. Pasture consumption and plant preference were monitored at 10-day intervals. After each monitoring period, the entire pasture plot was rotated. Pasture consumption, herbage mass and BC were assessed. External and internal egg quality were evaluated at the beginning and at the end of each 10-day period. Isa Brown hens consumed significantly more pasture compared to WL hens, with a mean consumption of 43.9 g per day versus 28.5 g per hen per day, respectively (P < 0.0001). The post-grazing pasture height was 4.31 cm higher in plots grazed by WL hens (10.9 cm) compared to those grazed by IB (6.7 cm). Moreover, botanical composition of the pasture before and after grazing indicated a clear preference for broadleaf species over legumes, and legumes were preferred over grass species by both genotypes. Egg quality results showed that IB vs. WL had greater egg weight (62.01 vs. 58.96 g), egg width (44.18 vs. 43.23 mm), egg shape index (78.96 vs. 77.65%), yolk color (10.13 vs. 8.97 units), yolk index (46.02 vs. 45.46%). In contrast, WL vs. IB was greater in eggshell percentage (9.87 vs. 9.71%), albumen index (13.27 vs. 10.89%) and haugh units (91.21 vs. 86.11). No difference for egg length were found between genotypes. These findings provide valuable insights into the grazing behavior and pasture preferences of different laying hen genotypes, as well as their potential impacts on pasture management and egg production systems.
本研究的目的是评估牧草生长、植物组成（BC）的变化，以及牧草采食对伊莎褐（IB）和白来航（WL）蛋鸡产蛋性能和蛋品质的影响。本实验共使用了30只18周龄的母鸡：15只IB和15只WL，实验在经过两周的适应期后开始。母鸡被随机分配到三个田间重复组，每组由一个20平方米的牧场地块组成，每个地块有5只母鸡。每只母鸡每天饲喂120克平衡的浓缩饲料。每隔10天监测一次牧草采食情况和植物偏好。在每个监测期结束后，将整个牧场地块进行轮作。评估牧草采食情况、牧草质量和植物组成。在每个10天周期开始和结束时评估蛋的外部和内部品质。与WL母鸡相比，IB母鸡采食的牧草显著更多，平均采食量分别为每天43.9克和每天28.5克（P < 0.0001）。WL母鸡放牧的地块（10.9厘米）放牧后的牧草高度比IB母鸡放牧的地块（6.7厘米）高4.31厘米。此外，放牧前后牧草的植物组成表明，两种基因型的母鸡都明显更喜欢阔叶物种而不是豆科植物，并且更喜欢豆科植物而不是禾本科植物。蛋品质结果显示，IB与WL相比，蛋重更大（62.01克对58.96克）、蛋宽更大（44.18毫米对43.23毫米）、蛋形指数更高（78.96%对77.65%）、蛋黄颜色更深（10.13单位对8.97单位）、蛋黄指数更高（46.02%对45.46%）。相比之下，WL与IB相比，蛋壳百分比更高（9.87%对9.71%）、蛋白指数更高（13.27%对10.89%）和哈夫单位更高（91.21对86.11）。不同基因型之间蛋长没有差异。这些发现为不同产蛋鸡基因型的放牧行为和牧草偏好，以及它们对牧场管理和蛋生产系统的潜在影响提供了有价值的见解。
