The Response of Layer Hen Productivity and Egg Quality to an Additional Limestone Source When Offered Diets Differing in Calcium Concentrations and the Inclusion of Phytase

Animals

Aaron J. Cowieson¹  Stuart Wilkinson²  Isabelle Ruhnke³  Terence Zimazile Sibanda³  Cormac John O’Shea⁴  Dylana Caporale⁵  Mini Singh⁵  Stephan Bucker⁵  Yeasmin Akter⁵  Stephanie Maldonado⁵  Patrick Hughes⁵ 

[1] DSM Nutritional Products, Wurmisweg, 576 Kaiseraugst, Switzerland;Feedworks, Romsey, VIC 3434, Australia;School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia;School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2570, Australia;Sydney School of Veterinary Science, University of Sydney, Sydney, NSW 2570, Australia;

关键词: behavior;    choice-feeding;    feed;    performance;    poultry;    selection;   

DOI  :  10.3390/ani11102991

来源: DOAJ

【 摘 要 】

Laying hens require substantial quantities of calcium (Ca) to maintain egg production. However, maintaining recommended dietary Ca through inclusion of limestone may impede nutrient digestibility, including that of other minerals. It was hypothesized that providing a separate source of dietary Ca in the form of limestone grit would preserve Ca intake of hens offered diets containing suboptimal Ca concentrations. Furthermore, the impact of dietary phytase at a “superdosing” inclusion rate on the voluntary consumption of limestone grit was evaluated. One hundred and forty-four laying hens (19 weeks of age) were assigned to one of six dietary treatments in a 3 × 2 factorial arrangement comprising three dietary Ca concentrations (40, 30, and 20 g/kg) and ±dietary phytase (3500 FYT/kg diet) on an ad libitum basis for six weeks. Limestone grit (3.4 ± 1.0 mm) was provided to all hens ad libitum. Hens offered diets containing phytase consumed significantly less limestone grit p = 0.024). Egg weight, rate of lay, and egg mass were unaffected by dietary treatment (p > 0.05). Egg shell weight % (p < 0.001), shell thickness (p < 0.001), and shell breaking strength (p < 0.01) decreased in line with dietary Ca levels. In summary, dietary superdosing with phytase reduced the consumption of a separate limestone source in individually housed, early lay ISA Brown hens. Egg shell quality variables but not egg production worsened in line with lower dietary Ca levels.

【 授权许可】

Unknown