STUDIES REGARDING HAEMATOLOGICAL INDICATORS OF LAYING HENS AND WELFARE ASSURED CONDITION

C. Spridon, Paula Viorela Druc, Carmen Irimia (Gavrilescu), Roxana Nicoleta Raţu, M.G. Usturoi

Abstract
    Investigations were carried out on ISA Brown laying hens, exploited in according with the specifications from rearing guide, in two rearing systems agreed by EU (in batteries and in loft). Blood samples were gathered in weeks 25, 35, 45 and 55 of birds life and served for determination of metabolic and enzymatic indicators. At hens which are the end of laying period were founded superior levels for proteins (higher with 21.2-25.7%), triglycerides (with 4.7-5.4%) and cholesterol (with 39.5-43.0%), in comparison with the birds which were at the beginning of laying. Also minerals had a similar dynamics, being determined in superior rates at the end of laying period, when were higher with 32.4-35.0% for calcium and with 29.6-31.2% for phosphorous that at beginning of laying period. Sanguine enzymes were correlated with birds’ laying rhythm, being higher at the end of laying with 8.3-8.5% for alanine aminotransferase and respectively, with 22.8-23.2% for aspartate aminotransferase, than at beginning of laying. The conclusion of the study was that biochemical indicators were correlated with laying intensity and with birds’ freedom of movement; their level in blood increasing gradually, at the same time with birds’ aging and decreasing of laid on eggs number, because were necessary smaller quantities of nutritive substances for eggs' forming.

Key words: hens, rearing system, biochemistry, welfare