Dry Matter Intake and Blood Parameters of Nonlactating Holstein and Jersey Cows in Late Gestation

摘要

An experiment was conducted using 14 multiparous Holstein and 14 multiparous Jersey cows to determine if dry matter intake (DMI), specifically the decline in prepartum DMI and plasma parameters differed between breeds. Cows were blocked by expected calving date and received a dry cow total mixed ration (15% crude protein and 39% neutral detergent fiber) beginning 30 d before expected calving date. At calving, cows were switched to a lactation total mixed ration (17% crude protein and 33% neutral detergent fiber). Data were collected from d 23 prepartum to d 1 postpartum. Body weight was greater for Holsteins compared with Jerseys, but body condition score did not differ between breeds. Dry matter intake decreased for both Holsteins and Jerseys as parturition approached. The interaction of breed x day prepartum was significant for DMI with the magnitude of depression being greater for Holsteins compared with Jerseys. Plasma glucose and β-hydroxy-butyrate was similar between breeds. Plasma nonester-ified fatty acids (NEFA) were similar for the two breeds up to d 5 prepartum, but greater for Holsteins compared with Jerseys thereafter. The decline in prepartum DMI was positively correlated to plasma NEFA for Holsteins, but not for Jerseys. These results indicate that breed differences exist for the decline in prepartum DMI and plasma NEFA. In addition, these data show an association between prepartum DMI depression and plasma NEFA but do not suggest a causal relationship.