This experiment was carried out to investigate the effects of different amounts of feeding energy and undegradable protein (UDP) in five weeks of late gestation on dry matter intake, health, milk yield and milk composition in the subsequent early lactation. twenty four Holstein friesian cows in late gestation were blocked into groups of two on the basis of gestation number (second and third). Within each group, animals were randomly allocated to one of the following three pre-calving treatments: ration 1 (NEL=1.27 Mcal/kg DM, CP=125 g/ kg DM); ration 2(NEL=1.47 Mcal/kg DM, CP=152 g/kg DM, with UDP = 50.2 g/ kg DM), and ration 3 (NEL=1.6 MCal/kg DM, CP=160 g/ kg DM, with UDP = 58g/kgDM). Following parturition, a single ration (NEL=1.65 Mcal/kg DM, CP=11g 6.5 g/kgDM, with UDP=55.2 g/kgDM) was offered ad libitum through the first 9 weeks of lactation. Animals did not differ in body condition score. Prepartum dry matter intake, milk yield were measured daily and milk samples analysed once weekly for fat, protein and lactose. Body condition scores were taken bi-weekly. Blood samples were taken also and analysed for glucose, calcium, phosphorous, protein, albumin and urea. Feed intake for all cows decreased in the few days before calving but the reduction was less pronounced among the rations. Prepartum ration did not significantly influence calf birth weight. Prepartum rations containing high energy and undegradable protein improved body condition score at calving through week 9 and were significant. Mean daily milk yield, corrected (FCM) for 4 and 3.2 percentage, fat and protein percentage were greater for ration 3 than other (P<0.05), but there was no significant. There were no significant differences between treatments in any of the blood metabolites measured before and after claving, although blood glucose concentration often was higher on treatment 3. These results demonstrated that NRC recommendation energy and protein especially UDP in the rations of dry and pregnant dairy cows may not be adequate for support of milk production and animal health in late gestation and early lactation. Higher feeding energy and undegradable protein in prepartum may increase body available protein reserved and improve postpartum performance.
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