The Impact of Neonatal Nutrition on the Growth, Fertility, Health, Milk Yield and Day Old Calf Performances of Holstein Dairy Heifers



Abd Kadir, S
(2017) The Impact of Neonatal Nutrition on the Growth, Fertility, Health, Milk Yield and Day Old Calf Performances of Holstein Dairy Heifers. Doctor of Philosophy thesis, University of Liverpool.

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Abstract

Neonatal nutrition may influence performance in later life in many species; however, there have been a few studies of this phenomenon in cattle. Determining if there are direct and residual effects of nutrition during the first 60 days of life may help optimise lifetime productivity. Underfeeding reduces calf weaning weight and delays puberty, which reduces the potential lifetime productivity of the dairy heifers. As well as repercussions on calf health, growth and welfare; many studies in human suggest that underfeeding of the newborn is a major risk factor for metabolic diseases in the adult. The aims of this study were to investigate the performances of Holstein heifers that were fed increased milk replacer compared to restricted volumes during their early life and to determine the impact of this on key performance indicators of these animals as future potential the best cows in the herd. Thus, a total of eighty eight heifers were included in this study, which forty seven heifers were in Group A (ad libitum milk replacer fed group) and forty one heifers were in Group R (restricted milk replacer fed group). They were enrolled 8 weeks prior to predicted calving based on artificial insemination dates of pregnancies confirmed by per rectum ultrasound examination of the uterus and 282 days of gestation period. The body weight, body condition score, withers and loin height, heart and belly girth, crown to rump length and hock fetlock length were recorded from 8 weeks prior to predicted calving until 30 weeks of postpartum. Blood samples were collected for β-hydroxybutyrate (BHB) concentration measurements and milk samples were collected for pregnane profiles analysis. Data on physical measurements (heifers and calves), pregnane profiles, reproductive parameters, BHB concentration values, health parameters, milk yield and milk components were analysed. The MilkBot parameters were used to describe the lactation curve between the 2 groups. There was no large effect of different pre-weaning feeding strategies during early life of heifers on their growth, fertility, health, milk yield and day old calf performances between Group A and Group R during first lactation period. There were no differences in MilkBot parameters; estimated scale, decay, persistence, peak milk and peak day between the 2 groups. However, several significant findings were observed; heifers in Group A had higher milk protein percentage and higher in somatic cell counts (SCC). Meanwhile, heifers in Group R had higher number of delayed ovulation type 1 (DOV1) profile, higher incidence of subclinical ketosis (SCK) and higher in estimated ramp. Another finding was heifers produced more milk following birth of a bull calf regardless of groups.

Item Type: Thesis (Doctor of Philosophy)
Divisions: Fac of Health & Life Sciences > Institute of Veterinary Science
Depositing User: Symplectic Admin
Date Deposited: 16 Aug 2018 11:48
Last Modified: 19 Aug 2020 15:36
DOI: 10.17638/03022404
Supervisors:
URI: http://livrepository.liverpool.ac.uk/id/eprint/3022404