Effect of nutrient restriction during gestation on body composition changes in large and small mature size heifers and their offspring /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1986.
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| Subjects: | |
| Online Access: | Link to ProQuest copy Link to OAKTrust copy |
| Abstract: | A total of 46 pregnant, 2 yr old, crossbred heifers were used in a study to determine the impact of nutrient restriction during gestation on changes in live weight, empty body (EB) weight, EB protein and EB fat. Large mature size (MS) and small MS heifers were fed at either 1.0 (R) or 1.5% (NA) of body weight daily. The heifers were fed th eir respective diets from 90 d gestation until parturition and then fed ad libitum until weaning. Body composition was measured at 90, 200 d gestation and within 1 wk after parturition utilizing standard two-pool D20 dilution techniques. Restricted heifers lost 92 kg (20.5%) while NA heifers lost only 3.7 kg (1.0%) of liv e weight from 90 d gestation to parturition. EB protein averaged 63, 58, 54 and 51 (kg) at 90 d; increased to 67, 63, 57 and 57 (kg) at 200 d; but decreased to 57, 59, 47 and 56 (kg), respectively, following parturition. Restricted heifers lost 10 kg EB protein vs only 2.5 kg for NA heifers from 200 d to parturition. Restricted heifers lost more (P <.05) EB fat (98 vs 50 kg) than NA heifers. As a consequence, EB protein (% of EB weight) increased by 13.1 and 9.3% in R and NA heifers while EB fa t decreased by 31.7 and 23.5% from 90 d to parturition . Restricted heifers lost EB weight at a faster (P <.01) rate (312 vs 52 g /d). The NA heifers gained protein at a faster (P <.01) rate (63 vs 44 g/d and lost fat at a slower (P <.01) rate (-98 vs -238 g/d) than R heifers. Maintenance requirements (Mem) were 6.4% higher (P<.01), (169 vs 158 kcal/kg^.75), and efficiency of ME use was lower (31.2 vs 36.5%) for large MS than small MS heifers. Efficiency was 54% greater (P <.05) in early gestation than in late gestation (45.4 vs 29.4%). Efficiency decreased by 35% and MEm increased by 25% with advancing gestation. Preweaning growth of R dams was greater (P <.05) than NA dams. Milk production across all periods was similar for both R and NA dams. Steers from R dams grew slower from birth to weaning than steers from NA dams but similarly to heifer calves from both R or NA dams. |
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| Item Description: | "Major subject: Nutrition." Typescript (photocopy). Vita. |
| Physical Description: | viii, 91 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 80-90). |