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Neonate immunity, growth and puberty in dairy calves: Influence of dietary conjugated linoleic acid supplementation of the dam
Dissertation (MSc (Veterinary Reproduction))--University of Pretoria, 2016.
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| Format: | Thesis |
| Language: | English |
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2026
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| _version_ | 1867613629089579008 |
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| access_status_str | Open Access |
| author2 | Esposito, Giulia |
| author_browse | Esposito, Giulia |
| author_facet | Esposito, Giulia |
| collection | Thesis |
| description | Dissertation (MSc (Veterinary Reproduction))--University of Pretoria, 2016. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/110177 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:39:11.002Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2026 |
| publishDateRange | 2026 |
| publishDateSort | 2026 |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/110177 Neonate immunity, growth and puberty in dairy calves: Influence of dietary conjugated linoleic acid supplementation of the dam Esposito, Giulia dracardoso@gmail.com Cardoso, Claudia Colostrum CLA ADG growth puberty Dissertation (MSc (Veterinary Reproduction))--University of Pretoria, 2016. Colostrum provides the neonate calf with maturational, immune-modulatory and antimicrobial factors. Feeding isomers of conjugated linoleic acid (CLA) reportedly increases immunoglobulins (Ig) production in rats and circulating IGF-I levels in cows. The objective of the study was to evaluate the effect of CLA dietary supplementation of the dam on colostrum quality and calves immune system, growth and attainment of puberty. Thirty-four Holstein cows, blocked by parity, body weight and body condition score were randomly assigned to two groups: control (CTL) (100gr/cow/day of calcium salts) and CLA (100 gr/cow/day of CLA). Individual top-dressed supplementation started 20±7 days before calving until 35 days in milk. From day 0 to 3 each calf was individually fed its mother’s colostrum. The same was sampled for immunoglobulins G (IgG) quantification. Calves were bled every other day from 0 to 15 days for IgG and total protein (TP) levels. Weekly, from day 7 to 35, calves were bled for growth hormone (GH) and insulin-like growth factor I (IGF-I) quantification; furthermore body measurements and weight were recorded for growth rate. Attainment of puberty was monitored from five (males) and seven (females) months respectively. Monthly, body measurements and weight were recorded. In males, scrotal circumference (SC) was measured. Semen collection by electroejaculation was performed in animals with SC > 23 cm for evaluation of semen parameters (volume, colour, mass and individual motility, concentration). Puberty was declared with concentration of 50 million spermatozoa/ejaculate with at least 10% progressive motility. Females were bled fortnightly for progesterone levels, while ovarian activity was monitored by ultrasonography. Puberty was attained when a corpus luteum was present and progesterone levels were ≥ 1 ng/mL. 1 2 Data were analysed with SAS 9.3 (SAS Institute Inc Cary, NC). Average daily gain (ADG) of each animal was calculated between birth and weaning and between weaning and final body weight (300 days) by one-way ANOVA using the general linear model (GLM, SAS 9.3) including treatment and gender as fixed effects. For ADG at final weight, weaning weight was included as covariate. The same analysis was used to compare weights at birth and attainment of puberty, including in the model treatment and gender as fixed effects and dam’s weight as covariate. Levels of IgG, TP, GH and IGF-I were analysed by ANOVA using GLM, SAS 9.3 with a mathematical model where gender, treatment, age, interactions treatment/age and treatment/gender were the fixed effects while the calf was the random effect. Decrease rate of colostrum parameters were calculated by regression of concentration against time (PROC REG, SAS 9.3). Slopes were compared with F-test. When the effect of gender and its interaction with the treatment were significant, data were analysed separately by gender. Growth was analysed in two periods, weight to 35 days and 180 to 300 days by ANOVA using the proc. mixed model (SAS 9.3) were gender, treatment, age and interactions treatment x age were fixed effects while the calf was the random effect. Birth weight was used as covariate. Group and gender growth curves on the period 180 to 300 days were calculated by regression of weights against time (PROC REG, SAS 9.3). Regression slopes were compared with F-test. Significance was declared at P _ 0.05 while trend was declared at P _ 0.1. A trend of higher TP levels was detected in CLA calves (P _ 0.1). CLA male calves showed higher ADG pre-weaning (P _ 0.05) and growth rate from 180 days of age compared to control (P _ 0.01). Furthermore, a trend for higher SC (P _ 0.1) and significant major ejaculate volume (P _ 0.05) was observed in the CLA group. In conclusion, colostrum from CLA supplemented dams proved to have a supplementation time-dependant effect on calves’ ADG pre-weaning and carry over effects possibly mediated by improved feed efficiency on growth pre-puberty. However, it failed to alter age at attainment of puberty. Production Animal Studies MSc (Veterinary Reproduction) 2026-05-15T17:26:34Z 2026-05-15T17:26:34Z 16/12/09 2016 Dissertation http://hdl.handle.net/2263/110177 en application/pdf |
| spellingShingle | Colostrum CLA ADG growth puberty Neonate immunity, growth and puberty in dairy calves: Influence of dietary conjugated linoleic acid supplementation of the dam |
| title | Neonate immunity, growth and puberty in dairy calves: Influence of dietary conjugated linoleic acid supplementation of the dam |
| title_full | Neonate immunity, growth and puberty in dairy calves: Influence of dietary conjugated linoleic acid supplementation of the dam |
| title_fullStr | Neonate immunity, growth and puberty in dairy calves: Influence of dietary conjugated linoleic acid supplementation of the dam |
| title_full_unstemmed | Neonate immunity, growth and puberty in dairy calves: Influence of dietary conjugated linoleic acid supplementation of the dam |
| title_short | Neonate immunity, growth and puberty in dairy calves: Influence of dietary conjugated linoleic acid supplementation of the dam |
| title_sort | neonate immunity growth and puberty in dairy calves influence of dietary conjugated linoleic acid supplementation of the dam |
| topic | Colostrum CLA ADG growth puberty |
| url | http://hdl.handle.net/2263/110177 |