Antibiotics are routinely used in modern livestock production systems to treat and
prevent disease as well as to enhance livestock production and/or outputs. This
widespread use of antibiotics has led to a growing worldwide interest in antibioticfree
animal production. The addition of feed supplements such as nucleotides to
improve intestinal health as well as the early development of the immune system
needs to be investigated as an environmentally-friendly nutritional management
activity. In this study four (4) groups of newborn Holstein calves (n=24) were
evaluated after being treated as follows: Group 1 (Negative control), Group 2
(Investigational Veterinary Product (IVP) 1 – Oral supplement containing nucleotides,
vitamins, essential fatty acids, essential amino acids, pre-biotics and trace-minerals),
Group 3 (IVP 2 – Oral supplement containing nucleotides only at concentration and
dosage equal to IVP1) and Group 4 (IVP 3 - Parenteral glucocorticoids).
Results of the study indicated that:
Pre-colostral Serum IgG titres – After titration of the serum the anti-BVDV results
showed no difference between the study groups. All calves recorded a SP ratio of zero
value (0.00 ± 0.2) indicating that they had not been nursed by their mothers prior to
the start of the study. This was an entrance requirement for the calves to be enrolled
into the study.
Apparent Efficiency of Absorption % (AEA%) – Literature shows that an AEA% result
of between 20%-30% is good and 35% is excellent. The AEA% recorded for this
study fell within this range although there was no statistically significant difference
shown between the groups. In spite of a strictly controlled study protocol, 7 of the 24
calves (29%) still suffered from FPT in this study. The result falls within the range of
19% - 37% reported on United States of America (USA) farms by Doepel and Bartier
in 2014.
Serum cortisol - When compared to the control group, there were no statistical
significant difference evident for group 2 and group 3. However, the difference
between the Glucocorticoid – Group 4 and the control and other groups was
statistically significant (P = 0.0001; table 12) at the various time intervals. It was also evident that the inclusion of parenteral glucocorticoids (group 4) may have assisted in
prolonging the natural “gut closure”.
Gut closure – a positive 2 point linear regression forecast line indicated an increasing
trend in IgG absorption post-24 hours for group number 4 whilst groups 1, 2 and 3
each had a negative 2 point linear regression forecast line (figure 23).
Weight / ADG (D42) - Group 2 showed a statistically significant increase in mean D42
weight (P = 0.0042) of 59.167 kg ± 3.545 kg when compared to the other study
groups and compared to the control group (P = 0.0227). A comparison of the relative
increase in mass of groups indicated that Group 2 efficiently achieved this result with
a statistically significant ADG of 0.536 kg (P = 0.014) compared to the other study
groups and compared to the control group (P = 0.022). In addition, weight / FCR –
FCR was calculated for all groups as follows: G1 – 4.000 kg, G2 - 2.593 kg, G3 –
2.703 kg and G4 - 3.012 kg feed required for the production of 1 kg meat. The results
indicated that the group 2 feed input was the most economical followed by groups 3, 4
and control respectively.
In conclusion, it is evident that a nutritional supplement containing nucleotides,
vitamins, trace- minerals, essential fatty acids, essential amino acids and pre-biotics
may contribute significantly to important economic indicators such as weight gain,
ADG and FCR on a commercial dairy farm. / Environmental Sciences / Ph. D. (Environmental Science)
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:unisa/oai:uir.unisa.ac.za:10500/18949 |
| Date | 03 1900 |
| Creators | Schoombee, Wilhelm Sternberg |
| Contributors | Dewar, J. B., Bartkowiak-Higgo, A. J. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 1 online resource (xvi, 122 leaves) |
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