BestBETs for Vets are generated by the Centre for Evidence-based Veterinary Medicine at the University of Nottingham to help answer specific questions and assist in clinical decision making. Although evidence is often limited, they aim to find, present and draw conclusions from the best available evidence, using a standardised framework. A more detailed description of how BestBETs for Vets are produced was published in Veterinary Record earlier this year (VR, April 4, 2015, vol 176, pp 354-356)
- British Veterinary Association
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You are called out to attend to a neonatal Holstein heifer calf with diarrhoea. After successfully treating the calf with fluid therapy, you begin a thorough discussion of the risk factors for neonatal diarrhoea and get on to the subject of colostrum management, emphasising that prompt and adequate colostrum is essential for neonatal calf health. The farmer points out that he has a very high Johne's disease prevalence and so tries to snatch rear heifer calves and feed them frozen colostrum from ‘clean’ cows, but he struggles to store enough. You suggest using a plasma-derived colostrum product due to its simplicity, but the farmer is very cynical and, although you manage to convince him that these products will be Johne's disease-free and that they may well help with the neonatal diarrhoea, he asks whether the heifers will perform as well in the long term. Due to his Johne's disease prevalence, he has a high culling rate and wants his heifers to last in the herd.
In [calves] does [giving plasma-derived colostrum compared to maternally derived colostrum at birth] [decrease life expectancy]?
The search strategy can be viewed at http://bestbetsforvets.org/bet/147, it is also available as a supplement to this article on Veterinary Record's website at http://veterinaryrecord.bmj.com/content/177/15/393
▪ 46 papers found in Medline search
▪ 43 papers excluded as they did not meet the question
▪ Three total relevant papers from Medline
▪ 92 papers found in CAB search
▪ 87 papers excluded as they did not meet the question
▪ Two papers excluded as they are review articles/in vitro research/conference proceedings
▪ Three total relevant papers from CAB
▪ Three relevant papers from both Medline and CAB Abstracts.
Search last performed
September 9, 2015.
Only two of the three ‘usable’ papers were included in the summary of evidence, as the papers of two of the studies appeared to include the same cohort of calves.
Summary of evidence
Paper 1: Effect of feeding maternal colostrum or plasma-derived or colostrum-derived colostrum replacer on passive transfer of immunity, health and performance of preweaning heifer calves (Priestley and others 2013).
Patient group: Holstein heifer calves from birth to weaning, n=150.
Study type: Randomised controlled trial.
Outcomes: Death of cows; birth weight; weight gain; weaning weight; serum total protein; IgG levels; and disease incidence were measured.
Key results: There was no significant difference in mortality between maternally derived colostrum and plasma-derived colostrum groups (P=0.22). Serum total protein (P<0.001) and serum IgG (P<0.0001) was significantly higher in the maternally derived colostrum group compared to the plasma-derived colostrum group. Weaning weights were significantly greater in the maternally derived colostrum group (P=0.002) than the plasma-derived group. Weight gain from birth to weaning was significantly greater in the maternally derived colostrum group (P=0.002) than the plasma-derived group. Morbidity was significantly lower in the maternally derived colostrum group (P=0.04) than the plasma-derived group.
Study weaknesses: It was calculated that 50 calves were needed in each group, yet only 49 per group were used in the analysis. Due to losses during the study, the number of calves used in the analysis for weight gain by weaning was even further reduced
Paper 2: Effect of a plasma-derived colostrum replacement feeding program on adult performance and longevity in Holstein cows (Pithua and others 2010).
Patient group: Heifer calves from birth to approximately 54 months of age, n=497.
Study type: Controlled clinical trial.
Outcomes: Death, culling and combined death/culling for any reason from birth to 54 months of age, and from first calving to 54 months of age; breeding performance indices (age at first calving, birth to first calving interval, number of inseminations per conception and calving to conception interval); and milk yield indices (milk yield in first and second lactation, life time milk yield and length of lactations) were measured.
Key results: There was no significant difference between groups in the number of calves that died (P=0.35), were culled (P=0.59) or died or were culled (P=0.78) from birth up to 54 months of age. The hazard ratio comparing combined death and culling events between colostrum replacer and maternally derived colostrum was 1.1 (P=0.61). There was no significant difference between groups in the number of calves that died (P=0.60), were culled (P= 0.94) or died or were culled (P=0.71) from first calving up to 54 months of age. The hazard ratio comparing death events between colostrum replacer and maternally derived colostrum was 1.22 (P=0.46). There was no observed difference between groups in the length of time to combined death or culling. Feeding colostrum replacer compared to maternally derived colostrum had no effect on any of the breeding performance outcomes: age at first calving (P=0.34); number of inseminations per conception (first calving P=0.83, second calving P=0.32); calving to conception interval (first calving P=0.70, second calving P=0.21). Feeding colostrum replacer compared to maternally derived colostrum had no effect on milk yield in the second lactation (P=0.18), or on total milk yield (P=0.50), but did significantly decrease milk yield in the first lactation (P=0.02).
Study weaknesses: A sample size calculation was not undertaken. Calves were not randomised to treatment groups, instead a systematic allocation procedure was used. Groups were not of even size: 261 calves received maternal colostrum, whereas 236 received colostrum replacer. This was due to lack of adherence to the allocation procedure at the beginning of the trial. It is unclear if the outcomes were assessed blind.
The calf feeding protocol used was slightly different between farms in terms of number of feedings, volume given at each feeding, and method of administrations (bottle or oesophageal feeding tube) at each feeding, both between and within the studies. However, overall, each calf received the same amount of maternally derived or plasma-derived colostrum within the correct time frame, so this is unlikely to have affected the results. The two studies measured different survival outcomes. Pithua and others recorded data up to 54 months of age, whereas Priestley and others only recorded data until weaning. This means that it was hard for us to directly compare the findings of the studies.
Feeding plasma-derived colostrum replacer rather than maternally derived colostrum appears to have no detrimental effect on survival of calves to weaning or 54 months of age.