More growth and health in outdoor housing
Thorough calf rearing is essential for good performance as a dairy cow. With a high feeding regime and an all-in, all-out housing in small, fixed groups, calves perform best. For example, research by Dairy Campus/WUR with 224 breeding calves in four different rounds. CalfOTel's outdoor housing in group hutches came out well in this investigation. The calves grew significantly faster and less antibiotics were needed. All-in, all-out with small, fixed groups seem to be an important key to success.
Study
Three alternative concepts used in the rearing of calves from 0 to 4 months old were tested in relation to their references, i.e. regular accommodation, regular milk schedule and regular feed.
| Test factor | Code | Reference | Alternative treatment | >Duration |
| Accommodation | H | H1: regular | H2: calf accommodation in accordance with VDK Products | 0-18 weeks |
| Milk | M | M1: regular | M2: high artificial milk schedule in accordance with Trouw Nutrition | 0-9 weeks |
| Coarse/concentrated feed | R | R1: regular | R2: all-in-one mixture in accordance with ForFarmers | 0-18 weeks |
Animals: 224 calves in 4 rounds of 56 animals, kept at Dairy Campus from 0 to 4 months, then kept at an external rearing farm for up to 6 months, after which end measurements were taken.
Results
How to read this report: The effects of the three test factors were tested statistically separately from each other compared to their references. Only statistically significant differences are discussed here.
Weight: at 9 weeks
- In VDK accommodation, 9-week-old calves were 3.1 kg heavier than calves in regular accommodation. Growth from birth to 9 weeks was 59 g/day higher.
- With a high milk schedule, 9-week-old calves were 2.7 kg heavier than calves on a regular milk schedule. Growth from birth to 9 weeks was 38 g/day higher.
Weight: at 18 weeks
- In VDK accommodation, 18-week-old calves were 8.5 kg heavier than calves in regular accommodation. Growth from birth to 18 weeks was 71 g/day higher.
- With a high milk schedule, 18-week-old calves were 4.8 kg heavier than calves on a regular milk schedule. Growth from birth to 18 weeks was 36 g/day higher.
Weight: at 26 weeks
- The weight and growth of calves reared in VDK accommodation were on average still higher than in calves kept in regular accommodation, but the differences were no longer significant.
- With a high milk schedule (from 0 to 9 weeks), 26-week-old calves were 6.7 kg heavier than calves on a regular milk schedule. Growth from birth to 26 weeks was 36 g/day higher.
Health: IgG in serum
Immunoglobulin G are antibodies in the blood and can contribute to defence against infections. IgG is a measure of the potential capacity of the immune system, and was measured on day 2 and in weeks 6 and 10.
- The IgG in serum on day 2 did not differ significantly between regular and alternative treatments, indicating an equivalent baseline situation.
- In this study, the IgG in serum on day 2 was mainly determined by the IgG content in the first colostrum feed and the amount of the first colostrum feed, and at an average of 14.2 mg/ml it was above the lower limit of 10 mg/ml for adequate passive immunity.
- In this study, the IgG in serum on day 2 displayed no relationship to growth and health in later life.
- At 6 weeks old, the IgG titre in calves with the all-in-one mixture was 1.84 mg/ml (significantly) lower than in calves with regular coarse and concentrated feed, but in week 10 it was actually 2.65 mg/ml higher (non-significant). The clinical relevance of these differences is unclear.
Health: Acute phase proteins
Acute phase proteins (haptoglobin) are proteins in blood whose concentration increases at an early stage of inflammation. Acute phase proteins are a measure of the presence of inflammatory responses and are measured at three ages (day 2, week 6, week 10).
- At 10 weeks of age, the haptoglobin content in calves fed the all-in-one mixture (0.10 g/L) was significantly higher than in calves being given regular coarse and concentrated feed (0.05 g/L). This could indicate more inflammation, but both levels are favourable compared to operational averages (0.08 – 0.18 g/L) as we know from the literature.
Health: Reaction to rabies vaccination
At 6 weeks old, the calves were inoculated with a rabies vaccine. At the age of 10 weeks, the specific anti-rabies antibodies in blood serum were measured to characterise the humoral (non-cellular) defences after vaccination.
- Calves fed the all-in-one mixture displayed a better humoral immune response (antibody titre was 0.47 higher) than calves given the regular coarse and concentrated feed.
Health: Qualitative assessment
Calves were clinically assessed by a veterinarian once a month on a wide range of health aspects. These were given weighting factors and added together to make up a disease score A. Disease score B is the same score except for the addition of an assessment of soiling by the calf.
- Calves in VDK accommodation displayed no (significant) difference in disease score A compared to calves in regular accommodation, but they did display a difference in disease score B, with calves in VDK accommodation being more soiled on average. (Explainable, because the reference calves are kept on gratings, which has been compared with housing on straw)
- Calves with the high milk schedule displayed no (significant) difference in disease score A compared to calves with the regular milk schedule, but they did display a difference in disease score B, with calves with a high milk schedule being less soiled on average.
Health: Antibiotic treatments
For all the calves, the total number of treatment days with antibiotics were added together, as were the number of treatment days specifically against respiratory diseases.
- Calves in VDK accommodation displayed both fewer treatment days total (2.0 fewer days) and fewer treatment days for respiratory (1.7 fewer days) than calves in regular accommodation.
Behaviour
A few weeks after birth, calves were fitted with sensors around the neck (Smarttag Neck) and leg (Smarttag Leg) in order to automatically obtain an impression of their behaviour. Parameters are indicative of standing and lying (together 100% of time), steps, lying bouts, eating and rumination, and were calculated separately at 2, 3 and 4 months of age.
- Calves in VDK accommodation spent less time standing (i.e. spent more time lying down) than calves in regular accommodation; this applied at 2 months of age (1% less/24 hours), at 3 months of age (3% less/24 hours), and at 4 months of age (4% less/24 hours).
- Calves in VDK accommodation took fewer steps (i.e. spent more time lying down) than calves in regular accommodation; this applied at 3 months of age (507 steps/d less), and at 4 months of age (673 steps/d less).
- Calves in VDK accommodation lay down less often than calves in regular accommodation; this applied at 2 months of age (4 laying bouts/day fewer), at 3 months of age (4 laying bouts/day fewer), and at 4 months age (2 laying bouts/day fewer).
- Calves fed the all-in-one mixture spent less time eating (5% less/24 hours) and ruminating (9% less/24 hours) than calves given regular coarse and concentrated feed.
Conclusions
- High milk schedule and VDK accommodation system positively influenced the growth and health of calves compared to the references.
- The all-in-one mixture influenced a number of immune parameters compared to the reference, but the clinical relevance is unclear.
- Calves fed the all-in-one mixture displayed a higher specific rabies and IgG titre.
- Practical colostrum management appeared to be sufficient -> no effect of time of first colostrum feed on IgG in serum on day 2 (unknown aspect: did newborn calves drink milk from their mothers?).
- Calves in VDK accommodation were more soiled on average and calves with a high milk schedule were cleaner on average compared to the reference calves. (Explainable, because the reference calves are kept on gratings, which has been compared with housing on straw).
- Calves in VDK accommodation stood less, walked less and lay down less.
- Calves at 4 months of age who were fed the all-in-one mixture spent less time eating and ruminating.