Cuniculture: impacts of moderate heat stress on doe and litter performance Logo Feedia

Even between 19°C and 25°C, heat affects the feed intake and performance of both does and their kits. Discover the results of an exclusive 12-year meta-analysis and the nutritional levers to secure performance in the maternity.

Rising temperatures impact the performance of rabbit farms. Many studies demonstrate this, but they often focus on extreme conditions—typically seen in tropical climates—which are not representative of European commercial farms. The latter, thanks to modern housing equipped with ventilation and cooling systems, maintain more controlled environments. However, the summer period and the late summer transition continue to affect farm performance.

This report decodes the results of an exclusive Techna meta-analysis, covering 12 years of data from 83 batches in an experimental station. It quantifies the effects of heat, even when moderate, specifically within an average temperature range of 19°C to 25°C.

Even moderate heat significantly reduces feed intake

Feed intake is the first indicator affected by a rise in temperature and serves as the primary lever for zootechnical performance. Indeed, animals eat less to limit their own production of metabolic heat.

Consequently, does reduce their intake as soon as kindling is over (by approximately -20g/day). The same applies to kits between 25 and 32 days of age (approximately -3g/day).

To illustrate the scale of this phenomenon, a 6°C temperature increase (from 19°C to 25°C) results in a decrease in cage feed intake of 112.8g/day. According to the study's database, this represents a 21.9% drop in total intake.

Average feed intake

Doe and kit performance is directly penalised by rising temperatures

The reduction in feed intake, combined with the physiological stress induced by heat-even below 25°C-inevitably degrades key performance indicators in the maternity.

The most direct consequence of lower consumption is a significant slowdown in kit growth:

  • From birth (87.2g between 19-21°C, 84.3g between 21-23°C, and 83.4g between 23-25°C).
  • Up to weaning at 32 days (926.3g between 19-21°C, 905.9g between 21-23°C, and 876.9g between 23-25°C).
Average kit weight

Beyond growth, other essential parameters are affected, revealing a decline in the animals' overall condition:

  • General health: both kit and doe viability decrease significantly as temperatures rise.

  • Doe body weight balance: females lose weight between successive weanings. This weight loss is primarily due to poorer recovery between the 11th and 25th day of lactation (+219g between 23-25°C compared to +322g between 19-21°C). This is a critical phase where the doe should normally replenish her reserves. This inability to rebuild body reserves has serious implications, as it weakens the doe and sets the stage for the fertility declines observed in consecutive batches.

It is, however, important to note that within this moderate temperature range (19-25°C), direct reproductive performance (palpation rate, prolificacy) does not appear to be impacted. This effect is generally only observed during more extreme thermal stress.

Doe body weight change

The effects of heat persist in consecutive batches, despite an apparent recovery

Analysing the "post-heat" effect is crucial, as it reveals a misleading situation. While kit growth and doe weight appear to recover quickly after a heat period, underlying indicators such as fertility suffer a lasting decline.

Palpation rate does

This "heat debt" impacts the profitability of autumn batches long after temperatures have dropped, creating a "false recovery" trap. In fact, certain parameters -such as palpation rate and doe viability- do not fully recover:

  • Palpation rate: (91.0% before heat, 90.3% during heat, 88.6% after heat)
  • Female viability: (93.1% before heat, 91.8% during heat, 91.9% after heat)
Doe viability

Strategic recommendations

This analysis demonstrates unequivocally that even a moderate rise in temperature -well below heatwave levels- has negative and quantifiable technico-economic consequences for rabbit farms. It confirms that a rabbit's comfort zone is around 21°C; every additional degree forces the animals to divert resources towards thermoregulation at the expense of production.

Based on these findings, two strategic lines of action are essential:

  • Managing the environment
    It is vital to manage and limit temperature fluctuations as much as possible, particularly during the summer. Optimising the use of existing tools, such as dynamic ventilation and cooling systems, is a profitable investment to stabilise the environment and reduce the thermal range experienced by the animals.
  • Adapting the nutritional strategy
    Anticipation is key. Taking action as early as spring helps to consolidate the does' body condition before the onset of thermal stress. A tailored nutritional strategy must be implemented to support the animals' needs - not only during the summer but also in advance- to minimise the impact of heat on both does and their kits.

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