Final answer:
The problem of newborn piglets in the winter consists of several parts, including host-dependent offspring quality, off-host survival, and seasonally challenging environments.
Step-by-step explanation:
The question is asking how many parts make up the problem of newborn piglets in the winter.
In the given information, there are several relevant parts mentioned in relation to newborn piglets in the winter. These include:
- Host-dependent offspring quality
- Off-host survival affected by environmental harshness and duration of period outside the host
- Seasonally challenging environments and low survival probability of early-born small autumn pupae
- Risk of freezing for newborn pupae produced throughout winter months
- Cold tolerance and insulating snow cover for winter survival
These are some of the parts that make up the problem of newborn piglets in the winter.