# Early-Life Behavioral Time Budgets of a Local Dairy Sheep Breed in Indoor and Pasture Systems

## TL;DR

This study examines how Massese lambs' behaviors change in their first two months under indoor and pasture systems, revealing differences in weaning patterns.

## Contribution

The study identifies a behavior-based weaning window in Massese lambs linked to rearing systems.

## Key findings

- Suckling ceased at 40 days in indoor lambs and 50 days in pasture lambs.
- Pasture lambs spent more time moving and grazing compared to indoor lambs.
- Solid feed intake and rumination increased with age, showing a shift toward independence.

## Abstract

Knowledge about the early-life behavior of Massese sheep, a traditional Italian dairy breed, is still limited. This study aimed to describe how lamb behavior changes during the first two months of life when animals are raised in two common farming systems: Indoor housing and outdoor Pasture. Twenty-two lambs, staying continuously with their mothers and having free access to milk and solid feed, were observed regularly, and behaviors such as suckling, feeding (hay or concentrate, grazing), ruminating, resting, moving, and grooming were recorded over time. Results showed that as lambs grew, suckling and grooming gradually decreased, while eating solid food and ruminating increased, indicating a natural progression toward independence from the mother. The age at which suckling tended to stop differed between farming systems: 40 days in Indoor and 50 days in Pasture lambs. Lambs raised on Pasture spent more time moving and grazing, whereas indoor lambs spent more time resting. These findings represent a first step towards the identification of a behavior-based weaning window in Massese lambs.

Given the limited knowledge of early-life behavior in the Massese dairy breed, this study investigated lamb behavior from 5 to 70 days under two rearing conditions to identify age-related behavioral phases potentially relevant to weaning. Twenty-two Massese lambs were reared either in an Indoor housing system during the winter or in an outdoor Pasture system during the spring, in accordance with traditional seasonal management practices. Lambs in both systems remained with their dams with continuous access to milk. Behavioral variables, recorded weekly during daylight and expressed as relative frequencies, were analyzed against age and rearing system, using THI as covariate. Growth influenced most behaviors, with similar age-related trends across rearing systems. Suckling behavior decreased significantly with age, tending to cease at approximately 40 days in Indoor lambs and 50 days in Pasture lambs. Grooming also declined over time, indicating reduced affiliative interactions irrespective of the rearing system. In contrast, solid feed intake and rumination increased progressively, reflecting a transition toward nutritional independence. Pasture lambs engaged in moving and grazing activities while indoor lambs spent most of their time lying. These results suggest preliminary insights into a management context-associated, behavior-based weaning window in Massese lambs.