Time budget, social and ingestive behaviours expressed by native beef cows in Mediterranean conditions

摘要

In order to evaluate the degree of adaptability of three native cattle breeds to the natural pastures of southern Italy, the diurnal grazing behavioural pattern was monitored on 84 multiparous cows: 28 Podolian (14 suckling and 14 non-suckling), 28 Chianina (14 suckling and 14 non-suckling) and 28 Romagnola (14 suckling and 14 non-suckling). From August to October 2009 ten sessions of 9 h of behavioural observations were performed, from 07.00 to 19.00 h, through continuous focal animal recording method. Every hour, bite rate was recorded and bite mass and botanical preferences were determined on hand-plucked samples. Chianina cows selected proportionally more percent legumes than Romagnola and Podolian animals (P<0.01), whereas Podolian cows chose a higher percentage of ferns (P<0.05). Grasses represented a large proportion of the diet ingested by cows; these plant species were predominantly ingested in a late stage of maturation, which, in turn, induced the animals to take larger bites. Conversely, bite rate was positively related to high quality forages and negatively related to bite mass. Due to low genetic diversity and "allelo-mimetic" behaviour, no marked differences were observed among Chianina, Romagnola and Podolian breeds in terms of activity budget, ingestive behaviour and chemical composition of the diet as assessed through hand plucking. Based on rough estimations, all three breeds were able to reach the minimum ingestion levels needed to cover their maintenance and productive requirements of energy and protein. The three genotypes spent most of their time on grazing activity, followed by walking, whereas less time was spent resting. Animals were more active during mornings and afternoons in terms of grazing and walking (P<0.05). Vocalizations were not influenced by breed but were significantly more frequent in cows with calf (4-5 months of age) than in non-suckling animals (P<0.001). The presence of calf had no significant effect on the other behavioural variables. Cows from different breeds expressed preferential spatial relationships with other members of the herd. These results along with the low levels of agonistic and non-agonistic interactions occurring between herd-mates suggest that extensive systems based on grazing allow social stability, expression of species-specific behaviours and fulfilment of maintenance and productive requirements of cows from native breeds