Univ. of Arkansas workers analyzed 25 years of data from five breed groups of cows to determine variables affecting cow behavior at calving time. Postpartum maternal behavior scores (MBS) were recorded on 5070 births representing 142 sires. Breeds were Angus, Charolais, Hereford, Polled Hereford, and Red Poll. The scoring system was on a 1 to 4 basis as follows: 1=Very aggressive, cow fought handler to protect calf; 2=Very attentive, mild aggression; 3=Indifferent, showed no aggression but remained in sight of calf; 4=Apathetic, cow showed no emotion toward calf.

Three- and four-year-old cows had significantly higher (P<0.05) MBS than 5-year-old and older cows. Cows giving birth to thin calves had significantly higher (P<0.05) MBS than those with fleshier calves. MBS scores by breed were: Angus, 2.10; Charolais, 2.24; Polled Hereford, 2.34; Hereford, 2.39; Red Poll, 2.47. Angus and Charolais were significantly more aggressive/protective (P<0.05) than the other three breeds.

Perhaps the most interesting findings were the highly significant (P<0.001) differences in calf survival rate between maternal behavior groups. These results are summarized in Table 1.

Table 1. Cow maternal behavior score and calf survivability rate
Cow maternal behavior score	Calf survivability, %
1	93%
2	86%
3	77%
4	60%

As shown above, calf survival rate declined when cow behavior became less aggressive/protective. Conversely, calf survivability rate increased markedly as maternal behavior became more aggressive/protective. The authors stated these results indicate that the more attentive cows at birth enhanced survivability of their offspring, whether caused by protection from predation or other factors that might have been involved (Sandelin et al. 2005. Prof. Anim. Sci. 2005. 21:73).