Organic farming: use of chickpeas (Cicer arietinum) in Maremmana young bulls diets.

Development of feeding strategies based on the available feed resources is one of the research efforts for organic livestock production. This problem is particularly relevant in marginal beef production areas of central and southern Italy, where traditionally local breeds are used and diets are based on home grown cereal with scarce or no use of expensive organic protein source. The present study aims to evaluate the effects of dietary inclusion of home grown chickpea (Cicer arietinum) on growth performance and carcass characteristics of Maremmana young bulls, organically farmed. The study was conduced in an extensive farm located in Viterbo province, in central Italy. Twelve Maremmana bulls (232 kg average live weight, 9 months of age) were allotted into two homogenous groups. The control group was fed the same diets used by the farmer prior to and during the experiment, based on barley meal, maize meal and alfalfa hay; four diets were used throughout the study. The experimental group was fed diets in which barley meal was substituted by chickpea meal. The dietary content of chickpea ranged from 23 to 11% (as fed basis). The average hay/concentrate ratio of diets was 60/40. The nutritive characteristics of the diets were, on average, 0.82 vs 0.83 Meat FU/kg DM and 11.0 vs 12.7 CP %DM, for control and experimental diets, respectively. Diets were not designed to be isocaloric or isonitrogenous, but to assess the effect of dietary inclusion of a protein source on performance of Maremmana bulls. Animals were weighted at the age of 9 months and thereafter every two weeks until to the fixed slaughter weight of 630 kg. Carcasses were scored for carcass conformation and fat score, according to SEUROP grading system. Average growth curves were calculated by the regression of weights against time. The growth curves showed a good fit to a linear -regression model (control group R2=0.94, b=0.009455; experimental group R2=0.93, b=0.0112018). Chickpea-fed bulls showed higher live weight from the age of 410 days onward. This finding is consistent with the high average daily gain (945 vs 1120 g day−1 for the control and experimental groups, respectively) and the younger slaughter age (675 vs 630 d) observed for chickpea-fed group. No differences were observed for carcass weight and dressing percentage (cold carcass weight/slaughter weight). Carcasses from bulls fed chickpea were graded as R (100%) in the SEUROP scale with a fat score of 3 (50%) and 4 (50%). Control carcasses were graded as R (40%) and O (60%) in the SEUROP scale with a fat score of 3 (50%) and 2 (50%). The higher fattening score of chickpea fed bulls suggests that some attention should be paid to the energy intake in last phase of finishing in order to prevent excessive fat deposition. Although, the chickpea cost was higher than that of barley, the estimated dietary costs were lower for chickpea-fed bulls, which reached slaughter weight 45 days before the control group. Overall, the use of home grown chickpea in organic diets for young bulls could be an advantageous choice for animal performance, feeding cost, crop rotation and sustainability.