The study explored the relationship between the performance of calves and calving season in a Mediterranean rangeland-based beef livestock system.Twenty multiparous Sarda cows,grazing on a natural pasture,with two dis...The study explored the relationship between the performance of calves and calving season in a Mediterranean rangeland-based beef livestock system.Twenty multiparous Sarda cows,grazing on a natural pasture,with two distinct calving periods(group A,11 animals,calving date 15/10/2016±16(means±s.d.),and group W,nine animals,calving date 26/01/2017±11)were used.Meteorological data,herbage quality,daily milk yield(DMY),total milk yield(TMY),body weight(BW)of cows and calf,body-weight daily gain(ADG)of calves,body condition score(BCS)and calving interval(CI)of cows were assessed.A mixed-effects model was used to DMY and ADG data while TMY,BCS,weaning weight(WW)and CI data were analyzed by a linear model.The most determining factors in the DMY and ADG were detected by means of partial least square regression(PLSR)procedure.Group W showed higher DMY(6.5±0.3 kg/d vs.4.5±0.3 kg/d,p<0.001)and TMY(1,189±70 kg vs.830±60 kg,p=0.002)than Group A,but this did not result in a greater ADG of calves(Group A:0.83±0.04 kg/d/animal and Group W:0.99±0.09 kg/d/animal,p-value not significant)or WW when adjusted for their age(Group A:216±14 kg/animal and Group W:250±22 kg/animal,p-value not significant).In contrast,the WW actually measured were higher in Group A than in Group W(257±7 kg vs.175±8 kg,p<0.001).The Group W cows experienced a minor CI than Group A cows(288±13 d vs.320±8 d,p=0.04).The results of PLSR suggest that the factors with utmost importance for both DMY and ADG were the age and the body-weight of cows,highlighting the excellent maternal ability of Sarda breed and its good adaptation to environment.展开更多
基金The excellent cooperation of Mr.Gianni Meloni,Stefano Picconi,Salvatore Pintus and Nino Lei as well as the staff of Foresta Burgos research farm and the laboratory staff of AGRIS is highly appreciated.
文摘The study explored the relationship between the performance of calves and calving season in a Mediterranean rangeland-based beef livestock system.Twenty multiparous Sarda cows,grazing on a natural pasture,with two distinct calving periods(group A,11 animals,calving date 15/10/2016±16(means±s.d.),and group W,nine animals,calving date 26/01/2017±11)were used.Meteorological data,herbage quality,daily milk yield(DMY),total milk yield(TMY),body weight(BW)of cows and calf,body-weight daily gain(ADG)of calves,body condition score(BCS)and calving interval(CI)of cows were assessed.A mixed-effects model was used to DMY and ADG data while TMY,BCS,weaning weight(WW)and CI data were analyzed by a linear model.The most determining factors in the DMY and ADG were detected by means of partial least square regression(PLSR)procedure.Group W showed higher DMY(6.5±0.3 kg/d vs.4.5±0.3 kg/d,p<0.001)and TMY(1,189±70 kg vs.830±60 kg,p=0.002)than Group A,but this did not result in a greater ADG of calves(Group A:0.83±0.04 kg/d/animal and Group W:0.99±0.09 kg/d/animal,p-value not significant)or WW when adjusted for their age(Group A:216±14 kg/animal and Group W:250±22 kg/animal,p-value not significant).In contrast,the WW actually measured were higher in Group A than in Group W(257±7 kg vs.175±8 kg,p<0.001).The Group W cows experienced a minor CI than Group A cows(288±13 d vs.320±8 d,p=0.04).The results of PLSR suggest that the factors with utmost importance for both DMY and ADG were the age and the body-weight of cows,highlighting the excellent maternal ability of Sarda breed and its good adaptation to environment.