A prepartum diet supplemented with rolled sunflower seed increased calf weight, the incidence of dystocia and colostrum immunoglobulin content in Holstein cows
Supplementing dietary fats during late gestation period has certain advantages, but its effects on the incidence of dystocia, calf weight and colostrum quality are sparsely reported. Our objective was to investigate whether prepartum diets supplemented with sunflower or canola seed will affect calf birth-weight, calving-ease and colostrum immunoglobulin content. Pregnant Holstein cows, blocked by BCS, were assigned to 1-of-3 prepartum diets supplemented with canola (n=43, CAN; high oleic acid), sunflower (n=46, SUN; high linoleic acid), or control (no oilseed, n=43; CON) from 35 d (d -35) before expected calving date until parturition (d0). The concentrate portion of CAN- and SUN-diets contained 0.99 kg rolled oilseeds (DM basis) providing 0.27 kg/d oleic or 0.31 kg/d linoleic acid. Feed intake was recorded daily from d -35 to d0, and BCS was evaluated on d -35 and d0. After parturition, colostrum samples (n=13 per treatment) were collected at first milking and stored at -20°c until evaluating total fat, protein, fatty acid profile and IgG. Calves (n=132) were weighed at birth. Colostrum immunoglobulin content was estimated using a Brix refractometer. Cows fed CON had greater (P<0.05) mean DMI (15.3±0.6 kg/d) than those fed SUN (13.3±0.5) and CAN (13.5±0.5) during prepartum. The BCS on d -35 did not differ among treatments, but cows fed SUN (3.5±0.0) and CAN (3.5±0.0) had higher BCS on d0 than CON (3.4±0.0). The difference in BCS between d -35 and 0 was greater in SUN (0.22±0.02) than in CON (0.12±0.02) but not CAN (0.18±0.02).Total fat content of colostrum (%) was higher in CON (5.8±0.5) compared to CAN (4.5±0.4) and SUN (3.8±0.4), whereas, total protein (%) was significantly higher in SUN (15.0±0.6) than in CON (12.1±0.8) and CAN (12.5±0.8) fed cows. Mean colostrum immunoglobulin (brix%) was significantly higher in SUN (24.1±0.9) than in CON (20.4±1.0) and CAN (20.0±1.0). Cows given SUN during prepartum delivered heavier (kg) calves (44.3±0.9) than those fed CON (41.2±0.8) or CAN (42.9±0.8). Moreover, cows fed SUN (35%) during prepartum had a tendency to have higher incidence of dystocia at parturition than those fed CON (17%, P=0.07) or CAN (18%, P=0.08). In summary, cows fed supplemental oilseeds during late gestation consumed less DM than those fed a no oilseed control diet, but had greater BCS at parturition. Calf birth weight and the incidence of dystocia were higher in cows fed SUN; colostrum IgG and total protein content were also higher in cows fed SUN.