Evaluation of 2 different treatment procedures after calving to improve harvesting of high-quantity and high-quality colostrum

摘要

The objective of this study was to evaluate 2 differenttreatment procedures at the first milking aftercalving to increase colostrum quantity and to improvecolostrum quality in dairy cows. We hypothesized thateither exogenous treatment with oxytocin or the presenceof the calf at first milking would lead to highercolostrum quantity and higher IgG concentration. Thestudy was conducted from October to December 2017on a commercial dairy farm in Germany. A total of 567cows at the time of calving were enrolled, but for thefinal analyses only 521 animals were considered. Thecows were randomly assigned on a daily basis into 1 of3 groups: (1) control group (n = 177), (2) applicationof 20 IU of oxytocin i.m. (OXY; n = 163), and (3)presence of the calf (CA; n = 181) before and duringmilking. Cows in the control and oxytocin grouphad no contact with their calves after calving and weremilked in a separate milking parlor. Cows in the oxytocingroup were injected with 20 IU of oxytocin i.m.3 min before manual stimulation. For cows in the thirdgroup, the calf was placed into a calf cart and locatedin front of the cow 3 min before manipulation of thecow. Colostrum quantity was determined by a digitalhanging scale. The colostrum quality was assessed withdigital Brix refractometry and ELISA. To evaluate theeffect of 2 different treatment procedures, a generalizedlinear mixed model was constructed using SPSS (SPSSInc., IBM, Ehningen, Germany). The mean (±SE) colostrumquantity was 4.17 ± 0.30 kg. The treatmentprocedures and the harvesting time after calving had noeffect on colostrum quantity. Parity, calf birth weight,and calving time affected colostrum quantity. Cowsin second parity had the lowest quantity of colostrum(3.74 ± 0.37 kg) compared with cows in parity 1 (4.75± 0.34 kg) and cows in parity 3 or greater (4.75 ± 0.38kg). Cows calving during the night (2200 until 0600 h;4.93 ± 0.37 kg) had the highest quantity of colostrumcompared with cows calving in the morning (0600 until1400 h; 4.17 ± 0.38 kg) or afternoon (1400 until 2200h; 4.14 ± 0.34 kg). Regarding colostrum quality, 48%of the colostrum samples contained ≥50 mg of IgG/mL.The mean IgG concentration was 54.6 ± 2.80 mg ofIgG/mL. Colostrum quality was affected by the treatmentprocedures, colostrum quantity, parity, calvingtime, harvesting time after calving, and the calving dayduring the week. Both treatment procedures (i.e., OXYwith mean IgG concentration results of 57.0 mg ofIgG/mL and CA with 56.0 mg of IgG/mL) resulted inhigher IgG concentrations in colostrum compared withthe control group (50.7 mg of IgG/mL). With increasingcolostrum quantity, the colostrum quality decreasedin primiparous and multiparous cows. A longer timelag between calving and milking negatively affected thecolostrum quality. Concentration of IgG was higher forcows in parity 3 or greater (64.6 ± 2.59 mg of IgG/mL) compared with cows in parity 1 (48.5 ± 2.86 mg ofIgG/mL) and cows in parity 2 (50.7 ± 2.89 mg of IgG/mL). Cows calving during the night had greater IgGconcentrations (60.4 ± 2.92 mg of IgG/mL) comparedwith cows calving in the morning (51.9 ± 2.98 mg ofIgG/mL) or afternoon (51.3 ± 2.71 mg of IgG/mL).Harvesting colostrum on quieter days, such as Sundays,resulted in higher IgG concentrations (61.4 ± 3.70 mgof IgG/mL). The assessment by Brix refractometry resultedin a mean result of 26.0 ± 0.20% Brix. Treatmentprocedures and the harvesting time after calving hadno effect on colostrum quality. A negative associationwas observed between colostrum quantity and qualityin primiparous and multiparous cows determined byBrix refractometry. Brix readings were greater for cowsin parity 3 or higher (27.7 ± 0.26% Brix) comparedwith cows in parity 1 (25.3 ± 0.30% Brix) and cowsin parity 2 (25.0 ± 0.32% Brix). In conclusion, thetreatment procedure for the first milking is irrelevant to improve the quantity of colostrum. Both treatmentprocedures, however, increased IgG concentrations asdetermined by ELISA.