Innovation of prediction equations for milk composition estimation in milk recording at alternative sampling and half a day milking interval

At dairying cost reduction and effort about maintenance of milk recording (MR) range the MR cost decrease is also important. Aim was to revise the older prediction equations for alternative reduced milk sampling (morning - M or evening - E) for assurance of MR reliable results at twice milking a day (TMD) with balanced interval 12/12. Individual milk samples (n = 619 animals) were obtained during TMD (M, E and REF; n = 1 857 samples). Fat (F), protein (P), lactose (L) and somatic cell count (SCC) were analysed. Czech Fleckvieh and Holstein breeds were included. The reference values (REF) of day milking were obtained in regular MR (A4P). M and E milking results were related to the REF. Older prediction equations with lower validity because of time and breeding were revised: a) for F from M on REF y = 0.6932x + 1.381, where r = 0.752 and P ≤ 0.001; b) for P from M on REF y = 0.9432x + 0.2274, where r = 0.949 and P ≤ 0.001; c) for L from E on REF y = 0.8145x + 0.9095, where r = 0.87 and P ≤ 0.001; d) for log SCC from E on REF y = 0.8829x + 0.2367, where r = 0.94 and P ≤ 0.001. MR cost reduction is possible using method of alternative sampling including corresponding prediction equations.