Abstract

The effects of selection and crossbreeding on New Zealand dairy industry return were evaluated with a deterministic simulation model over 25 years. Several crossbreeding strategies involving Holstein-Friesian (F), Jersey (J) and Ayrshire (A) cattle were evaluated. These strategies were straightbreeding, upgrading to F (UPGF), upgrading to J (UPGJ), upgrading to A, and two- and three-breed rotational crosses. Total production of milk, fat, protein, lactose and ash were calculated assuming that 12,000 kg dry matter/ha was eaten for 1,224,911 ha. Yields of standardised whole milk powder (WMP), casein and butter were calculated. For the base year all the protein was utilised in WMP and for subsequent years, some increases in protein were sold in the form of casein. Casein and WMP were valued at $6.00 and $3.31 per kg respectively over the 25 years, whereas butter was valued at $3.00 per kg for base year production levels and $0.45 per kg for marginal increases in production. Production for the base year was 9,874 million l milk, 467 million kg fat, 359 million kg protein and 464 million kg lactose which yielded 1,263 million kg WMP and 157 million kg butter for an industry return of $4,646 million. Relative to the base year, UPGF resulted in the largest increase in WMP (128 million kg, 10%), the lowest increase in casein (36 million kg) and increased returns by $639 million (14%). UPGJ resulted in the lowest increase in WMP (73 million kg, 6.0%), the largest increases in butter (67 million kg, 43%), casein (65 million kg) and returns ($662 million, 14%). Two-breed rotational (F,J) resulted in product flows for WMP and butter that were above the intermediate between UPGF and UPGJ but return that was equal to UPGJ. Selection within-breed in combination with crossbreeding can increase industry returns. However, the net financial outcome of all changes must be assessed taking into account farm expenses, income from culled stock and factory costs in processing milk with different composition in order to determine optimum crossbreeding strategies.

N, Lopez-Villalobos, DJ Garrick, RJ Spelman, CW Holmes, and HT Blair

Proceedings of the New Zealand Society of Animal Production, Volume 58, , 64-67, 1998