Discipline: breeding; Keywords: crossbreeding, herd management, herd profitability
The crossing of parents of unrelated strains, or breeds, often results in offspring that are more robust, with better health, growth, fertility, and production. In dairy cattle, crossbreeding has also been shown to improve functional traits such as fertility, health, calving ability, and survival. Despite the compelling evidence of the benefits of crossbreeding, the majority of dairy farmers still prefer traditional pure breeding, and crossbreeding in dairy cattle is far from common. The reluctance of farmers to use crossbreeding as a strategy in their herds may be due to their lack of knowledge of the economic gains. The aims of a study by Dr J.B. Clasen and colleagues in Sweden therefore, were to simulate the outcomes for herd dynamics and profitability when terminal or rotational crossbreeding with Swedish Holstein × Swedish Red are implemented and to compare these outcomes with those for pure breeding with Swedish Holstein. The authors hypothesized that crossbreeding between the two breeds would generate economic gains in both organic and conventional Swedish herds. The results of their study were published in the Journal of Dairy Science, Volume 103 of 2020, page 514 to 528, the title being: Economic consequences of dairy crossbreeding in conventional and organic herds in Sweden.
Two base herds were simulated using a stochastic herd simulation model, SimHerd Crossbred. The herds reflected average Swedish conventional and organic herds having purebred Swedish Holstein. For each base herd, three breeding strategies were simulated: pure breeding, two-breed terminal crossbreeding, and two-breed rotational crossbreeding. The terminal crossbreeding implied having a nucleus of Swedish Holstein and a proportion of F1 Swedish Red × Swedish Holstein crossbred cows within the same herd. The crossbreds in this herd did not produce replacement heifers but exclusively beef × dairy cross calves. Beef semen was also used in the pure breeding (10–20% in cows) and the rotational crossbreeding (40% in cows) to retain a limited surplus of replacement heifers. To ensure an adequate number of crossbreds in the terminal crossbreeding strategy, X-sorted sexed semen was used for insemination in all the purebred heifers. The outcome was 67% purebred and 31% F1 crossbreds in the herd. In addition, 31% heterosis was expressed compared with 67% heterosis expressed using the two-breed rotational crossbreeding strategy.
Compared with pure breeding, crossbreeding increased the annual contribution margin per cow by €20 to €59, with the rotational crossbreeding strategy creating the largest profitability. The increased profitability was mainly due to improved functional traits, especially fertility. For the conventional production system, the replacement rate was 39.3% in pure breeding which decreased to 35.8 and 30.1% in terminal and rotational crossbreeding, respectively. Similar changes happened in the organic production system. Additionally, crossbreeding earned €22 to €42 more annually per cow from selling live calves for slaughter due to the extended use of beef semen. Milk production was similar between pure breeding and terminal crossbreeding, and only decreased 1 to 2% in rotational crossbreeding.
These results show that crossbreeding between Swedish Holstein and Swedish Red can be profitable in both conventional and organic Swedish herds using the strategies which have been simulated. However, some aspects remain to be investigated, such as the economically optimal breeding strategy, genetic improvement, and transition strategies. In general also, the breeds considered for crossbreeding must be economically similar to make the crossbreeding system economically beneficial relative to pure breeding. Swedish Holstein and Swedish Red were previously estimated to be at the same economic level, with the former providing higher income from milk yield and the latter incur lower costs related to health and other functional traits. In other words, the two breeds complement the strengths and weaknesses of each other and are therefore potentially suited for use in a crossbreeding system.