The traits of production health and fertility in the NRF breed
For many years, most dairy cattle breeding programme have focused mainly on milk production traits. As a result, the genetic capacity for production has improved substantially. But milk yield has unfavorable genetic correlations with reproduction and health traits. Therefore, even though these traits have low heritabilities, not including them in the breeding programme may lead to poorer reproductive performance and more health problems in the long run. This is the main reason why farmers today experience increasing problems with fertility and health in their dairy cows.
Geno has for the last 30 years carried out a selection programme including health and fertility. The philosophy behind is that the best cow is high producing and well functioning. This has resulted in a substantial genetic gain not only for milk yield, butalso for fertility and mastitis resistance. Fig 1. The NRF Breed is probably the only population in the world that can present a positive genetic trend for these important traits. The salient point is to balance the weighting of the health/fertility traits against the production trait. At present the mentioned traits have the following weight:
Production 24%, mastitis resistance 22%, fertility 15 %
Fig. 1, Genetic trends
International merits
In the last years there has been an increasing interest for functional traits in dairy cattle, and the Norwegian Red has been chosen for comparison trials with Holstein in more countries.
- Moorepark in Fermoy Ireland imported 30 Norwegian Red heifers in 2000. The NRF cows has been compared to Holstein, Normande and Montbeliarde plus crossbreds of the French breeds with Holstein. Conclutions after 3 lactations, NRF has
o excellent reproductive performance
o good body condition score
o the lovest live weight
o numerically lower milk yield than Holstein
- To verify the first test of NRF in Ireland and to provide parameters for crossbreeding, Moorepark Ireland has started an extended trial with NRF heifers. In June 2004 400 female NRF arrived in Moorepark. The trial that is carried out on 50 farms will compare pure NRF, pure Holstein and crosses NRF x Holstein, 400 animals in each group.
- Crossbreeding-trial in California, crossbreds of Norwegian Red and Swedish Red with Holstein in 7 large dairies. Scandinavian crossbreds have:
o 7% higher production of protein and fat than Holstein
o Significant easier calving and fewer stillbirths than Holstein
o Significant lower somatic cell count than the other breeds.
(The Californian trial will be presented by professor Les Hansen at the IRCC)
Crossbreeding
Effective crossbreeding begins with two superior breeds. These breeds must complement each other well and must independently have a large enough selection base to continue their own unique breeding goals.
The purebred Holstein is undeniably the top dairy breed globally, and it has been effectively selected for production for decades. The Holstein cow today is a big roomy cow with excellent udder conformation allowing for high production levels.
The Norwegian Red is a breed that decreases the costs through lower calf mortality rates, higher female fertility and lower disease incidence. The NRF also carries the polled gene which reduces the setbacks and dehorning labor.
This bringing together two breeds with desirable genes is called complementarity. It describes breeds that are competitive production-wise and are distinctly superior for other traits offering a desirable outcome in the crossbred.
Heterosis is an increase in characteristics such as vitality, disease resistance, fertility and yield in crossbreds over its parents. The Heterosis is low for milk yield, about 5 % but higher for female fertility, resistance to mastitis and vitality.
TWOPLUS
To offer a better dairy cow for the commercial dairy farmers, Geno Global and Semex Alliance have launched a crossbreeding programme TWOPLUS. It is a rotational crossbreeding system whereby the Holstein and the NRF breeds are used alternately to produce the next generation, as in figure 2.
With such a system the level of hybrid vigor will be two-thirds of the full heterosis in F1, and the crossbred cows will become more uniform over time.
Crossbreeding programs must be designed to fit the species. In dairy cattle the eproductive rate is low, and crossbred females must be used to produce the next generation of crossbreds. Therefore the most logical crossbreeding system in dairy cattle is rotational crossing. In order to examine the TWOPLUS system, Geno Geneticists developed a complex simulation model of a 200 cow herd over a period of 22 years. The long term effect on milk yield, fertility, mastitis and calf survival has been calculated. Compared to pure Holstein, the crossbred cows will slightly increase milk yield, and the other traits will improve by 12 – 15 %.
The important parameters put into the model are the additive genetic level of each breed for each trait, and the percent hybrid vigor assumed for each breed and trait. The results of trials in Ireland and California have been used for estimation of the parameters.
Figure 2
Future challange for Geno
It is vital for a breeding programme to have enough capacity for testing and
consequently selection. We pay much attention to the following matters:
- Keep up the number of tested bulls (125)
- Keep up the number of daughters per tested bull (300)
- Keep up the genetic variety, especially important by establishing of the waiting bull scheme from 2005
Norwegian Red 482 Ida, sire: 5063 Vistnes
Norwegian Red 807 Sonja Sire: 5654 Olstad
Holstein x Norwegian Red in California
Norwegian Red 2225 Åse Sire: 4841 Viddal
1 st lactation, 14.953 kg 32% above herd average
SCC 50.000 below herd average
95 days to new pregnancy |