**3. Genetic improvement programs**

In the dairy cattle industry, particularly with the raising of exotic breeds, there had been doubled amounts in milk production globally over the past 50 years (5 decades), while there were declining rates in the dairy cows' population [5]. These were achieved through the intensification of the milk production systems and direct genetic selection for milk yield and other related traits. There were developed the application of modern technologies such as artificial insemination and genomic selection [5]. There had been intensified inbreeding among few well known breeds for high milk production. The positive results of the intensive selection for milk yield however also brought about unfavourable genetic responses such as fertility reduction, adverse effect on the health, longevity and environmental responses sensitivity in the dairy cows. Despite these drawbacks, breeding goals needed to be continued with the focus towards animal welfare, health and longevity, without sacrificing the need to maintain the traits for high milk yield. Achievements were also directed towards breeding for traits that were heritable in terms of their phenotypic expressions. There were also the attainment of long term sustainability goals geared towards organic farming cultures, and pasturebased and mountain-grazing farming systems.

*A Global Overview of the Intensification of Beef and Dairy Cattle Production Systems DOI: http://dx.doi.org/10.5772/intechopen.106062*

#### **3.1 Breeding for high milk production**

#### *3.1.1 Some unfavourable outcomes of breeding for high milk production*

Intense selection for high milk production was observed to result in unfavourably correlated responses on other important traits [13] such as conception rate, health (SCC), less control over environmental temperatures, relative humidity and wind speed. There were also more dependence on human feed inputs such as cereals, protein sources and high quality forages. Thus, the observation pointed to the fact that genetic improvement might require more sophisticated approaches.

Some of the developed solutions to these included the incorporation of female fertility traits into breeding programs, improvement in nutrition, health and cows' comfort. Also, dairy farmers on becoming aware of the negative results and the consequences of continuous practice of inbreeding were still seeking mitigation alternatives such as the use of mating software and assistance from extension specialists [13].

#### *3.1.2 Cost effective ways to genetically improve milk production in local dairy cattle breeds*

In the developing countries where there were mainly low milk producing local dairy cattle breeds, the cows could continually be upgraded through the application of controlled cross-breeding programs. Local dairy cattle breeds could be crossbred with exotic breeds with the aim of developing new composite breeds. Different selection indices would need to be developed to select animals with higher milk production and that could perform well in terms of animal welfare or fitness, health and longevity under an economically sustainable production system. The cross-breeding of local dairy cattle breeds with exotic dairy cattle breeds such as the Holstein Friesian and Jersey could be improved upon to lead to high milk production, while at the same time there could result improved adaptation to the environment, and the animals also retaining their fitness [5].

In all these research efforts much care need be taken to avoid losses in the achieved genetic diversity traits among the dairy cattle populations [5]. Some other group of researchers [14] pointed out that the refinement of breeding programs to incorporate novel breeding objectives required the development of high-throughput phenotyping technologies such as structural and continuous data recording streams and the investigation of the genetic relationship between novel traits and those that were commonly observed. There could be large scale genome studies, especially genomic predictions and genome-wide association studies, refinement of selection indices to reflect improved knowledge of Biology, new resources of data and changing conditions in the environment. Some of the novel traits in dairy production included health (udder health, hoof health and metabolic disorders), fertility, feed efficiency, methane emissions efficiency, longevity and overall resilience [14].
