The results on the various aspects of performance of yak presented in this chapter indicate the kind of production levels relevant to a variety of conditions. There are few circumstances, however, where productivity could not be improved. Improvements might be produced by changes to breeding practice, changes in animal management and feeding, by the optimization of herd structure and by environmental interventions, such as changes to pasture and range management, provision of shelter, and so on. Such measures are dealt with in other chapters of this book.
Not all changes, however, result in improvements in productivity, or, even if they do, they are not necessarily cost effective. For example, hybridization by mating yak to "improved" breeds of dairy cattle like the Holstein, can lead to dramatic increases in the milk output by the hybrids, compared to the pure yak - but at the expense of a lower fat content of the milk and much higher feed and management costs, in addition to a more complicated breeding strategy (see Chapter 3). In the same way, the costs of changes, whether in management (Chapter 8), feeding (Chapters 8 and 14), the use of feed supplements referred to earlier, or by changes in range and grassland management (Chapter 13), should be more than offset by the value of any additional outputs, if such changes are to be worth making. Also, as discussed in Chapter 12, the social and cultural context of yak keeping, as much as the economic conditions, will influence what is appropriate in particular circumstances and what is not.
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