Agroecology uses ecological processes and local resources rather than chemical inputs to develop productive and resilient livestock and crop production systems. In this context, breeding innovations are necessary to obtain animals that are both productive and adapted to a broad range of local contexts and diversity of systems. Breeding strategies to promote agroecological systems are similar for different animal species. However, current practices differ regarding the breeding of ruminants, pigs and poultry. Ruminant breeding is still an open system where farmers continue to choose their own breeds and strategies. Conversely, pig and poultry breeding is more or less the exclusive domain of international breeding companies which supply farmers with hybrid animals. Innovations in breeding strategies must therefore be adapted to the different species. In developed countries, reorienting current breeding programmes seems to be more effective than developing programmes dedicated to agroecological systems that will struggle to be really effective because of the small size of the populations currently concerned by such systems. Particular attention needs to be paid to determining the respective usefulness of cross-breeding v. straight breeding strategies of well-adapted local breeds. While cross-breeding may offer some immediate benefits in terms of improving certain traits that enable the animals to adapt well to local environmental conditions, it may be difficult to sustain these benefits in the longer term and could also induce an important loss of genetic diversity if the initial pure-bred populations are no longer produced. As well as supporting the value of within-breed diversity, we must preserve between-breed diversity in order to maintain numerous options for adaptation to a variety of production environments and contexts. This may involve specific public policies to maintain and characterize local breeds (in terms of both phenotypes and genotypes), which could be used more effectively if they benefited from the scientific and technical resources currently available for more common breeds. Last but not least, public policies need to enable improved information concerning the genetic resources and breeding tools available for the agroecological management of livestock production systems, and facilitate its assimilation by farmers and farm technicians.

Cross-breeding with European beef breeds has become a standard approach for the intensification of smallholder cattle production in Indonesia. This study assessed the environmental impact of cross-breeding, in terms of Global Warming Potential (GWP) and land use. We sampled 90 local Ongole and 162 cross-bred (Simmental × Ongole) cattle farms in four study areas. Expressed per kilogram of live weight of young stock produced, GWP (26.9 kg CO2–equivalents) and land use (34.2 m2) of farms with Ongole breeding stock were not significantly different from the GWP (28.9 kg CO2–equivalents) and land use (37.4 m2) of cross-bred farms. Cross-bred young stock grew faster, but in general cross-bred cattle required more feed. In the current smallholder production system, the dominant cross-breeding practice of using Simmental semen on Ongole and F1 cross-bred cows does not result in lower greenhouse gas emissions or land use per kilogram of live weight produced compared with farms with Ongole cows. The advantage from the faster growth of cross-breds is counteracted by the higher emissions from feed production for cross-breds.

Turkey's 21.8 million head of sheep comprise a rich array of fat-tailed and thin-tailed native breeds and crosses of these with animals of exotic origin. The structure of agriculture is such that most farms are predominantly subsistence oriented, of small size, keep few animals and provide only minimal inputs. Native breeds have evolved to meet these conditions and are generally well adapted to the natural environment, inadequate and unbalanced nutrition and disease stress. In the last 80 years, there have been attempts to modify the natural gene pool and many distinct breed types are in danger of or have already suffered extinction. This paper describes some of the major sheep genetic resources and their conservation status. The government is now aware of the danger of impoverishment or loss of this important aspect of biodiversity and has established programmes for conservation and preservation of several native breeds. Government, research institutions and producers should work together to ensure that the local gene pool is preserved and can thus continue to contribute to biodiversity and sustainable livestock production.

This paper reviews experiences with cross-breeding for milk production in the tropics. Data were compiled from 23 different studies evaluating the performance of different grades of cross-bred animals as well as local breeds. Relative performance of indigenous breeds compared with different grades of cross-breeds was calculated for three climatic zones. Traits considered were milk yield per lactation, age at first calving, services per conception, lifetime milk yield and total number of lactations completed. At 50 percent Bos taurus blood, lactation milk yields were 2.6, 2.4 and 2.2 times higher than those of local cattle in the highland, tropical wet and dry, and semi-arid climatic zones, respectively; lactation lengths increased by 1.2, 1.2 and 1.9 months in the above-mentioned climatic zones, respectively; there was a reduction in calving interval by 0.8 times and in age at first calving by 0.9 times. Similarly, cross-breds with 50 percent B. taurus genes had 1.8 times higher lifetime milk yields and a 1.2 times higher number of total lactations. Although cross-breeding faces a number of challenges such as better infrastructure, higher demand for health care, there are many advantages of using it. These are higher production per animal, higher income for the families and provision of high-value food. It is therefore likely to continue to be an important livestock improvement tool in the tropics in the future, where farmers can provide sufficient management for maintaining animals with higher input requirements and access to the milk market can be secured.

Data from 113 Dutch organic farms were analysed to determine the effect of cross-breeding on production and functional traits. In total, data on 33 788 lactations between January 2003 and February 2009 from 15 015 cows were available. Holstein–Friesian pure-bred cows produced most kg of milk in 305 days, but with the lowest percentages of fat and protein of all pure-bred cows in the data set. Cross-breeding Holstein dairy cows with other breeds (Brown Swiss, Dutch Friesian, Groningen White Headed, Jersey, Meuse Rhine Yssel, Montbéliarde or Fleckvieh) decreased milk production, but improved fertility and udder health in most cross-bred animals. In most breeds, heterosis had a significant effect (P < 0.05) on milk (kg in 305 days), fat and protein-corrected milk production (kg in 305 days) and calving interval (CI) in the favourable direction (i.e. more milk, shorter CI), but unfavourably for somatic cell count (higher cell count). Recombination was unfavourable for the milk production traits, but favourable for the functional traits (fertility and udder health). Farm characteristics, like soil type or housing system, affected the regression coefficients on breed components significantly. The effect of the Holstein breed on milk yield was twice as large in cubicle housing as in other housing systems. Jerseys had a negative effect on fertility only on farms on sandy soils. Hence, breed effects differ across farming systems in the organic farming and farmers can use such information to dovetail their farming system with the type of cow they use.

Goats were first domesticated in Turkey some 10 000–11 000 years ago. The country's population of 5.1 million goats in 2009 (down from 24.6 million in 1960) are still an important livelihood asset for smallholder farmers and nationally are a rich array of farm animal genetic resources of current enormous and future inestimable value. The structure of agriculture is such that most farms are predominantly subsistence oriented, of small size, keep few animals and provide only minimal inputs. Native breeds have evolved to meet these conditions and are generally well adapted to the natural environment, inadequate and unbalanced nutrition and disease stress. In general, there are two classes of goat, the one being the iconic Angora that produces mohair and the other the “common” or “hair” goat. The reduction in numbers is owing to a variety of reasons both internal and external to the country, but the Angora, which now amounts to only 2.5 percent of national goat numbers, has suffered relatively more than the hair types. This paper, based on detailed reviews of the literature and on the authors' own experiences, provides information on 17 breeds or recognized populations of Turkey's goat genetic resources and their conservation status. The government is now aware of the danger of the impoverishment or loss of this important aspect of biodiversity and has established programmes for conservation and preservation of several native breeds. The government, research institutions and producers should work together to ensure that the local gene pool is preserved and can thus continue to contribute to biodiversity and sustainable livestock production.

Turkey's 10.6 million head of cattle comprise a rich array of native breeds and types but these are being increasingly eroded by the often indiscriminate use of exotic genotypes. The structure of agriculture is such that most farms are predominantly subsistence oriented, of small size, keep few animals and provide only minimal inputs. Native breeds have evolved to meet these conditions and are generally well adapted to the natural environment, inadequate and unbalanced nutrition and disease stress. In the last 80 years, there has been much modification of the natural gene pool and many distinct breed types are in danger of or have already suffered extinction. This paper describes some of the major remaining cattle genetic resources and their conservation status. Government is now aware of the danger of the impoverishment or loss of this important aspect of biodiversity and has established programmes for conservation and preservation of several native breeds. Government, research institutions and producers should work together to ensure that the local gene pool is preserved and can thus continue to contribute to biodiversity and sustainable livestock production.

Entomopathogenic nematodes of the genus Heterorhabditis are morphologically conservative, consequently the majority of isolates remain unassigned at the species level. When a Heterorhabditis infective juvenile infects an insect host, it develops into a protandrous hermaphrodite female. These first-generation females give rise to a second generation which contains both males and females. Because of this complex life-cycle and also because of uncertainty as to whether second-generation females are amphimictic, cross-breeding studies to facilitate species determination have not been carried out previously. We demonstrate here that second-generation Heterorhabditis females are amphimictic. Because of this finding, we have been able to develop a successful cross-breeding technique for the purposes of species determination in Heterorhabditis. Interstrain crosses using second-generation males and females from the appropriate strains have been successfully set up in Xenorhabdus luminescens-treated G. mellonella cadavers and also on agar plates. Using the techniques described here we confirm that H. bacteriophora (Brecon strain), H. megidis and H. zealandica are distinct biological species, we note that the H. bacteriophora group contains at least 2 species and we provide evidence for the existence of a new Irish species of Heterorhabditis.