Muriel Tichit

Putting meaning back into “sustainable intensification”

In light of human population growth, global food insecurity is an escalating concern. To meet increasing demand for food, leading scientists have called for “sustainable intensification”, defined as the process of enhancing agricultural yields with minimal environmental impact and without expanding the existing agricultural land base. We argue that this definition is inadequate to merit the term “sustainable”, because it lacks engagement with established principles that are central to sustainability. Sustainable intensification is likely to fail in improving food security if it continues to focus narrowly on food production ahead of other equally or more important variables that influence food security. Sustainable solutions for food security must be holistic and must address issues such as food accessibility. Wider consideration of issues related to equitable distribution of food and individual empowerment in the intensification decision process (distributive and procedural justice) is needed to put meaning back into the term “sustainable intensification”.

Simple representation of physiological regulations in a model of lactating female: application to the dairy goat

A dynamic model of the lactating dairy goat, combining a minimum of mechanistic representations of homeorhetic regulations and a long-term approach, was developed. It describes (i) the main changes in body weight, dry-matter intake, milk production and composition of a dairy goat; (ii) the succession of pregnancy and lactation throughout the productive life; and (iii) the major changes in dynamics induced by the female profile (production potential and body weight at maturity). The model adopts a pull approach including a systematic expression of the production potential and not representing any feed limitation. It involves three sub-systems. The reproductive events sub-system drives the dynamics through time with three major events: service, kidding and drying off. It also accounts for the effect of production potential (kg of milk at the peak of lactation) and lactation number (potential reached at the fourth lactation). The regulating sub-system represents the homeorhetic mechanisms during pregnancy and lactation with two sets of theoretical hormones, one representing gestation and the other lactation. The operating sub-system describes the main physiological flows and the energetic requirements linked to these functions through a compartmental structure. Simulations were run in order to test (i) the behaviour of the model at the scale of the productive life for an average profile of female (60 kg at maturity and 4 kg of milk at peak); (ii) the sensitivity of the simulated dynamics (mainly milk production and body reserves) to the production potential and body weight at maturity; (iii) external validation with comparison of model outputs to data from the experimental flock of Grignon and data from the French milk record organization (French organism in charge of animal recording for dairy farmers). The results at the scale of one productive life show the model simulates a relevant set of dynamics. The sensitivity analysis suggests that the model fairly well simulates the link between a females ability to produce and mobilise reserves. Finally, external validation confirms the models ability to simulate a relevant set of physiological dynamics while pointing out some limits of the model (simulation of milk fat and protein content dynamics, for example). The results illustrate the relevance of the model in simulating biological dynamics and confirm the possibility of including minimum representations of homeorhetic regulations with a simple structure. This simplicity gives an opportunity to integrate this basic element in a herd simulator and test interactions between females regulations and management rules.

The Response of Farmland Bird Communities to Agricultural Intensity as Influenced by Its Spatial Aggregation

The shape of the relationship between biodiversity and agricultural intensity determines the range of intensities that should be targeted by conservation policies to obtain the greatest environmental benefits. Although preliminary evidence of this relationship exists, the influence of the spatial arrangement of intensity on biodiversity remains untested. We conducted a nationwide study linking agricultural intensity and its spatial arrangement to a farmland bird community of 22 species. Intensity was described with a continuous indicator based on Input Cost per hectare, which was relevant for both livestock and crop production. We used the French Breeding Bird Survey to compute several descriptors of the farmland bird community along the intensity gradient and tested for the significance of an interaction effect between intensity and its spatial aggregation on these descriptors. We found that the bird community was comprised of both winner and loser species with regard to intensity. The community composition descriptors (trophic level, specialisation, and specialisation for grassland indices) displayed non-linear relationships to intensity, with steeper slopes in the lower intensity range. We found a significant interaction effect between intensity and its spatial aggregation on the grassland specialisation index of the bird community; the effect of agricultural intensity was strengthened by its spatial aggregation. We suggest that an opportunity to improve the effectiveness of conservation policies exists by targeting measures in areas where intensity is moderate to low and aggregated. The effect of the aggregation of agricultural intensity on biodiversity should be considered in other scales and taxa when developing optimal policy targeting and intensity allocation strategies.

Develop, then intensify

We applaud the recent effort by T. Garnett et al. (“Sustainable intensification in agriculture: Premises and policies,” Policy Forum, 5 July, p. [33][1]) to place the concept of sustainable intensification into a decision-making context. The authors emphasize that sustainable intensification

Synergy between selection for production and longevity and the use of extended lactation: Insights from a resource allocation model in a dairy goat herd

Although most of the genetic progress in production efficiency is achieved through selection at a global scale, locally, farm managers can also influence the selection process to better match genotypes and their varying herd environment. This study focused on the influence of a particular management decision--the use of extended lactation (EL) in dairy goat production systems--as it affects the survival and reproduction rates at the herd level, which may then shape different long-term selection responses. The objective was to understand and quantify the influences of EL and variability in achieved intake level on the responses to selection for production, reproduction, and longevity. An animal model of resource allocation between life functions was applied to the dairy goat. It predicts the trajectory of change in the herd genetic composition as affected by the feeding level and the selection pressure applied by the manager. During 40 yr, goats were selected for milk yield, reproduction, and, with a different selection weight for age (WAGE), for longevity. Under varying achieved intake levels, increasing WAGE improved the survival rate but a nonlinear effect was observed for the average milk yield and BCS. When moderately increasing WAGE from 0, resources were reallocated from lactation towards body reserves and survival, which led to a trade-off at the herd level between improving survival and BCS and increasing milk yield. When further increasing WAGE, old females became systematically preferred regardless of their reproductive status and the proportion of EL in the herd increased. Females undergoing EL had reduced energetic costs of reproduction, which improved their probability of survival. Across generations, an increased herd incidence of EL led to a relaxation of the selection pressure on the resource allocation to body reserves, which is normally imposed by the managers priority to achieve successful reproduction at each mating. As selection for longevity progressed, the incidence of high-producing females increased within the herd, driving a long-term trend in increased milk production. Thus, the use of EL as a management tool led to an alleviation of the trade-off between milk yield progress and survival improvement. Although the model simplifies the underlying physiology of nutrient allocation, it provides insights into how farm manager strategies can influence the development of genotype × environment interactions and promote herd robustness.

Evaluation of two feeding strategies with a herd model integrating individual variability

Individual variability is a key element to understand and predict herd response to management practices. To study how individual variability is generated within the herd, an individual-based herd model was developed. It was applied to intensive dairy goat systems. The model combines a decisional with a biological sub-model. The decisional sub-model represents technical decisions relative to reproduction, feeding and replacement management. The biological sub-model represents each individual within the herd and is based on a dairy goat model. This latter simulates body weight and milk production dynamics throughout each goat’s productive life. Individual goat performance depends on its production potential, physiological regulations and responses to diet. As each goat model has its own individual performance scaling and its own operation driven by management decisions, individual variability is an output of simulation. In the present work, the herd model was used to simulate two feeding strategies involving two-step (2S) or five-step (5S) feeding sequences. The 5S feeding sequence is based on a regular adjustment of the quantity of concentrate feedstuff throughout lactation whereas the 2S feeding sequence is based on a single adjustment in late lactation. Results show that increasing the number of steps within the feeding sequence did not lead to a major difference in terms of milk production and feed cost. When focusing at individual level, results show that the 2S feeding sequence led to a greater proportion of goats whose body weight was lower than their potential body weight. For the 2S feeding sequence, production and efficiency relied on goats which tended to lose more weight than those fed with the 5S sequence. Hence, the same level of herd production and efficiency can be achieved with different biological underlying processes. This result stresses the importance of understanding the mechanisms behind overall performance to achieve a sound evaluation of management effects.

Multi-scale trade-offs between production and environment in grassland agroecosystems: application to livestock farming systems and biodiversity conservation

Bearing in mind the objectives of this study to investigate the Barbary sheep fertility under our climatic conditions and to evaluate the efficiency of the prostaglandin f2α(pgf2α)injections in induction of fertile estrus in different seasons. For these objectives, some experiments were performed during the period from July,2008 to March, 2009. A total number of 300 Libyan Barbary ewes(3-6 years old, weighing 40-60 kg) was used in this experiment. Ewes were kept in privet farms, fed and managed similarly. Ewes were divided to four season groups(summer, autumn, winter and spring groups). Each season group was divided into treated and control. Animals in the treated groups were injected with double injections of 125 μg of prostaglandin f2α intramuscularly(i/m), 11 days apart. While those in control groups were injected with two injections of 1.0 ml of 0.9% NACL saline solution simultaneously with the treated ewes. At the same day (day 11) rams wearing painted sponges on their briskets regions were introduced for natural mating. Treated groups showed shorter estrus response time than control groups in all seasons(P<0.05). Estrus duration was longer in winter and spring than in summer and autumn (P<0.001),but no difference was found between treated and control groups inside seasons. Treated group showed higher pregnancy rate(P<0.001) in winter season than control group. Percentage of ewes lambed in winter was significantly high (P<0.001) among treated ewes than control (80 vs 38%). Lambing rate differed significantly (P<0.001) among treated groups in all seasons. Data were collected and calculated statistically using SPSS system for percentages, means, standard deviation(mean ± sd) analysis of variance (anova), Chi square and Dunacan’s test were used accordingly. Other values were measured, calculated and analyzed similarly. Adoption of technology in sheep farms of La Mancha, Spain J. Rivas1, C. De Pablos2, J. Perea1, C. Barba1, R. Dios-Palomares1, M. Morantes1 and A. García1 1Universidad de Córdoba, Campus Rabanales, 14014, Córdoba, Spain, 2Universidad Rey Juan Carlos, Paseo de los Artilleros, 28034, Madrid, Spain; pa1gamaa@uco.es Recently in Spain the milk production coming from sheep farms shows higher degrees of specialization based on the adoption of technologies. The aim of this research is to examine the pattern of adoption of technologies in sheep farms of La Mancha. Based on previous researches, from 77 questions, only 38 questions were selected by using qualitative and participatory methods; the chosen variables were grouped into six technology packages (TP): management, feeding, animal health and milk quality, pasture and land use, equipment and facilities, and reproduction and breeding program. The survey was applied to a sample of 157 farms. Using descriptive statistics each TP was characterized and the pattern of adoption was determined. The average of technologies adopted was of 18.4±6.0 (48.3%). TP showing higher degrees of implementation are animal health and milk quality (67.8%), feeding (56.0%) and management (55.7%), but their adoption is not sequential or responds to independent events. This research facilitates the identification of a number of technologies that must be implemented from an organizational strategy point of view. Moreover, all technologies are seeking a dynamic balance system that allows firms migrate to more efficient processes without losing their main attributes. As a technological challenge, an andrologic evaluation of ram, gynecologic evaluation of ewes prior to mating, early detection of non-productive animals are proposed; and a better use of productive records for the decision-making; aspects are recommended. The results of this analysis will have an impact on future research that attempts to improve the use of subproducts, forage reserves and improved rangeland management and hygiene control system, taking the quality milk as an strategic asset, so further research is necessary to assess the impact of each technology on the operating of the mixed system in the Mancha region. Session 40 Poster 20 Session 40 Poster 19In Italy, as in other European countries, since 2005 a program of selection for scrapie resistance in sheep, based on the PRNP polymorphism, has been implemented with the aim of increasing ARR ‘resistant’ allele and eliminating VRQ ‘susceptible’ allele. In a small breed, the ARR-carriers may be more related to each other than ranndomly chosen animals; as a consequence, for an equal number of reproducers the effective size may be smaller than expected in a pure genetic drift condition (1). In the Sambucana sheep breed (reared in Piemonte region, north-west Italy) the ARR allele frequency was higher than in other breeds, like Biellese for example, before the selection plan started (2). On the other hand, due to the reduced number of animals (3500), this breed is considered at risk of extinction (Piemonte Regional Rural Development Plan for 2007-2013 period). The aim of the present investigation was to evalute the impact of scrapie resistance selection on genetic variation of the Sambucana. INTRODUCTIONCONCLUSIONS During the last decade there has been growing scientific interest in the use of genomic information as an additional tool in conventional dairy cows’ breeding schemes. It is now well established that dairy cows’ fertility has declined during the last decades and this may not be remedied only by improved management. Given that there is a substantial genetic background in this decline, emphasis should be placed in efforts to improve dairy cows’ fertility through genetic selection. Although there are substantial genetic effects that contribute to this infertility, little progress has been made on the identification of major genes affecting reproduction traits. There is an urgent need to identify the genetic factors responsible for the decline in fertility in cattle. The objective of this study was to investigate the association of two specific polymorphisms, the SNP12195 and SNP11646 polymorphisms of the Signal Transducer and Activator of Transcription 5A (STAT5A) and Fibroblast Growth Factor 2 (FGF2) genes respectively with fertility in cattle. These genes have been previously reported to be associated with in vitro fertilization and embryonic survival rate in cattle.In European grasslands, grazing and mowing regimes are major drivers of the maintenance of many wild species, either through direct or indirect effects. To date, both types of effects were studied separately, mainly at the field scale and with no quantification of performance. Objective of this study was to model the trade-offs between ecological and productive performance of a grassland agro-ecosystem at two nested scales i.e. field and farm scales. We developed a dynamic model linking grass dynamics controlled by grazing or mowing to stochastic population dynamics of two grassland bird species. Bird dynamics were driven by both direct and indirect effects of management. Viable control framework was used to predict productive and ecological performance. At field scale, results showed that the best ecological performance was obtained at intermediate levels of productive performance (60 to 108 grazing days /ha /year). Above 108 grazing days, no grazing strategy was viable for either species due to the negative direct effects of management. Between 108 and 240 grazing days, the ecological-productive relationship showed a concave Pareto like frontier. Any improvement in productive performance entailed a strong decrease in ecological performance. As expected, at farm scale the best ecological performance was obtained with extensive farms. However, the ecological-productive relationship showed a convex Pareto like frontier indicating the occurrence of compensations among management regimes. In intensive farms, it was necessary to allocate 40% of farm area in low-intensity grazing in order to compensate for the negative effects of mowing and high-intensity grazing on birds. However this land allocation involved a 25% reduction in productive performance. Finally, we explore several forms of complementarities among farm types to improve overall performance.