Sustainable Livestock Production Systems Research Articles

Browse from Three Tree Legumes Increases Forage Production for Cattle in a Silvopastoral System in the Southwest Amazon.

Assessing the palatability of forage from locally adapted trees could improve the sustainability of livestock production systems. However, grasses continue to dominate livestock feed across the Amazon. We established a silvopastoral cattle farming system in Peru, comparing three different forage tree species with grass monocultures using a randomised block design. Trees were arranged in alleys of 0.5 × 7.5 m, planted alongside grass, and were directly browsed by cattle. Browse removal was estimated by three methods: destructive sampling, canopy measurements and leaf counts. We found that all three tree species were palatable to cattle. Plots containing trees and grass produced more available forage (mean > 2.2 Mg ha-1) for cattle than the grass monocultures (mean = 1.5 Mg ha-1). Destructive sampling below 1.6 m demonstrated that cattle consumed 99% of the available Erythrina berteroana forage, 75% of the available Inga edulis forage and 80% of the available Leucaena leucocephala forage in 8 days. This research demonstrates methodologies to estimate the intake of locally adapted browse species by cattle and highlights the potential benefits of silvopastoral systems in the Amazon. Planting trees could also benefit animal health and provide ecosystem services such as soil regeneration, enhanced nutrient cycling and carbon capture.

The risk of unintended deforestation from scaling sustainable livestock production systems

AbstractSilvopastoral systems (SPS)—production systems integrating trees, forages, and livestock within the same land area—are recognized as critical for reducing tropical deforestation and improving livelihoods, ecosystem services, and carbon sinks. Yet, research on how scaling SPS influences forest cover changes at large geographical scales is scant. Our study delves deeper into the interlinkages between scaling SPS and deforestation. In two surveys conducted among 144 Colombian Amazon livestock producers with traditional or SPS farms, we assessed changes in herd composition between 2016 and 2020. Results showed a change in herd composition, with fewer males and more cows/heifers, suggesting a shift toward specializing in milk production, which, with the appropriate environmental incentives and safeguards, would unlikely broaden deforestation. However, interlinkages between the dairy and beef value chains suggest that extra male cattle from SPS intensification would be moved for fattening as a source of beef to new pastures at the forest border. If SPS scaling interventions in the Colombian Amazon are to be truly deforestation‐free, they need to be designed based on a clear understanding of the interlinkages between food and land systems. Therefore, policies advancing the livestock and land‐use agenda must create mechanisms that support deforestation‐free livestock intensification, based on biophysical and socioeconomic evaluations.

Drought sensitivity of pastures related to soil and landform in the eastern Amazon

Livestock in the Amazon is mainly limited by the lack of forage biomass production in the dry season. The sensitivity of pasture to drought depends on pasture management and on certain natural factors that enable the grass cover to stay green for longer under low rainfall. The sustainability of livestock production systems depends on identifying these natural factors to make better use of their forage production potential without consuming additional water resources or resorting to deforestation. We built an index of pasture dependence on rainfall at the beginning of the dry season by calculating the slope of the linear regression between the MODIS enhanced vegetation index and monthly cumulative rainfall obtained from the Tropical Rainfall Measuring Mission. The index was calculated in Paragominas municipality. A 15-year time series (2000 to 2014) was used to assess the sensitivity of pasture to drought. A map of geomorphological units was overlaid on the index map to check whether the soil and the landform influence drought sensitivity at a large scale. Drought resistance was shown to be higher in lowland areas with loamy sand with a shallow groundwater table and on plateaus covered by fertile sedimentary clay. The escarpments with a ferruginous duricrust and mottled clay were shown to be the most sensitive to drought. These results underline the importance of natural factors in pasture productivity in tropical humid areas.

Production of clean water in agriculture headwater catchments: A model based on the payment for environmental services

This study aimed to present a payment for ecosystem services model that promotes a symbiotic coexistence between agriculture and clean water production. The model favors application to headwater catchments where clean water production is expected. However, the frequent invasion of these areas with intensive agriculture and livestock production systems affects water quality threatening the use of this resource, namely as drinking water. The proposed Agriculture for Clean Water Yield (ACWY) model reconciles agriculture with clean water production through the incentive approach, giving the farmers a financial compensation if they are willing to replace intensive by sustainable agriculture and livestock production systems, namely agro-forestry systems. The reconciliation through the incentive approach is justified because clean water and food are both vital goods for human survival. The compensation rises as function of increasing catchment water yield capacity and conversion costs. For example, landowners receive more if land conversion occurs in slopping than undulated landscapes. The model applied to Fazenda Glória watershed, composed of 19 headwater catchments (96.7 ha on average), proposed financial incentives in the range 218.73–576.5 US$/ha/year depending on the catchment's water yield capacity, which rise to 284.35–749.45 US$/ha/year if conversions occur in extreme vulnerable areas. The watershed, located in São Paulo state, Brazil, covers 18.4 km2 and is the source of drinking water to 70,000 people living in Jaboticabal city. Monitoring is essential to assess the performance of ACWY and adjust the compensation dynamically. For instance, noteworthy improvements in water yields and water quality or land conversions performed in short periods can expect the most generous compensation. Two concerns about implementing the model in Fazenda Glória rely on the lack of political will in spite of existing federal and state legal support, as well as on the financial sources to make the model a real project.

The Carbon Footprint Of Smallholder Dairy Farming In Sub-Saharan Africa: A Review

Agriculture sector is one of major sources of income and livelihood to many populations of Sub-Saharan Africa (SSA). Over the past years animal production has been playing a vital role not only in generating revenues to farmers but also as a source of high qualitative proteins and essential micronutrients (i.e iron, zinc and vitamins) and boosting the agricultural productivity due to its importance in farmyards organic fertilization (i.e manure). Livestock production and Milk market in SSA are dominated by smallholder dairy farming (SDF) which employ nearly 70% of all livestock farmers. Despite its positive impact on people and SSA countries’ economy, SDF has been the major fastest growing agricultural contributors of GHG emissions such as CH4, N2O and CO2 (i.e 9t CO2e per tonne of milk; the highest in the world compared to other regions) thus accelerating global warming effect.Although several articles have investigated the impacts of livestock production on climate change, to the best of our knowledge the existing literature doesn’t contain any studies that provide insight review of smallholder dairy farming’s carbon footprint (CF) in SSA. This review paper is therefore aimed at critical analysis of current knowledge in terms of CF of smallholder dairy farming in SSA and effective mitigation strategies (dietary, manure and animal management) recently proposed to reduce CH4 and N2O emissions from ruminants. SSA was selected because of rapid rise of SDF in the region therefore it is expected to rapidly increase its GHG emissions in future if no sustainable measures are taken.The critical analysis, what is known and gaps in SDF from this review will help to inform the farmers, researchers, decision and policy makers interested in GHG emissions thus to provide the next direction in research and improvement of the sector for sustainability. Capacity building for raising awareness among farmers was identified as paramount to better understand the issue and the options to mitigate emissions on-farm. As longer as adaptation and mitigation strategies become paramount on national and regional agenda, SDF will make significant contribution to economies, improved livelihood and become sustainable livestock production systems in SSA at large.

Influence of intra-row plant spacing, phosphorus application and growth stage on the forage, seed yields and quality of phasey bean (Macroptilium lathyroides) in subhumid area of Nigeria

Forage, seed yields and herbage chemical composition of phasey bean Macroptilium lathyroides) were investigated at 3 intra-row plant spacings (15, 30 and 45cm between plants; 50 cm between roms), 4 phosphorus (P) fertilizer application rates (O), 50, 100 and 750 kg/ha P) and 5 harvest stages (uncut control, 6, 9, 12 and 15 weeks post sowing) in two growing seasons at Shika in northern Nigeria. The least intra-row plant spacing (15cm) produced higher (p<0.01) total DM vield (1.50 t/ha) than wider spacings. The proportion of leaf was least (40 %) in the widest spacing compared with other spacings (59-62 %). The P-fertilized plots produced 58-60% more total DM vields than the unfertilized plots and total DM yields increased with advanced plant growth. The highest percentage (61-63) of leaf was recorded from 6 to 12 weeks post sowing. Nitrogen level in herbage increased (p<0.05) with increased intra-row plant spacing and P application. Phosphorus and Calcium. Levels in herbage did not respond to intra-row plant spacing but increased with P application. The Ca:P ratios at the harvest stages were between 1:1 and 6:1. The highest seed yields (198 and 188 kg/ha) were recorded respectiely in the least intra-row plant spacing and the application of 100 kg Piha. Supplementation of calves on grasses/cereal stovers with phasey bean hay in a sustainable crop livestock production systems is suggested.

Sustainability assessment of small dairy farms from the main cattle farming systems in the North of Tunisia

Demand for animal products is expected to increase due to human population growth, resulting in a need for increased production. At the same time, climate change poses a major threat to the viability and sustainability of livestock production systems. This study aimed to evaluate and compare the sus-tainability of dairy cattle farms belonging to three farming systems (rainfed, irrigated, and mixed) at the northeast zone of Tunisia using the IDEA method (version 3). Collected data of 102 farms were subjected to an analysis of variance using the GLM procedure of SAS software (version 9.4). Results showed that the socio-territorial scale was the limiting factor for all systems and that the irrigated sys-tem had the lowest scores of agro-ecological and socio-territorial scales, compared to the other ones, but it recorded the highest score for the economic scale. The best agro-ecological and socio-territorial scores characterized the mixed system. However, it had the lowest score on the economic scale. Finally, the rain-fed system was exhibited medium performances of the three scales. It was concluded a differ-ence between the three farm systems, but there was no disassociation between the three sustainability dimensions; thus, improvements should proceed across all scales simultaneously.

ISOLATION AND NILE RED SCREENING OF INDIGENOUS MICROALGAE SPECIES FROM PAHANG LAKES AS POTENTIAL LIPID SOURCE IN AQUACULTURE FEED

The high nutritional composition of microalgae that includes lipids is considered as one of the promising alternative lipid sources for animal feeds enrichment. Since microalgae have higher photosynthetic efficiencies than terrestrial plants, highly adaptable to environmental changes, and do not compete with conventional agriculture for resources, the inclusion of lipid sources from microalgae in feed could help the sustainability of livestock production systems. This study has reported the indigenous microalgae strains from Pahang lakes and determined lipid-rich strains that have the potential for alternative lipid sources. Pure isolated strains were identified using an 18S rDNA marker. The microalgae strain biomass was determined for 15 days. Meanwhile, the screening for high-rich lipid contents in microalgae strains was carried out using Nile Red fluorescent dye. A total of 11 strains were successfully isolated that consist of 8 different species (Carteria radiosa, Spongiosaccinopsis terrestris, Desmodesmus sp., Desmodesmus abundans, Dendodesmus brasiliensis, Chlamydomonas reinhardtii, Mychonastes timauensis, and Mychonastes ovahimbae). Results showed that PHG C01, PHG C02, and PHG F03 have the highest biomass production among all strains. Meanwhile, for lipid production, PHG B01 and PHG F03 showed the highest results. Thus, PHG B01 and PHG F03 strains were chosen as potential candidates to be used as an alternative lipid source in animal feed feedstock.

Pretreatments of Broussonetia papyrifera: in vitro assessment on gas and methane production, fermentation characteristic, and methanogenic archaea profile.

ObjectiveThe present study was conducted to examine the gas production, fermentation characteristics, nutrient degradation, and methanogenic community composition of a rumen fluid culture with Broussonetia papyrifera (B. papyrifera) subjected to ensiling or steam explosion (SE) pretreatment.MethodsFresh B. papyrifera was collected and pretreated by ensiling or SE, which was then fermented with ruminal fluids as ensiled B. papyrifera group, steam-exploded B. papyrifera group, and untreated B. papyrifera group. The gas and methane production, fermentation characteristics, nutrient degradation, and methanogenic community were determined during the fermentation.ResultsCumulative methane production was significantly improved with SE pretreatment compared with ensiled or untreated biomass accompanied with more volatile fatty acids production. After 72 h incubation, SE and ensiling pretreatments decreased the acid detergent fiber contents by 39.4% and 22.9%, and neutral detergent fiber contents by 10.6% and 47.2%, respectively. Changes of methanogenic diversity and abundance of methanogenic archaea corresponded to the variations in fermentation pattern and methane production.ConclusionCompared with ensiling pretreatment, SE can be a promising technique for the efficient utilization of B. papyrifera, which would contribute to sustainable livestock production systems.

Effects of Land Use Change from Natural Forest to Livestock on Soil C, N and P Dynamics along a Rainfall Gradient in Mexico

The effects of converting native forests to livestock systems on soil C, N and P contents across various climatic zones are not well understood for the tropical region. The goal of this study was to test how soil C, N and P dynamics are affected by the land-use change from natural forests to livestock production systems (extensive pasture and intensive silvopastoral systems) across a rainfall gradient of 1611–711 mm per year in the Mexican tropics. A total of 15 soil-based biogeochemical metrics were measured in samples collected during the dry and rainy seasons in livestock systems and mature forests for land-use and intersite comparisons of the nutrient status. Our results show that land-use change from natural forests to livestock production systems had a negative effect on soil C, N and P contents. In general, soil basal respiration and C-acquiring enzyme activities increased under livestock production systems. Additionally, reduction in mean annual rainfall affected moisture-sensitive biogeochemical processes affecting the C, N and P dynamics. Our findings imply that land-use changes alter soil C, N and P dynamics and contents, with potential negative consequences for the sustainability of livestock production systems in the tropical regions of Mexico investigated.

Climate Change, Rangelands, and Sustainability of Ranching in the Western United States

Accelerated climate change is a global challenge that is increasingly putting pressure on the sustainability of livestock production systems that heavily depend on rangeland ecosystems. Rangeland management practices have low potential to sequester greenhouse gases. However, mismanagement of rangelands and their conversion into ex-urban, urban, and industrial landscapes can significantly exacerbate the climate change process. Under conditions of more droughts, heat waves, and other extreme weather events, management of risks (climate, biological, financial, political) will probably be more important to the sustainability of ranching than capability to expand output of livestock products in response to rising demand due to population growth. Replacing traditional domestic livestock with a combination of highly adapted livestock and game animals valued for both hunting and meat may be the best strategy on many arid rangelands. Eventually, traditional ranching could become financially unsound across large areas if climate change is not adequately addressed. Rangeland policy, management, and research will need to be heavily focused on the climate change problem.

Thermoregulatory Responses of Heat Acclimatized Buffaloes to Simulated Heat Waves.

Simple SummaryThe simulated heat wave triggered a relevant thermoregulatory response in heat-acclimatized buffaloes. During the simulated heat wave the high respiratory rate and seating rate limited the heat storage and the levels of hyperthermia. Moderate and transient hyperthermia combined with complete recovery of homeothermy during the night prevented changes in blood parameters, except for ion potassium. The high sweating rates seem to have been crucial for the homeothermy’s maintenance. For the first time, early in the morning, adaptive hypothermia was recorded in buffaloes.Climate change is seen as a significant threat to the sustainability of livestock production systems in many parts of the world, particularly in tropical regions. Extreme meteorological events can result in catastrophic production and death of livestock. Heat waves in particular can push vulnerable animals beyond their survival threshold limits. However, there is little information about buffalo responses to sudden changes in the thermal environment, specifically the heat waves. This study aimed to quantify the thermoregulatory and blood biochemical responses of heat-acclimatized buffaloes to a simulated heat wave. The experiment was designed in a climatic chamber with two periods of 4 days each. Twelve heat acclimated buffalo heifers aged 18 months were used. The climatic chamber environment was set as follows: 4-day period (P1) simulating the same weather conditions of a summer in humid tropical climate used as a baseline, with daily cycle with Ta and RH at 27 ± 1 °C and 76% from 0600 h to 1900 h and 24 ± 1 °C and 80% from 1900 h to 0600 h, and 4-day period (P2), simulating a daily heat wave cycle, from 0600 h to 1900 h with Ta and RH kept at 36 °C and 78% and from 1900 h to 0600 h, 27 °C and 74%. All animals were subject to both treatments and data were analyzed by a repeated measure analysis of variance, with post-hoc pooling comparison performed by Tukey’s test. In P2, there was observed a significant increase in respiratory frequency (p < 0.01), found four times in P1. The sweating rates were quite high in both periods; still, there were significant increases in P2 compared to P1 (p < 0.01) (4931 and 3201 g/m2/h, respectively). A slight but significant increase in rectal temperature was observed during the day (p < 0.01), with a rising until 1900 h. The simulated heat wave in P2 did not affect the values of the erythrogram or leukogram, excluding the significant reduction in K+ (p < 0.05). The low heat storage and the subsequent fast and full recovery of the thermal balance late afternoon appear to be related to the high sweating rate values. The massive sweating rate emphasizes its relevance in the maintenance of buffalo homeothermy. The absence of changes in hematological parameters has revealed the considerable physiological resilience of buffaloes toward simulated heat waves.

Water footprint and economic water productivity assessment of eight dairy cattle farms based on field measurement

Water scarcity prevailing in the drylands is threatening the sustainability of livestock production systems. The water footprint (WF) indicator was proposed as a metric of water use. This study aimed to determine the WF and the economic water productivity (EWP) of 1 kg of fat and protein-corrected milk (FPCM) in eight dairy farms (n = 8; animals = 117 ± 62; area = 198 ± 127; 95% confidence level) in northern Tunisia. Then, to assess the effects of three simulation scenarios targeting the reduction of the WF of milk production (scenario A: using triticale silage to replace, on DM basis, the silage of maize, sorghum or ray-grass; scenario B: reducing by 56% the wastage of water devoted to milking, cooling, cleaning and servicing; scenario C: using concentrate feeds imported from Brazil and Argentina instead of that imported from France). A year-round monitoring of on-farm practices was performed using water-meters and recording equipment installed in key locations in the target dairy farms: (i) water used for feed production, (ii) cow watering, (iii) servicing water, (v) crop and forage production and (iv) economic and production performance were controlled by water source (green and blue). Over the eight farms evaluated, milk production consumed on average 1.36 ± 0.41 m3/kg FPCM, of which 0.93 ± 0.40 m3/kg FPCM was green water and 0.42 ± 0.30 m3/kg FPCM was blue water. However, virtual water of 1 kg FPCM averaged 43% ± 14.3%. Water used for feed production for lactating cows represents approximately 87% ± 6% of the total WF of milk production. However, drinking and servicing water contributed by 3.75% ± 2% and 9% ± 5% to the total WF of milk, respectively. The EWP assessment revealed that the selected dairy farms had a relatively small gross margin per m3 of water averaging US$ 0.05 ± 0.04. The variation in WF of milk was mainly associated with diets’ ingredients, which affected milk productivity and water consumption. Scenario analysis indicated that using feed with less water requirements or importing feeds from countries where its water consumption is low could reduce consumptive water use for milk production by up to 16%. The efficient use of servicing water could reduce blue WF of milk by up to 4%. The implementation of these measures would lead to potential total water savings in the Tunisian dairy sector of 646 million m3 per year (30%).

Rethinking livestock production systems on the Galápagos Islands: Organizing knowledge-practice interfaces through reflexive interactive design

Different economic interests and frames of meaning around livestock production and environmental management usually lead to controversies. This is also the case on the Galápagos Islands. The literature usually focusses on Galápagos’ ecosystems and wildlife. However, less attention is given to livestock production systems on the archipelago. In this article, we introduce an initiative to redesign the livestock (i.e., pigs and poultry) production systems on the Galápagos Islands to achieve a higher degree of socio-ecological sustainability by deploying the first phase of the ‘reflexive interactive design’ (RIO) approach. On the basis of an interactive system analysis, this article answers the following question: What redesign options can be coproduced, and how, to enable a change towards sustainable livestock production systems? To analyse this (re)design process this article deploys and further elaborates the concept of knowledge-practice interfaces.

Analytics in sustainable precision animal nutrition.

The global population, resource, and climate dynamics suggest we must improve sustainability of food production systems (Ohlsson, 2014; Kleinman et al., 2018). Improving livestock production sustainability is particularly important because a significant portion of the projected increases in global food demand is anticipated to come from livestock (Thornton, 2010). Improving sustainability of livestock production systems can be achieved through optimized reproductive, genetic, nutritional, and health management (White et al., 2014, 2015). Management decisions within livestock production can be thought of as two interleaved feedback loops. The first feedback loop is between the animal and the environment: the animal is influenced by its environment and, in turn, influences its environment. The second feedback loop is between the animal and the manager: the manager takes information about the animal’s behavior and attempts to influence the environment to optimize the animal’s performance (Figure 1). Managers make management decisions on different timescales ranging from immediate to relaxed. An example of an immediate management decision would be a farmer identifying an animal as sick, isolating the animal, and treating the animal for the illness. We term this immediate because the farmer must identify the sick animal as soon as possible and must react to the diagnosis as soon as possible. An example of a relaxed management decision would be the farmer electing to change the feed provided to his animals in response to something observed about their production (i.e., the cows are producing poorly, so change the ration to provide higher nutrient density to correct a nutrient shortfall). This decision is more relaxed because its formulation and response are subjected to natural, biological delays (i.e., it may take days to weeks to see a production response to a new diet). Improving the precision of these decision-making processes and reducing the burden of decision making on farmers are two critical steps toward improving sustainability of livestock production. Precision agricultural technologies have been identified as one possible solution (Berckmans, 2014; Tullo et al., 2019). Open in a separate window Figure 1. Depiction of the feedback loops between the farm manager, animal, and environment. The animal and environment influence each other, as do the animal and the manager’s decisions about the animal. Additionally, the manager can make decisions about the environment that will influence the animal.

Impact of Water Governance Regimes on Forage Characteristics and Soil Properties in Kajiado County, Kenya

Water governance regimes have a profound effect on vegetation and soil attributes. This is because they directly impact on grazing patterns. Kenyan peri-urban drylands are grappling with climate change and variability, population spill-over from neighboring towns and cities and land degradation that put strain on water resources. Water demand therefore outstrips supply. Sustainable water governance regimes are therefore a prerequisite for climate change resilience, building of adaptive capacities and reduction of climate induced vulnerabilities. This study sought to evaluate the impact of various water regimes on vegetation and soil attributes. Organizational and operational characteristics of diverse water governance regimes were studied and measured against respective vegetation and soil physio-chemical attributes. Soil and vegetation data was analyzed using one-way ANOVA on GenStat 15th edition. The study revealed a shifting trend from traditional water resource management institutions to more formalized regimes. Both public and private water governance regimes and systems existed though most of these lacked proper documentation and clearly defined terms of engagement among relevant actors. These systems applied diverse water management approaches creating significance differences in plant species diversity (p<0.05, F=0.565), richness (p<0.05, F=14.717), soil organic carbon (p<0.001, F=10.67), pH (p<0.05, F=4.84) and particle size distribution (p<0.05, F=5.72) because of varying extents of range access and use. This study concluded that there is need for integrating indigenous knowledge into modern water governance approaches for sustainable crop and livestock production systems. Both national and devolved governance structures should therefore invest in awareness and capacity building to enhance knowledge and skill transfer that would spur development of ecologically, socially and economically responsive systems aimed at augmenting climate resilience of current and emerging production systems and livelihoods.

Response to a selection index including environmental costs and risk preferences of producers.

Genetic improvement of animals plays an important role in improving the economic and environmental sustainability of livestock production systems. This paper proposes a method to incorporate mitigation of environmental impacts and risk preferences of producers into a breeding objective via economic values (EVs). The paper assesses the effects of using these alternative EVs of breeding goal traits on discounted economic response to selection and on environmental impacts at commercial farm level. The application focuses on a Brazilian pig production system. Separate dam- and sire-line breeding programs that supply parents in a 3-tier production system for producing crossbreds (fattening pigs) at commercial level were assumed. Using EVs that are derived from utility functions by incorporating risk aversion increases the cumulative discounted economic response to selection in sire-line selection (6%) while reducing response in dam-line selection (12%) compared with the use of traditional EVs. The use of EVs that include environmental costs increases the cumulative discounted social response to selection in both dam-line (5%) and sire-line (10%) selections. Emission of greenhouse gases, and excretion of nitrogen and phosphorus can be reduced more with genetic improvements of production traits than reproduction traits for the typical Brazilian farrow-to-finish pig farm. Reductions in environmental impacts do not, however, depend on the use of the different EVs (i.e., with and without taking into account environmental costs and risk). Both environmental costs and risk preferences of producers need to be considered in sire-line selection, and only environmental costs in dam-line selection to improve, at the same time, the economic and environmental sustainability of the Brazilian pig production system.

PRLH and SOD1 gene variations associated with heat tolerance in Chinese cattle.

With the proposed global climate change, heat tolerance is becoming increasingly important to the sustainability of livestock production systems. Results from previous studies showed that variants in the prolactin releasing hormone (PRLH) (AC_000160.1:g.11764610G>A) and superoxide dismutase 1 (SOD1) (AC_000158.1:g.3116044T>A) genes play an important role in heat tolerance in African indicine cattle. However, it is unknown whether or not the mutations are associated with heat tolerance in Chinese cattle. In this study, PCR and DNA sequencing were used to genotype two missense mutations in 725 individuals of 30 cattle breeds. Analysis results demonstrated that two classes of base substitution were detected at two loci: AC_000160.1:g.11764610G>A and AC_000158.1:g.3116044T>A or T>C respectively, with amino acid substitutions arginine to histidine and phenylalanine to isoleucine or leucine. The frequencies of the G and T alleles of the two loci gradually diminished from northern groups to southern groups of native Chinese cattle, whereas the frequencies of A and A or C alleles showed a contrary pattern, displaying a significant geographical difference across native Chinese cattle breeds. Additionally, analysis of these two loci in Chinese indigenous cattle revealed that two SNPs were significantly associated with mean annual temperature (T), relative humidity (RH) and temperature humidity index (THI) (P<0.01), suggesting that cattle with A or C alleles were distributed in regions with higher T, RH and THI. Our results suggest that the two mutations of PRLH and SOD1 genes in Chinese cattle were associated with the heat tolerance.

Use of Unpalatable Forages by Ruminants: The Influence of Experience with the Biophysical and Social Environment.

Simple SummaryUnpalatable forages, due to either low nutrient content or the presence of toxic compounds, are widespread and represent a challenge for ruminant nutrition, health, and welfare. If we find ways to encourage consumption of unpalatable forages, they could provide at least part of the nutrient requirements of ruminants. Our objective was to synthesize the role of diverse environmental experiences on the use of unpalatable forages by ruminants. Experimental evidence shows that experience can alter both morpho-physiological and psychological (learning) mechanisms to better cope with unpalatable forages, particularly early in life when body functions are more amenable to change. Furthermore, experiential learning provides flexibility in diet selection, which is critical in changing foraging environments. By understanding and applying behavioural principles, it is possible to better devise management plans that optimize the nutrition, health, and welfare of herbivores grazing unpalatable forages throughout their life. In addition, a more uniform use of resources can be achieved from the landscape level down to the individual plant, with consequent benefits to ecosystem integrity and stability.Unpalatable forage resources (low nutrient density, potentially toxic metabolites) are widespread and represent a challenge for ruminant nutrition, health, and welfare. Our objective was to synthesize the role of biophysical and social experience on the use of unpalatable forages by ruminants, and highlight derived behavioural solutions for the well-being of soils, plants, and animals. Environmental experiences early in life modulate gene expression and promote learning, which alters morpho-physiological and psychological mechanisms that modify behavioural responses and change food and habitat selection. In this process, ruminants can become better adapted to the habitat where they are reared. Moreover, experiential learning provides flexibility in diet selection, which is critical for changing foraging environments. Learned associations between unpalatable and palatable foods, if ingested in appropriate amounts, sequence, and close temporal association, induce the development of preference for the former type of food. In this way, a more uniform use of resources can be achieved from the landscape level down to the individual plant, with the associated benefits to ecosystem integrity and stability. Ruminants can also learn the medicinal benefits of ingesting foods with toxins (e.g., condensed tannins and saponins with antiparasitic properties). This knowledge on behavioural processes can be translated into behavioural applications that provide low-cost solutions to many challenges that producers face in managing sustainable livestock production systems.

Responses of body fat mobilization to isoproterenol or epinephrine challenge in adult cows: influence of energy level, breed, and body fatness.

The sustainability of livestock production systems facing climatic or economic changes is linked in part to the potential of the female ruminants to adapt to feeding constraints through metabolic and hormonal regulation, notably responses of body fat mobilization, depending on adipose tissue (AT) lipolysis. Our hypothesis was that these responses could change according to genotype (breed) and body fatness. Six fat, nonpregnant, nonlactating Charolais cows, six fat Holstein cows, and six lean Holstein cows were used in a 2 × 2 crossover design with two treatments (underfeeding or overfeeding, at 62% [low] or 128% [high] of maintenance energy requirements [MER], respectively) and two periods. Isoproterenol (ISO, a nonselective β-adrenergic agonist) or epinephrine (EPI, a β- and α2-adrenergic agonist) was injected (6 nmol/kg of lean mass). Blood samples were collected regularly from -20 to 75 min after the injection and then were analyzed for NEFA, glycerol, glucose, and L-lactate. Underfeeding greatly increased (P < 0.001) basal plasma NEFA concentrations (+467%, +264%, and +600% for fat Charolais, fat Holstein, and lean Holstein cows, respectively). For each drug, underfed cows had higher NEFA or glycerol responses to adrenergic challenges than overfed cows. Fat Charolais cows had higher basal plasma NEFA (P < 0.05) concentrations (+64.9%) than fat Holstein cows. The plasma NEFA or glycerol response at 5 min (P < 0.05) was higher for fat Charolais than for fat Holstein cows, whatever the injected drug. Basal plasma lactate concentration and lactate response to ISO or EPI were higher (P < 0.05) for fat Charolais cows than for fat Holstein cows. Fat Holstein cows had higher (P < 0.01) basal glycerol (+18.4%) than lean Holstein cows. This increase could be linked to the increased AT mass. ISO increased more lipolytic responses in fat than in lean Holstein cows, whereas EPI increased more these responses in lean than in fat Holstein cows (drug × fatness interaction), suggesting an increased antilipolytic effect due to α2-AR stimulation in fat cows. Breed had a significant effect on basal and stimulated fat mobilization as well as lactate concentrations, suggesting that the Charolais breed could be more sensitive to stress.