Unraveling the Genomic Association for Milk Production Traits and Signatures of Selection of Cattle in a Harsh Tropical Environment.

A study was designed to identify the genomic regions associated with milk production traits in a dairy cattle population reared by smallholder farmers in the harsh and challenging tropical savanna climate of Bengaluru, India. This study is a first-of-its-kind attempt to identify the selection sweeps for the dairy cattle breeds reared in such an environment. Two hundred forty lactating dairy cows reared by 68 farmers across the rural-urban transiting regions of Bengaluru were selected for this study. A genome-wide association study (GWAS) was performed to identify candidate genes for test-day milk yield, solids-not-fat (SNF), milk lactose, milk density and clinical mastitis. Furthermore, the cross-population extended haplotype homozygosity (XP-EHH) methodology was adopted to scan the dairy cattle breeds (Holstein Friesian, Jersey and Crossbred) in Bengaluru. Two SNPs, rs109340659 and rs41571523, were observed to be significantly associated with test-day milk yield. No significant SNPs were observed for the remaining production traits. The GWAS for milk lactose revealed one SNP (rs41634101) that was very close to the threshold limit, though not significant. The potential candidate genes fibrosin-like 1 (FBRSL) and calcium voltage-gated channel auxiliary subunit gamma 3 (CACN) were identified to be in close proximity to the SNP identified for test-day milk yield. These genes were observed to be associated with milk production traits based on previous reports. Furthermore, the selection signature analysis revealed a number of regions under selection for the breed-group comparisons (Crossbred-HF, Crossbred-J and HF-J). Functional analysis of these annotated genes under selection indicated pathways and mechanisms involving ubiquitination, cell signaling and immune response. These findings point towards the probable selection of dairy cows in Bengaluru for thermotolerance.

Selective Sweeps in Cattle Genomes in Response to the Influence of Urbanization and Environmental Contamination.

A genomic study was conducted to identify the effects of urbanization and environmental contaminants with heavy metals on selection footprints in dairy cattle populations reared in the megacity of Bengaluru, South India. Dairy cattle reared along the rural-urban interface of Bengaluru with/without access to roughage from public lakeshores were selected. The genotyped animals were subjected to the cross-population-extended haplotype homozygosity (XP-EHH) methodology to infer selection sweeps caused by urbanization (rural, mixed, and urban) and environmental contamination with cadmium and lead. We postulated that social-ecological challenges contribute to mechanisms of natural selection. A number of selection sweeps were identified when comparing the genomes of cattle located in rural, mixed, or urban regions. The largest effects were identified on BTA21, displaying pronounced peaks for selection sweeps for all three urbanization levels (urban_vs_rural, urban_vs_mixed and rural_vs_mixed). Selection sweeps are located in chromosomal segments in close proximity to the genes lrand rab interactor 3 (RIN3), solute carrier family 24 member 4 (SLC24A4), tetraspanin 3 (TSPAN3), and proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1). Functional enrichment analyses of the selection sweeps for all three comparisons revealed a number of gene ontology (GO) and KEGG terms, which were associated with reproduction, metabolism, and cell signaling-related functional mechanisms. Likewise, a number of the chromosomal segments under selection were observed when creating cattle groups according to cadmium and lead contaminations. Stronger and more intense positive selection sweeps were observed for the cadmium contaminated group, i.e., signals of selection on BTA 16 and BTA19 in close proximity to genes regulating the somatotropic axis (growth factor receptor bound protein 2 (GRB2) and cell ion exchange (chloride voltage-gated channel 6 (CLCN6)). A few novel, so far uncharacterized genes, mostly with effects on immune physiology, were identified. The lead contaminated group revealed sweeps which were annotated with genes involved in carcass traits (TNNC2, SLC12A5, and GABRA4), milk yield (HTR1D, SLCO3A1, TEK, and OPCML), reproduction (GABRA4), hypoxia/stress response (OPRD1 and KDR), cell adhesion (PCDHGC3), inflammatory response (ADORA2A), and immune defense mechanism (ALCAM). Thus, the findings from this study provide a deeper insight into the genomic regions under selection under the effects of urbanization and environmental contamination.

Digestibility and nitrogen balance of goats on high and low protein rations supplemented with a commercial tannin feed-additive.

Despite the increasing importance of goat production in response to high demand for their products and their relative robustness to environmental stressors, and in contrast to other ruminant species, little data is available on how tannin extract feeding affects their feed intake, nutrient digestion and nitrogen (N) metabolism. Therefore, a trial in Oman investigated the respective variables by using a commercial tannin feed additive. In a 4 (treatments) x 3 (periods) x 2 (animals) Youden square, two weaned Batinah bucks each were fed a high or low protein diet of Rhodes grass hay and crushed barley grain, with or without the addition of a chestnut and quebracho tannin extract at 2 g/kg metabolic weight. Feed offered, feed refused and faeces and urine excreted were quantified to determine diet digestibility, total N excretion, N retention and rumen microbial protein synthesis (MPS). Due to their young age and low live weight, feed intake of goats was relatively low. Crude protein level and tannin addition had no statistically significant effect on dry matter (DM) and N intake, DM digestibility, N excretion in faeces and urine, as well as MPS. In consequence, no benefit of tannin feeding could be confirmed for the goats' N retention, irrespective of diet composition. These results indicate, on one hand, an effective neutralisation of the tested tannin extract along the gastrointestinal tract of goats, but on the other hand, that stimulation of MPS or N retention by tannins cannot be evidenced when diet components are present that simultaneously release energy and protein, as is the case with barley.

Accuracy of enteric methane emission models for cattle in sub-Saharan Africa: status quo and the way forward.

Cattle emit over 65% of enteric methane (CH4) in sub-Saharan Africa (SSA), making them the focus of many mitigation strategies targeting livestock emissions. Since measured feed intake data are sparse, emission factors for enteric CH4 (EFCH4) are mainly estimated indirectly from gross energy intake (GEI) using the net energy (NE) requirements for different metabolic processes in cattle. However, all NE requirement systems commonly used for cattle in SSA were developed for cattle in temperate regions. Therefore, we assessed the suitability of different enteric CH4 models for estimating the GEI of cattle in SSA. The Intergovernmental Panel on Climate Change (IPCC) and South African models were identified as the main tier 2-based methods used to estimate enteric CH4 emissions from cattle in SSA. In the IPCC model, EFCH4 was estimated as (GEI * [Ym/100])/55.65, where Ym is the conversion factor (%) of gross energy in feed to CH4 and 55.65 the energy content of CH4 (MJ/kg). The GEI was estimated based on NE requirements for different metabolic processes in cattle as per the American National Research Council. In the South African model, EFCH4 was estimated as (Y/100 * GEI/55.22), where Y is the CH4 yield and 55.22 is the energy content of CH4; Y was calculated from the dry matter (DM) digestibility while GEI was calculated by predicting DM intake and multiplying it by 18.4 MJ (gross energy per kilogram DM). Also, the suitability of the British and German NE requirement systems was assessed as alternatives used for cattle nutrition in SSA. These NE systems were implemented in the IPCC model to yield the "AFRC" and "GfE" models, respectively. The four models were then evaluated using an evaluation dataset summarizing feed quality and DM intake results from 21 studies conducted in SSA, with 125 dietary treatments, and 822 cattle observations. The relative prediction error (RPE) and concordance correlation coefficient (CCC) were used to evaluate the models' accuracy. Only the South African model estimated the GEI in dairy cattle with an acceptable RPE (18.9%) and highest CCC (0.87), while the other three models yielded estimates with RPE > 20%. None of the four models we assessed estimated GEI for other cattle (i.e., nondairy) with an RPE < 20% or CCC > 0.30. The inaccuracy in GEI estimates suggests an error of the same magnitude in EFCH4 estimates. Therefore, a concerted effort is needed to improve the accuracy of enteric CH4 estimation models for cattle in SSA.

Accurate estimates of enteric methane (CH4) emissions are needed to ascertain the efficacy of mitigation strategies proposed for cattle in sub-Saharan Africa (SSA). Models used for cattle in SSA were developed using data on metabolic processes measured from cattle in temperate regions which may lead to inaccurate enteric CH4 estimates. Therefore, we assessed the suitability of different enteric CH4 models for estimating the gross energy intake (GEI) of cattle in SSA. The Intergovernmental Panel on Climate Change (IPCC) and South African models were identified as tier 2-based methods for estimating enteric CH4 emissions from cattle in SSA. Also, the British and German net energy systems were implemented in the IPCC model to yield two other models. These four models were evaluated using a dataset summarizing feed quality and intake results from 21 studies conducted in SSA. Only the South African model estimated the GEI of dairy cattle with an error of <20% (acceptable cutoff point), while the other three models yielded estimates with the error of >20%. None of the four models estimated GEI for nondairy cattle with an error of <20%. We provide the first estimate of model uncertainty that may be applied to enteric CH4 estimates from cattle in SSA.

Urbanisation threats to dairy cattle health: Insights from Greater Bengaluru, India.

Complex urbanisation dynamics, on the one hand, create a high demand for animal products, and on the other hand put enormous pressure on arable land with negative consequences for animal feed production. To explore the impact of accelerated urbanisation on dairy cattle health in urban farming systems, 151 farmers from different parts of the Greater Bengaluru metropolitan area in India were individually interviewed on aspects addressing cattle management and cattle health. In addition, 97 samples of forages from the shores of 10 different lakes, and vegetable leftovers used in cattle feeding were collected for nutritional analysis. Along with the use of cultivated forages, crop residues, and concentrate feed, 47% and 77% of the farmers occasionally or frequently used lake fodder and food leftovers, respectively. Nutritionally, lake fodder corresponded to high-quality pasture vegetation, but 43% of the samples contained toxic heavy metals such as arsenic, cadmium, chromium, and lead above official critical threshold levels. Therefore, lake fodder may affect cows' health if consumed regularly; however, heavy metal concentrations varied between lakes (P < 0.05), but not between fodder types (P > 0.05). Although 60% of the interviewed farmers believed that their cows were in good health, logit model applications revealed that insufficient drinking water supply and the use of lake fodder negatively impacted cattle health (P < 0.05). While it remains unknown if regular feeding of lake fodder results in heavy metal accumulation in animal products, farmers and farm advisors must address this and other urbanization-related challenges to protect cattle health.

Rurbanity: a concept for the interdisciplinary study of rural-urban transformation.

Along with climate change, population growth, and overexploitation of natural resources, urbanisation is among the major global challenges of our time. It is a nexus where many of the world's grand challenges intersect, and thus key to sustainable development. The widespread understanding of urbanisation as a successive and unidirectional transformation of landscapes and societies from a rural to an urban state is increasingly questioned. Examples from around the globe show that 'the rural' and 'the urban' are not only highly interdependent, but actually coexist and often merge in the same space or livelihood strategy. Our concept of rurbanity provides an integrated theoretical framework which overcomes the rural-urban divide and can be operationalised for empirical research. Rurbanity is the next stringent step following the gradual widening of previous concepts from urban-centred approaches through the emphasis on urban peripheries to attempts of abolishing any distinction of a rural environment and acknowledging the highly dynamic nature of globalising urbanisation. Building on complex systems theory and assemblage thinking, our concept explores complementary aspects of the distinct epistemic worldviews dominating the natural and social sciences. Within this theoretical frame, we derive four analytical dimensions as entry points for empirical research: Endowments and Place, Flows and Connectivity, Institutions and Behaviour, and Lifestyles and Livelihoods. Two examples illustrate how these dimensions apply, interact, and together lead to a comprehensive, insightful understanding of rurban phenomena. Such understanding can be an effective starting point for assessing potential contributions of rurbanity to long-term global sustainability.

Showcasing the multifaceted aspects of agricultural transformation: The example of mountain oases in Oman.

In the Anthropocene the consequences of land-use transformation on ecosystem services are of growing concern, particularly in fragile areas of mountain agriculture that often represent high nature-value farmland. This study uses a decadal repeated survey approach to analyse the effects of modernisation on oasis systems in the Jabal Al Akhdar region of northern Oman. This rugged mountain region at the north-eastern tip of the Arabian Peninsula experiences a growing influx of regional and international tourists since the opening of a modern highway 15 years ago. In 2007, at the onset of transformation processes, a survey was conducted with all households (HH) located in three major settlements along the 1000-m-altitude gradient of the Wadi Muaydin watershed. The survey was repeated in 2018, including all remaining HH of the three settlements. This longitudinal approach allowed studying the consequences of social-ecological transformation processes on crop and livestock husbandry, agricultural labour use, product marketing, and perception of the region's future by its local residents. Though the village inhabitants are aging and declining in numbers, they still adhere to agriculture, largely because of tradition and identity. Fallowing and abandoning farmland increased over the investigated time span but was paralleled by increased application of agrochemicals and animal manure on fields, purchase of roughage and concentrate feeds for small ruminants, concentration on cash crop and meat production for sale, and increased employment of migrant workers. These indicators of modernisation of oasis agriculture are accompanied by predominantly pessimistic views on future prospects of oasis farming. Commonly perceived problems are shortage of irrigation water and profound societal change. Against these challenges, value chain generation and direct marketing opportunities for local agricultural produce are seen as prerequisites to keep the high nature-value farmland of these mountain oases alive.

Phenotypic and genetic diversity of domestic yak (Bos grunniens) in high-altitude rangelands of Gilgit-Baltistan, Pakistan.

Due to climate change, irrigated agriculture may become restricted in the mountain valleys in northern Pakistan in the future. Hence, the importance of yak (Bos grunniens) keeping in the mountain ranges as risk-mitigating strategy for mountain dwellers will potentially increase. However, little is known about the current status of the domestic yak in this region. We therefore used phenotypic characteristics and 13 microsatellite loci to determine the phenotypic differences and the level of genetic differentiation between populations of six valleys. Larger body measures and partially different physical appearance were observed in Shimshal and Khaplu yaks, especially when compared with yaks in the Chapurson valley. Overall, the mean observed heterozygosity was similar to the mean expected heterozygosity. Average genetic diversity was highest in the Hopar population and lowest in the Haramosh population. A low FIS value indicated that individuals were less related than expected under a model of random mating. Three distinct genetic clusters were found for the six yak populations under study. Genetic distances were largest between Shimshal and Khaplu populations, and lowest between populations of Phandar and Hopar. It is concluded that yaks of Shimshal, Khaplu and Haramosh valleys were genetically distinct from yak populations in Chapurson, Hopar and Phandar valleys, indicating that the free-range conditions and pastoral yak rearing system in the region have preserved the underlying genetic diversity of the yak populations.

Seasonal Variations in Voluntary Intake and ApparentDigestibility of Forages by Goats in the Chinese Altai Mountains.

Forage availability and quality directly impact animal performance, ultimately affecting productivity and health. This study aimed to understand the interaction between qualitative and quantitative vegetation availability and feed intake of goats on alpine pastures in the Chinese Altai Mountains. The daily grazing routes of three goats from a local herding family were monitored with GPS devices set at a logging rate of 64 s during spring and the early and late summer season in 2013 and 2014. The quantity and quality of vegetation along their grazing routes was determined, and the amount of feces excreted was measured in a total of five goats per season for the indirect determination of the animals' feed intake. The grazing routes were longer in spring than in summer, leading to larger grazing areas visited in spring. Vegetation on offer ranged from 980 to 2400 kg dry mass per hectare and was similar in the spring and summer seasons but higher in 2013 than in 2014. Feed consumption of forage and nutrients did not significantly differ between seasons and years, respectively, suggesting that the goats' nutrient intake was not restricted by interannual variability of forage on offer. Regular monitoring of animal numbers and of vegetation quantity and quality on the mountain rangelands can help responsible government agencies to estimate forage offtake of small ruminants in order to timely adjust grazing pressure in the study region.

Molecular, Physiological and Hematological Responses of Crossbred Dairy Cattle in a Tropical Savanna Climate.

A comprehensive study was conducted to assess the effects of seasonal transition and temperature humidity index (THI) on the adaptive responses in crossbred dairy cows reared in a tropical savanna region. A total of 40 lactating dairy cattle reared by small-scale dairy farmers in Bengaluru, India, were selected for this study. The research period comprised the transitioning season of summer to monsoon, wherein all traits were recorded at two points, one representing late summer (June) and the other early monsoon (July). A set of extensive variables representing physiological responses (pulse rate, respiration rate, rectal temperature, skin surface temperature), hematological responses (hematological profile), production (test day milk yield, milk composition) and molecular patterns (PBMC mRNA relative expression of selective stress response genes) were assessed. A significant effect of seasonal transition was identified on respiration rate (RR), skin surface temperature, mean platelet volume (MPV), platelet distribution width (PDWc), test day milk yield and on milk composition variables (milk density, lactose, solids-not-fat (SNF) and salts). The THI had a significant effect on RR, skin surface temperature, platelet count (PLT), plateletcrit (PCT) and PDWc. Lastly, THI and/or seasonal transition significantly affected the relative PBMC mRNA expression of heat shock protein 70 (HSP70), interferon beta (IFNß), IFNγ, tumor necrosis factor alpha (TNFα), growth hormone (GH) and insulin-like growth factor-1 (IGF-1) genes. The results from this study reveal environmental sensitivity of novel physiological traits and gene expressions to climatic stressors, highlighting their potential as THI-independent heat stress biomarkers.

Dairy production in an urbanizing environment-Typology and linkages in the megacity of Bengaluru, India.

Urbanization is a main driver of agricultural transition in the Global South but how it shapes trends of intensification or extensification is not yet well understood. The Indian megacity of Bengaluru combines rapid urbanization with a high demand for dairy products, which is partly supplied by urban and peri-urban dairy producers. To study the impacts of urbanization on dairy production and to identify key features of dairy production systems across Bengaluru's rural-urban interface, 337 dairy producers were surveyed on the socio-economic profile of their household, their dairy herd and management, resources availability and, in- and output markets. A two-step cluster analysis identified four spatially explicit dairy production systems based on urbanization level of their neighborhood, reliance on self-cultivated forages, pasture use, cattle in- and outflow and share of specialized dairy genotypes. The most extensive dairy production system, common to the whole rural-urban interface, utilized publicly available feed resources and pasture grounds rather than to cultivate forages. In rural areas, two semi-intensive and one intensive dairy production systems relying on self-cultivation of forage with or without pasture further distinguished themselves by their herd and breeding management. In rural areas, the village's dairy cooperative, which also provided access to inputs such as exotic genotype through artificial insemination, concentrate feeds and health care, was often the only marketing channel available to dairy producers, irrespective of the dairy production system to which they belonged. In urban areas, milk was mostly sold through direct marketing or a middleman. Despite rapidly progressing urbanization and a population of 10 million, Bengaluru's dairy sector still relies on small-scale family dairy farms. Shifts in resources availability, such as land and labor, are potential drivers of market-oriented intensification but also extensification of dairy production in an urbanizing environment.

Agro-ecological landuse transformation in oasis systems of Al Jabal Al Akhdar, northern Oman.

The millenia-old oasis systems in the Western Hajar Mountains of Northern Oman have received widespread attention as models of sustainable irrigated agriculture in hyperarid Arabia. Given Oman's rampant urbanization, growing scarcity of water and skilled labour, we quantified chances in water use, land use, and land cover between 2007 and 2018 using a rare time-series approach of detailed GIS-based crop mapping. Results from satellite image analysis and comprehensive ground truthing showed that urban areas grew from 206 ha in 2009 to 230 ha in 2014 and 252 ha in 2018. Throughout this decade, irrigated areas in backyards and front-house gardens of the town, planted largely to tree crops and vegetables, increased from 13.5 to 23.3 ha. Between 2007 and 2018 the actively used area of the studied oasis systems declined by 2.0% and the share of perennial crops without underplanting by 5.1%, while land under agroforestry increased by 2.1% and fallow land by 3.5%. Rising water demand of the sprawling town Sayh Qatanah led to terraces of Al 'Ayn and Ash Sharayjah now being partly irrigated with treated wastewater which accelerated the abandonment of the old settlement structures. The labour- and water use efficiency-driven transformation of the Al Jabal Al Akhdar oasis agriculture into increasingly market-oriented landuse systems questions its function as example of sustainable, bio-cultural heritage of Arabia.

Feed Quality and Feeding Level Effects on Faecal Composition in East African Cattle Farming Systems.

Effects of feeding levels below maintenance requirements of metabolizable energy (MER) and of feed supplementation on fecal nutrient and microbial C concentrations were evaluated. In experiment 1, Rhodes grass hay only was offered to Boran steers at 80%, 60%, and 40% of individual MER, while steers at 100% MER additionally received a concentrated mixture. This reduction in MER decreased N, increased fungal C but did not affect bacterial C concentrations in feces. In experiment 2, Holstein × Boran heifers were offered a poor-quality roughage diet without supplement, with sweet potato vine silage or with a urea-molasses block. These two supplements did not affect the fecal chemical composition or fungal C but increased bacterial C concentrations in feces. Across all data, the fungal C/bacterial C ratio was positively related to N and negatively to neutral detergent fiber concentrations in feces, indicating diet-induced shifts in the fecal microbial community.

Confronting pastoralists' knowledge of cattle breeds raised in the extensive production systems of Benin with multivariate analyses of morphological traits.

Cross-border seasonal livestock movements in West Africa bring into close contact several cattle breeds. In the coastal countries hosting migrating herders from the Sahel, it often affects the genetic variability and geographical distribution of traditional cattle breeds, through their indiscriminate but also intended crossbreeding with larger-framed Sahelian cattle breeds. The need to secure and effectively manage this genetic variability, in order to respond to changing production and market conditions, is widely recognized by the scientific community, livestock herders and policy-makers. This however requires a comprehensive knowledge of the breeds' characteristics. The indigenous criteria used by pastoralists to characterize and distinguish cattle breeds remain unclear and further validation is required. This study was therefore designed to document and validate herders' knowledge on cattle breeds. From June 2015 to June 2016, 803 cattle herders participated in a phenotypic breed description in seven pastoral communities across the country. Each cattle herder was asked to name and describe morphologically the different cattle breeds in his herd. Subsequently, fifteen body measurements taken on a total of 1401 adult cattle (964 cows and 439 bulls) were submitted to multivariate analyses. Participants distinguished ten different cattle breeds kept in traditional herds according to six primary morphological traits and clearly separated zebuine from taurine breeds. These results were consistent with those of the multivariate analyses of the measured traits. However, herders' classification approach proved to be more accurate in distinguishing breeds within the zebuine subspecies. Hence, while metric measurements and molecular genetic analyses are promising approaches to fill the knowledge gap on the diversity of local farm animal genetic resources, they should integrate livestock herders' traditional knowledge for more precision.

Digesta passage and nutrient digestibility in Boran steers at low feed intake levels.

The present study evaluated the effects of energetic undernutrition on liquid and solid digesta passage and on nutrient digestibility as well as their interdependencies. Using a 4 x 4 Latin square design, 12 growing Boran steers (183 ± 15.2 kg live weight) were allocated to four levels of metabolizable energy (ME) supply fixed at 100, 80, 60 and 40% of individual maintenance energy requirements (MER) during four experimental periods. Each period comprised three weeks of adaptation, two weeks of data collection and two weeks of recovery. Diets MER80, MER60 and MER40 only consisted of Rhodes grass hay (RGH), whereas diet MER100 contained (as fed) 83% RGH, 8% cotton seed meal and 9% sugarcane molasses. Feed intake differed between treatments (p < .001) and ranged from 40 ± 0.6 g dry matter (DM) per kg of metabolic weight (kg0.75 ) in MER40 to 81 ± 1.3 g DM in MER100. Digestibility of neutral and acid detergent fibre (NDF, ADF) was highest at MER80, whereas rumen retention time of liquid and solid digesta was longest at MER40. The correlation of rumen retention time of liquid and solid digesta with the digestibility of proximate diet components was weak but positive, whereas the correlation of liquid and solid rumen retention time with quantitative feed and nutrient intake was strong (p < .01) and negative. Our results suggest that tropical cattle are able to buffer a moderate energy deficit by prolonging rumen retention time of digesta and hence improve diet digestibility. Conversely, a severe energy deficit cannot be buffered by digestive adaptation mechanisms and will inevitably lead to productivity losses.

Supplementing Tropical Cattle for Improved Nutrient Utilization and Reduced Enteric Methane Emissions.

Given their high nitrogen (N) concentration and low costs, sweet potato vine silage (SPVS) and urea-molasses blocks (UMB) are recommended supplements for tropical regions; therefore, they were investigated in this study. Six heifers were allocated to three diets: the roughage diet (R) consisted of wheat straw (0.61) and Rhodes grass hay (0.39; on dry matter (DM) basis); R + SPVS combined R (0.81) and SPVS (0.19); and with R + UMB animals had access to UMB. During two experimental periods, feed intake, feces and urine excretion, digesta passage, and rumen microbial protein synthesis were determined during seven days and methane emissions during three days. There was no treatment effect (p > 0.05) on DM and N intake. Apparent DM digestibility of R + SPVS (510 g/kg) was higher (p < 0.05) than of R (474 g/kg). Digesta passage and duodenal microbial N flow were similar for all diets (p > 0.05), while N retention was highest with R + SPVS (p > 0.05). Methane emissions per unit of digested feed (g CH4/kg dDM) were lower (p < 0.05) for R + SPVS (55.2) than for R (64.7). Hence, SPVS supplementation to poor-quality roughage has the potential to increase diet digestibility and N retention while reducing CH4 emissions.

Effects of feed intake level on efficiency of microbial protein synthesis and nitrogen balance in Boran steers consuming tropical poor-quality forage.

This study aimed at evaluating the effects of feed intake level on the efficiency of rumen microbial protein synthesis (EMPS), nitrogen (N) excretion, and N balance in twelve 18-months old Boran (Bos indicus) steers with initial average liveweight of 183 kg (standard deviation (SD) 15.2). The experiment followed a 4 × 4 complete Latin Square design with four dietary treatments tested in four periods. Each period ran for 5 weeks with 3 weeks of adaptation and 2 weeks of sample collection; separated by 2 weeks of re-feeding. Steers were fed at 100%, 80%, 60%, and 40% of their metabolisable energy requirement for maintenance (MER, referred to as MER100, MER80, MER60, and MER40, respectively). Steers receiving MER80, MER60, and MER40 were only fed Rhodes grass hay. MER100 steers were offered Rhodes grass hay at 80% of their MER and cottonseed meal and sugarcane molasses at each 10% of MER. Mean daily dry matter intake differed between treatments (p < 0.001) and ranged between 2.1 kg/animal (SD 0.13) in MER40 and 4.5 kg/animal (SD 0.31) in MER100. Urinary N excretion and N balance did not differ between MER80, MER60, and MER40. According to contrast test, declining feed intake level from MER80 to MER40 reduced duodenal microbial crude protein flow (p < 0.001), but did not alter the EMPS (g microbial N/kg digestible organic matter intake). Yet, if scaled to N intake, EMPS increased (p < 0.049), whereas total N and faecal N excretions decreased linearly with declining intake level (p < 0.001 for both variables). At similar grass hay intake, duodenal microbial crude protein flow was 41% higher in MER100 than in MER80 steers (p < 0.001). In cattle offered poor-quality tropical forage below their MER, the very low EMPS and thus microbial protein supply aggravate the negative effects of low dietary nutrient and energy intakes in periods of feed shortage.

Genetic and nongenetic factors affecting on-farm performance of peri-urban dairy cattle in west Africa.

Population growth and urbanization lead to an increasing demand for milk in sub-Saharan Africa, but the production potential of the 65.9 million dairy cows in the region is far from being fully exploited to meet this demand. With the aim to support decision-making for breeding and management of dairy cattle in commercial farms, we performed a comparative study of daily milk offtake, chemical composition of milk, prevalence of metabolic disorders, and body weight development of local and crossbred cattle genotypes in peri-urban commercial farms in Ouagadougou, Burkina Faso. We used data that were collected during regular visits of 7 farms in peri-urban areas of the city over a 16-mo period. Animals belonged to 3 breed groups (123 local zebu, 49 Sahelian crossbred, and 42 European crossbred cows). We applied a mixed model approach to evaluate the genetic and seasonal effects on daily milk offtake, milk composition, and body weight. Nonlinear growth models were fitted to model the body weight development according to genotype, season, and reproductive status of cows. The milk fat-to-milk protein ratio was used to determine the prevalence of ketosis and acidosis. Daily milk offtake from crossbred cows was 3.1- to 4.3-fold higher than from local zebu cows; furthermore, crossbred cows had a higher body weight and maturity rate than local zebu cows. In contrast, no genotype differences were found in milk fat and milk protein percentage and prevalence of ketosis and acidosis. Additionally, seasonal effects suggested that higher production performances could be realized through improved management of dairy cows, particularly in the late dry and rainy season. Improved feeding management could also reduce the risk of metabolic disorders. In summary, production performances of crossbred dairy cows in peri-urban production systems in Burkina Faso are higher as compared with local zebu cows. However, environmental effects suggest that further studies are needed to systematically assess genotype by environment interactions to guide the development of sustainable breeding and management programs for dairy cattle in Burkina Faso.

Effects of quebracho tannin extract (Schinopsis balansae Engl.) and activated charcoal on nitrogen balance, rumen microbial protein synthesis and faecal composition of growing Boer goats.

Under irrigated arid conditions, organic fertiliser rich in slowly decomposable nitrogen (N) and carbon (C) is needed for soil fertility maintenance. Feeding ruminants with condensed tannins will lower ruminal protein degradation, reduce urinary N excretion and might increase the faecal fraction of slowly decomposable N. Supplementation with activated charcoal (AC) might enrich manure with slowly degrading C. Therefore, we investigated the effects of feeding quebracho tannin extract (QTE) and AC on the N balance of goats, the efficiency of microbial protein synthesis in the rumen (EMPS) and the composition of faeces. The feeding trial comprised three periods; in each period, 12 male Boer goats (28 ± 3.9 kg live weight) were assigned to six treatments: a Control diet (per kg diet 500 g grass hay and 500 g concentrate) and to further five treatments the Control diet was supplemented with QTE (20 g and 40 g/kg; diets QTE2 and QTE4, respectively), with AC (15 g and 30 g/kg, diets AC1.5 and AC3.0, respectively) and a mixture of QTE (20 g/kg) plus AC (15 g/kg) (diet QTEAC). In addition to the N balance, EMPS was calculated from daily excretions of purine derivatives, and the composition of faecal N was determined. There was no effect of QTE and AC supplementation on the intake of organic matter (OM), N and fibre, but apparent total tract digestibility of OM was reduced (p = 0.035). Feeding QTE induced a shift in N excretion from urine to faeces (p ≤ 0.001) without altering N retention. Total N excretion tended to decrease with QTE treatments (p = 0.053), but EMPS was not different between treatments. Faecal C excretion was higher in QTE and AC treatments (p = 0.001) compared with the Control, while the composition of faecal N differed only in concentration of undigested dietary N (p = 0.001). The results demonstrate that QTE can be included into diets of goats up to 40 g/kg, without affecting N utilisation, but simultaneously increasing the excretion of slowly decomposable N and C fractions. Feeding AC up to 30 g/kg of the diet increases slowly degradable faecal C concentration, without negative effects on N metabolism of goats.

Production objectives and breeding practices of urban goat and sheep keepers in West Africa: regional analysis and implications for the development of supportive breeding programs.

To better understand the relative importance of the multi-purpose functions of small ruminants for their urban owners and related breeding practices including selection criteria, we undertook a comparative analysis across the West African cities of Kano (Nigeria), Bobo Dioulasso (Burkina Faso) and Sikasso (Mali). Semi-structured questionnaires were used to collect the required information from 301 sheep farmers (100, 102 and 99 in Kano, Bobo Dioulasso and Sikasso) and 306 goat farmers (100, 99 and 107 in Kano, Bobo Dioulasso and Sikasso). Sheep and goats were kept for a variety of reasons including income generation, insurance (sale for cash to meet unexpected expenditures) and economic security (sale for cash to support foreseeable expenses), social/religious functions and prestige in ownership. The relative importance given by respondents to the different functions varied significantly (p < 0.001) across cities and between species within a city. However, irrespective of city, both species were primarily kept for their financial functions whereby sheep were perceived as having higher economic value. Although breeding practices were very similar in many respects (low practice of castration, culling and replacement strategies, uncontrolled mating, no record keeping and selection criteria), the emphasis put on each selection criteria varied across cities and between species. Irrespective of city, most of the goats were of the indigenous type while keeping crossbred animals and/or maintaining more than one genotype in the same flock was more commonly practiced by sheep keepers. This points to a higher motivation for strategic breeding among sheep than goat keepers and indicates that the former might be interested in joining carefully designed participatory flock improvement programs.