Intensive grazing and maize silage to enhance the sustainability of small-scale dairy systems in the highlands of Mexico

Tropical Animal Health and Production - The effects of two innovative feeding strategies—intensive grazing (GR) and maize silage (MS)—on the sustainability of small-scale dairy systems...     

Exploring Current and Future Situation of Mediterranean Silvopastoral Systems: Case Study in Southern Spain

Extensive range-based livestock production has suffered a sharp decrease in Mediterranean Spain in recent decades due to two opposing trends in land use: progressive abandonment of practices in marginal rural areas and land use intensification in more productive areas. In this study, we explored the visions of key stakeholders on the current and future situation of silvopastoral systems in the Sierra Morena mountain range of southern Spain, where extensive livestock grazing is declining because of competition with other more profitable activities, such as intensive olive groves and game hunting. We performed a discourse analysis using Q methodology and evaluated the existing relationships of information exchange and conflict among local institutions such as farmer’s associations, the provincial council, and conservation organizations using social network analysis. Semistructured interviews were conducted with key stakeholders representing local formal and nonformal institutions involved in extensive livestock production. Results showed three distinct discourses among stakeholders related to profitability, conservation, and modernization. There was a strong consensus on the management strategies that should be promoted to support extensive livestock production and preserve the associated silvopastoral systems. Social networks revealed high cohesion and communication exchange and a low level of conflict among stakeholders, with few exceptions. The low influence of livestock producers on policy decision making largely hinders the development of participatory management schemes. Nevertheless, similarities among the visions and opinions of different institutions suggest that new possibilities might emerge for silvopastoral systems through the collaboration among the different socioeconomic sectors present in the area.     

奶山羊CIDEa基因的克隆、序列分析与组织表达

为获得奶山羊CIDEa基因序列并检测其在乳腺组织中的表达,采用RT-PCR技术从奶山羊乳腺组织扩增CIDEa基因序列,利用生物信息学软件对其进行预测分析,并采用荧光定量PCR检测CIDEa在干奶期和不同泌乳时期乳腺组织中的表达。结果表明:通过克隆测序得到奶山羊CIDEa基因CDS区660 bp,编码219个氨基酸,与GenBank公布的绵羊、牛、人和猪的核苷酸序列同源性分别为99%、96%、85%、85%。奶山羊CIDEa蛋白属于碱性、不稳定亲水蛋白,不存在跨膜结构和信号肽;蛋白主要定位在细胞质、线粒体和细胞核。CIDEa蛋白结构主要由α螺旋、β折叠和不规则卷曲组成。奶山羊CIDEa在泌乳前期、盛期和中期乳腺组织中表达量均显著高于干奶期(P<0.05)。说明CIDEa可能参与奶山羊乳腺的泌乳过程,为进一步研究其在奶山羊乳腺组织中的功能及对乳品质的调控作用奠定基础。     

A survey of Salmonella spp and Campylobacter spp in dairy goat faeces and bulk tank milk in the Murcia region of Spain

This study was designed to investigate the occurrence of Salmonella spp and Campylobacter spp in faeces samples from 222 healthy Murciano-Granadina dairy goats reared on 12 farms in Spain and in samples of bulk tank milk from 11 of those herds. Neither Salmonella spp nor Campylobacter spp were isolated from any of the samples. Our results suggest that, under the management practices applied to this breed in Spain, Murciano-Granadina goats are not likely to be a significant reservoir for these food-borne pathogens.     

Bovine brucellosis serum agglutination test prevalence and breed disposition according to prevalent management systems in the Lake Victoria zone of Tanzania

A total of 13078 cattle 8 months of age and older belonging to 558 units in the Lake Victoria zone of Tanzania were screened for brucellosis using the serum agglutination test (SAT). This exercise was executed as a Tanzanian Agriculture Ministry's directive for screening all adult bovines in the country reared under controlled grazing and receiving good veterinary supervision and inputs so that brucellosis control measures could be instituted. In this category two types of management systems were encountered: Dairy, comprising 15 units totalling 3626 Exotic (Friesian and Ayrshire) and Grade (Zebu and Exotic) crosses, and Ranch, comprising two units totalling 6756 mainly dual-purpose Mpwapwa (MPW) animals. These three animal types have much higher milk production potential than the indigenous Tanganyika shorthorn Zebu (TSZ). This latter beef type is reared under local management system and owned wholly by subsistence stock owners practising uncontrolled communal grazing and having little or no veterinary supervision and inputs. However, TSZ animals from 541 farm units totalling 2705 members were also screened from the east and south sub-zones because of their close proximity to the Dairy/Ranch units and also the Serengeti Wildlife National Park. This exercise revealed an overall prevalence rate of 10.8%. There was moreover a significant difference in the seroprevalence rates among the management systems (P < 0.001). The lowest prevalence rate (4.3%) was found in the Local management system, with Dairy intermediate (6.3%) and Ranch highest (15.8%). There was also significant variation in prevalence rates between TSZ and Grade animals, and between MPW and Exotic animals (P < 0.001).     

Silage from maize (Zea mays), annual ryegrass (Lolium multiflorum) or their mixture in the dry season feeding of grazing dairy cows in small-scale dairy production systems in the Highlands of Mexico

Small-scale dairy systems based on grazing have dry-season herbage shortages. A repeated 3 × 3 Latin Square experiment evaluated grazing with silage from maize (MS), annual ryegrass (ARG) or a mixture (MIX) with 9 cows with 3 week periods; continuously grazed at 3.6 cows/ha with 3.6 kg DM/day of concentrate. Treatments were 7 kg DM of MS, ARG or a 2 MS:1 ARG mixture. Milk yield (MY), milk composition, live-weight, body condition, silage and concentrate intake were recorded. Herbage DM intake was estimated indirectly. Activity budgets were done for economic analysis. MY on MS (21.5 kg/cow/d) was 0.06 higher than on ARG (P < 0.09) with no differences on MIX. There were no differences for milk fat, milk protein, or body condition score. Live-weight on ARG was higher (P < 0.01) than on MS or MIX. Silage intake was higher (P < 0.01) on ARG and MS than on MIX. Herbage intake was lower (P < 0.05) on MS, compared with MIX and ARG. Total DM intake on ARG was higher than MS (P < 0.01), and MIX in between. MS resulted in 0.12 higher economic returns over ARG which had highest costs. Annual ryegrass may have a place in small-scale systems, but not as silage due to higher costs.     

Constraints on smallholder market oriented dairy systems in the north eastern coastal region of Tanzania

Twenty five smallholder dairy farmers and other stakeholders, through a Participatory Rural Appraisal in three wards of the Tanga township of north east coastal Tanzania, ranked their perceived constraints in descending order of importance: Low milk price and marketing, feed shortage in the dry season, poor management, low animal productivity, poor reproductive performance and diseases. Tick borne diseases were reported on a majority of farms. An Economic Opportunity Survey revealed wide ranges in management indices and improvement in annual milk production, age at first calving and lactation length to represent the best potential for gain. Performance generally was below locally set targets. Farmers spent on average in the three wards between 39% and 77% of income from milk on feed costs yearly. Interventions were instituted emphasising those that farmers could afford immediately. They included farmer training, dry season feed supplementation, tick control, improvement of animal shed/house cleanliness and the formation of a cooperative for milk marketing. Partial budgeting is being used to monitor success. Follow-up meetings and regular visits to farms by field officers are disseminating information on outcomes to encourage farmers to continue with interventions and spread useful knowledge to friends and neighbours.     

An integrated approach to studying the role of grazing livestock systems in the conservation of rangelands in a protected natural park (Sierra de Guara, Spain)

The ‘Sierra de Guara’ Natural Park (81,491 ha, Huesca, Spain) is a protected Mediterranean mountain area dominated by shrub and forest pastures. Traditional agriculture, mainly extensive grazing systems, has decreased in the last decades; concurrently, invasion of shrub vegetation, landscape changes and higher risk of forest fires have been observed.A study, which started in 2000, was carried out with two broad objectives: at the farm level, to analyse the farming systems and evaluate management strategies; at the regional level, to give useful information to conservation authorities for better decision-making.An integrated approach with different spatial scales and methods of analysis was used. First, a survey covering all farms that utilized the Park was carried out and livestock farming systems were characterized in terms of grazing management, technical and socio-economic factors. Second, six representative areas were selected to evaluate, depending on livestock utilization, grass and shrub vegetation dynamics (biomass, green/dead ratio). Third, vegetation and livestock data were analysed using a Geographic Information System to identify constraining factors and areas of intervention. Key imbalances were identified that can threaten the sustainability of the Park: low continuity of farming families; intensification of the management system; degradation of grazing resources; and concentration of grazing areas. A number of management recommendations are raised.     

藏南农牧交错带农牧互作模式下土地利用效益耦合度分析

农牧耦合是提升农牧交错带生态系统综合效益的有效途径之一。研究采用土地利用耦合模型,定量分析了西藏藏南地区“牧繁农育”和“农草牧补”两种农牧耦合模式土地利用社会经济效益和生态环境效益的耦合度。结果表明,2008-2016年“牧繁农育”模式的土地利用生态环境效益和社会经济效益均呈逐渐增加的趋势,“农草牧补”模式的土地利用生态环境效益虽呈增加趋势,但社会经济效益处于波动状的稳定状态;虽然“牧繁农育”模式和“农草牧补”模式均处于协调发展状态,但“牧繁农育”土地利用社会经济效益与生态环境效益较“农草牧补”随年际的变化具有相对稳定性,这为类似地区定量评价农牧耦合模型效益提供了范式。     

Estimation of genetic parameters for milk and fertility traits within and between low,medium and high dairy production systems in Kenya to account for genotype-by-environment interaction

Dairy records from the Dairy Recording Service of Kenya were classified into low, medium and high production systems based on mean 305-day milk yield using the K-means clustering method. Milk and fertility records were then analysed to develop genetic evaluation systems accounting for genotype-by-environment interaction between the production systems. Data comprised 26,638 lactation yield, 3,505 fat yield, 9,235 age at first calving and 17,870 calving interval records from 12,631 cows which were descendants of 2,554 sires and 8,433 dams. An animal model was used to estimate variance components, genetic correlations and breeding values for the production systems. Variance components increased with production means, apart from genetic group variances, which decreased from the low to the high production system. Moderate heritabilities were estimated for milk traits (0.21–0.27) and fat traits (0.11–0.38). Low heritabilities were estimated for lactation length (0.04–0.10) and calving interval (0.03–0.06). Moderate heritabilities (0.25–0.26) were estimated for age at first calving, except under the high production system (0.05). Within production systems, lactation milk yield, 305-day milk yield and lactation length had high positive genetic correlations (0.52–0.96), while lactation milk yield and lactation length with age at first calving had negative genetic correlations. Milk yield and calving interval were positively correlated except under the low production system. The genetic correlations for lactation milk yield and 305-day milk yield between low and medium (0.48 ± 0.20 and 0.46 ± 0.21) and low and high production systems’ (0.74 ± 0.15 and 0.62 ± 0.17) were significantly lower than one. Milk yield in the low production system is, therefore, a genetically different trait. The low genetic correlations between the three production systems for most milk production and fertility traits suggested that sires should be selected based on progeny performance in the targeted production system.     

The use of indicators to assess the degree of mobilisation of body reserves in dairy cows in early lactation on a pasture-based diet

The accuracy of predicting energy balance (EB) using various milk, blood, and other indicators was determined in 23 Holstein-Friesian cows that were grazing pasture in very early lactation. The concentration of milk acetone was negatively correlated (r=−0.64) with EB (p<0.05) as were β-hydroxybutyrate 6 (BHBA) (r=0.76) and non-esterified fatty acids (r=0.56) in plasma, age (r=−0.49), and mean liveweight (r=−0.46). The concentration of plasma glucose was positively correlated (r=0.79) with EB (p<0.05) as were insulin-like growth factor-1 (IGF-1) (r=0.57) in plasma and change in liveweight (r=0.39). The best prediction model for EB included plasma glucose and plasma BHBA (r=0.84). Milk acetone alone (r=0.64) formed the best prediction model as an ‘on-farm’ indicator.Milk acetone concentration was correlated (r=0.89) with plasma BHBA so that a milk acetone concentration of 0.14 mmol/L was equivalent to a blood BHBA concentration of 1.2 mmol/L (critical level for identification of cows with sub-clinical ketosis). The relationship between plasma glucose and IGF-1 was curvilinear with levels of IGF-1 rapidly increasing above a plasma glucose concentration of 3.2 mmol/L. Body condition score (BCS) converged to 4 (scale 1-8) post-partum with the loss increasing rapidly when BCS at calving was above 5.5.The results of this study confirm that milk acetone may be an accurate and practical indicator for estimating EB of cows in early lactation on a predominantly pasture-based diet. Where cows may be sampled on a once-off basis, plasma glucose and plasma BHBA together explain a large portion of the variation in EB.     

Comparison of two milk pricing systems and their effect on milk price and milk revenue of dairy farms in the Central region of Thailand

A study was conducted to investigate determinates of how milk pricing system, farm location, farm size, and month and year affected farm milk price (FMP), farm milk revenue (FMR) and loss in FMR of dairy farms in the Central region of Thailand. A total of 58,575 milk price and 813,636 milk yield records from 1034 farms were collected from November of 2004 to June of 2006. Farms were located in the districts of Muaklek, Pak Chong, Wang Muang, and Kaeng Khoi. A fixed linear model was used to analyze milk price of farms. Two pricing systems were defined as 1 = base price plus additions/deductions for milk fat percentage, solids-non-fat, and bacterial score, and 2 = same as 1 plus bulk tank somatic cell count (BTSCC). Farm size (small, medium, and large) was based on the number of cows milked per day of farms. Results showed that FMP were lower (P < 0.05) in pricing system 1 than pricing system 2. Most small farms had higher (P < 0.05) milk prices than medium and large farms across both pricing systems. Large farms lost more milk revenue due to deductions from bacterial score and BTSCC than small and medium farms.     

Investigating the value dairy farmers place on a reduction of lameness in their herds using a willingness to pay approach

A survey was conducted to elicit dairy farmers’ willingness to pay (WTP) to reduce the prevalence of lameness in their herds. A choice experiment questionnaire was administered using face-to-face interviews of 163 farmers in England and Wales. Whole herd lameness assessments by trained researchers recorded a mean lameness prevalence of nearly 24% which was substantially higher than that estimated by farmers. Farmers’ responses to a series of attitudinal questions showed that they strongly agreed that cows can suffer a lot of pain from lameness and believed that they could reduce lameness in their herds.Farmers’ mean WTP to avoid lameness amounted to UK£411 per lame cow but with considerable variation across the sample. Median WTP of UK£249 per lame cow was considered a better measure of central tendency for the sample. In addition, the survey found that farmers had a substantial WTP to avoid the inconvenience associated with lameness control (a median value of UK£97 per lame cow) but that they were generally prepared to incur greater inconvenience if it reduced lameness. The study findings suggest that farmers need a better understanding of the scale and costs of lameness in their herds and the benefits of control. To encourage action, farmers need to be convinced that lameness control measures perceived as inconvenient will be cost effective.     

Evaluation of in vitro culture systems for goat preantral follicles using reused ovaries from reproductive biotechniques: An alternative to maximize the potential of reproduction

This study aimed to examine the in vitro culture of secondary preantral follicles, using reused ovaries, to compare both the 2D and 3D methods of in vitro culture of preantral follicles, and the system of medium replacement. Twenty‐five pairs of ovaries from mixed‐breed goats were used for the experiment. Follicular puncture of antral follicles was performed for in vitro production. After this procedure, the secondary preantral follicles were submitted to a microdissection procedure. The isolated preantral follicles were randomly divided into three treatments: (a) Two‐dimensional culture with partial replacement of medium during culture (2D PR), (b) Three‐dimensional culture with addition of medium during culture (3D AD) and (c) Three‐dimensional culture with partial replacement of medium (3D PR). The culture period was 18 days. All treatments at the end of the in vitro culture period (18 days) presented a follicular survival rate which ranged from 59% to 70%, demonstrating that it was possible to perform an experiment with preantral follicles using ovaries that had previously been used in another reproductive biotechnique. The 3D AD treatment showed a survival percentage and follicular diameter higher than the 2D PR treatment, however, it did not differ from the 3D PR treatment. In conclusion, experiments employing the use of preantral follicles can be performed with success after the ovaries have been used for experiments with antral follicles. Moreover, the three‐dimensional system with the addition of medium is recommended for in vitro culture of preantral follicles, since this system is more practical and financially feasible.     

Changes in the predicted function of the rumen bacterial community of Japanese Black beef cattle during the fattening stages according to Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses

We investigated changes in the predicted functions of the rumen bacterial community in Japanese Black beef cattle during fattening. Nine cattle were fed a high-concentrate diet during the early, middle, and late fattening stages consecutively (10–14, 15–22, and 23–30 months of age, respectively). The rumen fluid and solid samples collected at each stage were subjected to sequencing analyses. The sequencing results were clustered and classified into operational taxonomic units (OTUs). Representative sequences and a raw counting table for each OTU were submitted to the Piphillin website. The predicted functions were revealed by the Kyoto Encyclopedia of Genes and Genomes database as the ratio of the total sequence. In the early stage, “Biosynthesis of secondary metabolites” was significantly higher in the fluid fraction than in the solid fraction. “Two-component system” in the middle stage was significantly lower and “Purine metabolism” in the late stage was significantly higher in the fluid fraction than those in the solid fraction. The fluid fraction was significantly correlated with acetic acid, propionic acid, and bacterial metabolism, such as “Biosynthesis of secondary metabolites” and “Sugar metabolism.” Moreover, the solid fraction was correlated with “Purine metabolism” and “Biosynthesis of secondary metabolism”. These results suggest that the rumen bacterial community in Japanese Black beef cattle adapts to changes in rumen conditions by altering their functions in response to a long-term high-grain diet.     

Prevalence of agglutinating antibodies to Toxoplasma gondii in small ruminants of the Madrid region,Spain, and identification of factors influencing seropositivity by multivariate analysis

A seroepidemiological survey of Toxoplasma gondii infection in sheep and goats was conducted in the Madrid region of Spain. Sera were collected from 60 herds, for which farming management information and other relevant data for their characterization were also obtained through a questionnaire. The seroprevalence was 11.8% (64 out of 541), using the modified (2-mercaptoethanol) direct agglutination technique with a 1:64 cut-off titre. The relationship between seropositivity and the variables in the questionnaire was assessed by multivariate analysis. Four variables were found to be significantly associated with seroprevalence. Two of them, the presence of cats and a previous history of abortion outbreaks in the farm, were factors known to be linked with toxoplasmosis, indicating the validity of the serological data. Seropositivity was also related to a lack of replacements in the preceding year. Proximity to other farms appeared to be a protective factor negatively associated with seropositivity, probably because it was an indicator of proximity to an urban area and the availability of local sanitary facilities.Abbreviations AIDS acquired immune deficiency syndrome - logistic regression coefficient - CI confidence interval - MDAT modified direct agglutination test - OR odds ratio - p level of significance - SE standard error     

抗感枯萎病香蕉品种组织培养性状与耐毒素能力差异分析

为了明确抗感枯萎病香蕉品种在组织培养性状和耐毒素能力上的差异,本研究对不同抗感病香蕉品种进行了组织培养不同阶段性状的观察及其生根苗耐毒素能力的测定。结果表明,在增殖培养阶段,感病品种大丰1号和天宝中杆丛生芽增殖的平均数量分别为7.10个和5.90个,而抗病品种粉杂1号、柴蕉、海南贡蕉和抗枯5号芽增殖的平均数量分别仅1.10个、2.10个、4.00个和3.50个;在芽苗分化阶段,大丰1号和天宝中杆的苗分化率分别为73.03%和70.06%,且显著高于其他4个抗病品种;在生根苗生长阶段,粉杂1号和柴蕉的生根苗根长较长,平均分别可达10.99和11.01 mm,显著长于其他2个感病品种。说明感病品种的芽增殖能力和苗分化能力较强,但在长势上,抗病品种表现为芽体粗大,分化苗和生根苗生长健壮,根系发达。此外,生根苗的耐毒素能力测定结果表明,感病品种大丰1号和天宝中杆的病情指数较高,分别为81.90和94.28,而其余抗病品种的病情指数介于2.38~29.05之间,说明抗病品种的生根苗耐毒素能力较强。     

Intercropped oats (<Emphasis Type="Italic">Avena sativa</Emphasis>) - common vetch (<Emphasis Type="Italic">Vicia sativa</Emphasis>) silage in the dry season for small-scale dairy systems in the Highlands of Central Mexico

Small-scale dairy systems in the highlands of central Mexico require feeding strategies based on quality home-grown forage that may reduce high concentrate costs. Eight Holstein cows paired by parity and date of calving were used in a split-plot experiment to evaluate supplementing 6 kg DM/cow/d of oat-vetch silage (OVS) in comparison to maize silage (MS) as dry season feeding, for a more intensive use of the land through an oat-vetch catch crop. Cows had 9 h/d access to continuous grazing of perennial ryegrass – white clover pasture and 4 kg/d of commercial concentrate. The 9 week experiment, recorded weekly milk yield and composition, and body condition score and live-weight every fortnight. Milk yield was 20.1 kg/cow/d for OVS and 15.4 for MS (SEM ±2.9, P > 0.05), with no differences for fat or protein content, body condition score, or live-weight (P > 0.05). The economic analysis showed that although feeding costs were higher for OVS, margins were greater than for MS, with feeding cost per litre of $0.21 for MS and $0.16 for OVS. OVS is a viable catch crop after the MS harvest that can substitute MS in the dry season enabling a more intensive use of the land.     

河西绿洲灌区灌漠土长期秸秆还田土壤肥力和作物产量特征分析

系统研究长期秸秆还田对河西绿洲灌区灌漠土壤养分的演变规律、土壤肥力特征的影响,分析作物产量及稳定性和持续性,为秸秆还田培肥土壤和资源化利用提供科学和理论依据.利用河西绿洲灌区31年(1988-2018年)的灌漠土长期定位培肥试验,开展了以秸秆与磷肥配施(SP)、秸秆与氮磷肥配施[1/2(S+N)P]、氮磷配施(NP)、不施肥(CK)为处理的田间定位试验,测定了耕层0～20 cm土壤有机质(SOM)、全氮(TN)、全磷(TP)、全钾(TK)、速效氮(AN)、速效磷(AP)、速效钾(AK)、pH,研究了长期秸秆还田对小麦/玉米间作体系灌漠土土壤养分演变规律和作物产量的影响.结果表明:秸秆还田第31年和逐年平均值与试验初始值相比,土壤有机质增加73.3％和25.8％,土壤全氮增加50.6％和21.7％,土壤全磷增加22.5％和3.8％,土壤全钾含量增加19.9％和38.2％;与对照(CK)相比,土壤有机质增加55.3％和20.0％;土壤全氮增加28.8％和15.9％,土壤全磷增加50.2％和13.4％;土壤全钾增加23.5％和0.2％.秸秆连续还田9年后小麦产量比对照平均降低5.8％,第10年开始小麦产量逐年增加,比对照平均增加65.9％.玉米产量在秸秆连续还田13年间比对照平均降低8.2％,之后较对照平均增加22.0％.河西绿洲灌区灌漠土长期施用秸秆或秸秆氮磷肥配施,土壤培肥效果均显著优于单施化肥,可显著增加土壤有机质含量,提升土壤肥力,秸秆与氮磷化肥配施能持续提升作物产量及其稳定性和可持续性.