Dairy goat performance in two grazing regimes: silvopastoral rangeland or abandoned agricultural land, and two supplementation treatments in central Mexico.

Twenty Saanen third parturition dairy goats were used in an on-farm 2 × 2 factorial arrangement that ran for 12 weeks, with two grazing regimes and two concentrate types. The grazing regimes evaluated were an extensive silvopastoral native rangeland (SPR) and grazing in an abandoned agricultural land (AAL). Grazing happened between 9:00 and 17:00 h. The two types of concentrate supplement were a high protein concentrate (HP = 180 g CP/kg DM and 13 MJ ME/kg DM) or high energy concentrate (HE = 110  g CP/kg DM and 14.3 MJ ME/kg DM). Goats were milked once a day, providing 250 g of concentrate supplement per goat and day. Animal variables were fat and protein corrected milk yield recorded every day, and milk composition determined for two consecutive days at the end of each experimental week. Flora in the experimental paddocks was characerised and sampled, including grasses, shrubs, trees, legumes and cacti. The data was analysed with the R software using a mixed model with day nested in period as random effect and goat as repeated measure. The SPR had greater (P = 0.002) fat and protein corrected milk yield than AAL, with no differences between concentrate type and no interaction (P > 0.05). There was an interaction (P < 0.01) between grazing regime and concentrate type for fat content in milk, where a reduction in fat content was notorious in the SPR regime. Protein content of milk was greater (P < 0.01) in SPR with no significant effects of concentrate type or the interaction. The number of plant species in SPR was greater. The native silvopastoral system supplemented with the high energy concentrate was the strategy with higher milk yield, and protein and milk fat content, although the interaction between grazing regime and supplement was significant only for milk fat content.

In vitro assessment of ruminal biohydrogenation of polyunsaturated fatty acids in diets with different types and levels of protected fat and diverse sources of fibre.

The objective was to assess the in vitro rumen fermentation characteristics, methane production, and biohydrogenation of unsaturated fatty acids of diets with two protected fat (PF) sources from soybean or linseed oil, two levels of PF (0 and 6%) and two forage sources (canola silage (CS) or alfalfa hay (AH)) in a factorial 2x2x2 completely randomised design. Only fatty acids content at final incubation was affected (P<0.05) by triple interaction, where C18:2 was highest with AH plus 6% soybean PF (4.41mg/g DM), while C18:3 was with CS plus 6% linseed oil protected (1.98mg/g DM). C18:2 cis-9 trans-11 had high concentration (308 mg/g DM; P<0.05) with AH plus 6% PF regardless PF type, and C18:1 trans-11 was higher with 6% PF than without PF (13.41 vs 7.89 mg/g DM). Cumulative methane production was not affected by treatments (0.9973 ± 0.1549 mmol/g DM; P>0.05). Gas production and in vitro NDF digestibility were lower with 6% PF of linseed than soybean (160.88 vs 150.97 ml; and 69.28vs 62.89 %, respectively P<0.05). With linseed PF the NH3-N concentration was highest in CS than AH (41.27 vs 27.95 mg/dL; P<0.05) but IVDMD had the opposite result (78.54 vs 85.04). In conclusion, although methane production was not affected and in vitro digestibility and gas production were reduced with linseed PF, the concentration of C18:3 and C18:1 trans-11 was increased, which could improve the lipid profile of milk. The negative effects on digestibility were less with AH than of CS regardless of PF type and level.

Análise das prescrições de pacientes com covid-19 em uso de hidroxicloroquina em uma unidade de terapia intensiva / Analysis of prescriptions of patients with COVID-19 using hydroxychloroquine in an Intensive Care Unit / Análisis de las prescripciones de pacientes con COVID-19 en uso hidroxicloroquina en una unidad de terapia intensiva

Mesmo em emergências sanitárias, quando terapias experimentais são empregadas, é importante prezar pela segurança e eficácia no uso de medicamentos, e a análise de prescrições médicas é uma das maneiras de monitorar aspectos de segurança. Objetivo: Quantificar e classificar as interações medicamentosas potenciais com hidroxicloroquina de acordo com o riscoem prescrições de pacientes com COVID-19 em pacientes com COVID-19 em uso de hidroxicloroquina admitidos em uma unidade de terapia intensiva de um Hospital de Ensino.Metodologia:Este estudo transversal baseou-se na análise de 162 prescrições de 38 pacientes admitidos em uma unidade de terapia intensiva de um Hospital de ensino entre abril e junho de 2020.O Micromedex® e o UpToDate® foram as bases de dados de apoio à conduta clínica utilizadas para estabelecer as interações medicamentosas potenciais. Resultados:A média de dias de internamento foi de 16,1 ± 14,0 e a média de dias em uso de hidroxicloroquina foi de 4,26 ± 1,74. 87,14% das prescrições apresentaram interações medicamentosas potenciais e a mais comum foi entre hidroxicloroquina e azitromicina. 76,4% das prescrições analisadas apresentaram interações medicamentosas potenciais com hidroxicloroquina. 73,5% das prescrições tiverampelo menos uma interação medicamentosa potencial entre medicamentos que prolongam o intervalo QT. Conclusões: Tendo em vista os riscos da exposição de pacientes críticos às interações medicamentosas, este estudo demonstra a necessidade de fortalecer nas instituições hospitalares a cultura de monitoramento de parâmetros de segurança e eficáciano uso de medicamentos, inclusive em terapias experimentais com a utilização de medicamentos off-labelpara minimizar riscos e ampliar possíveis benefícios (AU).

Even in health emergencies, when experimental therapies are employed, it is important to ensure the safety and efficacy of medicines, and the analysis of medical prescriptions is one of the ways to monitor safety aspects.Objective: Quantify and rank potential drug interactions with hydroxychloroquine according to risk in prescriptions of COVID-19 patients taking hydroxychloroquine admitted to an intensive care unit of a TeachingHospital.Methodology: This cross-sectional study was based on the analysis of 162 prescriptions of 38 patients admitted to an intensive care unit of a teaching hospital between April and June 2020. Micromedex® and UpToDate® were the clinical practice support databases used to establish potential drug interactions. Results: The mean number of days of hospitalization was 16.1 ± 14.0 and the mean number of days of days on hydroxychloroquine was 4.26 ± 1.74. 87.14% of the prescriptions presented potential drug interactions and the most common was between hydroxychloroquine and azithromycin. 76.4% of the analyzed prescriptions had potential drug interactions with hydroxychloroquine. 73.5% of prescriptions had at least one potential drug interaction between drugs that prolong the QT interval. Conclusions: In view of the risks of exposure of critically ill patients to drug interactions, this study interactions, this study demonstrates the need to strengthen in hospital institutions the culture of institutions the culture of monitoring safety and efficacy parameters in the use of medicines, including experimental therapies with the use of off-label drugs to minimize risks and increase possible benefits (AU).

Aunque en médio aemergencias sanitarias, cuando son empleadas terapias experimentales, es importante estimar la seguridad y eficacia en el uso de los medicamentos, y el análisis de prescripciones es una de las formas de acompanhar los aspectos de seguridad. Objetivo:Cuantificar y clasificar las interaciones farmacologicas potenciales con hidroxicloroquina de acuerdo com el riesgo em prescripciones de pacientes com Covid-19 em uso de hidroxicloroquina andmitidos em unidad de terapia intensiva de um Hospital Docente. Metodología: Este estudio transversal se asienta en el análisis de 162 prescripciones de 38 pacientes admitidos em uma unidad de terapia intensiva de um Hospital Docente entre abril y junio de 2020. El Micromedex®ï¸y el UpToDate®ï¸fueron las bases de datos de apoyo a la actuación clínica utilizadas para establecer las interacciones farmacológicas potenciales. Resultados:El promedio de días de internamiento fue de 16,1 ± 14,0 y el promedio de días en uso hidroxicloroquina fuede 4,26 ± 1,74. 87,14% de las prescripciones presentaron interacciones farmacológicas potenciales y la más común fue entre hidroxicloroquina y azitromicina. 76,4% de las prescripciones analizadas presentaron interaciones farmacológicas com hidroxicloroquina. 73,5% de las prescripciones tuvierion por lo menos uma interacción farmacológica potencial entre medicamentos que prolongam el intervalo QT. Conclusiones:Tenendo a la vista los riesgos de la exposición de pacientes críticos a las interaciones farmacológicas, este estudio demuestra la necesidad de reforzar em las instituiciones hospitalarias la cultura de monitoreo de parâmetros de seguridade y eficacio em el uso de medicamentos, incluso en terapias experimentales con utilización de medicamentos off-label, para minorar riesgos y ampliar los posibles beneficios (AU).

Obesity in Pediatric Congenital Heart Disease: The Role of Age, Complexity, and Sociodemographics.

The prevalence of obesity in children with congenital heart disease (CHD) is greater than 25%, putting these patients at-risk for increased surgical morbidity and mortality. Our goal was to determine the association between CHD complexity, sociodemographic factors, and obesity. Our hypothesis was that among CHD patients, the odds of obesity would be highest in older children with simple CHD, and in all children with a lower socioeconomic status. We conducted a retrospective cohort study, reviewing electronic medical records of children aged 2-17 years from over 50 outpatient pediatric clinics in Houston, TX. Children were classified as simple or moderate/complex CHD, and obesity was defined by BMI ≥ 95th percentile for age and sex. Logistic regression was used to determine the association between sociodemographic factors and CHD complexity with obesity. We identified 648 CHD and 369,776 non-CHD patients. Children with simple CHD had a similar odds of obesity as non-CHD children. Children with CHD had a higher prevalence of obesity if they were older, male, Black, Hispanic, and publicly insured. Children with moderate/complex CHD had lower odds of obesity [OR 0.24 (95% CI 0.07-0.73)], however their predicted probability of obesity approached that of the general population as they aged. Additionally, there was an incremental relationship with poverty and obesity [1.01 (1.01-1.01)]. Awareness of which patients with CHD are at highest risk of obesity may help in targeting interventions to assist at-risk patients maintain a healthy lifestyle.

Characterisation and sensory appraisal of fresh 'molido' cheese from cows fed different levels of sunflower silage inclusion in small-scale dairy systems.

Small-scale dairy systems require feeding strategies to improve their productivity and sustainability. These systems in central Mexico mostly sell their milk to local artisan cheese makers. Cow diets influence milk and dairy products composition; therefore, the objective was to evaluate the effect on physicochemical characteristics, sensory appraisal, and economic performance of cheese made with milk from cows fed different levels of sunflower silage (SFSL). Treatments were the inclusion of SFSL in the forage DM component of diets (T0 = 0% SFSL; T20 = 20%; T40 = 40%; and, T60 = 60%). Physicochemical composition was analysed by analysis of variance in a completely randomised design and the sensory assessment of the cheese was with a hedonistic five-point scale and the results were analysed by means of descriptive statistics and a radar graph. Partial budgets were used for economic analyses. There were significant differences (P < 0.05) for all physicochemical variables (moisture content, cheese yield, protein, fat content, and pH) of the cheese, with higher values for yield, protein, and fat content in the treatments that included SFSL. Sensory assessment values were in the average perception range of judges. Treatments that included SFSL had lower production costs, higher margins over costs, and higher returns/costs ratios. The inclusion of sunflower silage at 40 and 60% of the forage component of diets for dairy cows in small-scale dairy systems had positive effects. Yields of cheese as well as protein and fat content were higher. There were positive sensory attributes that meant acceptance by consumers, lower production costs, and higher incomes from cheese making.

Factors affecting the lactation curve parameters of crossbred dairy ewes in a flock of the highlands of Mexico.

Sheep milk production is incipient in Mexico with scarce knowledge on the performance of dairy ewes from different breeds. The objective of this study was to evaluate the effect of breed (Awassi (Aw), East Friesian (EF) and other (Ot)), parity number (1, 2 and 3 or more (+ 3)), litter size (1 and 2 or more (+ 2)) and lambing season (spring-summer (SS) and autumn-winter (AW)) on day of peak yield (DP), peak yield (PY), persistency (P), total milk yield (TMY), 305-day milk yield (TMY305d), 150-day milk yield (TMY150d) and lactation length (LL) of crossbred dairy ewes in a flock of the central highlands of Mexico. A total of 4312 weekly milk yield records collected from 2014 to 2015 were used to model 133 lactations using a random regression model with a fifth-order orthogonal polynomial. Flock mean values of curve parameters were 42 days at DP, 1.2 kg/day at PY, - 3.5 g/day of P, 190 kg TMY, 189 kg TMY305, 124 kg TMY150 and 269 days of LL. Multiparous ewes had significantly higher (P < 0.05) PY and TMY than primiparous ewes. Ewes that lambed in AW had 15% higher PY and produced 14% more TMY than ewes that lambed in SS (P < 0.05). Correlations among curve parameters were significant except for the correlation between PY and LL and between P and TMY150d. TMY was strongly correlated with LL (0.91). Predominantly Awassi crossbred ewes had lower curve parameter values than predominantly East Friesian and other crossbred ewes.

Characterisation of landrace 'criollo' maize silage from the highlands of Mexico in terms of starch content.

Maize silage is appreciated for dairy cows due to its high energy content. Mexico is a centre of origin for maize and small-scale dairy farmers use landrace 'criollo' maize silages to feed their herds. However, the characteristics of landrace 'criollo' maize silages in terms of starch content, which defines their nutritional value in terms of energy, are not known. The objective was to characterise criollo maize silages in terms of starch content. Seventy-seven silage samples from 2011 to 2015 were analysed for contents of dry matter (DM), organic matter (OM), neutral detergent fibre (NDF), acid detergent fibre (ADF), crude protein (CP), in vitro dry matter digestibility (IVDMD), and starch content. A factor analysis using principal component analysis as an extraction method was undertaken, and a hierarchical cluster analysis performed. Five factors affected the starch content of silages and five maize silage clusters identified. There was a positive association between IVDMD and metabolisable energy and between crude protein and acid detergent fibre; moreover, a positive relation was found between dry matter and maize starch contents. Significant differences were found (P < 0.001) for the contents of IVDMD, ME, ashes, OM, DM, and starch. The DM content of group 1 silage did not show any significant differences from other groups, except with group 2 silage, which had the lowest contents of DM and starch. Therefore, group 1 and 5 silage had the highest DM and starch contents, while group 3 silage had the highest IVDMD values and ME contents; finally, group 4 had the highest ash contents. Starch content in criollo maize silages was higher that reports for other maize races and is influenced by climate conditions and dry matter content.

The economic effects of grazing in small-scale lamb fattening production systems in central México through a scenario analysis.

The objective was to assess grazing as an element of profitability and competitiveness of a small-scale lamb fattening production system in central México and compare its economic performance by means of an analysis of scenarios. Two scenarios were analysed to assess the contribution of grazing on profitability and competitiveness. The first analysis was when grazing was the feed base, and secondly, costs of opportunity and economic impacts were studied under the assumption that sheep do not graze, and total feed has to be bought from external suppliers. The economic effect of grazing on the profitability was analysed by means of the Policy Analysis Matrix. Differences were found between strata; farmers with more than 70 sheep have the best profitability indices and the least vulnerability under the non-grazing scenario. Grazing had a positive effect reducing the cost of production and increasing competitiveness in the four strata assessed. However, farmers with higher technical level, specialised breeds and larger flocks (strata 3 and 4) have higher economic profits. The conclusion was that the profitability in fattening sheep is linked to taking advantage of grazing. However, to keep and improve the current financial performance, there is a need for the adoption of strategies for an integral improvement of the system and the adoption of better grazing management to further reduce production costs.

Nitrogen use efficiency and soil chemical composition in small-scale dairy systems.

In dairy production systems, the efficient use of resources is required to guarantee its sustainability. Worldwide, the efficiency of feed utilization and its effects have been widely studied. However, few studies have quantified animal nitrogen use and its corresponding soil contribution in small-scale production systems. Therefore, this study aimed to determine the efficiency of feed utilization and quantify the soil chemical composition in small-scale production systems using two different feeding strategies. Twelve dairy farms were evaluated from May 2016 to April 2017. Data analysis was performed using an ANOVA following a completely randomized model and using feeding strategies as treatment. Regarding the feeding systems' characteristics, significant differences (P < 0.05) were only observed in land surface and land used to produce mixed-grass and corn. Nitrogen (N) input and output in dairy cattle were significantly different (P < 0.05) for crude protein intake. The highest results were observed in grazing feeding systems. The cut and carry strategies excreted 71% of the consumed N in the manure; grazing strategies excreted 72%. The efficiency of feed utilization (EFU) is low; only 19% of the consumed N is recovered during milk production. As for the soil chemical composition, significant differences (P < 0.05) were observed in the percentage of total N and the carbon to nitrogen (C:N) ratio. The remaining components behaved similarly in both feeding systems. Systems that include crops and livestock can positively change the biophysical and socioeconomic dynamics of agricultural systems.

Grazed rain-fed small-grain cereals as a forage option for small-scale dairy systems in central Mexico.

Small-scale dairy systems face reduced availability of water for irrigation of pastures and disruption in the amount or pattern of rains due to climate change, so research on alternative short-cycle rain-fed forages is needed. Grazing reduces feeding costs and small-grain cereals may be an option. The objective was to assess on-farm the performance of dairy cows grazing 6 h/day of three small-grain cereals: rye (RYE), wheat (WHT), and triticale (TRT), and supplemented 4.5 kg dry matter (DM)/cow/day of concentrate. Twelve Holstein cows were used in repeated 3 × 3 Latin squares with 14-day experimental periods. Pasture variables were analysed with a split-plot design, and economic analysis was performed with partial budgets. Sampling of forage (sward height, net herbage accumulation, botanical and chemical composition of herbage) and animal variables (milk yield and composition, live weight, and body condition score) were at the end of each period. The RYE showed a trend (P > 0.05) for higher net herbage accumulation (NHA) with highly significant differences (P < 0.001) among periods. The RYE had higher DM, a lower crude protein (CP) content (P < 0.05), and no differences for other chemical components between treatments (P > 0.05). The RYE proportion in pasture was consistently higher, whilst the lowest cereal proportion was in WHT. There were no differences (P > 0.05) for any animal variable. The RYE and TRT treatments proved useful as rain-fed forage alternatives under grazing. WHT showed lower crop and economic performance. However, given the higher cereal component in pastures, regrowth potential, and post-grazing herbage mass, as well as better economic performance, the RYE treatment was better ranked by the participating farmer.

The effect of feeding whole-crop barley or black oat silage in the fatty acid content of milk from cows in small-scale dairy systems in the highlands of Mexico.

Diets have an important effect on the fatty acid (FA) content in milk from dairy cows so that feeding strategies may modify the FA profile. There is little information on the fatty acid contents of whole-crop barley (BLY) and black oat (BKO) silages and on milk from cows fed these silages that are an alternative forage for small-scale dairy systems (SSDS). Given the growing interest in foods with favourable health attributes, the objective was to identify the FA content of milk from dairy cows fed whole-crop BLY and BKO silages in small-scale systems. Three inclusion levels of BLY and BKO silage were assessed in nine lactating cows at pasture for 8 h/day and supplemented with 4.6 kg/DM/cow/day commercial concentrate. Treatments were BLY: 10 kg DM/cow/day BLY silage; BKO: 10 kg DM/cow/d BKO silage; and BLY/BKO: 5 kg BLY and 5 kg DM/cow/d BKO silages (50:50). A 3 × 3 Latin square design repeated three times with nine cows and 14-day periods was utilised. Variables evaluated were the content of fatty acids present in feeds and milk. Contents of linoleic (C18:2n-6) and linolenic (C18:3n-3) acids, as precursors of polyunsaturated fatty acids, were 46 in BLY and 50 BKO g/100 g, lower than for multispecies pasture (61 g/100 g). There were statistical differences in the content of short-chain fatty acids in milk (P < 0.05), being lower for BLY (18.9 g/100 g) compared with BKO (20.4 g/100 g) and BLY/BKO (20.6 g/100 g), the saturated fatty acids and linoleic acid (C18:2n-6c) were higher in BLY/BKO in relation to BLY and BKO. Content of health-promoting polyunsaturated fatty acids in milk was higher in BLY/BKO (P < 0.05). There were no differences (P < 0.05) in the atherogenic index, with values within reports. Small-grain cereal forages may produce milk with a favourable fatty acid content for human health.

In vitro nutritional quality and antioxidant activity of three weed species as feed additives for sheep in the Central Highlands of Mexico.

Sheep production is traditional for rural communities in Mexico, based on natural grasslands and semi-stabled feeding. Quality forages are necessary to improve productivity in these systems. Weeds are an alternative to feed ruminants and to manage crops. Also, many plants have secondary metabolites beneficial for livestock. The objective was to assess the nutritive value in vitro and the antioxidant activity of three weeds (Tithonia tubiformis, Cosmos bipinnatus, and Tagetes lucida) and four treatments (T0 = control diet, T1 = diet + 5% T. tubiformis, T2 = diet + 5% C. bipinnatus, and T3 = diet + 5% T. lucida). Nutritive value was determined from chemical composition by standard methods and mineral contents by inductively coupled plasma analyses. Secondary compounds, total phenols (TP), total tannins (TT), condensed tannins (CT), and phenolic compounds, were determined by high-performance liquid chromatography, and total antioxidant activity was determined by measuring the oxygen radical absorbance capacity. Rumen fermentation kinetics and in vitro digestibility of dry matter (IVDMD), organic matter (IVOMD), and neutral detergent fibre (IVNDFD) were determined per species and treatment by in vitro gas production. T. tubiformis had the highest CP and TP contents (P < 0.05), and C. bipinnatus had the highest fibre and CT contents (P < 0.05). Inclusion of T. lucida in the diet resulted in an 18% increase in TP content and a 30% increase in antioxidant activity in comparison to the control diet. No significant differences (P > 0.05) were found in rumen kinetics parameters, IVDMD, IVOMD, IVNDFD, or metabolizable energy, indicating that the tested weeds can be used as additives to increase antioxidant activity in sheep diets without negative effects.

Relationship between calving interval and profitability of Brown Swiss cows in a subtropical region of Mexico.

Brown Swiss cattle have replaced Zebus in some dual-purpose farms in tropical and subtropical regions of Mexico, under extensive grazing management. There is limited information about the productive and reproductive performance of this breed under tropical conditions; the lack of records from small farms may be the main reason. The objectives of the study were to evaluate the relationship between calving interval (CI) and milk and beef (weaned male calves) profit in Brown Swiss cows from a dual-purpose farm under extensive management in a subtropical region of Mexico. Data from 156 cows calving from 2000 to 2014 were analysed with both a linear and a survival model. Mean CI was 438 ± 49 days, mean age at first calving was 40 ± 6 months and length of productive life was 7 ± 3 years. The effects of parity, calving year and calving season were significantly related to CI (P < 0.05), whereas the effect of calf sex was not. Cows calving in the autumn and winter had shorter calving intervals, probably because supplements received during the dry season months improved energy balance. The highest culling rate was 28% at 45 months of age. Milk yield and total profit increased as CI increased from 12 to 20 months; beef contribution to total profit decreased as CI and milk yield increased. Calving intervals of more than 12 and up to 20 months had a positive effect on the milk production and profitability of dual-purpose cows in a subtropical region of Mexico.

Feeding Forage Mixtures of Ryegrass (Lolium spp.) with Clover (Trifolium spp.) Supplemented with Local Feed Diets to Reduce Enteric Methane Emission Efficiency in Small-Scale Dairy Systems: A Simulated Study.

In cattle, greenhouse gas (GHG) emissions and nutrient balance are influenced by factors such as diet composition, intake, and digestibility. This study evaluated CH4 emissions and surpluses of crude protein, using five simulated scenarios of supplementation in small-scale dairy systems (SSDS). In addition, two pasture managements (cut-and-carry versus grazing) and two varieties of legumes (red clover vs. white clover) were considered. The diets were tested considering similar milk yield and chemical composition; CH4 emission was estimated using Tier-2 methodology from the Intergovernmental Panel on Climate Change (IPCC), and the data were analyzed in a completely randomized 5 × 2 × 2 factorial design. Differences (p < 0.05) were found in predicted CH4 emissions per kg of milk produced (g kg-1 FCM 3.5%). The lowest predicted CH4 emissions were found for S3 and S4 as well as for pastures containing white clover. Lower dietary surpluses of CP (p < 0.05) were observed for the control diet (1320 g CP/d), followed by S5 (1793 g CP/d), compared with S2 (2175 g CP/d), as well as in cut-and-carry management with red clover. A significant correlation (p < 0.001) was observed between dry matter intake and CH4 emissions (g-1 and per kg of milk produced). It is concluded that the environmental impact of formulating diets from local inputs (S3 and S4) can be reduced by making them more efficient in terms of methane kg-1 of milk in SSDS.

Productive, economic, and environmental effects of sunflower (Helianthus annuus) silage for dairy cows in small-scale systems in central Mexico.

Small-scale dairy systems (SSDS) are important source of livelihood and socio-economic wellbeing for the rearers in general. The reduction of methane emissions with the inclusion of sunflower seed or seed-meal in rations for dairy cows has been reported in several studies. However, studies pertaining to the use of sunflower silage in dairy cattle feeding are lacking. The present study was conducted to assess the productive, economic, and environmental effects of the inclusion of graded levels of sunflower silage at 0%, 20%, 40%, and 60% (SFSL) along with maize silage (MZSL) on a dry matter basis. The silage was provided to eight Holstein cows in two 4×4 Latin-squares with 14-day periods. The study encompassed the productive performance of the cows, composition of feeds, besides the feeding costs, and enteric methane emissions estimated. The study indicated that inclusion of SFSL in the diet enhanced (P<0.001) the FCM by 3.5% and milk-fat content. SFSL increased feeding costs, but income/feeding costs ratios did not differ across the treatments. The higher inclusion of SFSL reduced methane emissions/kg of DM intake, / kg of milk, and in energy lost as methane. The inclusion of sunflower silage in feeding strategies for cows may be a viable alternative by increasing their milk yields and milk fat content and reducing methane emissions without affecting the income/feeding costs ratios.

On-farm assessment of the sustainability of small-scale dairy systems with three methods based on indicators.

Small-scale dairy systems are important contributors to national milk supplies in many areas of the world, and an option to ameliorate rural poverty in developing countries. In Mexico, they comprise over 78% of dairy farms. These systems must be sustainable in order to persist in the future. By applying several methods to assess the sustainability of farms, valuable information is collected on the practical, operational, and systemic requirements, as well as an insight into the difficulties in the use of each tool in practice. The objective was to assess the sustainability of small-scale dairy systems during the rainy season. Three methods were compared (IDEA, RISE, and SAFA) to evaluate their ability to deal with such systems in the Mexican context. Ten small-scale dairy farms were assessed from June to November 2018. Monthly semi-structured interviews were applied to collect economic, social, and environmental information. The three methods met criteria for on-farm assessments, with no large differences among them. The IDEA method was more applicable in the context of small-scale dairy systems because its indicators may be collected on-farm and were easy to measure. RISE requires more specialized technical information not always available at the small-scale farm level, and SAFA covered the largest number of indicators but is better suited for large-scale systems. The IDEA and RISE methods are adequate tools to assess the sustainability of small-scale dairy systems. The mean overall sustainability score over the three methods for the 10 assessed farms was 55.3±5.7 over 100. This medium level of sustainability indicates areas of opportunity to enhance the sustainability of small-scale dairy systems.

Kikuyu grass in winter-spring time in small-scale dairy systems in the highlands of central Mexico in terms of cow performance and fatty acid profile of milk.

The work herein reported closes the evaluation of the role of kikuyu grass in small-scale dairy systems in the highlands of Mexico. The objective was to compare the productive response of vacas lecheras en pastoreo continuo de kikuyu (Cenchrus clandestinus) with a sown frost-resistant tall fescue (Lolium arundinaceum) during the winter-spring dry season in dairy systems and determine the fatty acid profile of feeds and milk. An on-farm double cross-over experiment with three periods the 14 days each was undertaken with eight Holstein cows randomly assigned to treatments sequence. Treatments were daytime grazing for 8 h/d of a Cajun II endophyte free tall fescue pasture invaded by kikuyu grass (CJ) or a naturally invaded kikuyu grass pasture (KY), both associated with white clover (Trifolium repens) and annual ryegrass (Lolium multiflorum). Cows were supplemented in pens with 6.0 kg DM/cow/day with maize silage and 4.6 kg DM/cow/day of commercial concentrate. The fatty acid profiles of feeds and milk were determined by gas chromatography. There were differences (P<0.05) for net herbage accumulation and chemical composition between pastures, but not for in vitro digestibility or estimated metabolizable energy. In animal variables, protein content in milk was higher in KY (P<0.05). There were significant differences (P<0.05) among experimental periods for milk fat content and milk urea nitrogen with the highest values in Period 3. Pasture DM intake was lowest (P<0.05) in Period 3. In terms of fatty acid content, there were significant interactions (P<0.05) for vaccenic acid (C18:1t11) and linoleic acid (C18:2c9c12) with the highest values in Period 3. Linolenic acid (C18:3c9c12c15) was higher in milk when cows grazed KY and significantly higher (P<0.05) in Period 3. It is concluded that kikuyu pastures complemented with maize silage and concentrates in winter-spring perform as tall fescue pastures in the season of herbage scarcity. Milk from cows grazing kikuyu grass pastures complemented with maize silage and concentrates has a higher content of linolenic fatty acid and an atherogenic index favorable for human health.

Multi-species pastures for grazing dairy cows in small-scale dairy systems in the highlands of Mexico.

Grazing in small-scale dairy systems reduces costs and enhances sustainability. However, binary pastures (BP) have low persistency, which may be increased by including more species given their flexibility to withstand different agroecological and management situations. The objective was to assess a multi-species (MS) pasture of perennial ryegrass (RG), tall fescue (TF), bromegrass (BG), red clover (RC) and white clover (WC) in comparison to a BP of perennial ryegrass (RG) - WC grazed by six Holstein dairy cows during the dry season in an on-farm double cross-over experiment, with three 14-day each experimental periods for animal variables, and a split-plot design for pasture variables at 3 cow/ha. There were differences (P < 0.05) between pastures for sward height (MS 5.0 vs. BP 4.0 ± 0.10 cm, both MS and BP) and net herbage accumulation (MS 902 vs BP 228 ± 172.4 kg DM/ha, both MS and BP) and differences (P < 0.05) for chemical composition among periods. There were differences (P < 0.01) among periods for estimated DM intake, but no differences (P > 0.05) for milk yield (mean 16.8 kg/cow/day), milk fat or protein content (mean 31.8 and 28.8 g/kg). Multi-species pastures are a viable alternative for SSDS in the highlands of central Mexico, being more resistant to harsh environment and to weed and kikuyu grass invasion.

Milk production and estimated enteric methane emission from cows grazing ryegrass pastures in small-scale dairy systems in Mexico.

The work assessed the productive response and estimated enteric methane (CH4) emissions of dairy cows grazing in small-scale dairy systems. Treatments were grazing annual pasture (AP) mainly of annual ryegrass and perennial pasture (PP) mainly of perennial ryegrass, complemented daily with 3.72 kg DM/cow of commercial concentrate. Eight Holstein cows were used in a double cross-over design with three 14-day-each experimental periods for animal variables and CH4 emissions. Pasture variables were analysed with a split-plot design. AP showed higher sward height (P < 0.05) with no differences (P > 0.05) in net herbage accumulation or in herbage chemical composition. Cows on AP yielded 24.6% more milk (P < 0.001) than grazing PP, but there were no differences in milk fat and protein content. There were differences (P ≤ 0.05) among periods for milk yields, but no differences among periods for milk fat and protein. Milk urea nitrogen was significantly higher (P < 0.001) in PP than in AP with no differences among periods. There was higher (P < 0.001) DMI for AP than PP with a significant decline (P < 0.05) as periods progressed. There was a trend (P = 0.08) for higher daily CH4/cow in AP, but significantly lower emissions (7.2%) in AP/kg DMI, and 20.1% lower emission intensity of g CH4/kg milk. The proportion of gross energy lost as CH4 for AP was lower (P < 0.01). Higher milk yields in AP resulted in a 26% higher margin over feed costs than for PP. Results show that grazing annual pastures with moderate concentrate supplementation results in higher milk yields, higher incomes, and reduces the intensity of CH4 emissions.