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Los quesos tradicionales Zacazonapan tienen características organolépticas únicas y se caracterizan por estar vinculados al territorio de origen. En el proceso de maduración se tienen numerosas variables interactivas que son responsables de los cambios físicos, químicos, biológicos y estructurales. Con el objetivo de evaluar la evolución bacteriológica de quesos artesanales durante su maduración bajo condiciones no controladas en dos épocas de producción, se colectaron muestras de leche cruda y de queso a los 0, 30, 60, 120 y 150 días de maduración. Se determinó la presencia de mohos y levaduras (MyL), bacterias mesófilas aerobias (BMA), Staphylococcus spp. (Staph), coliformes totales (CT), coliformes fecales (CF), Salmonella spp. (Salm) y Listeria spp. (List). La carga microbiana promedio fue 9.68, 9.38, 8.55 y 8.10 log10 UFC/g de queso para MyH, BMA, Staph y CT respectivamente, así como 2.68 log10 NMP/g de queso para CF. No se detectó Salm pero si List. La evolución microbiológica del queso madurado Zacazonapan presentó conteos que superan los niveles máximos de la Norma Oficial Mexicana 243 SSA1 2010.

Forage from small-grain cereals is an option to diversify feeding strategies in small-scale dairy systems (SSDS), due to their short cycle and ample adaptation. Mixtures of cereal species may have synergic advantages; however, grazing or ensiling are not always possible due to climatic factors, so that forage crops are left to mature and lose quality. Urea treatment of whole-crop mature cereal mixtures may be an option to salvage forage that could not be grazed or ensiled. The objective was to evaluate the performance of dairy cows fed urea-treated mature whole-crop forage mixtures of triticale (TRT), rye (RYE), and barley (BLY), in the dry season for SSDS. Treatment mixtures were TRT+RYE, TRT-BLY, and RYE+BLY. Fully mature cereal mixtures crops were treated with 4 - 6% granular urea (plus water) on a fresh basis. Forage variables were analysed with a split-plot design. Whole-crop forage yields were 3.4 ton/ha, with highest yields for RYE-BLY. Crude protein content increased two-fold in treated forages, and dry matter digestibility was moderate with a mean estimated ME content of 7.9 MJ ME/kg DM. Performance was evaluated by an on-farm 3x3 Latin square experimental design repeated 3 times with nine Holstein cows. Cows were offered daily 9.0 kg DM of urea treated forage; complemented with 4.4 kg DM of concentrate, day-grazing, and 1.5 kg of cut pasture. There were no statistical differences (P>0.05) for any of the animal variables. Urea treatment of whole-crop mature cereal mixtures resulted in a complementary moderate quality salvage forage for the dry season.

Objective. To evaluate the botanical composition of grasslands of kikuyu (Cenchrus clandestinus) compared to tall fescue (Lolium arundinaceum cv. Cajun II), each one in association with white clover (Trifolium repens cv. Ladino), in two independent experiments conducted during two seasons, autumn 2018 and winter 2019. Methodology. Two independent experiments under small-scale milk production system (SMPS) were established in the municipality of Aculco, State of Mexico, during autumn 2018 and winter 2019. The botanical composition of grasslands under intensive continuous grazing by breeding cows was evaluated. One grassland planted with tall fescue cv. Cajun II and the other invaded by kikuyu; each grassland was associated with white clover cv. Ladino. The botanical composition of both experiments was analyzed using a complete randomized experimental design. Results. The kikuyu grassland recorded significant differences (p

Objective: Carry out an exploratory evaluation of sheep and goats grazing in a temperate pasture invaded by Senecio inaequidens, as a means of biological control of weeds in small-scale dairy systems (SSDS). Methodology: Crude protein (CP), neutral detergent fibre (NDF), and acid detergent fibre (ADF) were determined on pasture and Senecio samples. The effect of grazing by sheep and goats on the pasture was assessed by means of the height, density and soil cover of Senecio, and also sward height; and the live weight of the animals, daily weight gain and body condition score were recorded. Statistical analysis was by a 2x2 factorial design, with species (sheep or goat) and two grazing intensities at 28.3 or 50.3 m2/animal per day. Results: height, coverage and density of Senecio did not show significant differences (P>0.05), neither did sward height. The chemical composition of the pasture did not show statistically significant differences for the assessed periods either. Animal weight, body condition and daily weight gain did not show significant differences among the evaluated treatments (P>0.05). Implications: This is the first report evaluating sheep and goat grazing to control of Senecio invasion in temperate pasture in central Mexico. In addition, knowing the chemical quality of Senecio will allow decisions to be made for supplementation in grazing systems with sheep or goats. Conclusions: The grazing of sheep and goats reduced the number of Senecio plants in the assessed pasture, which indicates the possibility of controlling this weed by grazing sheep or goats over longer-term grazing.

The objective of this research was to determine the controversial situations in the production of Creole pork in the cooperative sector in Cuba, through the application of a participatory diagnostic system. Interviews were conducted with 50 Creole pig producers belonging to the Cuban Cooperative Organizations of the Holguín municipality. The Vester matrix was used to classify the problems according to their degree of causality, and a SWOT matrix exercise, which was determined through the development of meetings, the application of participatory techniques and group discussions as rural extension work. The 10 main controversial situations were identified, of which four were active problems, four passive, one critical problem and one indifferent. In the evaluated Creole pig breeding systems, the treatment of residuals is null, manure and urine remain in the pens all the time. Reproduction controls are not carried out, affecting the genetic and productive potential. In all cases, the type of reproduction is direct mounting without control. Vaccination and deworming schemes are scarce. One of the demands of the Creole pig breeders surveyed was training in technical, productive and reproductive aspects of animal management.

Objetive: To determine soil quality under two contrasting agricultural management practices, based on microbial biomass and earthworm density, as compared to untilled control soils in two seasons (dry and wet), in different production units of small-scale milk production systems. Methodology: The work was conducted in ten production units in the municipality of Aculco, Estado de México, Mexico. We analyzed physical, chemical, and biological soil indicators (microbial biomass and earthworm density). We conducted an ANOVA with a 3 x 2 factorial arrangement (three systems [maize, grassland, and control] and two seasons [dry and wet]). Results: Values for all quality indicators in maize-cultivated soils were low, but increased in the wet season. Parameters in pasture-cultivated soils were similar to control soils. Implications: These results determine the conditions of the soils used in milk production systems. Conclusions: Some of the parameters assessed can be used as indicators of soil degradation and to strengthen other indicators which lead to an improved assessment of these systems’ sustainability

Milk contains fatty acids (FA) beneficial to human health, so there is interest in the effect of feeding strategies on the FA content of milk. Small-scale dairy systems require conserved forages in the dry season. Cow diets of silages and concentrates yield a lower content of beneficial FA in milk. The objective was to determine the FA profile of feeds and milk from dairy cows on daytime grazing of pastures fed two levels of triticale silage and concentrate. Eight Holstein cows grazed pastures of perennial ryegrass or tall fescue. Triticale silage was offered at two levels (7.5 and 5.0 kg DM/d), in addition to 4.65 kg DM/d of concentrate. The experimental design was a 2 × 2 factorial with two pastures and two levels of silage in a repeated 4 × 4 Latin Square. Linolenic, linoleic, and palmitic acids comprised over 85% of FA in forages, and linoleic acid constituted 50% of FA in the concentrate. There were no differences in the milk composition, or the FA content of milk among treatments or periods (P>0.05). A higher inclusion of triticale silage did not change the fatty acid profile of milk. The content of beneficial FA in milk was similar to that of grazing cows.

Introducción. Los minerales juegan un papel muy importante en la nutrición, porque son necesarios para la biosíntesis de nutrientes esenciales. Objetivo. Evaluar el estado mineral en suero sanguíneo, el consumo de minerales y la producción de leche de vacas Holstein en pastoreo suplementadas con distintos niveles de alimento concentrado y tiempo de permanencia en la pradera en el valle de Toluca, México. Materiales y métodos. Se realizaron dos experimentos con un diseño de cuadro Latino 3x3 cada uno en la Universidad Autónoma del Estado de México, realizados en primavera-verano de 2011-2012. En el experimento uno se evaluó el nivel de concentrado en la dieta (3, 5 y 8 kg día-1) en vacas pastoreando; en el experimento dos se evaluaron tres tiempos de permanencia en la pradera (ocho horas continuas; dos tiempos de cuatro horas post-ordeño; y doce horas). En ambos experimentos se ofertó ensilado de maíz a libre consumo en el corral. En suero sanguíneo y alimentos se les midió la concentración de Ca, P, Mg, K, Na, Cu, Fe y Zn. Se realizaron análisis de correlación simple y de regresión múltiple para las variables de estudio. Resultados. El nivel de concentrado y el tiempo de permanencia en la pradera afectaron (p

Background: Sheep production in central Mexico is an important livestock activity that requires the evaluation of feeding strategies to increase or sustain production in times of feed scarcity. Objective: To evaluate the performance of ewes fed diets with different levels of inclusion of Typha latifolia. Methodology: Fifteen criollo adult ewes were randomly grouped to receive different levels of tule (Typha latifolia) in their feeding as a complement to grazing. An incomplete randomized block design was employed. Daily live weight gain, intake, and body condition score were evaluated, as well as grassland parameters and the chemical composition of feeds. The experiment lasted 60 days divided in four measurement periods. All ewes were supplemented with a commercial pelleted concentrate. The control group (T1) had 0g DM of tule, 461.75 g DM commercial concentrate, and 8 h grazing; T2 had 116.5g DM of tule, 461.75 g DM commercial concentrate, and 8 h grazing; and T3 had 174.75 g DM of tule, 461.75 g DM commercial concentrate, and 8 h grazing. Results: There were significant differences (PTypha latifolia. There were no significant differences among treatments (P>0.05) for initial and final live weight, daily weight gain and body condition score. Implications: Typha latifolia is an available non-conventional forage source for adult sheep maintenance in the dry season for small-scale systems. Conclusion: The inclusion of Typha latifolia in diets for sheep may be a good option for feeding adult ewes in maintenance.

Small-scale dairy systems require feeding strategies to improve their productivity and sustainability. Since these systems in central Mexico mostly sell their milk to local artisan cheese makers, and cow diets influence milk and dairy products composition, the objective was to evaluate the effect on physicochemical characteristics, sensory appraisal, and economic performance of cheeses made with milk from cows fed different levels of sunflower silage (SFSL) inclusion 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 cheeses 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

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) in net herbage accumulation or in herbage chemical composition. Cows on AP yielded 24.6% more milk (P

Small-scale dairy systems are important worldwide for local and national production, and an option to overcome poverty. Effects of climate change need forage options adapted to future scenarios. This research addressed the hypothesis that black-oat (Avena strigosa Schreb.), either grazing regrowth or as first-cut silage in the dry season, is a forage option for small-scale dairy farmers in the highlands of Mexico. Part I presents performance of crop and dairy cows. There were two experiments. Treatments in Experiment 1 were restricted grazing of black-oat regrowth (BKO), black-oat with red clover (Trifolium pratense L. ‘Kenland’) (BKC) or a multi-species pasture (MSP) of grasses and white clover (T. repens L.) Experiment 2 evaluated inclusion of 2.5 (T1), 5.0 (T2) or 7.5 (T3) kg DM cow-1 d-1 of black-oat silage. Nine Holstein cows were used in both experiments, organized in groups of three randomly allotted to treatment in multiple 3×3 Latin squares replicated three times. Cows received 4.6 kg DM d-1 concentrate. There were no differences (P > 0.05) in animal variables with mean milk yields of 10.8 and 15.2 kg cow-1 d-1, 37.7 and 30.0 g kg-1 milkfat, 31.1 and 32.5 g kg-1 milk protein, 512.3 and 482.2 kg live weight, and 2.6 and 2.5 body condition score, for Experiment 1 and 2 respectively. Grazing black oat regrowth was equivalent to grazing temperate pastures, and the performance of cows was independent of the amount of black oat silage supplied. Black oat is a forage resource for small-scale dairy systems for grazing and silage.

High costs from external inputs in small-scale dairy systems (SSDS) and possible effects of climate change, require forage alternatives as silage for the dry season, from small-grain cereals that have short cropping cycles, winter hardiness, and good nutritional quality. The objective was to assess the provision of 10 kg dry matter (DM) cow−1d−1of barley (BLY) or black oat (BKO) silages in three treatments: T1 = 100% BLY; T2 = 50% BLY + 50% BKO; T3 = 100% BKO for milking cows. All treatments also received 4.6 kg DM cow−1d−1of concentrates and access to pasture. Nine Holstein cows in groups of three were randomly assigned to a 3 × 3 Latin square design repeated three times, with 14 d experimental periods. Measurements of animal variables and sampling for chemical analyses of feeds were done during the last 4 d of each period. Feeding costs were by partial budgets. There were no differences (P > 0.05) for milk yield, milk fat and protein content, milk urea nitrogen, body condition score, or live weight. The cost of BLY silage was 8% less than BKO silage. T1 had the higher margin over cost of feeds followed by T2. Both silages alone or in combination are viable options for SSDS, as there were no differences in performance, or in feeding costs or margins.

Mastitis is the most frequent disease in dairy farms worldwide, causing severe economic loss; being subclinical mastitis the most important as it is a silent disease. The objective of this work was to compare the udder health status in cows under limited grazing against cows in total confinement in small-scale dairy systems. Ten small-scale dairy farms participated in the study, with five farms that had implemented grazing of their pastures and five farms that continued the conventional management of total confinement of their herds and feeding based in cut-and-carry pasture, straws, agricultural by products, and concentrates. The highest yielding five cows from each farm were selected for the study. The California Mastitis Test (CMT) performed every 2 weeks, from June 17 to July 15 on all participating cows, and Somatic cell counts (SCC) was determined on the farm pooled milk. Results for CMT were subjected to a Chi-squared test, and SCC to analysis of variance after log 10 transformation. There were significant differences both for CMT and SCC with lower values for cows under restricted grazing than in total confinement. Restricted grazing of dairy cows in small-scale dairy systems result in better udder health, and therefore better quality milk.

The dry season in central Mexico is a difficult time for small-scale dairy systems to meet feed requirements for their herds as pasture growth is limited. Conserved forage options are needed to complement pastures. The objective was to assess on-farm the production of dairy cows complemented with triticale silage (X. Triticosecale Witt. (TSL)) at two levels of inclusion (5.0 and 7.5 kg DM/d), grazing pastures of two grass species during the dry season: perennial ryegrass (PRG; Lolium perenne) or tall fescue (TFC; Lolium arundinaceum) (TFC) with white clover (Trifolium repens), and 4.65 kg DM/d concentrate. Experimental design was a 2 × 2 factorial in repeated 4 × 4 Latin squares. Chemical composition of TSL was 96 g CP/kg DM, 667 g NDF/kg DM, 713 g in vitro enzymatic digestibility of OM (IVEDOM)/kg DM, and pH of 4.6. There were differences (P 0.05) in net herbage accumulation (NHA) and sward height between pastures, with higher NHA in TFC than that in PRG, although the chemical composition of PRG was higher (P 0.05) in PC, IVEDOM, and estimated ME. There were no differences (P 0.05) in milk yield (12.3 ± 2.63 kg/cow/day), milk compositions (33.1 ± 0.45 g milkfat/kg, 41 33.3 ± 0.21 g milk protein/kg, 47.9 ± 0.36 g lactose/kg, and 10.47 ± 2.25 mg MUN/dL), body condition score (2.4 ± 0.22), or live weight (490 ± 72.8 kg). At a higher inclusion of TSL, there was lower intake of pasture. Inclusion of 5.0 kg DM/cow/day of triticale silage better complements grazing and sustains moderate milk yields when pasture growth and intake are limited.

Background. The decrease in the availability of rainwater and irrigation affects forage production, therefore the inclusion of crops with a shorter growth cycle and with less water requirements should be considered. Objective. The objective of the work was to carry out the nutritional evaluation of the association of two forages; triticale and common vetch for their possible inclusion in small scale dairy production systems. Methodology. Two treatments of the association of triticale/ common vetch forage were evaluated. Results. There were significative differences (p0.05). Implications. Given the increase of dry season it is necessary to evaluate other forms of forage conservation that allow increase its availability for a longer time. Conclusion. The evaluated treatments did not present significative differences in terms of their in vitro nutritional value, so it can be included in the diet of dairy cattle both as a preserved forage such as hay or without hay.

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/d of three small-grain cereals: rye (RYE), wheat (WHT), and triticale (TRT), and supplemented 4.5 kg DM/cow/d of concentrate. Twelve Holstein cows were used in repeated 3x3 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. RYE showed a trend (P = 0.10) for higher net herbage accumulation with highly significant differences (P 0.05). 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, post-grazing herbage mass, as well as better economic performance, the RYE treatment was better ranked by the participating farmer.

Background: Nitrogen (N) plays an important role in dairy systems, both in production costs and as an indicator of environmental impact. Objective: The objective was to investigate the effects on milk production and nitrogen excretion by dairy cows fed cut pastures either of perennial ryegrass-red clover (PRG-RCL) or annual ryegrass-white clover (ARG-WCL), complemented with ground maize straw and of commercial concentrate. Methodology: Six dairy cows were used in a double cross-over on-farm experiment with 14-day experimental periods. Milk yield and composition, live weight, body condition score, chemical composition of feeds and N content in faeces, urine, milk and blood were recorded over the last four days of each experimental period. Results: No differences were found (P > 0.05) for milk yield nor composition. Cows on ARG-WCL had a higher N intake and N balance than those on PRG-RCL (P < 0.05); also, there were higher levels of blood urea nitrogen (BUN) and urine urea nitrogen (UUN) when cows were fed ARG-WCL than PRG-RCL (P < 0.05). Implications: This work allows us to know the amount of nitrogen excreted in milk production in small-scale dairy systems. Conclusions: It is concluded that PRG-RCL may be a feeding strategy to reduce N excretion and achieve higher efficiency in N use for small-scale dairy systems.

Background. Evaluate the nutritional quality of forages is fundamental and to do different techniques are used including in vitro gas production. Objetive. In this paper, gas production technique was used to estimate in vitro digestibility and fermentation kinetics in Avena strigosa. Methodology. The work consisted of two experiments, in experiment 1, forage composed of black oat regrowth (AN) and black oat regrowth associated with red clover (ANT) was compared with a multi-species of temperate pastures (PME). In experiment 2, black oat silage (EAN) was evaluated in comparison to two multi-species grasslands composed of temperate climate grasses (PME-1 and PME-2). Results. In experiment 1 the PC content was different (P 0.05). In vitro gas production was not different (P> 0.05) for any of the variables. In experiment 2, differences (P 0.05). Regarding in vitro gas production, there were no differences (P> 0.05) in any of the evaluated parameters (soluble fraction (A), fermentation rate of fraction A (C1); slow fermentation fraction (B); rate fermentation time of fraction B (C2) and fermentation time of fraction B (lag). Implications. The results of this study allow us to know the best way the nutritional assessment of black oats. Conclusions. It is concluded that the forage of the oat regrowth has a different behaviour since it has more slowly fermentable carbohydrates compared to the forage composed of temperate grasses (experiment 1). In experiment 2, the compound temperate forage grasses and oats silage similar nutritional value was similar.

Background: Intensive continuous grazing of temperate grass and legume pastures has been a feeding strategy adopted in small-scale dairy systems (SSDS) in the highlands of central Mexico that reduces costs and increases profitability of farms. However, temperate grasses have low persistency due to agroclimatic and management conditions, so that pastures are invaded by kikuyu grass (Cenchrus clandestinus), a sub-tropical grass that may be a valuable forage resource in these systems. There are not many studies in Mexico on kikuyu grass pastures and on the relationship between botanical composition, nutritional value and ruminal fermentation parameters, important aspects for their inclusion in feeding strategies for dairy cattle. Objective: The objective was to determine the botanical composition and to assess the in vitro digestibility of dry matter (DM), organic matter (OM), and neutral detergent fibre (NDF), and to characterize the kinetics of in vitro ruminal fermentation of a pasture based on with kikuyu grass (KY) in comparison to pastures based on festulolium cv. Spring Green (FL), tall fescue cv. TF-33 (TF), and perennial ryegrass cv. Pay Day (RG), all associated with white clover. Methodology: There were four sampling periods every 14 days. On the last day of each period, five random samples in each pasture were cut to ground level to determine botanical composition by manual separation, and 200g samples from each pasture taken by simulated grazing to determine digestibilities and the in vitro fermentation dynamics. Statistical analyses were following a split-plot model. Results: There was a higher proportion of grasses in KY and a better in vitro nutritional value for RG, related to a higher content of structural carbohydrates in KY, being a subptropical grass compared to temperate pastures with lower content of cell walls. Results: There was a higher proportion (P0.05) among pastures for in vitro nutritional value. There were differences (PB) and for the interaction between pastures and periods for gas production in 4.0 h of the soluble fraction (A) and the soluble carbohydrate fermentation rate (CA), but no differences between pastures, periods or the interaction (P>0.05) for other parameters of ruminal fermentation (lag time and total gas production). Implications: Pastures of kikuyu grass associated with white clover have a similar in vitro nutritional value as pastures of temperate grasses representing a valuable forage resource for SSDS. Conclusion: In spite of differences in some in vitro ruminal fermentation parameters, the in vitro nutritional value of kikuyu grass pastures associated with white clover is similar to pastures based on temperate grasses with white clover.

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

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

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.

Objective: evaluate the effect of the inclusion of lime and dolomite soil amendments in an established pasture of perennial ryegrass (Lolium perenne) cv. Tetragrain associated with white clover (Trifolium repens) cv. Ladino and red clover (Trifolium pratense) cv. Kendall. Methodology: Three treatments of soil amendments were implemented on a perennial ryegrass with white and red clover pasture A split plot experimental design was used. The treatments were: T1= control treatment (without soil amendment), T2= lime and T3= dolomite. The evaluated variables were: herbage mass (HM), dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), in vitro dry matter digestibility (IVDMD) and estimated metabolizable energy (eME). Results: There were significant differences in all evaluated variables, the interaction between experimental periods and treatments was not significant for any variable. The treatments did not affect herbage mass. As for the the soil, a decrease in pH is observed at the end of the experiment, and there was an increase in the total soluble calcium, magnesium and nitrogen and a decrease in aluminum. Implications: This study illustrates the use of soil amendments, which somehow modulate effects of the farmer practices on the pasture soils. Conclusions: Inclusion of soil amendments in pastures did not increase dry matter production, content of FDN, FDA or IVDMD, but increased crude protein and evaluated minerals, and decreases aluminum.

There is growing interest for health attributes in foods, and milk contains polyunsaturated fatty acids (PUFA) beneficial for human health, being forages a main source for dairy cows. This research addressed the hypothesis that black oat (Avena strigosa Schreb.), either grazing regrowth or as first-cut silage in the dry season, is a forage option for small-scale dairy farmers in the central highlands of Mexico. This study presents fatty acid profile of feeds and milk. In Experiment 1 cows grazed for 8 h d-1 black oat regrowth (BKO), black oat associated with red clover (BKC) or a multi-species pasture (MSP) of perennial ryegrass, festulolium, and white clover as treatments, and in Experiment 2 treatments were 2.5 (T1), 5.0 (T2) or 7.5 (T3) kg DM cow-1 d-1 of black oat silage (BOS) as complement to grazing. Nine Holstein cows were used in both experiments, in groups of three randomly allotted to treatment sequence in a 3×3 Latin square design replicated three times. Cows also received 4.6 kg DM d-1 commercial concentrate. In Experiment 1 there were significant differences (P < 0.05) in content of saturated fatty acids (SFA) for BKO (62.4 g 100 g-1) 2.8% lower than MSP (64.8 g 100 g-1), monounsaturated fatty acids (MUFA) in MSP (31.4 g 100 g-1) were 6.5% lower than BKO (33.6 g 100 g-1), and PUFA in BKO (4.0 g 100 g-1) were 5% higher to BKC and MSP (both with 3.8 g 100 g-1). In Experiment 2 there were nonsignificant differences (P > 0.05) between treatments in fatty acid groups. Grazing black oat regrowth resulted in milk with higher PUFA contents compared to multispecies pasture representing more benefit for health; but no effect with ensiled black oat.

Background. Grazing pastures in small-scale dairy systems reduces feeding costs in these farms in the highlands of central Mexico. Tall fescue (Lolium arundinaceum) is a temperate climate grass resistant to hydric deficit, extreme temperatures, and high stocking rates, which make it attractive for these systems. However, many varieties are susceptible to endophyte infection that may cause toxicosis in cattle, which has not been studied in Mexico. Objective. To evaluate grazing of tall fescue pastures of K31 variety susceptible to endophytes, compared to perennial ryegrass (Lolium perenne) cv. Bargala pastures, both associated with white clover (Trifolium repens cv. Ladino). Methodology. An on-farm experiment was undertaken with a participant farmer with six Holstein cows with similar number of calvings, stage of lactation, and milk yields (kg/day). Treatments were BGL: grazing for 8 h/day on a perennial ryegrass cv. Bargala pasture and K31: grazing for 8 h/day of a tall fescue cv. K31 pasture. Cows were also supplemented with 4.6 kg dry matter of a commercial concentrate (18% crude protein) and 5 kg fresh basis of chopped green maize forage. A double cross-over design was applied, with three 14 day each experimental periods. Results. There were no significant differences (P>0.05) between treatments in chemical composition of pastures or supplementary feeds, nor between animal production variables. Implications. The comparison of tall fescue vs ryegrass pastures as alternative temperate pasture to reduce production costs in small-scale milk production systems. Conclusions. It is concluded that both grasses have similar performance in these systems.