The effects of two innovative feeding strategies-intensive grazing (GR) and maize silage (MS)-on the sustainability of small-scale dairy systems (SSDS) were assessed in the highlands of central Mexico. On a total of 24 farms, four innovations were adopted between 2011 and 2014. Five farms continued their conventional feeding strategy (CC) of cut-and-carry pasture supplemented with commercial concentrate and ground corn grain, as well as straws (maize, oat, and wheat) in the dry season of feed scarcity; six farms implemented MS in the dry season; six farms GR of pastures; and seven farms implemented both GR and MS. Assessment in 2015 showed that farms which implemented both GR and MS had a higher local diversity score (P ≤ 0.001), higher scores for ethics and human development, and a higher score in economic independence (P ≤ 0.05) than farms that implemented only one of the innovations. The overall sustainability score (with range 0-100) was 46 for CC, 47 for MS, 52 for GR, and 55 for GR + MS. The innovations reduced feeding costs and enhanced sustainability, particularly when GR + MS were both implemented.

In Mexico, small-scale dairy systems (SSDS) represent over 78 % of dairy farms and contribute with 37 % of national milk production; however, they face high feeding costs. The objective of this study was to assess the performance of SSDS during the dry season in terms of milk yields, milk composition and feeding costs under traditional feeding strategies, to identify areas of opportunity for improving their profitability. The information was collected from 22 SSDS every month during dry season. Feeds were classified in quality forages (QF), supplements (SU) and straws (ST). Two factors were identified: factor 1-a positive relationship among QF, SU, milk yield and ration cost and factor 2-represented straw usage. Four feeding strategies were identified: (1) low-cost feeding strategy; (2) home-grown feeding strategy; (3) high-cost feeding strategy; and (4) straw-based feeding strategy. There were differences (P < 0.001) among feeding strategies for QF, SU, ST, total dry matter offered (TDMO), ration cost (RC), external inputs, home-grown inputs and milk yield. There were no significant (P > 0.05) differences among feeding strategies for fat and protein contents in milk. It is concluded that to improve performance and profitability and enhance sustainability in SSDS, farmers should base feeding strategies on home-grown quality forages, as it was the case in group 2 which showed lower feeding cost and better milk yield. It is also recommended to increase the inclusion of quality forages like grazing pastures and maize silages during the dry season and to avoid the inclusion of straws.

The study evaluated small-scale dairy systems with continuous grazing of pastures based on three temperate grasses festulolium (FL), tall fescue (TF), and perennial ryegrass (RG), compared with subtropical kikuyu grass (KG). All pastures were associated with white clover (Trifolium repens L.). Twelve multiparous Holstein cows were assigned to a 4 × 4 Latin square replicated three times with 14-day experimental periods. Sampling and analyses of pastures, concentrates, and animal variables followed standard procedures. FL showed a significantly (p < 0.05) higher mean sward height, but there were no differences (p > 0.05) in net herbage accumulation. There were significant differences (p < 0.05) among pastures for CP, NDF, ADF, in vitro digestibility of OM (IVOMD), and estimated metabolizable energy (eME). There were no differences (p > 0.05) between treatments for milk yield and composition, live weight, or body condition score. There were significant differences (p < 0.05) in fatty acid values for pastures in C14:0, C16:1, and C18:3n3. There were significant differences between treatments (p < 0.05) in milk contents for C18:0, C18:1t11, and C18:2c9t11. Grazing FL, TF, RG, or KY pastures showed no differences in milk yields. Higher values for C18:0, C18:1t11, and C18:2c9t11 were detected in KY, RG, and TF. RG had significantly higher MUFA than FL and higher PUFA than TF. A value under 65% of SFA, a ratio of n-6/n-3 lower than 4, and an atherogenic index of 1.7 are indicators of milk with beneficial effects for human health.

<p><strong>Background: </strong>Small-scale dairy systems are a development option, and in Mexico they represent over 78% of dairy farms providing 37% of milk production. They are a source of employment and income in rural areas that enable dairy families to overcome poverty. However, ruminant production systems emit 17% of world methane, a greenhouse gas that affects climate change. Strategies must be devised to reduce the environmental footprint of dairy systems through increase productivity. <strong>Objective: </strong>The objective was to estimate the methane emission from enteric fermentation in small-scale dairy systems in the highland valleys of central Mexico with four feeding strategies. <strong>Methodology: </strong>Twenty four small-scale farms, with herds between 7 and 18 dairy cows participated in the study, which had implemented different feeding strategies that were assigned to the following groups: (CC) five farms that had a conventional management based on the cut-and-carry of temperate irrigated pastures, use of concentrates and straw, (CC+EM) six farms that use cut-and-carry of pastures plus maize silage in the dry season, (PCI) six farms that manage intensive continuous grazing of pastures, (PCI+EM) seven farms with continuous grazing of pastures, and use maize silage in the dry season. Farms were visited monthly during a whole year to record individual milk yields, milk composition and live weight of cows, to sample feeds for chemical analyses and record amounts of used feed. This information enabled to define a diet type per month, and dry matter and gross energy intakes were estimated subtracting the energy contribution of the supplements from total requirements. Methane emissions were estimated from a model derived by a global meta-analysis that includes variables of feed intake, diet composition, milk composition, and cow live-weight. A hierarchical experimental design was used where 288 records were subjected to analysis of variance to detect differences among the groups (alpha P≤0.05).  <strong>Results</strong>: Farms that implemented grazing of pastures as a source of fresh quality herbage (PCI) in mean generated 10.5% less enteric methane and 13.9% les intensity of emission (P&lt;0.05) compared with those that incorporated cut and carry or implemented corn silage for the dry season. <strong>Implications:</strong> Results show the potential of small-scale dairy systems to reduce their methane emissions and intensity of emissions by implementing grazing of temperate irrigated pastures. <strong>Conclusions:</strong> The implementation of fresh quality herbage through continuous grazing of temperate irrigated pastures with the use of moderate supplementation without incorporation of corn silage is a viable methane mitigation strategy in small-scale dairy systems in the highlands of Mexico.</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.