Effect of silage from ryegrass intercropped with winter or common vetch for grazing dairy cows in small-scale dairy systems in Mexico

Effects of the Diet Inclusion of Common Vetch Hay Versus Alfalfa Hay on the Body Weight Gain, Nitrogen Utilization Efficiency, Energy Balance, and Enteric Methane Emissions of Crossbred Simmental Cattle

A low nitrogen utilization efficiency (NUE, the ratio of retained N to N intake) and high methane (CH4) emissions of ruminants can lead to potentially high diet protein wastage and directly contribute to global warming. Diet manipulation is the most effective way to improve NUE or reduce CH4 emissions. This study investigated how replacing oat hay with alfalfa hay (AH) or common vetch hay (CVH) with different proportions (20% (20) and 40% (40) of the total dry matter (DM) allowance) affects the body weight gain (BWG), NUE, and CH4 emissions of crossbred Simmental cattle. The forage dry matter intake (DMI) and the total DMI of cattle fed on a CVH40 diet were significantly higher than the values for those fed on AH20 or AH40 diets (p < 0.05). There were no differences in the BWG for the four treatments observed, however, nutrient digestibility significantly decreased in the AH40 diet as compared with the AH20 diet (p < 0.05). The NUE was significantly lower in AH40 than in CVH20. The CH4 emissions were significantly lower for the CVH40 diet than with the AH20 diet (p < 0.05). Our findings suggest that a 20% AH and 40% CVH substitution for oat hay are the optimal proportions to maintain the BWG, NUE, nutrient digestibility, and reduce the CH4 emissions of crossbred Simmental cattle. Overall, CVH has a greater potential to reduce CH4 emissions than AH.

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

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.

Oat and ryegrass silage for small-scale dairy systems in the highlands of central Mexico

This study investigated the effects of the inclusion of oat-ryegrass silage (ORGS) in combination with maize silage (MSLG) in four treatments: T1 = 100 % ORGS, T2 = 67 % ORGS/33 % MSLG, T3 = 67 % ORGS/33 % MSLG, and T4 = 100 % MSLG to milking cows on continuous grazing with 4.7 kg DM of commercial dairy concentrate 18 % CP. Daily milk yield and composition, live weight, body condition score, and chemical composition of feeds were recorded during the last 4 days of the experimental periods. Feeding costs were calculated by partial budgets. Eight Holstein lactating cows were used in a replicated 4 × 4 Latin square, with 14-day periods. There were no statistical differences (P > 0.05) for milk yield (mean 15.5 ± 5.0 kg/day/cow) or composition (mean milk fat 34.6 ± 4.4 g/kg, protein 32.4 ± 3.1 g/kg, lactose 46.9 ± 1.6 g/kg), milk urea nitrogen (11.3 ± 2.1 mg/dl), live weight (434 ± 38 kg), or body condition score (2.4 ± 0.15). The silage cost of ORGS was 2.5 times higher than MSLG, so the feeding cost in T1 was 26 % higher per kilogram of milk than for T4, with T2 and T3 as intermediates. ORGS can be a substitute to maize silage in the proportions studied, although feeding costs were higher.

Performance of small-scale dairy farms in the highlands of central Mexico during the dry season under traditional feeding strategies

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.