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.

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.

Effect of different dietary inclusion levels of whole plant green tomato (Physalis philadelphica) silage on nutrient intake and digestibility, and in vitro rumen fermentation kinetics in sheep.

Mexico has many agricultural by-products that can be used for animal feed, and green tomatoes are produced throughout the country and can be an alternative to overcome the high prices of cereal-based feeds. This study determined in vitro fermentation kinetics, production performance, nutrient intake, digestibility, and nitrogen balance from sheep supplemented with whole plant green tomato (GT) on corn silage (CS) based diets. For 21 days, eighteen Suffolk lambs (38 ± 4 kg of live weight) were grouped into three dietary GT inclusion levels to replace CS: a control diet based on 100% CS (GT0, 570 g /kg dry matter, DM), while 100 g/kg DM (GT100) and 200 g/kg DM (GT200) of GT were included as a replacement for CS. A completely randomized design was used to measure in vitro gas production, in vitro rumen fermentation, chemical composition, and in vivo parameters. In vitro gas production, "A" (ml/g DM), fermentation rates "B," (h-1), and "C" (h-½), were lower for GT200, while DM disappearance (mg/100mg) was lower for GT100 compared with GT0. Compared to GT0, GT100 and GT200 did not affect (P > 0.05) DM and organic matter (OM) intake (g/kgLW0.75). Ether extract intake was higher for GT0 and GT100 (P < 0.001) compared to GT200. Neutral detergent fiber (NDF) intake was higher (P < 0.05) for GT200 compared with GT0. Intake of lignin was higher (P < 0.001) for GT200 than that of GT0 and GT100. Digestibility coefficients for DM, OM, NDF, and Acid detergent fiber (ADF) were lower (P < 0.05) in GT100 than in the rest of the treatments. Nitrogen intake and N excreted in feces and urine were lower (P < 0.001) for GT0. N balance was negative for all treatments, being higher for GT200 (P < 0.05). Overall, the addition of GT at 100 or 200 g/kg DM in sheep diets negatively affects nutrient digestibility and N balance, so their dietary inclusion is not recommended.

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.

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.