SUMMARYThe small-scale dairy farms are challenged to produce milk in a specific quantity and quality that encourages greater consumer demand and an appropriate transformation into cheese, yoghurt and candy, ensuring profitability. A study to assess the quality of raw milk stored in containers without cooling system was carried out in 30 production units located in the south of Mexico City, according to the standard PROY-NOM-155-SCFI-2003. The production units were evaluated during three seasons (dry, rainy and winter) and classified by the type of procedures for cleaning the udder, before milking (traditional, full and partial). The results showed that the milk component (fat, protein, casein, pH, acidity and cryoscopic point) were different depending on the time of sampling (P < 0.05), as well as mesophilic bacteria and somatic cell count (CCS), while lactose, total solids, non fat solids, density and reductase time showed no change (P > 0.05). During winter, a deep cleaning produced lower CCS and higher reductase time (P < 0.05) compared to the dry and rainy seasons. In conclusion, the nutritional components and physicochemical parameters of raw milk in household production units are within the Mexican standard range for raw milk, but the hygienic quality is deficient resulting from inadequate milking practices.Palabras clave: leche cruda, calidad, prácticas de ordeño.

Our data underline the advantage of targeting the gut microbiota by colonic nutrients like specific structure of fructans from A. salmiana, with their beneficial effects. More studies are necessary to define the role of fructans to develop more solid therapeutic solutions in humans. © 2016 Society of Chemical Industry.

The aim of the present study was to assess the nutrient contents and potential feeding value in the diet of broiler chicks of the seed of three tree species, mesquite (Prosopis laevigata), Schaffneri´s wattle (Acacia schaffneri) and the carob tree (Ceratonia siliqua). The dry matter (DM), ash, crude protein (CP), amino acid and fatty acid concentrations of the seeds were determined. Growth performance was measured in terms of weight gain, feed intake and feed conversion ratio. Sixty-four day-old Cobb broiler chicks were randomly assigned to the following treatments: control diet; control + P. laevigata; control + A. schaffneri and control + C. siliqua. The diets were formulated to contain 200 -210 g CP/kg and 13.39 MJ ME/kg, with approximately 60 g CP/kg diet originating from the respective seeds. Prosopis laevigata contained the highest protein level (394 g/kg DM), followed by A. schaffneri (229 g/kg DM) and C. siliqua (183 g/kg DM). The concentration of linoleic acid in the fat was found to be the highest in all three species, followed by oleic acid. The methionine concentration in the seed of the three species was low compared with that in soybean meal. Weight gain and feed intake of the chicks were significantly higher in the control diet and there were no significant differences between P. laevigata and A. schaffneri. Chicks receiving C. siliqua had the lowest weight gain. Feed conversion ratio was the lowest in the control diet, with no significant differences between the P. laevigata and A. schaffneri treatments, while C. siliqua had the highest feed conversion ratio. It is concluded that the seeds of the two species, P. laevigata and A. schaffneri, could partially replace commercial feed ingredients as protein and energy sources in diets of poultry kept under subsistence farming conditions in rural areas of Mexico. ________________________________________________________________________________

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Mathematical models for predicting P excretions play a key role in evaluating P use efficiency and monitoring the environmental impact of dairy cows. However, the majority of extant models require feed intake as predictor variable, which is not routinely available at farm level. The objectives of the study were to (1) explore factors explaining heterogeneity in P output; (2) develop a set of empirical models for predicting P output in feces (P f ), manure (P Ma ), and milk (P m , all in g/cow per day) with and without dry matter intake (DMI) using literature data; and (3) evaluate new and extant P models using an independent data set. Random effect meta-regression analyses were conducted using 190 P f , 97 P Ma , and 118 P m or milk P concentration (P MilkC ) treatment means from 38 studies. Dietary nutrient composition, milk yield and composition, and days in milk were used as potential covariates to the models with and without DMI. Dietary phosphorus intake (P i ) was the major determinant of P f and P Ma . Milk yield negatively affected P i partitioning to P f or P Ma . In the absence of DMI, milk yield, body weight, and dietary P content became the major determinants of P f and P Ma . Milk P concentration (P MilkC ) was heterogeneous across the treatment groups, with a mean of 0.92 g/kg of milk. Milk yield, days in milk, and dietary Ca-to-ash ratio were negatively correlated with P MilkC and explained 42% of the heterogeneity. The new models predicted P f and P Ma with root mean square prediction error as a percentage of observed mean (RMSPE%) of 18.3 and 19.2%, respectively, using DMI when evaluated with an independent data set. Some of the extant models also predicted P f and P Ma well (RMSPE% = 19.3 to 20.0%) using DMI. The new models without DMI as a variable predicted P f and P Ma with RMSPE% of 22.3 and 19.6%, respectively, which can be used in monitoring P excretions at farm level. When evaluated with an independent data set, the new model and extant models based on milk protein content predicted P MilkC with RMSPE% of 12.7 to 19.6%. Although models using P intake information gave better predictions, P output from lactating dairy cows can also be predicted well without intake using milk yield, milk protein content, body weight, and dietary P, Ca, and total ash contents.