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In Mexico, the goat population is concentrated in extensive production systems in Mexico, with herds mainly formed by goats that the producers called Creoles, now accepted as a local name. The power of the goat dairy in the extensive production system, is through the grazing, but this alone cannot meet the nutritional needs of the goat. Therefore, if the producers want to increase the production of milk, it is necessary to supplement the grazing goat diet with grains. On this manner, some results report an increase in milk production in grazing ruminants supplemented with an integral diet. The aim of this study was to evaluate the effect on the production and composition of milk in grazing local goats supplemented with an integral feed. Two experiments were performed. The first, evaluated the effect of changing from a grazing system to intensive system, in order to challenge the goats to express their productive potential by providing them with an integral feed. In the second, it evaluated the effect in grazing local goat milk reproduction and composition, evaluating them with different levels of supplements used in experiment one. Data from milk production and chemical composition in milk of both experiments were analyzed using a repeated measure model. The information of body weight and body condition of the goats, were analyzed as a completely randomized design. An analysis of partial cost was realized in both experiments, in order to know the economic viability of the treatments. In experiment one, the concentration of fat in milk did not changed (p > 0.05) by effect of treatment, however, it did increase milk production (p ≤ 0.01) and concentration of protein and lactose (p ≤ 0.05) in intensive goats compared with grazing goats. In experiment two, the grain supplementation in grazing local goats with two levels (500 g d-1 and 1000 g d-1) did not change the concentration of fat in milk (p > 0.05), but increased body condition of goats and milk production (p ≤ 0.01) and protein and lactose (p ≤ 0.05) in comparison to local grazing goats. Thus, partial costs analysis indicated that the supplementation of grazing goats is not economically viable. For future references, further research is recommended under low-cost food and negotiation to improve prices for quality of milk. [ABSTRACT FROM AUTHOR]

Management of goat herds in the Comarca Lagunera region mainly is on extensive system, feeding consist in rangeland species and agricultural waste, this provides a low input of nutrients and thereby low milk production. By this reason is necessary work up in supplementary strategies that increase goat milk production and quality. The aim of this study was to determine protected fat supplementation effect on production and chemical properties of milk in extensive grazing conditions. A total 12 lactating does were randomly assigned into three groups (control, 40 and 80 g fat). Experimental design was completely random with four repetitions. Goats had two weeks like adjustment period and ten experimental weeks. Milk samples were obtained one day in each experimental week. The variables measured were production milk and fat, protein and lactose concentration. Statistical analysis was with repeated measures model from MIXED from SAS. Supplementation with fat 40 and 80 g was no changes in milk production, protein and lactose; however, there was an effect on fat concentration since the week eight. [ABSTRACT FROM AUTHOR]

The objective was to evaluate some morphological characteristics of backyard chickens (n=255) coming from 65 rural production units located in 52 municipalities of 18 States of the Mexican Republic. The statistical model included sex, state, and municipality within state. Sex affected all the response variables (P<0.0001), except massiveness index (P=0.3369). State affected all the response variables (P<0.0001) and municipality was only important for wingspan (P<0.0001), body weight (P<0.0271) and stockiness index (P<0.0267). Male chickens had greater (P<0.0001) body length (4.85 cm more), wingspan (5.66 cm more), breast circumference (2.94 cm more), shank length (1.73 cm more), body weight (0.65 kg more) and massiveness index (0.99 percentage points) than female chickens. Body weight increased 126 g (P<0.01) in males and 61 g in females (P<0.01) for each centimeter increment in breast circumference. Body weight showed to be moderately correlated (P<0.01) with body length (r= 0.65), wing span (r= 0.49), length of the shank (r= 0.67) and highly correlated with breast circumference (r= 0.76 in males). The Mexican backyard chicken presented significant morphological differences between males and females for traits studied, except for massiveness index. [ABSTRACT FROM AUTHOR]

Data from 241 interviews collected in 2013 was analyzed to characterize populations of pigs (Mexican Hairless Pig (MH), Cuino Pig (CU) and Crossbred Pig (UD)). Variables were body weight (BW), head length (HL), body length (BL), thoracic perimeter (CG), height at withers (HW), croup width (RW), number of nipples (TC), dense or sparse hair (HD), presence or absence of tusks (TU), short or long snout (ST), upright or floppy ears (ER), calm or restless temperament (TM), proportionality index (PI), body index (BI) and relative weight index (RWI). Analyses were carried out with GLM and GENMOD of SAS. Models included state and population. Population was significant (P<0.05) for BW, BL, CG, HW, RW, TU, TM, PI, BI and RWI. Coefficients of variation (VC) showed the minor and major values for BW (18.8 %) and CG (27.8 %). VC were 13.0, 14.6 and 45.8 % for PI, BI and RWI. Least squares means for MH, CU and UD were: 48.06±6.17a, 35.93±3.04b and 61.11±7.42a kg (BW); 77.81±3.65ab, 69.56±2.02a and 88.52±4.93b cm (BL); 80.55±3.98ab, 71.72±2.20a and 93.23±5.37b cm (CG); 56.88±2.45ab, 51.26±1.36a and 60.32±3.31b cm (HW); 57±4a, 71±19b and 62±34a % (HD); 68±31ab, 70±14a and 61±27b% (TU); 65±30a, 56±12b and 62±3a% (TM). The MH and UD populations were similar in morphometry and different from the CU population. The CU population showed lower weight, smaller size and calmer temperament. The characterization of these populations is important for designing strategies for their conservation and efficient use. [ABSTRACT FROM AUTHOR]

The objective was to evaluate some morphological characteristics of backyard turkeys (n=248) coming from 126 rural production units located in 75 municipalities of 24 States of the Mexican Republic. The statistical model included sex, state, and municipality within state. The three explanatory variables affected all the response variables (P<0.01), except municipality, which did not affect breast circumference (P>0.05). Male turkeys had greater (P<0.001) body length (10.7 cm more), wingspan (11.4 cm more), breast circumference (13.8 cm more), shank length (2.5 cm more), body weight (2.5 kg more), stockiness (9.0 percentage units more) and massiveness (2.8 percentage units more) than female turkeys. Body weight showed to be highly correlated phenotypically (P<0.01) with breast circumference in both males (r=0.74) and females (r=0.71). Body length was lowly correlated with shank length (r=0.25; P<0.01) in males, but it was not correlated with shank length in females (r=0.05; P>0.05). Body weight increased 143 g in males (P<0.01) and 113 g in females (P<0.01) for each centimeter increment in breast circumference. The predominant colors in the plumage, skin and tarsus were black, white and brown, respectively. The Mexican backyard turkey presented significant sexual dimorphism and strong phenotypic correlation between breast circumference and body weight. [ABSTRACT FROM AUTHOR]