The objective of this research was to analyze the effect of GnRH applied at the beginning of estrus or in artificial insemination, considering that low fertility problems in dairy herds is one of the factors that most affects production and profitability levels. 146 Jersey cows with 2.2 lactations, 40.2 days in milk and 2.8 of body condition were used, which were synchronized with two applications of prostaglandin F2α, at the beginning of estrus, they were randomly assigned to one of three treatments, T1: GnRH/I.A; n = 51, T2: GnRH/SD; n=49; and T3: Without GnRH, the pregnancy percentage was analyzed by logistic regression with the glm procedure with the R software. The percentage of pregnancies was not different between treatments, with values of 45, 59 and 46 respectively, possibly because in this exploitation, nutrition, management, health and heat detection are optimal. Therefore, it is concluded that in the conditions in which this research was carried out, GnRH did not improve fertility.

The objective of this study was to know the economic profitability of an integral farm located in the state of Puebla, Mexico. 1000 sheep of 20.0 kg live weight on average, hybrids (F1), with 2 to 3 months of age were used. The animals were finished with a diet high in grains (90 %) and forage (10 %). The economic indicators were analyzed to know the profitability, the investment required was $1,517,295.40for fattening, which included; fixed and variable costs, depreciation was calculated in $126,522.00annualand $23,430.00 for fattening. The total income from the sale of 995 sheep of 40 kg live weight was $1,830,800.00. The net income per invested peso was 1.16, the accounting rate of return per fattening was 15.8 % and the net rate of return per year was 85.32 %. It is concluded that the fattening of sheep in an integral farm, under the conditions of this experiment, has an annual profitability of more than 80 %.

The objective of this work was to evaluate the reproductive response in Pelibuey ewes comparing the oral administration of three nutraceuticals for five days; T1; 10 g of aminosilicate with minerals, T2; 6 g of a gluconeogenic (Lipofeed), T3; 10 g of organic minerals Se and Cr in inert yeast (Biotecap) and T4; 10 ml of drinking water. All ewes were synchronized using a 5-day protocol with reused CIDRS plus prostaglandin F2α and eCG. Statistical analysis was performed using the GLM procedure of SAS and nonparametric variables using a logistic regression test. The percentage of ewes showing estrus was not different between treatments with percentages between 80 and 90. Hours to estrus was lower (P<0.05) in T1, T2 and T3 with less dispersion with respect to the mean, compared to T4 which had a higher mean. The percentage of gestation was not different between treatments with values of 70 and 80. Prolificacy was higher in T2 and T3 with values of 1.75 and 1.87 (P<0.05) with respect to T1 and T4 with values of 1.4. Blood glucose concentration was not different in T1, T2 and T3 in which less variation was also observed with respect to the mean (P<0.05) with respect to T4. It is concluded that the administration of nutraceuticals in targeted nutrition can improve some reproductive variables in ewes in anestrus, synchronized with an ultra-short protocol with reused CID¨R.