FACTORES QUE AFECTAN LA PRODUCCI 3N TOTAL POR LACTANCIA DEL MESTIZO HOLSTEIN - BRAHM\uc1N EN CONDICIONES DE BOSQUE SECO TROPICAL

En el presente trabajo se determinaron los factores que influyen sobre la producci\uf3n total por lactancia del mestizo Holstein - Brahm\ue1n en condiciones ambientales de Bosque Seco Tropical. Los animales estudiados est\ue1n ubicados en una explotaci\uf3n comercial del Municipio Aut\uf3nomo Monay del estado Trujillo, un \ue1rea que corresponde a una zona de vida con temperatura media anual de 27,9\ub0C, humedad relativa de 71,0% y una pluv\uedosidad que var\ueda entre 1.000 y 1.280 rnm/a\uf1o. El grupo experimental estuvo conformado por 81 vacas Vi Holstein - lA Brahm\ue1n y 51 vacas 3/+ Holstein - 'A Brahm\ue1n, de una poblaci\uf3n total de 340 vacas mestizas Holstein - Brahm\ue1n. Utilizando el Modelo Lineal General (GLM) y el an\ue1lisis de varianza-covarianza del Sistema de An\ue1lisis Estad\uedstico (SAS\uae), se consider\uf3 el efecto de los factores: Producci\uf3n promedio por lactancia (PPL), duraci\uf3n de la lactancia (DL), n\ufamero de lactancias (NL), d\uedas secos (DS), mes de secado (MS), mes de parto (MP), a\uf1o de parto (AP) e \uedndice temperatura -humedad (ITH) sobre la producci\uf3n total por lactancia (PTL) y corregida a 305 d\uedas (PTL305). La PTL (4.214,5 Kg.) y PTL305 (4.581,6 Kg.) para el media sangre, fueron afectadas significativamente (p ABSTRACT(Factors that affect total milkproductionper lactation of Holstetn-Brahman Crossbred Catite under Tropical Dry Forest conditions) In this project, the factors that affect total mitk production per lactation of Holstein-Brahman crossbred cattle under Tropical Dry Forest conditions were studied. Anim\ue1is on the study were located on a commercial farm at Monay County. Trujillo State, a zone were annual media temperature is 27.9\ub0C, relative humidity is 71.0% and rainfall var\uedes between 1,000 and 1,280 mm/year. Experimental groups consisted of 81 Vi Holstein Vi Brahm\ue1n cows and 51 V* Holstein V* Brahm\ue1n cows. Using the General Lineal Model (GLM) and variance - covariance analyses of SAS\uae the effect of the following factors on Total Milk Production per Lactation (PTL) and Milk Production corrected to 305 days (PTL305) were analyzed: Mean Production per Lactation (PPL), Days on Lactation (DL), Number of Lactation (NL), Dry Days (DS), Dry Month (MS), Month of Calving (MP), Year of Calving (AP) and Temperature-Humidity \uedndex (ITH). PTL (4,214.5 Kg.) and PTL305 (4,581.6 Kg.) of Fl cows were statistically affected (p<0.0001) by PPL, NL, DL, DS, MS, MP and AP. On the other hand, PTL (5,147.8) of the 3\uc1 Holstein cows were affected (p