Reproductive and production performance of a dairy herd Gir

Abstract

The race Gir is used in order hardiness and productivity of half the face of adversity of environment. The gain genetic in characteristics of interest economic depends on the efficiency reproductive and productive. In this context, the adoption of statistical methodologies applied to databases established by zootechnical control becomes indispensable to the knowledge of reproductive and productive performance of livestock. Thus it is possible to evaluate the existing situation and propose solutions to identified deficiencies. The data used were derived from zootechnical control adopted in the Farm 5R, Conceição das Alagoas, Minas Gerais, for the period from June 2004 to October 2009. The property is integrated with the Brazilian Association of Zebu Breeders (ABCZ) and the Brazilian Association of Breeders of Dairy Gir (ABCGIL). Used the statistical program SAS and the program Microsoft Excel for the formation of archives, consistency and descriptive data analysis. The aim of this study consisted of descriptive statistical evaluation of variation involving reproductive and productive traits of Dairy Gir cattle, based on the zootechnical control computerized adopted on the property, proposing to know the profile of the reproductive and productive traits of the livestock. The mean for age at first calving was 1560.04 days (52 months), standard deviation of 478.65 days (15.95 months), the most frequent value of 1453 days (48.43 months), and coefficient of variation of 31% in 56 observations processed. The average recorded for calving interval was 509.50 days (16.98 months), standard deviation of 112.50 days (3.73 months), the most frequent value of 566 days, coefficient of variation of 22 % on 101 observations processed. The mean and standard deviation of the duration of the gestation period were 281.80 ± 6.63 days (9.39 ± 0.22 months), the most frequent value of 285 days (9.5 months), and coefficient variation of 2%, in 99 analyzed records. The mean for the production of milk in 305 days of lactation was 2636.18 kg, standard deviation of 1248.18 kg, coefficient of variation of 47% in 198 lactations processed. The mean and standard deviation observed for fat yield in 305 days of lactation were 76.90 ± 39.11 kg, coefficient of variation of 51% in 99 lactations analyzed. It was concluded that: the average age at first calving was found to be too late and the mean calving interval, too long, with possible repercussions on the profitability of the exploitation; the average gestation period was slightly lower than those generally reported in the literature and presented the existence of small amplitude of physiological variability among individuals, as it is a little quantitative trait phenotypically variable; the production of milk in 305 days of lactation showed a satisfactory performance of productive behavior of the herd, which did not occur to produce fat in 305 days of lactation. This performance of the production of milk in 305 days of lactation can be considered satisfactory taking into account the breed involved and some deficiencies found in the general management of creation.