Effect of the rearing system on financial returns from Murciano-Granadina breed goats

Abstract

[EN] In dairy goats, the kid rearing system can have critical importance in financial returns. Commonly used criteria for the choice of rearing system are not always clear due to the high number of factors involved. The aim of this study was to quantify all those factors to facilitate decision making. So, the effect of two different kid rearing systems, mixed (MRS) and artificial (ARS), on milk yield, milk composition and somatic cell count (SCC), milk yield loss at weaning for MRS, kid growth and costs of the different traits on the financial returns in Murciano-Granadina breed goats was studied. Twenty-four goats per group were used. In the MRS, goats reared only one kid, which had free access to goat milk 24 h a day and were weaned at week 6 of lactation, whereas kids in the ARS were separated from their mothers at kidding, colostrum and artificially reared. In both systems, dams were machine-milked once a day throughout lactation and the records took place weekly. Potential milk yield was estimated according to the oxytocin method up to week 12 of lactation, and was similar for both rearing systems, although a 12.3 per cent drop in potential milk yield at weaning was observed for MRS. During the first 6 weeks of lactation, marketable milk was lower for dams in MRS compared to those in ARS (72.1 versus 113.0 l), but similar for the rest of the experiment (101.5 versus 99.4 l, respectively). Marketable milk composition and SCC throughout the 12 weeks of lactation were unaffected by the rearing system. Artificial rearing system entailed an increment in production cost of 22.2 € per kid compared to the rearing by MRS. A similar economic return per goat and kid was obtained from ARS and MRS in this experiment, although, due to one herd¿s prolificacy of 1.8, the actual results would be 16.2 € per goat in favour of MRS. The real interest of this experiment may be the possibility of extrapolation to different flocks with diverse levels of milk production, prolificacy and prices and costs for incomes and outputs, to estimate the production system that increases returns. In conclusion, the results showed an increase in the cost of € 22.2 per kid bred in the artificial rearing system, compared to the mixed rearing system, and a final return of 16.2 € per goat in favour of the mixed system.