Pero Mijić

Influence of temperature-humidity index (THI) on daily production of dairy cows in Mediterranean region in Croatia

With the aim of analysis the influence of temperature-humidity index (THI) on daily performance of dairy cows in Croatian Mediterranean region, 217,509 test-day records collected from January 2005 until April 2010 were extracted from HPA (Croatian Agricultural Agency) database. Milk recording in Croatia occurs according to the alternative milk recording method every four weeks, therefore, daily production of milk yields and components was projected using projection parameters estimated in authors’ earlier research (Gantner, 2008). Logical control of data was performed according to ICAR standards (2003). The yields recorded after the 500th lactation day was deleted from the dataset. According to the parity, cows were divided into three classes (heifers, cows in second lactation and cows in third and higher lactations) while, regarding the calving date, cows were divided in two calving season subgroups. According to the test date, four measuring season subgroups were created. Based on temperature and relative humidity recorded in stable at each milking control the daily temperature-humidity index (THI) values were calculated using the equation by Kibler (1964). For estimation of the influence of exceeded THI (above critical value -72) on daily production of dairy cows statistical model that take into account effects of lactation stage, breed, calving season, measuring season as well as effect of THI group (T1 - THI under critical value; T2 - THI above critical value). The significance of differences between the means of the daily milk, fat, protein and lactose yield, as well as between the means of the daily fat, protein, and lactose content within the THI classes in regard to parity classes was tested with Scheffe test. For the statistical analysis and the figures drawing the SAS/STAT package was used (SAS Institute Inc., 2000). The exceeded THI significantly decrease daily milk, fat, protein and lactose yield in heifers and cows in third and higher lactations. In second lactation determined decrease was not significant. Highly significant decrease of daily fat and protein content was determined in all cows, regardless the parity. The daily lactose content was not significantly influenced by enhanced value of THI. Management strategies are needed to minimize heat stress and to attain optimal cows’ production in climatic condition of Croatian Mediterranean region.

The farm model production in Mediterranean Croatia

Models of farm production in the Mediterranean part of Croatia are special because they use traditional technologies and breeds at a significant level, respect consumer behaviour, and take care of the environment and its biodiversity. According to economic importance and impact on the environment, sheep production is dominant, followed by cattle production, while pig and poultry production are slightly present. Autochthonous sheep breeds of a smaller body frame are dominant and their main product is lamb meat. They produce from 70 to 300 kg milk per year. Dairy cattle production uses moderate levels of production intensification, modern technology and allochthonous genotypes. In beef production profiling of recognizable types of beef with the principles of organic production in the autochthonous breeds is noticeable. The main food sources for sheep and cattle production are Mediterranean pastures and grasslands, which partially limit the production, but on the other hand enrich the final product. Numerous recognizable animal products are part of the rural, gastronomic and touristic offer, and preserve their way of production in accordance with traditional heritage. Farm production does not distort the ecological harmony of the region, thanks to the traditional production technologies. Awareness of the need to maintain the tradition, recognition, economic vitality of rural areas, habitat quality and entire biodiversity is growing. Experiences in animal production in the Mediterranean part of Croatia point to effective models which combine traditional and new technological experiences in autochthonous breeds, with respect to consumer demands.

Influence of housing systems on stillbirth and mortality rate in preweaning pigs farrowed by different gilt breeds

Abstract The aim of this paper was to investigate the influence of housing systems on stillbirth and mortality rate in preweaning pigs farrowed by different gilt breeds. The investigation included first farrowings of 225 Large White (LW) gilts, 297 Swedish Landrace (SL) gilts and 260 crossbreed gilts (LWxSL) in the period of five years. Despite of positive influence of straw through decreased number of stillborn pigs, especially in LW gilts, in further process of production until weaning, less appropriate microclimatic conditions developed in farrowing houses with straw, especially if accompanied with poor ventilation, can result with higher number of perished pigs and lower number of weaned pigs. Most sensible to unsuitable microclimatic conditions in straw bedded farrowing houses, according to the number of perished pigs before weaning, were the pigs from SL gilts, while the pigs from crossbreed gilts LWxSL were the most resistant. These results suggest that adding straw requires special attention on influence of such production on microclimate conditions in pigs’ biozone in order to maintain its initial benefits in the time of farrowing through the whole preweaning period, especially in pure breeds of gilts.

Individual and combined usage of enzyme preparation and heat-treated cereals in pig fattening

In order to reach better production and financial results of pork production different technological ways of pig fattening are researched. The purpose of this paper is to show separate results of polyenzyme application and the results of the use of heat-treated cereals in pig fattening as well as the results of their combined applica - tion. Pigs fattened on a diet with polyenzyme preparation and heat-treated cereals, either separately or combined, were characterised by an insignificantly higher growth rate and their feed intake per kilogram of weight gain was low compared to pigs fed standard mixtures (control group). In statistical terms, the relative portion of muscle tissue in pork carcass was significantly lower in experimental group 3 fed the mixture with heat-treated cereals than in the other groups. The absolute portion of muscle tissue in pork carcass was statistically more important in experimental group 2 (45.15 kg) receiving the mixture of enzyme additive and heat-treated cereals, and the least important in experimental group 3 (40.92 kg) fed heat-treated cereals. During pig fattening the income for experimental groups was higher than for the control group because of better production results. Average values covering variable expenses show the increase only in the third experimental group in the second fattening period compared to the control group, but these differences were of no statistical importance.