Krešimir Salajpal

Relationship between udder and milking traits during lactation in Istrian dairy crossbreed ewes

Abstract The aim of this study was to determine the udder morphology and milking characteristics changes throughout lactation during machine milking of the sheep. Additionally, udder morphology was analyzed by using slide ruler and digital picture. Milking characteristics were influenced by milking interval and day of lactation. Udder morphology traits did not change throughout lactation, except for udder width. The repeatability between slide ruler and digital picture measurements was high (r=0.53 to 0.68). Milkability in Istrian dairy crossbreed ewes could be improved if udder traits are incorporated in selection scheme. Digital picture analysis for faster recording of udder morphology measurements in sheep can be used.

Fatty acid composition of muscle and adipose tissue of beef cattle

Abstract The fatty acid (FA) composition of muscle and adipose tissue was investigated in intensively fed beef cattle. Heifers had more intramuscular fat with higher proportion of monounsaturated FA, while bulls had higher proportion of polyunsaturated FA (PUFA). The same was found in adipose tissue accompanied by higher proportion of saturated FA (SFA) in bulls. The PUFA/SFA ratio was close to recommendation for human diet only in bulls’ muscle, while n-6/n-3 PUFA ratios were generally higher than recommended. The observed FA variability between sexes was due to the differences in fatness. To improve the nutritional value, the n-3 PUFA in beef should be increased.

The Effect of Sex and Dgat1 Gene Polymorphism on Fat Deposition Traits in Simmental Beef Cattle

This study investigated diacylglycerol O-acyltransferase 1 (DGAT1) gene K232A mutation in Simmental cattle and its effects on fat deposition traits. The sample (n=26) consisted of yearling bulls and beef heifers from an intensive rearing system in Croatia. Carcass fatness was assessed by total dissection method, whereas intramuscular fat (m. longissimus dorsi) content was determined using Soxhlet extraction with hydrolysis. Intramuscular fatty acid composition was determined by gas liquid chromatography using in situ transesterification. The muscle DNA was extracted and Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCRRFLP) analysis of the 411 bp fragment of DGAT1 gene was applied. The DGAT1 K allele was less frequent in heifers than in bulls, with the overall allelic frequency of 17% K allele. Only KA and AA genotypes were obtained, without deviation from the Hardy-Weinberg equilibrium. Heifers showed a higher degree of carcass and muscle fattening with more unsaturated intramuscular fat than bulls; however, there was no interaction between sex and DGAT1 gene. Generally, no significant difference between DGAT1 AA and KA animals was observed for any of the examined traits, except the slightly higher carcass share of the fattest beef category and higher intramuscular C14:0 desaturation index in KA heterozygous.

Diversity of equine major histocompatiblity complex class II DRA locus in Posavina and Croatian Coldblood horse: a new polymorphism detected

Abstract Domestic equidae display polymorphism within ELA-DRA locus which is not characteristic for other species. We characterised sequence polymorphism present at ELA-DRA locus exon 2 and estimated allele frequencies in two autochthonous breeds, Posavina and Croatian Coldblood. In 88 horses, four different alleles were found, one of them not reported before in horses. The new allele shows non-synonymous mutation at position 65 (T→A) causing amino acid change (Phe→Tyr) in antigen binding site and synonymous mutation at position 105 (C→T). Our findings emphasize the importance of DRA polymorphism among equids and some specific DRA frequency pattern potentially specific in draught horses.

Sequence polymorphism of PrP exon 3 gene in Istrian and crossbred sheep

Abstract Polymorphisms in sheep PrP (prion protein) gene are known for scrapie susceptibility. We sequenced part of PrP exon 3 gene in 92 autochthonous Istrian (IS) and 38 crossbred sheep (CBS). ARQ, ARR and AHQ alleles were predominant with frequency of 0.674 (0.526), 0.228 (0.132) and 0.082 (0.263) in IS (CBS), respectively, while VRQ (0.011 in IS) and ARH (0.005 in IS and 0.079 in CBS) alleles were rare. We also found non-synonymous mutations at codons 112 (M→T), 127 (G→S) and 143 (H→R), and synonymous mutations at codons 231 (R) and 237 (L). Additional mutations were associated only with AHQ, ARH and ARQ alleles. The polymorphism of PrP gene in IS was not critical with respect to scrapie susceptibility and with some efforts number of “favourable” genotypes can be increased.

The effect of MC4R polymorphism on carcass composition and meat quality traits in pigs slaughter at different live weights

Abstract Commercial crossbred pigs slaughtered at different live weights were used to investigate the effect of G1426A polymorphism in the melanocortin-4 receptor (MC4R) gene on carcass composition and meat quality traits. The significant effect of G/A substitution on backfat thickness (BF; P<0.01) was observed in pigs slaughtered at high live weight (123.0±6.5kg), but not in pigs slaughtered at low live weight (99.1±3.7kg). That was accompanied by tendency of decrease (P<0.10) in estimated lean meat percentage (LMP). The BF was higher and LMP was lower in AA compared to GG genotype (P<0.01). Meat quality traits were not affected by MC4R genotype. These results suggest that GG genotype could be favourable in pigs slaughtered at higher live weights due to lower BF and higher LMP.

Proteolysis of Livanjski cheese during ripening

Livanjski cheese belongs to the group of hard cheeses which is traditionally produced in Livno (Bosnia and Herzegovina). Proteolytic changes during the ripening of Livanjski cheese have not been investigated extensively. The aim of this paper was to determine its proteolytic changes during the different stages of ripening. Five Livanjski cheeses (from raw cow’s or a mixture of sheep’s and cow’s milk) were observed during the ripening to evaluate its typical proteolytic profile. An electophoretic profile of Livanjski cheese was determined by Urea-polyacrylamide gel electrophoresis (urea-PAGE) and a densitometric evaluation of the urea-PAGE gels was performed using a densitometer. The water-soluble nitrogen fraction in the total nitrogen (WSN %TN) and the 12%-TCA-soluble nitrogen fraction in the total nitrogen (TCA-SN %TN) of the cheese were determined using the Kjeldahl method. Degradation of αs1-casein by chymosin caused a significant decrease (P < 0.05) of relative content of this protein in Livanjski cheese at the sixth week point of ripening. Due to the activity of chymosin on αs1-casein, αs1-I-casein and αs1-II-casein developed, which caused a significant increase (P < 0.05) of Index alpha. The relative ratio of β-casein significantly decreased (P < 0.05) during ripening leading to a significant accumulation (P < 0.05) of degraded product (sum γ1-casein, γ2-casein and γ3-casein). These proteolytic changes caused a significant increase (P < 0.05) of Index betta. Accumulation of medium, small peptides and amino acids caused a significant (P < 0.05) increase of the relative content of WSN %TN and TCA-SN %TN. In general, proteolysis of Livanjski cheese during ripening was moderate probably due to the low moisture content and low water activity, although it was produced from raw milk. Taking into account that the ratio β-casein : αs1-casein at the end of ripening was 1.46, it could be concluded that degradation of αs1-casein could be the indicator of the maturity of Livanjski cheese. Due to that Livanjski cheese could be classified as “α-type of ripening” cheese.

Characteristics of calves rearing in northern Croatia

The aim of this study was to investigate characteristics of calves rearing technologies at family farms in northern Croatia (Varazdin and Medjumurje County). Calves up to eight weeks of age at family farms in Varazdin County were kept mostly tied (57.7%). After eight weeks of age, calves in both analysed Counties are dominantly kept tied. First colostrums ration was given to calves within first three hours after calving, i.e. on 99.2% of analysed farms in Varazdin County and 90% of analysed farms in Medjimurje County. On the majority of farms colostrums is given to the calves in amount of 1-1.5 litres (51.9% Varazdin, i.e. 65% Medjimurje County). Freezing of colostrum is done at 10.5% of analysed farms in Varazdin and 15% of analysed farms in Medjimurje County. In Varazdin County farmers feed calves with milk or milk replacer significantly longer (P<0.001) than farmers in Medjimurje County. Consequently, calves in Medjimurje County consumes significantly lower quantities of milk or milk replacer (P<0.001). Calves in the Medjimurje County are significantly earlier fed with solid feed: hay (P<0.05), pre-starter or starter (P<0.001), and water (P<0.001) than on farms at the Varazdin County. Total mixed ratio (TMR) was used neither in Varazdin nor in Medjmurje County in calves’ nutrition, and colostrums quality was checked only at 3% of farms in Varazdin County (4 farms), and only at one farm in Medjimurje County.

The impact of changes in the milk payment system and season on the hygienic quality of milk

The aims of this paper were to investigate the impact of changes in the milk payment system and the season on the hygienic quality of raw milk. The bulk cow’s milk samples were collected throughout the whole area of Bosnia and Herzegovina over the period of four years (2010-2013), from farms that deliver milk to the dairy industry. The total bacterial count (TBC) was analysed in 52,999 milk samples and the somatic cell count (SCC) in 53,363 milk samples. The results of the research showed that the proportion of bulk milk with the SCC < 300,000 mL-1 significantly increased in the observed period, as well as the proportion of farms that produce milk of EU quality (P < 0.05). The season had a significant effect (P < 0.05) on the SCC; in April the proportion of bulk milk with SCC < 300,000 mL-1 was significantly higher (P < 0.05). A significant increase (P < 0.05) in the proportion of milk with the TBC < 200,000 cfu∙mL -1 was perceived, as well as the proportion of farms which deliver that type of milk (P < 0.05). A Significant lower (P < 0.05) proportion of milk in the summer period with TBC < 200,000 cfu∙mL-1 was determined. It can be concluded that consistent appliance of regulations which determine the quality of milk, leads to the improvement of the hygienic quality of redeemed milk, as illustrated by the case of Bosnia and Herzegovina. This kind of milk payment system is important for both, the higher economic benefit of farms and the dairy processing industry.

Influence of different quantities of rapeseed meal and calcium on production results of broiler chicks

Abstract The aim of this research was to establish the influence of different quantities of rapeseed meal (RM) and calcium in feed mix on productive performance of 360 chicks divided in 12 groups during the 42-day experiment. It was found that chicks in group C (0% of RM) and E3-5 (10% of RM) achieved significantly (P<0.05) higher body gains than those in groups E6-11 (20 and 30% of RM) at the end of the experiment. In the same time average body weights of groups Ec,3,6,9 (0.8% of calcium) were significantly (P<0.05) higher than those in groups E1,4,7,10 (1.0% of calcium) and groups E2,5,8,11 (1.2% of calcium). We can conclude that 10% of RM in broiler diet didn’t have a negative effect on the production results. More than 0.8% of Ca in the broiler diet caused lower live weight.