Possible effects of the MC4R Asp298Asn polymorphism on pig production traits under ad libitum versus restricted feeding.

The missense mutation Asp298Asn in the melanocortin 4 receptor (MC4R) is associated with daily gain or fatness in pigs (Sus scrofa domesticus). However, to the best of our knowledge, no study has directly compared the effects of the polymorphism between different feeding levels, even though diet plays a vital role in the swine industry. To explore possible differences, data from 439 mostly commercial hybrids fattened ad libitum and 119 commercial hybrids fattened with restricted feed ration were collected. The recorded traits were average daily gain (ADG), feed conversion ratio (FCR), carcass weight (CW), dressing percentage (DP), lean meat content (LM), backfat thickness (BFT), lean cuts weight, and meat quality parameters such as pH, temperature, drip loss, and CIELAB colour space. The general linear model revealed that the overall effect of MC4R was not statistically significant, but significant differences (p < 0.05) were found in ADG, FCR, CW, DP, LM, and BFT. In the ad libitum category, the AA genotype (298Asn/298Asn) tended to be the most favourable for growth-related traits, with the lowest LM, which is consistent with previous findings. In the restricted category, on the other hand, GA heterozygotes (298Asp/298Asn) achieved the best performance in terms of growth, whereas AA homozygotes showed the worst performance. Therefore, these results raise the possibility of an interaction between MC4R and the feeding level.

Changes of Androstenone Concentrations in Saliva of Boars with Age.

With the increasing age of boars, the possibility of androstenone (5α-androst-16-en-3-one (AND), 5α-androst-16-en-3α-ol (α-AND), and 5α-androst-16-en-3ß-ol (ß-AND)) occurrence increases as well. The aim of this study was to evaluate concentrations of androstenone compounds in the saliva of boars concerning the age of animals. In total, 72 boars were evaluated (24 boars per replication). The effect of age (three different ages-152, 163, and 172 days) was observed, and (Landrace × Large White) × Pietrain genotypes were used. Chemical analysis of saliva samples was conducted by multidimensional gas chromatography/mass spectrometry (MDGC/MS). Salivary α-AND increased with age (p < 0.05), and positive correlations were found between age and submaxillary salivary gland weight (p < 0.05), age, and salivary AND concentration (p < 0.05), body weight and submaxillary salivary gland weight (p < 0.05), submaxillary salivary gland weight and salivary ß-AND concentration (p < 0.05), as well as submaxillary salivary gland weight and total salivary 5α-androstenone (AND total) concentration (p < 0.001). Nowadays, animal welfare is becoming a more and more discussed topic, and pig breeding is not an exception. Specifically, the castration ban is a current issue, so it is very important to know as much as possible about compounds responsible for boar taint. Androstenone's appearance in boars' saliva could be one of the most important precursors for future early detection of boar taint.

Changes in Fatty Acids Profile, Health Indices, and Physical Characteristics of Organic Eggs from Laying Hens at the Beginning of the First and Second Laying Cycles.

The present study compared the fatty acid profile and some physical parameters of eggs from hens reared according to the organic system at the beginning of the first and second laying cycle. A total of 1080 eggs were analysed at the beginning of the first (from the 28th to 30th week of age) and the second (from the 78th to 80th week of age) laying cycle. It was found that the hen ages influenced the egg weight, egg surface area, yolk proportion, and eggshell colour. Albumen and eggshell proportion, albumen, yolk index, Haugh unit score, and eggshell strength were lower in eggs from older hens compared with those produced from younger layers. Monounsaturated fatty acids were found in higher amounts than saturated fatty acids and polyunsaturated fatty acids in egg yolks of eggs from layers only at the beginning of the second laying cycle. The PUFAn-6/n-3 ratio, saturation, atherogenic, and thrombogenic indices were significantly lower in the egg yolks from older hens compared to younger layers. These findings (regarding the eggs from the older ones) prove that it is practical to utilize them in the organic farming system during a period of two years.

Guinea fowl (Numida meleagris) eggs and free-range housing: a convenient alternative to laying hens' eggs in terms of food safety?

The aim of this study was to evaluate the impact of the genotype (guinea fowl, native breed Leghorn, and commercial hybrid hens), storage time (0, 14, 28 d) and storage temperature (fresh, 5, 20°C) on eggshell quality traits and microbiological contamination of eggshell, eggshell membranes, and albumen. A total of 150 hens (50 hens per genotype-divided into 2 equal groups because of the results replication) were used. There were 150 eggs (50 per genotype) used for microbial analysis and 600 eggs used for the analysis of eggshell quality. The effects of genotype, storage time, and storage temperature were observed. Moreover, interactions between these factors were calculated. The significant effect of genotype (P = 0.0001) was found in egg weight, in all observed parameters of eggshell quality (proportion, thickness, strength, surface, and index), eggshell contamination of Escherichia coli (EC) and total number of micro-organisms (TNM), penetration of TNM into eggshell membranes (P = 0.0014), and penetration of TNM into albumen (P = 0.0019). Storage time significantly affected egg weight and all parameters of eggshell quality except the eggshell strength and index. It also significantly affected count of Enterococcus (ENT) on eggshell, TNM in eggshell membranes and TNM in albumen. Storage temperature significantly influenced egg weight (P = 0.0001) and all parameters but eggshell thickness and surface. Regarding the microbial contamination, storage temperature significantly affected a count of ENT on shell, TNM in shell membranes, and TNM in albumen. Concerning significant interactions, the interaction among genotype and storage time was found significant (P = 0.0148). Fresh and 28-day-old commercial hybrid eggs were the most contaminated, whereas guinea fowl eggs (fresh and 14 d old) and Leghorn hen eggs (fresh, 14, 28 d old) had the lowest level of contamination by EC. When looking for an alternative to laying hens, guinea fowls should be taken into consideration due to their higher resistance to diseases, ability of adaptation to different environmental conditions, and especially in terms of eggshell quality and therefore egg safety.

Negative Energy Balance Influences Nutritional Quality of Milk from Czech Fleckvieh Cows due Changes in Proportion of Fatty Acids.

The objective of this study was to evaluate the influence of negative energy balance on fatty acids proportion in the milk of Czech Fleckvieh cows after calving. Milk quality was determined based on fatty acid group proportion. Milk quality was evaluated in relation to selected negative energy balance (NEB) traits: body condition change (DEC) and milk citric acid content (CAC) after calving. Milk samples (n = 992) were collected once per week from 248 Czech Fleckvieh cows during the first month of lactation. Fatty acid content (%) in milk samples was determined and results were grouped as saturated (SFA) (hypercholesterolemic or volatile fatty acids) or unsaturated (UFA) (monounsaturated or polyunsaturated). Our results showed that cows with a deep NEB produce milk that is healthier for human consumption. Cows with a more significant DEC or the highest level of CAC in milk had the lowest proportion of SFA and the highest proportion of UFA (p < 0.01). These cows experienced higher physiological stress after calving; however, they produced milk of higher nutritional quality. Nowadays, we can see preventive efforts to mitigate NEB periods as a result of modern breeding trends regarding vitality, robustness, or longevity.

The Effect of Dietary Helianthus tuberosus L. on the Populations of Pig Faecal Bacteria and the Prevalence of Skatole.

Jerusalem artichoke contains inulin polysaccharide, which has prebiotic effects and influences the microbiota of the digestive tract. The addition of Jerusalem artichoke in boar diets may decrease the content of skatole and indole, which are the main constituents of boar taint, and may also negatively affect the taste and odor. The objective of this study was to evaluate the effects of different levels of Helianthus tuberosus L. (H. tuberosus) in feed mixtures on performance, carcass composition, the levels of microbiota in faecal samples, and the concentrations of skatole and indole in adipose tissue. The study was performed with 47 crossbred entire male pigs of the Large White sire × (Large White dame × Landrace) genotype fed a basal diet with 0%, 4.1%, 8.1% or 12.2% H. tuberosus for 13 days before slaughter. Significant differences in daily weight gain and daily feed intake were found (p = 0.045), with the values being lower in the group with the highest level of H. tuberosus. In addition, increasing levels of H. tuberosus decreased the concentration of skatole in the adipose tissue (p = 0.003). The highest level of H. tuberosus decreased the level of Escherichia coli (p ≤ 0.001) in the faeces. The enterococcal count increased (p = 0.029) in groups with a diet that included 4.1% and 8.1% H. tuberosus. There was also a significant correlation between the concentration of H. tuberosus and the concentration of E. coli (p < 0.001; -0.64) and the skatole levels in the adipose tissue (p = 0.001; -0.46). Moreover, there was also a positive correlation between the concentration of E. coli and the skatole levels in the adipose tissue (p = 0.023; 0.33). In conclusion, feeding pigs with H. tuberosus leads to decreased levels of skatole in the adipose tissue. According to the results of our study, a diet with 8.1% H. tuberosus is sufficient for decreasing skatole levels, which could be due to the decreased levels of pathogenic bacteria in the intestines.

Effect of Duration of Dietary Rapeseed and Soybean Oil Feeding on Physical Characteristics, Fatty Acid Profile, and Oxidative Stability of Pig Backfat.

This study compared the effect of two vegetable oils and their feeding duration on pig backfat quality. The experiment was conducted with 60 DanBred pigs that were fed a diet supplemented (40 g/kg) with rapeseed or soybean oil for 2, 4 or 6 weeks before slaughter at 152 d of age. The supplementation of both vegetable oils in the diets for 6 weeks negatively changed backfat consistency. The pigs fed soybean oil for 4 (17.64%) and 6 weeks (18.52%) before slaughter showed an increase in backfat linoleic acid content (p = 0.002), whereas, in contrast to the other groups, rapeseed oil in the diet for 6 weeks (2.38%) increased α-linolenic acid content (p = 0.039). The content of PUFAs (p = 0.024) and n-6 PUFAs (p = 0.003) was increased by adding soybean oil to the diet for 4 and 6 weeks. The ratio of n-6/n-3 PUFAs was decreased (p = 0.040) by supplementing rapeseed oil for 4 and 6 weeks. The oil feeding duration decreased (p < 0.001) the atherogenic and thrombogenic indices. The lipid oxidative stability of backfat stored for 3 and 5 days increased (p < 0.001) in pigs fed dietary vegetable oils for 6 weeks prior to slaughter. In conclusion, the feeding of rapeseed oil for 4 weeks before slaughter is sufficient for improving the FA profile without negative effect on the consistency of the backfat.

Association analysis of SNPs in the porcine CYP2E1 gene with skatole, indole, and androstenone levels in backfat of a crossbred pig population.

The occurrence of boar taint in meat from uncastrated males may significantly affect the economics of pork production. The aim of this study was to analyse associations of four single nucleotide polymorphisms (SNPs) in the porcine CYP2E1 gene with skatole, indole, and androstenone levels in the Czech Large White-Czech Landrace commercial crossbreds. The SNPs were: g.2412C>T, c.1422C>T, c.1423G>A and c.*14G>T. Skatole, indole and androstenone levels were estimated by HPLC, and genotypes at the SNPs were determined by PCR-RFLP. SNPs c.1423G>A and c.*14G>T were in complete linkage disequilibrium. In boars, all SNPs were associated with the indole levels (P<0.05; P<0.01). There also were differences in the skatole levels in different genotypes, but these were not significant. No associations with androstenone levels were found. The associations of the SNPs with indole compounds should be studied in other commercial populations of boars to verify the favourable alleles and genotypes, with the prospect for their application in marker-assisted selection.