Association of single nucleotide polymorphisms in fat metabolism candidate genes with fatty acid profiles of muscle and subcutaneous fat in heavy pigs.

Dietary and organoleptic qualities of pork products are largely influenced by the profiles of fatty acids (FAs) of meat and fat. The objective of this work was to investigate the potential associations between FA profile in subcutaneous adipose (back fat and leg fat) and muscular (longissimus dorsi and biceps femoris) tissues in heavy pigs (n = 129, 9-month-old) with single nucleotide polymorphisms (SNPs) in six candidate genes involved in fat metabolism: Stearoyl-CoA desaturase (SCD), Diacylglycerol acyltransferase 1 and 2 (DGAT1 &DGAT2), Microsomal Triglyceride Transfer Protein (MTTP), Fatty Acid Synthase (FASN) and Heart- fatty acid binding protein (H-FABP). Preliminary results suggest a putative association between MTTP, DGAT2 and FASN and the FA content in both fat and meat, whereas between DGAT1, SCD and H-FABP the association was found in adipose tissue only. However, the effect of the analyzed genes, needs to be verified in a larger and better characterized pig population to support the hypothesized associations with FA content.

Development of genetic and genomic evaluation for wellness traits in US Holstein cows.

In March 2016, Zoetis Genetics offered the first commercially available evaluation for wellness traits of Holstein dairy cattle. Phenotypic data on health events, pedigree, and genotypes were collected directly from producers upon obtaining their permission. Among all recorded health events, 6 traits were chosen to be included in the evaluation: mastitis, metritis, retained placenta, displaced abomasum, ketosis, and lameness. Each trait was defined as a binary event, having a value of 1 if a cow has been recorded with a disorder at any point during the lactation and zero otherwise. The number of phenotypic records ranged from 1.8 million for ketosis to 4.1 million for mastitis. Over 14 million pedigree records and 114,216 genotypes were included in the evaluation. All traits were analyzed using univariate threshold animal model with repeated observations, including fixed effect of parity and random effects of herd by year by season of calving, animal, and permanent environment. A total of 45,425 single nucleotide polymorphisms were used in the genomic analyses. Animals genotyped with low-density chips were imputed to the required number of single nucleotide polymorphisms. All analyses were based on the single-step genomic BLUP, a method that combines phenotype, pedigree, and genotype information. Predicted transmitting abilities were expressed in percentage points as a difference from the average estimated probability of a disorder in the base population. Reliabilities of breeding values were obtained by approximation based on partitioning of a function of reliability into contributions from records, pedigree, and genotypes. Reliabilities of genomic predicted transmitting abilities for young genotyped and pedigreed females without recorded health events had average values between 50.2% (displaced abomasum) and 51.9% (mastitis). Genomic predictions for wellness traits can provide new information about an animal's genetic potential for health and new selection tools for dairy wellness improvement.

Polymorphism of fat metabolism genes as candidate markers for meat quality and production traits in heavy pigs.

High meat quality is required for dry-cured ham production, which quality depends on meat fat quantity and composition. The aim was to study the polymorphisms of six genes involved in fat metabolism, namely, Stearoyl-CoA desaturase (SCD), Diacylglycerol acyltransferase 1 and 2 (DGAT1 &DGAT2), Microsomal triglyceride transfer protein (MTTP), Fatty acid synthase (FASN) and Heart fatty acid binding protein (H-FABP) in two traditional (Large White or Duroc × (Landrace × Large White)) and two industrial hybrids (Goland and Danbred), which are used for dry-cured ham production. Significant associations of SCD and MTTP were found with carcass weight. DGAT2 was associated with back fat thickness and L* fat colour (objective white colour score). Several genes (DGAT2, MTTP &FASN) were associated with weight loss during salting, first step in dry-cured ham production, affecting final yield. Finally, MTTP was associated with shear force. Our findings suggest that the SCD, DGAT2, MTTP and FASN polymorphisms are associated with quality of heavy pig meat products.

Metabolic and biochemical changes in plasma of the periparturient rabbit does with different litter size.

The aim of this study was to investigate the metabolic and biochemical changes in plasma that occur in the reproductive rabbit doe close to the parturition, as well as if the number of offspring affects the metabolism and the health status of the doe. At -3, 4 and 12 days from parturition (-D3, D4, and D12, respectively) nine rabbit does at their third parity from a commercial hybrid line (HYPLUS PS 19) selected for high prolificacy were weighted and blood was collected for a wide inflammometabolic profile. According to the number of offspring the does were retrospectively divided in two groups: high litter size group (HI; n=5) and low litter size group (LO; n=4). BW was higher (P<0.01) at -D3 and had the lowest values at D4. At D12, the BW was lower (P<0.05) in LO compared with HI. Several metabolites significantly changed from dry to lactation period. Glucose and cholesterol had the lowest levels at -D3; non-esterified fatty acid (NEFA) and aspartate aminotransferase had the highest values before parturition (P<0.05); creatinine and ß-hydroxybutyrate (BHBA) were higher at -D3 with respect to D4 (P<0.05). The lowest value of paraoxonase was observed in does at -D3 (P<0.05), whereas at this time ceruloplasmin and total bilirubin had the highest concentration (P<0.05). The differences for blood profile parameters between does grouped according to litter size were mainly evident before parturition (-D3). In particular, BHBA, NEFA and total bilirubin had higher concentrations (P<0.05) in HI v. LO group, whereas albumin and PON were lower in HI group (P<0.01). After parturition there were no significant differences for the metabolic parameters between the two groups. The results show that for reproductive rabbit doe the last days of gestation are very stressful from a metabolic and inflammatory point of view. The genetic selection of does for higher litter size has increased their ability to mobilize body reserves in order to guarantee the nutrients to a high number of kits. This exposes them to a more severe metabolic and inflammatory challenge during the transition period. Consequently, feeding and managerial strategies for high prolificacy periparturient rabbit does should be revised.

Plasma and follicular fluid fatty acid profiles in dairy cows.

Composition of follicular fluid to which the preovulatory follicle is exposed may be one of the major factors determining subsequent fertility, as fatty acids are a precursor of hormones involved in dominance, ovulation and atresia mechanisms. The objective of this paper is to observe fatty acid profiles in various lipid classes according to estrogenic activity of follicles. For each of the 18 cows, we analysed plasma and follicular fluid fatty acid profiles of phospholipids, non-esterified fatty acid (NEFA), cholesteryl esters and triglycerides fractions. Follicles were classified as active (ratio oestrogen to progesterone E2/P4 > 1) and inactive (E2/P4 < 1). For seven cows, we get both types of follicles, six had only one active follicle and five cows had only one inactive follicle. The NEFA profile for palmitic acid, stearic acid, oleic acid, linoleic acid, C20:3n6, arachidonic acid and docosapentaenoic acid (DPA; p < 0.001) is different between inactive and active follicles and plasma. Compared with active follicular fluid and plasma, follicular fluid of inactive follicles showed lower stearic acid, higher oleic acid, arachidonic acid and DPA (p < 0.05) in phospholipids. No significant differences were observed in the cholesteryl ester fraction, which is composted mainly of linoleic acid. Triglyceride concentrations were too low to get reliable results. This study suggests that follicles have a specific fatty acid metabolism depending on oestrogen activity.