Temporal changes in milk fatty acid distribution due to feeding different levels of rolled safflower seeds to lactating Holstein cows

Reporting temporal fluctuations of hepatic C16 and C18 fatty acids during late gestation and early lactation in dromedary camel

Based on current knowledge, C16 and C18 fatty acids (FA) are considered the most functional FA in hepatic metabolism. Although these FAs have been satisfyingly investigated in cattle, other species such as camel have been neglected. For this reason, the current study was designed to scrutinize changing patterns of C16 and C18 FAs in 10 dromedary camels from the last 2 months of gestation to the first months of lactation. Camels were grazed on natural pasture and supplemented with a balanced ration. Liver biopsies were obtained through blind biopsy technique at about 60, 45, 30, and 15-day antepartum (AP), and at 3, 15, 30, 45, and 60 post-partum (PP). Data were analyzed by the ANOVA procedure of SPSS with repeated measurements. From 15-day AP, saturated FA content of the liver declined (P < 0.01) and 15-day PP reached its peak (P = 0.02). At 30-day PP it went down (P < 0.01), and re-elevated at 45-day PP (P < 0.01) but remained at a steady state for the duration of the study. Mono-unsaturated and polyunsaturated FA content of hepatic tissue were constant throughout AP, albeit observed to peak at 15-day AP compared with 45 (P = 0.04) and 30-day AP (P < 0.01) for mono-unsaturated FAs, and with 60-, 45-, and 30-day AP (P ≤ 0.01) for polyunsaturated FAs. The palmitic acid content of the liver reached a nadir at 30-day AP (P < 0.01), increased sharply (P < 0.01) at the next sampling time-point, and had a trend to escalate until 3-day PP. Palmitoleic acid levels were unchanged from 60- to 30-day AP, decreased at 15 AP and 3-day PP, increased at 15-day PP, then remained constant until the end of the study period (P ≤ 0.04). Stearic acid content started to grow at 15-day AP and reached its peak at 15-day PP (P < 0.01). At 30-day PP, stearic level in liver dropped abruptly (P < 0.01), then intensified at 45-day PP and did not change after; hepatic content of stearic acid was lower during AP compared with PP time-points. Other C18 FAs changed significantly during the study period. These results suggest that parturition could have a profound effect on FA composition and other metabolites in camel liver. Further research is required to establish the metabolic mechanism behind these changes.

Supplementing Dairy Ewes Grazing Low Quality Pastures with Plant-Derived and Rumen-Protected Oils Containing Eicosapentaenoic Acid and Docosahexaenoic Acid Pellets Increases Body Condition Score and Milk, Fat, and Protein Yields

The Australian dairy sheep industry is small and mostly based on a natural grass grazing system, which can limit productivity. The current study tested different plant oil-infused and rumen protected polyunsaturated fats and their interactions with sire breeds to improve lactation traits and body condition scores (BCS) of ewes grazing low quality pastures. It was hypothesised that supplementing lactating ewe's diets with plant-derived polyunsaturated oils would improve milk production and composition without compromising BCS. Sixty ewes (n = 10/treatment) in mid-lactation, balanced by sire breed, parity, milk yield, body condition score, and liveweight, were supplemented with: (1) control: wheat-based pellets without oil inclusion; wheat-based pellets including; (2) canola oil (CO); (3) rice bran oil (RBO); (4) flaxseed oil (FSO); (5); safflower oil (SFO); and (6) rumen protected marine oil containing eicosapentaenoic acid and docosahexaenoic acid (RPO). Except for the control group, all supplementary diets included the same level of 50 mL/kg DM of oil and all diets were isocaloric and isonitrogenous. Experimental animals were grazed in the same paddock with ad libitum access to pasture, hay, and water during the 10-week study. RPO was the most effective diet that enhanced milk, fat, and protein yields by approximately 30%, 13%, and 31%, respectively (p < 0.0001). A significant increase in milk production was also observed with CO, RBO, and SFO treatments (p < 0.0001). Breed significantly influenced animal performance with higher milk yields recorded for crossbred Awassi × East Friesian (AW × EF) (578 g/day) vs. purebred Awassi (452 g/day) (p < 0.0001). This study provides empirical evidence for the use of rumen-protected and plant-derived oil-infused pellets as supplements under low quality pasture grazing conditions to improve the production performance of purebred Awassi and crossbred AW × EF ewes.