Feeding dihydroquercetin in wheat-based diets to laying hens: impact on egg production and quality of fresh and stored eggs.

1. This study assessed the impact of dietary dihydroquercetin (DHQ) in wheat-based diets on egg production, composition and quality when fed to laying hens. A total of 80 Hy-Line Brown hens were allocated to 20 enriched layer cages, over two tiers, in groups of four birds.2. Two wheat-based diets were used in the study. A basal diet, meeting the nutrient requirement of the hens, containing 11.56 MJ/kg AME and 172 g/kg crude protein, was mixed and split into two parts. One part was fed as prepared to the control group of birds. The second diet was made by adding 1.5 g DHQ per kg basal diet and fed to the treatment group of birds. This level was relatively high and extended the data on levels normally fed. The diets were fed in a meal form and did not contain any coccidiostat, antimicrobial growth promoters or other similar additives. Each diet was fed to hens in 10 replicate cages for 4 weeks, from 22 to 26 weeks of age, following randomisation.3. Subsequently, eggs were investigated to determine the impact of dietary DHQ on the quality variables of fresh and 28-d stored eggs.4. Overall, feeding 1.5 g/kg dietary DHQ for 4 weeks did not affect (P > 0.05) egg production or the quality of fresh and stored eggs. Any observed egg quality changes (P < 0.05) confirmed the expected effects of egg storage.

Fecal particle dry matter and fiber distribution of heifers fed ad libitum and restricted with low and high forage quality.

Wet sieving of manure can be used as a means of evaluating the nutrient utilization of diets by dairy cows. A commercially available system for this analysis (Nasco Digestion Analyzer, Nasco, Fort Atkinson, WI; NDA) employs principles of wet sieving for on-farm assessment. The objective of this study was to evaluate effects of diet manipulations and sampling techniques on fecal particle dry matter (DM), neutral detergent fiber (NDF), and starch distribution on NDA sieves. Eight Holstein heifers (means ± SD; age 18.4 ± 0.6 mo and BW 457.2 ± 27.3 kg), were randomly assigned to a split-plot 4 × 3 incomplete Latin square experimental design with 18-d periods (15 d of adaptation and 3 d of sampling). Treatment rations differed in forage quality (high ADF <35%, low ADF >35%) and fiber content (high NDF >45%, low NDF <40%) and were offered to heifers for ad libitum and restricted intakes. Diets were fed to allow 900 to 1,000 g/d of body weight gain and fed once daily. Fecal grab samples were collected 0, 6, 12, and 18 h after feeding all 3 d of the sampling period, and the remaining feces was collected in the manner of total fecal collection to represent a daily composite sample. After wet sieving of each sample using a NDA kit, the retained material on sieves was dried and analyzed for DM, NDF, and starch content. Sampling day and feeding regimen did not affect distributions of nutrients. Distributions of total fecal particle DM were greater for high forage quality and high fiber content diets (14.66 to 20.37% of sample DM). The NDF content in retained material decreased with decreasing sieve size (from 89.81 to 86.86%) and was not affected by forage quality and fiber content, whereas NDF retained on NDA (% DM) followed the same pattern as the retained particle DM weight. Starch content in retained material was below 0.5% in the majority of diets. Average retained fecal particle DM and NDF content varied depending on the time after feeding, resulting in the large differences between grab fecal samples and a daily total composite sample. However, average values of retained particle DM and NDF weight for all sampling time points were similar to ones from total daily composite sample.

Effect of forage to concentrate ratio with sorghum silage as a source of forage on rumen fermentation, N balance, and purine derivative excretion in limit-fed dairy heifers.

Sorghum silage has been shown to be a good alternative to corn silage for dairy cows; however, studies regarding heifers are insufficiently explored. Therefore, the objective of this study was to evaluate effects of changing forage to concentrate ratio (FOR:CON) in diets based on sorghum silage on N digestibility, rumen fermentation, N balance, C excretion, and microbial N yield in limit-fed dairy heifers. A split-plot 4×4 Latin square design with 19-d periods (15 d of adaptation and 4 d of sampling) was conducted with 8 rumen cannulated dairy heifers (age 13.7±0.6mo and weight 364.8±17.6kg). Heifers were fed sorghum silage-based diets with 4 FOR:CON (85:15, 75:25, 65:35, and 55:45) balanced for similar metabolizable energy intake per unit of body weight and crude protein concentration. Diets were fed to allow 900 to 1,000g/d body weight gain and were fed once daily. Total collection of feces and urine was completed on d 15 to 19 to determine N, C, urea N, allantoin, uric acid, and creatinine excretion. Rumen contents were sampled on d 19 at 0, 1.5, 3, 4.5, 6, 9, 13, 17, 21, and 23h after feeding to measure pH, volatile fatty acid (VFA), ammonia-N, and free AA concentrations. The pH decreased linearly while ammonia-N and free AA levels increased linearly with decreasing FOR:CON of diets. Although mean total VFA did not differ among treatment diets, molar proportions of VFA did. Acetate proportion decreased while propionate and butyrate increased with decreasing FOR:CON. Intake of N and urea N excretion decreased with decreasing forage proportion in diets while total N excretion, apparent N digestibility, and N retention were not different. Intake of C and excretion in feces (g/d) decreased linearly with decreasing FOR:CON in diets. Creatinine, allantoin, and uric acid excretion were not affected by FOR:CON; however, microbial N yield tended to increase linearly with greater concentrate in diets. Heifers limit fed diets based on sorghum silage demonstrated the effect of available ammonia-N and readily fermentable carbohydrates with subsequent effects on nutrient utilization when different FOR:CON were applied. Based on the presented results, FOR:CON 65:35 had the most suitable balance of available ammonia-N and readily fermentable carbohydrates for the most optimal results.