The lactational performance of 30 healthy multiparous Holstein dairy cows was tested when cows were fed 0, 10, and 20% dried distillers grains with solubles (DDGS) that contained 13.6% fat on a dry matter (DM) basis. Cows fed 10% DDGS on a DM basis experienced a reduction in milk fat percentage of 0.5 percentage points, but did not perform differently in other measures than did cows not fed DDGS. When cows were fed 20% DDGS on a DM basis, every common measure of feed utilization was impacted negatively.

Carcasses (n=40) with defined fat free lean and carcass weight were selected 45 minutes postmortem. Carcasses were split and sides subjected to conventional chill (CC) or blast chilling (BC) regimens. The Psoas Major (PM) from BC sides had increased purge loss, but was juicier, more tender and less chewy than the PM from CC sides. The Semimembranosus (SM) from BC sides had higher 30 hour pH, darker color scores, and had a lower Hunter a value than the SM from CC sides. No treatment effect was found in the Triceps Brachii.

Healthy mid-lactation Holstein dairy cows (n=24) were fed total mixed rations containing dried distillers grains with solubles (DDGS). The objective of this study was to examine the effect of feeding DDGS to lactating dairy cows on production parameters and flavor and oxidative stability of milk. Cows were assigned to two groups and fed one of three treatment diets (0% DDGS, 10% DDGS, 25% DDGS by dry matter (DM)) as a total mixed ration. Each group was fed all three of the diets after a wash-out period of 7 days. Milk yield was unaffected by both the 0% and 10% DDGS diets but decreased significantly when fed the 25% DDGS diet. Rumen volatile fatty acids were unaffected by treatment. Milk protein and solids-not-fat (SNF) increased with increasing inclusion of DDGS, but milk fat decreased concomitantly. Milk fatty acid composition was affected with milk fat from cows fed higher concentrations of DDGS producing milk with higher concentrations of unsaturated fatty acids. Milk oxidative stability was unaffected by dietary treatment, and milk flavor, as determined by a trained sensory panel, also was unaffected. The results of this study indicate that feeding of DDGS to lactating dairy cows, under controlled conditions, does not have negative effects on milk oxidative stability or flavor; however, feeding 25% DDGS did negatively impact milk production and changed milk fatty acid profile.

The results suggest that high pH product (above pH 5.8) can be expected to be superior to lower pH product with regard to sensory quality, texture, and cook loss. In general, at high pH, greater lipid content does not improve sensory tenderness, sensory chewiness, sensory juiciness or star probe values. At low pH (below pH 5.5), pork is of inferior quality in virtually every category. At low pH, greater lipid content does not improve sensory quality. Lipid content does contribute to pork sensory traits in pork loins with intermediate pH (between pH 5.5 and 5.8). The effects of lipid content within the intermediate pH classifications indicate that only a small portion of the variation in sensory quality can be attributed to variation in lipid content.

Heat stress affects a plethora of pork production variables, in part stemming from a reduction of feed intake. The experimental objective was to investigate the effect of heat stress on the pig’s response to dietary fat in terms of growth performance and digestibility over a 35 d finishing period. A total of 96 barrows were randomly allotted to 1 of 9 treatments arranged as a 3 × 3 factorial with the main effects of environment [thermonetural (TN), pair-fed thermoneutral (PFTN), or heat stress (HS)] and diet [a corn-soybean meal based diet with 0% added fat (CNTR), or the CNTRL with 3% added tallow (3%TAL), or 3% added corn oil (3%CO)]. Pigs were individually housed to record intake. Fecal samples were collected on d 17 (~ 114 kg). No significant interactions between environment and diet were observed (P > 0.100). HS decreased ADFI (27.8%; P< 0.001), ADG (HS = 0.72, TN = 1.03, PFTN = 0.78 kg/d; P < 0.001), and G:F (HS = 0.290, TN = 0.301, PFTN = 0.319; P = 0.006). G:F but not ADG or ADFI tended to increase with added fat (CNTR = 0.292, 3%TAL = 0.303, 3%CO = 0.314 g/100 g; P ≤ 0.073). Environment had no impact of TTTD of AEE (P = 0.118). In summary, HS decreased ADFI, ADG, G:F and ATTD of AEE, but had no significant impact on TTTD of AEE. Therefore, the pig’s response to dietary fat source is not different in heat stress conditions as compared to thermoneutral conditions.

Carcasses (n=40) with defined fat free lean and carcass weight were selected 45 minutes postmortem. Carcasses were split, and sides subjected to conventional or blast chilling regimens. Sides that were blast chilled had Longissimus dorsi (LD) chops with slower pH decline, greater cook loss and greater Warner-Bratzler Shear force than chops from conventionally chilled sides. These results demonstrate that current blast chilling practices have the potential to negatively impact pork tenderness.

The goal of this experiment was to determine the impact of high and low energy diets on sensory traits of pigs divergently selected for residual feed intake (RFI). Diet had little effect on sensory quality of loins. Line did have an impact on sensory rated juiciness of loins. Loins from animals of the LRFI line had greater juiciness than those of the HRFI line. This difference is most likely not numerically large enough to be detected by the untrained consumer.

Iodine value product (IVP) is commonly used to predict carcass fat iodine value (CIV). However, when higher fat diets are employed, IVP tends to emphasize the quantity of fat in the diet more than the composition of that fat. The objective of this experiment was to compare the effectiveness in predicting CIV by IVP versus individual fatty acid content in the diet or their daily intake. Forty-two gilts and 21 barrows (PIC 337 × C22/29) with an average initial weight of 77.8 ± 0.38 kg were allotted based on sex and weight across 7 treatments: a control diet with no added fat, and 6 diets containing either 3 or 6% of tallow, choice white grease, or corn oil. Pigs were individually housed to measure daily fatty acid intake. Adipose samples were collected from the jowl, loin, and belly at harvest (d 55). Of all the fatty acid intakes measured, only increased linoleic acid intake (LAI) generated a strong coefficient of determination in a positive correlation with CIV (CIV = 60.58 + (0.121× LAI/d (g)); R2 = 0.611; P < 0.05; Root MSE = 3.24). Comparison of IVP of the experimental diets was approximately equal (CIV = 58.10 + (0.215 × IVP); R2 = 0.93; P < 0.05; Root MSE = 1.45) to the treatment means of LAI (CIV = 58.57 + (0.139 × linoleic acid intake/d (g)); R2 = 0.94; P < 0.05; Root MSE = 1.37) as a predictor of CIV. Under the conditions of this experiment, a CIV standard of 74 g/100 g can be met by limiting LAI to less than 111 g/d. Linoleic acid is clearly the fatty acid that most affects CIV.

The goal of this experiment was to determine the impact of low and high energy diets on the meat quality of animals selected for divergent residual feed intake (RFI). Low RFI (efficient) and high RFI (less efficient) pigs were fed either a high energy, low fiber (HELF) or low energy, high fiber (LEHF) diet. Diet had little impact on meat quality. Selection for low RFI animals resulted in loins with greater water holding capacity and sensory juiciness. High RFI animals have loins with greater percent lipid, color and marbling scores, and a* values (are more red in color). It is unlikely that marbling and color differences are large enough to be detected by the consumer.

Differences in fiber diameter, method of metabolism, and glycogen content that arise between muscle fiber types can have a significant effect on a number of sensory traits that affect palatability. The vastus intermedius was the only muscle of the round with a high percentage of type I myosin heavy chain isoform. Within the muscles of the round we observed that a high percentage of type I myosin heavy chain is associated less intact troponin-t. Increased sensory juiciness was correlated with a greater proportion of type I muscle fibers. By identifying the fiber type of the muscles of the round we can better understand how fiber type influences the sensory characteristics of those muscles. With additional understanding comes the potential to predict those characteristics and produce a product that is juicier by manipulating the fiber type of those muscles.