Effects of graded levels of exogenous xylanase in corn-soy diets with two amino acid density and fat levels postpellet in broiler chickens: live performance, energy utilization, digestibility, and carcass characteristics.

This experiment evaluated the interactive effects among xylanase (XL; 0, 8,000, 16,000, and 32,000 BXU/kg), amino acid density (AA; high and low 10% difference), and additional fat (AF; 0 or +1.17%) applied postpellet in corn-soybean meal diets with dried distillers grains with solubles on performance, energy utilization, digestibility, and carcass traits in Ross 708 male broilers. A completely randomized block (pen location) design with 16 treatments arranged factorially (4 XL levels, 2 AA, and 2 AF) was analyzed using mixed models. No significant interactions or main effects were observed for feed intake at 49 d (P > 0.05) but chicks were heavier when consuming diets containing 0 or 8,000 BXU/kg (P = 0.015), high AA (P < 0.001), and 1.17% AF (P < 0.001). Feed efficiency did not vary with XL supplementation (P > 0.05) but was improved in broilers fed the higher AA and AF diet (P = 0.015 for AA × AF). AME, GE, and CP digestibility were assessed at days 17 and 42. There were multiple interactions observed at day 17 with a significant three-way showing that AME and CP digestibility improved when increasing the XL and AF levels in the high AA fed birds compared with the low-density diets. At day 42, XL and AF significantly affected AMEn, GE, or CP digestibility; however, there was a significant interaction between XL and AF. Diets supplemented with 1.17% AF improved AMEn significantly in broilers fed the highest XL level. Breast yield was not affected by treatments, but wing yield decreased with high AA density when diets contained 16,000 BXU/kg without differences for the other diets (P = 0.04 for XL × AA). Effects of XL, AA, and AF interactions on performance and cut-up-part yields have to be considered until day 42 for most of the variables studied. However, at 49 d of age, the dietary AA density and AF did not markedly influence the response to XL in maize-based diets.

A proteomic-based approach for the search of biomarkers in Iberian wild deer (Cervus elaphus) as indicators of meat quality.

The positive perception of deer meat among consumers is growing. Consequently, further efforts are needed to control its meat quality. Specifically, the aim of this study was to search protein biomarkers in connection with tenderness and intramuscular fat (IMF) content of Iberian wild red deer (Cervus elaphus) meat. Twelve venison samples classified as tender, intermediate and tough meat, as well as with different IMF were studied, using quantitative proteomic by SWATH-MS combined with bioinformatic analyses. The study of muscle proteome showed significant differences among these three groups of meat samples, since five differentially abundant proteins (IVD, LAMB1, MYL3, SDHC and SDHA) and six (FABP4, IVD, LAMB1, MYL3, CRYZ and SERPINB6) were strongly correlated with tenderness and IMF, respectively. The proteomic approach provides protein biomarkers linked to venison meat quality and marked changes in proteins related to oxidoreductase complex in skeletal muscle. SIGNIFICANCE: Meat tenderness and IMF are major concerns in game meat. The proteomic approach demonstrated a strong correlation between proteins and these quality traits, despite the complexity of samples (wild animals hunted at different ages). Our results suggest that several proteins can be biomarkers and provide a molecular insight.

Optimizing the use of spineless cactus in the finishing diet of lambs: physicochemical properties and sensory characteristics of meat.

BACKGROUND: The use of spineless cactus in finishing diets for lambs improves the carcass quality. However, data about its influence on meat traits is very scarce. The effects of spineless cactus inclusion in the finishing diet of lambs at four levels (0, 150, 300 and 450 g kg-1 of dry matter, DM) in replacement of Tifton hay on the physicochemical and sensory properties of meat were studied. RESULTS: The spineless cactus modified the chemical composition increasing the protein (P < 0.001) and the fat (P < 0.01) contents of meat, presenting the greatest values in lambs fed diets with 150 and 300 g kg-1 (DM) replacing levels, respectively. However, the spineless cactus did not influence the growth performance from 23.7 to 37.3 kg of body weight (on average). In addition, colour parameters of the meat were not affected by the inclusion of spineless cactus in the finishing diet of lambs, resulting in mean values of 37.55, 14.96 and 8.49 for lightness, redness and yellowness, respectively. There were no statistical differences among treatments for cooking loss and shear force, with mean values of 34.8% and 14.8 N, respectively. Finally, the sensorial properties were not affected by the inclusion of spineless cactus in the finishing diet of lambs. CONCLUSION: Spineless cactus could be included up to the level of 300 g kg-1 DM in the finishing diets of lambs to increase the fat content of meat without compromising its sensorial properties. However, further studies about the fatty acid composition of meat from lambs fed diets containing spineless cactus are necessary. © 2019 Society of Chemical Industry.

Carcass and meat quality characteristics from Iberian wild red deer (Cervus elaphus) hunted at different ages.

BACKGROUND: Deer-meat consumption is increasing in several countries based on claims that it is a healthy red meat. This study assessed the effect of slaughter age (low - 26 months and younger; medium - from 27 months to younger than 42 months; and high - 42 months and older) on carcass characteristics and meat physicochemical properties of 150 Iberian wild red deer. RESULTS: Whole carcass yields of neck, backbone and flank increased (P < 0.001) with age, while yields of shoulder, tenderloin and leg decreased (P < 0.05) with age. The pH measured at 48 h post mortem at 9th rib level was not affected by age, while pH measured at 72 h post mortem at the longissimus thoracis et lumborum muscle decreased (P < 0.05) with age. Meat chemical composition was not affected by slaughter age, except for intramuscular fat (IMF), which increased (P < 0.05) with slaughter age. Finally, cooking loss and shear force were higher (P < 0.05) in meat from older deer. CONCLUSION: Most characteristics of meat from wild red deer depend on age at slaughter. The greater IMF of meat from older animals may render it more palatable. However, meat shear force also increased with age. Additional studies testing palatability seem to be necessary to evaluate the effects of slaughter age on the sensorial quality of meat from Iberian wild red deer. © 2018 Society of Chemical Industry.

The Many Axes of Deer Lactation.

In undomesticated animals information about the production and composition of milk over time is still scarce. In general, for most mammals it is known that milk composition changes across lactation, is different for male and female offspring, and even that marsupials, such as kangaroos, can simultaneously produce milk of different compositions for young of different ages. Such parallel milk production of differing compositions has not yet been studied in single-offspring placental mammals, but may help to explain behavioural processes like allosuckling (feeding the young of other adults) and lateralized suckling preferences. In this study we analysed the production and composition of milk in red deer throughout the lactation period and now confirm for the first time that there are axial differences present. The front teats, which are the favoured suckling positions of the deer's offspring, produce milk with a greater protein-to-fat ratio. Also, from the beginning of lactation the yield is greater on the left side, the side preferred by calves in all of the studied species, both at population and individual level. The links between milk production and calf behaviour in deer deserve further study.

Effects of feeding rice and the degree of starch gelatinisation of rice on nutrient digestibility and ileal morphology of young pigs.

We evaluated the influence of the main cereal of the diet and the degree of heat processing of rice on apparent ileal and total tract digestibility of nutrients and ileum morphology of pigs at 37 d of age. Control pigs were fed a complex diet that contained 500 g/kg cooked and flaked maize with a degree of starch gelatinisation (SG) of 840 g/kg. Experimental groups received the same complex diet in which maize was substituted (w/w) by rice with three different degrees of SG; 110, 520 and 760 g/kg that corresponded to raw rice and cooked rice processed under two different set of conditions. The digestibility of dietary components, except for nitrogen, was greater for the cooked rice--than for the raw rice--and the maize diet (P<0.001). Pigs fed cooked rice had higher villus height to crypt depth ratio (P<0.001) and greater percentage of zigzag-oriented villi and lesser percentage of tongue-oriented villi (P<0.01) than pigs fed other diets. Compared with feeding maize, feeding rice improved dietary component digestibility and ileal morphology in piglets. Mild cooking of rice (SG = 520 g/kg) enhanced diet digestibility and ileum morphology. However, processing the rice to increase SG to 760 g/kg did not increase nutrient digestibility further and in fact impaired ileal morphology.