Dietary guanidinoacetic acid supplementation improved carcass characteristics, meat quality and muscle fibre traits in growing-finishing gilts.

This study was designed to evaluate the effects of guanidinoacetic acid (GAA) on growth performance, carcass characteristics, meat and muscle fibre traits of growing-finishing gilts. 300 female PIC pigs were randomly divided (30.10 ± 2.94 kg) into 2 treatments with 6 replicates of 25 each for a 100-day trial. Two dietary treatments were comprised of a control diet and a control diet fortified with 450 mg/kg GAA. Growth performance was evaluated for each phase. Carcass characteristics and meat quality were determined at last phase. Gilts had free access to feed and water during the experiment. The result indicated that GAA did not affect growth performance (p > 0.05). GAA not only increased longissimus dorsi (LM) muscle weight but also decreased its shear force, b*value and drip loss (p < 0.05). Mandibular fat index was decreased by GAA (p < 0.05). GAA upregulated myosin heavy chain (MyHC) I mRNA expression with lower myofibre cross-sectional area and fibre diameter in LM muscle (p < .05). In conclusion, GAA can improve carcass characteristics and meat quality by changing muscle fibre characteristics and reducing mandibular fat index in finishing gilts.

Effect of Yucca schidigera extract on the growth performance, intestinal antioxidant status, immune response, and tight junctions of mirror carp (Cyprinus carpio).

The current study was designed to evaluate the effect of Yucca schidigera extract (YSE) on the growth performance, intestinal antioxidant status, immune response, and tight junctions of mirror carp (Cyprinus carpio). A total of 450 mirror carp (45.21 ± 0.43 g) were fed diets supplemented with 0, 200, or 400 mg/kg YSE for 8 weeks. Compared with the control (0 mg/kg), the final body weight and weight gain rate were significantly higher in the 400 mg/kg YSE group (P < 0.05), and the serum ammonia concentration was significantly lower in both YSE groups (P < 0.05). Additionally, the total antioxidant capacity was significantly higher in the 400 mg/kg YSE group (P < 0.05), and the malondialdehyde content was significantly lower in both YSE groups (P < 0.05). Complement 3 and 4 contents were significantly higher in the 400 mg/kg YSE group (P < 0.05), and lysozyme was significantly higher in both YSE groups compared to the control group (P < 0.05). The relative mRNA levels of copper zinc superoxide dismutase, catalase, glutathione peroxidase1a, and nuclear factor erythroid 2-related factor 2 as well as transforming growth factor ß were significantly higher in both YSE supplemented groups compared to the control (P < 0.05), whereas the relative mRNA level of Kelch-like ECH-associated protein 1 was significantly lower in both YSE supplemented groups (P < 0.05). The relative mRNA levels of interleukin 1ß and interleukin 6 were significantly lower in the 400 mg/kg YSE supplemented group compared to the control (P < 0.05). Additionally, both YSE levels decreased the relative mRNA expression of tumour necrosis factor-α (P < 0.05). The relative mRNA levels of ZO-1 and claudin 11 were significantly higher in both YSE supplemented groups (P < 0.05), and the relative mRNA level of occludin was significantly higher in the 200 mg/kg YSE group than the control and 400 mg/kg YSE groups (P < 0.05). In conclusion, dietary supplementation with 400 mg/kg YSE improved the growth, intestinal antioxidant status, immune response, and tight junctions of mirror carp.

Effects of the different levels of dietary trace elements from organic or inorganic sources on growth performance, carcass traits, meat quality, and faecal mineral excretion of broilers.

This experiment was conducted to evaluate the effects of different sources and levels of trace elements on growth performance, carcass composition and mineral excretion levels of broilers. In a completely randomised experimental design, 900 one-day-old male Ross-308 broilers were assigned to 5 treatments, with 6 replicates of 30 birds each. The control group (CITE) was fed with a basal diet containing regular inclusion levels of inorganic trace elements. Treatment groups were supplied with reduced levels (30% and 50% of the regular level) of inorganic (ITE) or organic trace elements (OTE), respectively. Groups 50% ITE, 30% OTE and 50% OTE diets had equivalent average daily gain (ADG), average daily feed intake (ADFI), feed to gain ratio (F/G ratio) and mortality rate compared with group CITE in any phase. However, compared with group CITE chicks in group 30% ITE have lower ADG and ADFI and higher F/G ratio. The carcass yields were not affected by dietary treatments. Compared with group CITE, in groups 30% ITE, 50% ITE, 30% OTE and 50% OTE the shear force values of the breast muscle were only 71.8%, 83.4%, 63.5% and 59.4% (p < 0.05), respectively. Birds received diets containing reduced levels of trace elements had diminished excretions of Mn and Zn throughout the entire period (p < 0.01). In conclusion, the reduced supplementation of trace elements had no or slightly negative impact on growth performance, carcass yield and meat quality, but decreased faecal mineral excretion. Moreover, the trace element supply as OTE played a limited role on performance and excretion and was only partly beneficial for animal performance in case the trace element supply was reduced to 30%.

Estimation of the optimal standardized ileal digestible lysine requirement for primiparous lactating sows fed diets supplemented with crystalline amino acids.

This experiment was conducted to determine the optimal standardized ileal digestible lysine (SID Lys) level in diets fed to primiparous sows during lactation. A total of 150 (Landrace × Large White) crossbred gilts (weighing 211.1 ± 3.5 kg with a litter size of 11.1 ± 0.2) were fed lactation diets (3325 kcal metabolizable energy (ME)/kg) containing SID Lys levels of 0.76, 0.84, 0.94, 1.04 or 1.14%, through 28 days lactation. Gilts were allocated to treatments based on their body weight and backfat thickness 48 h after farrowing. Gilt body weight loss was significantly (P < 0.05) decreased by increasing dietary SID Lys levels. Fitted broken-line (P < 0.05) and quadratic plot (P < 0.05) analysis of body weight loss indicated that the optimal SID Lys for primiparous sows was 0.85 and 1.01%, respectively. Average daily feed intake (ADFI), weaning-to-estrus interval and subsequent conception rate were not affected by dietary SID Lys levels. Increasing dietary lysine had no effect on litter performances. Protein content in milk was increased by dietary SID Lys (P < 0.05). Dietary SID Lys tended to increase concentrations of serum insulin-like growth factor I (P = 0.066). These results of this experiment indicate that the optimal dietary SID Lys for lactating gilts was at least 0.85%, which approaches the recommendation of 0.84% that is estimated by the National Research Council (2012).