N. G. Torrentera-Olivera

Effects of zilpaterol hydrochloride on growth performance, carcass characteristics, and wholesale cut yield of hair-breed ewe lambs consuming feedlot diets under moderate environmental conditions.

Twenty-four Dorper × Pelibuey ewe lambs initially weighing 25.1 ± 0.6 kg were used in a 34-d feeding experiment and after slaughter to evaluate the effect of zilpaterol hydrochloride (ZH) on feedlot performance, carcass characteristics, and wholesale cut yield. Ewe lambs were individually housed in pens, blocked by initial BW, and assigned randomly within BW blocks to 1 of 2 treatments: 1) control (no ZH) and 2) supplemented with ZH (10 mg/ewe lamb daily) during 32-d and a 2-d withdrawal preslaughter period. Feeding ZH increased (P < 0.01) final BW, ADG, and G:F of ewe lambs, whereas feed intake was unaffected (P = 0.80). Hot and cold carcass weights, dressing percentage, and conformation score were improved (P < 0.001) when ZH was fed. Likewise, LM area was 3.7 ± 0.41 cm(2) larger (P < 0.001) for ZH than control ewe lambs. Feeding ZH did not affect (P ≥ 0.29) cooling loss, carcass length, fat thickness, or KPH. With exception of peritoneum (P < 0.001), head (P = 0.021), and neck (P < 0.001), ZH did not increase (P ≥ 0.12) noncarcass components or wholesale cut yield percentage. A trend to increase (P = 0.060) loin percentage from HCW was observed in lambs supplemented with ZH. In conclusion, feeding ZH to Dorper × Pelibuey ewe lambs improved feedlot performance and also some carcass traits (HCW, cool carcass weight, dressing percentage, and LM area) of economic importance; however, fat deposition was not affected by ZH.

Crecimiento y características de canal en corderos Pelibuey puros y cruzados F1 con razas Dorper y Katahdin en confinamiento.

The aim of this study was to evaluate feedlot performance and carcass characteristics of 36 male and female lambs from the genotypes pure Pelibuey, Dorper x ...

Effects of free ferulic acid on productive performance, blood metabolites, and carcass characteristics of feedlot finishing ewe lambs.

The aim of this study was to evaluate effects of free ferulic acid (FA) supplementation on productive performance, some blood metabolite concentrations, and carcass characteristics of ewe lambs finished in a feedlot. Dorper×Pelibuey ewe lambs (n=20; BW=28.5±0.5 kg; age=5 mo) were individually housed in pens and assigned under a randomized complete block design to the following dietary treatments (n=10): daily feeding without (control) or with 300 mg of FA/animal. The feedlot feeding period lasted 34 d and then all ewe lambs were slaughtered. Free FA did not affect (P≥0.16) BW gain, ADG, DMI, and G:F during the first 17 d, but BW gain (P=0.10) and ADG (P=0.10) tended to decrease for FA from d 17 to 34 and from d 1 to 34 without affecting (P≥0.16) DMI and G:F in ewe lambs. Serum concentrations of glucose, cholesterol, triglyceride, total protein, and urea were not affected (P>0.05) by FA at d 1, 17, and 34 of the feeding period. Carcass characteristics were not affected (P>0.05) by FA. Stomach percentage tended (P=0.08) to decrease and leg yields increased (P=0.02) for FA. Other noncarcass components and wholesale cut yields were not affected (P>0.10) by FA. In conclusion, FA supplementation did not improve productive performance, metabolic status, and carcass characteristics of ewe lambs receiving a feedlot finishing diet.

Effects of zilpaterol hydrochloride and soybean oil supplementation on feedlot performance and carcass characteristics of hair-breed ram lambs under heat stress conditions

Forty Dorper × Pelibuey ram lambs initially weighing 31.7 ± 2.30 kg were stratified by BW and randomly assigned to treatments under a completely randomized design with a 2 × 2 factorial arrangement of treatments to evaluate effects of zilpaterol hydrochloride (ZH; 0 or 10 mg/lamb daily) and soybean oil (SBO; 0 or 6%) on feedlot performance, carcass characteristics, and wholesale cut yield of ram lambs under heat stress conditions. After a 34-d feeding period, all lambs were harvested. Climatic conditions were of moderate heat stress (average temperature 35.7°C) for lambs during the study. Interactions ZH × SBO were not observed (P ≥ 0.11) for any of the variables evaluated. During the first 17 d of experiment, ZH increased (P ≤ 0.05) BW, ADG, and G:F without affecting feed intake (P = 0.40), but from d 18 to 34 and the entire 34-d feeding period, feedlot performance was not affected (P = 0.18) by ZH. Also, ZH decreased KPH, dressing percent, LM area, LM pH at 24 h postmortem, and leg perimeter (P ≤ 0.04). Renal fat (P = 0.03) decreased with ZH while other noncarcass components were not affected (P ≥ 0.06) by ZH supplementation. Leg yield (P = 0.01) and plain loin (P = 0.04) decreased with ZH and yields of other wholesale cuts were not affected (P ≥ 0.10) by ZH. Feedlot performance (P ≥ 0.20) and wholesale cut yield (P ≥ 0.21) were not affected by SBO. Additionally, dressing percentage decreased (P < 0.01) with SBO while other carcass characteristics (P ≥ 0.12) were not affected by SBO. In conclusion, inclusion of both ZH and SBO in feedlot finishing diets did not improve feedlot performance, carcass characteristics, or wholesale cut yield of hair-breed ram lambs under moderate heat stress. Feedlot performance responded only to ZH and only during the first 17 d of the feeding period. In addition, some carcass characteristics of economic importance, such as dressing, LM area, and leg yield, were improved by ZH.

Development of a predictive model for Salmonella spp. reduction in meat jerky product with temperature, potassium sorbate, pH, and water activity as controlling factors☆

The objective of this study was to develop a predictive model for the inactivation of Salmonella spp. in ground beef jerky as a function of temperature (T), pH, potassium sorbate (PS), and final water activity (aw). Following a central composite design, ground beef was combined with PS (0 to 0.3%, w/w), pH adjusted from 5 to 7, inoculated with a cocktail of 6 serotypes of Salmonella spp. and heat processed at temperatures between 65 and 85°C until the final aw ranging from 0.65 to 0.85 was achieved. Surviving Salmonella cells were enumerated on tryptic soy agar overlaid with xylose lysine deoxycholate agar (pre-tempered to 47°C) after incubation for 48h at 30°C. Bacterial inactivation was quantified in terms of logarithmic reductions of Salmonella counts (log10CFU/g) and inactivation rate (log10(CFU/g)/h). The results indicated that pH, PS and T significantly (p<0.05) interacted to inactivate Salmonella in beef jerky. Decreasing meat pH significantly (p<0.05) increased the efficacy of PS and T to reduce the levels of Salmonella spp. Beef jerky processed at 82°C, pH5.5, with 0.25% PS to a final aw of 0.7 resulted in a maximum Salmonella logarithmic reduction of 5.0log10CFU/g and an inactivation rate of 1.3log10(CFU/g)/h. The predictive model developed can be used to effectively design drying processes for beef jerky under low humidity conditions and thereby, ensuring an adequate degree of protection against risks associated with Salmonella spp.

Feedlot performance and carcass traits of hairbreed ewe lambs in response to zilpaterol hydrochloride and soybean oil supplementation.

The aim of the present study was to evaluate the impact of zilpaterol hydrochloride (ZH; 0 or 10 mg/lamb daily) and soybean oil (SBO; 0 or 6%) supplementation on feedlot performance, carcass traits, and wholesale cut yield of 32 Dorper × Pelibuey ewe lambs (30.55 ± 2. 57 kg of initial BW). Lambs were blocked by BW and randomly assigned to treatments under a randomized complete block design with a 2 × 2 factorial arrangement. After a 34-d feeding period, all ewes were slaughtered. No ZH × SBO interactions were detected (P ≥ 0.11) for the variables evaluated. In the overall feeding period and first 17 d of experiment, feedlot performance was not affected (P ≥ 0.26) by ZH supplementation, but from d 18 to 34, ZH increased (P ≤ 0.03) total gain, ADG, and G:F without affecting DMI (P = 0.58). Also, ZH increased (P ≤ 0.02) HCW, cold carcass weight, dressing percentage, LM area, and leg perimeter. Lung weight as percentage of final BW decreased (P = 0.05) whereas other noncarcass components and wholesale cut yields were not affected (P ≥ 0.06) by ZH supplementation. Inclusion of SBO did not affect (P ≥ 0.08) feedlot performance or wholesale cut yields. The LM pH at 24 h postmortem as well as liver and peritoneum percentages were decreased (P ≤ 0.05) by SBO supplementation, but no other carcass characteristics or noncarcass components were affected (P ≥ 0.08) by SBO. In conclusion, feedlot performance and carcass characteristics were not altered by the interaction of ZH × SBO. However, ZH alone increased the growth of ewes during the last 17 d of the feeding period. Likewise, carcass characteristics of economic importance (i.e., HCW, dressing percentage, LM area, and leg perimeter) increased with ZH supplementation. In general, feedlot performance, carcass traits, and wholesale cut yields were not altered by including 6% of SBO in the finishing diet of ewe lambs.

Nutritional quality of beef patties with added flaxseed and tomato paste

ABSTRACT The aim of this work was to evaluate the physicochemical, sensory and nutritional properties of beef patties with added combinations of flaxseed (FS) and tomato paste (TP). Treatments were as follows: control = 0%FS + 0%TP; T1 = 0%FS + 20%TP; T2 = 5%FS + 15%TP; T3 = 10%FS + 10%TP; T4 = 15%FS + 5%TP; and T5 = 20%FS + 0%TP. Sensory properties for treatments T1 and T2 were similar to the control, while T3 showed acceptable sensory scores (>5.0). The α-linolenic acid content of beef patties increased as FS addition increased. The polyunsaturated fatty acid (PUFA)/saturated fatty acid ratio increased from 0.24 in the control treatment to 4.49 in T5. The PUFAs ratio n6/n3 decreased from 7.18 in the control treatment to 0.29 in T5. A combination of FS and TP can be used as novel ingredients to develop beef patties with better nutritional profile without demerit of their sensory and physicochemical properties.

Impact of zilpaterol hydrochloride and soybean-oil supplementation on intramuscular fat, fatty acid profile and cholesterol concentration in the longissimus muscle of male hair lamb under moderate heat-stress conditions

Forty Dorper × Pelibuey crossbred male lambs (31.70 ± 2.30 kg, 4 months of age) were used to evaluate the effect of zilpaterol hydrochloride (ZH; 0 or 10 mg/lamb daily) and soybean-oil (SBO, 0 or 60 g/kg DM) supplementation on intramuscular fat, fatty acid (FA) profiles and cholesterol concentration of their meat. After 34 days, the animals were slaughtered, and their longissimus thoracis muscle was collected. The climatic conditions were of moderate heat stress (average temperature 35.7°C) during the study. Feedlot performance and carcass characteristics were not affected (P > 0.05) by ZH and SBO supplementation. The ZH treatment decreased the intramuscular fat content (by 30.4%), the amount of monounsaturated FA (by 3.5%) and the monounsaturated FA : saturated FA ratio (by 4.9%) compared with the control group. Supplementation with SBO decreased cis FA, C18:1 n-9c and C20:4 n-6, whereas the trans FA and cholesterol concentration increased. ZH use caused a decrease in body fat and intramuscular fat concentration. However, it caused a decrease in total monounsaturated fatty acids, which are among the healthiest fats in terms of the nutritional value of meat. Generally, principal changes in the lipid composition of hair lamb meat under heat-stress conditions were caused by SBO supplementation; however, they would have a minimal negative impact on human health.