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The objective of this study was to assess carcass traits' influence on pork eating quality as evaluated by consumers. A total of 1360 pork chops were used, with 824 from the sirloin end and 536 from the butt end of the loin (Longissimuss thoracis et lumborum), to produce 340 packages, each containing four pork chops. Untrained participants received one package of either sirloin or butt chops, being two pork chops from barrows and two from gilts. Participants answered a survey rating the tenderness, juiciness, flavour, and overall acceptability of each chop on an 8-point scale. Correlation analysis was conducted between carcass traits and pork eating quality attributes. For the descriptive analysis, classes (low, medium, and high) for carcass traits, Warner-Bratzler shear force (WBSF) and cooking loss were created based on our consumer responses dataset for palatability attributes. No significant correlations (P > 0.05) were observed between carcass traits and pork eating quality traits. Tenderness and overall acceptability were negatively correlated (P < 0.05) with cooking loss and WBSF. Loin intramuscular fat (IMF) content showed a weak negative correlation (P < 0.05) with WBSF and cooking loss. Consumers rated chops from the high and medium/high backfat thickness and loin IMF classes slightly higher for tenderness and juiciness, respectively. Additionally, chops from the low and/or medium WBSF and cooking loss classes received slightly higher scores for tenderness and juiciness than pork chops in the high classes. In conclusion, the study indicated that carcass traits had minimal impact on overall acceptability of pork by consumers.

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We evaluated the differences between the supplementation of urea in rumen and/or abomasum on forage digestion, N metabolism and urea kinetics in cattle fed a low-quality tropical forage. Five Nellore heifers were fitted with rumen and abomasum fistulas and assigned to a Latin square design. The treatments were control, continuous infusion of urea in the abomasum (AC), continuous infusion of urea in the rumen, a pulse dose of urea in the rumen every 12 h (PR) and a combination of PR and AC. The control exhibited the lowest (P < 0·10) faecal and urinary N losses, which were, overall, increased by supplementation. The highest urinary N losses (P < 0·10) were observed when urea was either totally or partially supplied as a ruminal pulse dose. The rumen N balance was negative for the control and when urea was totally supplied in the abomasum. The greatest microbial N production (P < 0·10) was obtained when urea was partially or totally supplied in the abomasum. Urea supplementation increased (P < 0·10) the amount of urea recycled to the gastrointestinal tract and the amount of urea-N returned to the ornithine cycle. The greatest (P < 0·10) amounts of urea-N used for anabolism were observed when urea was totally and continuously infused in the abomasum. The continuous abomasal infusion also resulted in the highest (P < 0·10) assimilation of microbial N from recycling. The continuous releasing of urea throughout day either in the rumen or abomasum is able to improve N accretion in the animal body, despite mechanism responsible for that being different.

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Abstract Background: Production of heart-of-palm from Alexander palm tree generates a waste that could be used as silage for feeding ruminants. Objective: To evaluate the chemical composition, fermentation parameters, and quality of silage made from waste of heart-of-palm production using Alexander palm. Methods: Three types of silage made from waste of heart-of-palm production were evaluated: 1) leaf silage, 2) sheath silage, and 3) compound (leaf + sheath) silage. The processed waste was packed in experimental silos and distributed in a completely randomized design with 10 replications. Means were compared pairwise using Tukey's test at the 5% significance level. Results: Leaf silage had the highest pH (p<0.05) and the lowest ammonia nitrogen (p<0.05) in relation to the other silages. No difference was observed (p>0.05) for lactic and butyric acids, whereas acetic acid was higher (p<0.05) in the sheath and compound silages. Dry matter and crude protein contents were the highest (p<0.05) in leaf silage. Neutral detergent fiber was higher (p<0.05) in sheath silage, followed by leaf and compound silages, respectively. The highest lignin content (p<0.05) was observed in sheath silage. Conclusions: Based on the fermentative parameters, waste from heart-of-palm from Alexander palm tree has potential for silage production. However, differences in silage composition at the time of feeding ruminants should be considered.

Resumen Antecedentes: Los residuos de la producción de palmito de Palma Real podrian utilizarse como ensilaje para alimentación de rumiantes. Objetivo: Determinar la composición, parámetros químicos de fermentación, y calidad del ensilaje elaborado a partir de residuos procedentes de la producción de palmito de Palma Real. Métodos: Tres tipos de ensilaje hechos con los residuos generados a partir de la producción de palmito fueron evaluados: 1) ensilaje de hojas, 2) ensilaje de vainas, y 3) ensilaje compuesto (hojas + vainas). Los residuos tratados fueron empacados en silos experimentales y distribuidos en un diseño completamente al azar con 10 repeticiones. Las medias fueron comparadas mediante la prueba de Tukey, con un nivel de significancia del 5%. Resultados: El ensilaje de hojas mostró el pH más alto (p<0,05) y el nivel más bajo de nitrógeno amoniacal (p<0,05) en comparación con los otros ensilajes. No se observaron diferencias (p>0,05) en los ácidos láctico y butírico, mientras que el ácido acético fue mayor en el ensilaje de vainas y en el compuesto en relación con el otro ensilaje. La materia seca (MS) y el contenido de proteína cruda (PC) fueron mayores (p<0,05) en el ensilaje de hojas. Los contenidos de fibra detergente neutra fueron mayores (p<0,05) en los ensilajes de vainas, seguido por los ensilajes de hojas y compuesto, respectivamente. El contenido de lignina fue más alto (p<0,05) en el ensilaje de vainas. Conclusiones: Según los parámetros fermentativos, los residuos de la producción de palmito de Palma Real tienen potencial para la producción de ensilaje. Sin embargo, se deben considerar las diferencias en la composición de los ensilajes al momento de alimentar rumiantes.

Resumo Antecedentes: Resíduos da produção de palmito da palmeira Real são um problema para a agroindústria devido sua falta de utilização e o seu uso na forma de silagem pode ser uma alternativa na alimentação de ruminantes. Objetivo: Avaliar a composição química e os parâmetros fermentativos, e verificar a qualidade da silagem produzida a partir do resíduo da produção de palmito da Palmeira Real Australiana. Métodos: Foram avaliadas três tipos de silagem de resíduo da produção de palmito da Palmeira Real: silagem de folha, silagem de bainha e silagem da composta (folha + bainha). O resíduo processado foi acondicionado em silos experimentais e distribuídos em um delineamento inteiramente casualizado com 10 repetições e as médias comparadas pelo teste de Tukey a 5% de significância. Resultados: A silagem de folha apresentou maior pH (p<0,05) em relação as demais silagens, enquanto para o nitrogênio amoniacal (p<0,05), apresentou menor teor em relação as demais silagens. Não observou-se diferença (p>0,05) para os ácidos lático e butírico, enquanto o ácido acético foi maior para as silagens de bainha e composta em relação as demais silagens. O teor de matéria seca (MS), proteína bruta (PB) foi maior (p<0,05) na silagem de folha em relação as demais silagens. A fibra em detergente neutro analisada estimada apresentou maiores valores (p<0,05) para a silagem de bainha, seguida pela silagem de folhas e silagem composta, respectivamente. O teor de lignina foi maior (p<0,05) para a silagem de bainha. Conclusões: De acordo com os parâmetros fermentativos, os resíduos da produção de palmito da Palmeira Real apresentam potencial para a produção de silagem. No entanto, as diferenças na composição das silagens devem ser consideradas quando oferecidas para animais ruminantes.

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The aim of this study was to compare the in vitro digestibility of dry matter (IVDMD) and neutral detergent fiber (IVNDFD) using 2 buffer solutions with or without urea addition. The study was comprised of 2 separate experiments. In both experiments, the treatments were composed of Kansas or McDougall's buffer solutions with or without urea addition, according to a 2 × 2 factorial arrangement. In Exp. I, the IVDMD and IVNDFD of 25 forages and 25 concentrates were evaluated. Samples were incubated for 48 h using an artificial fermenter and nonwoven textile filter bags (100 g/m2). In this experiment, the repeatability and discriminatory power among samples were calculated within forage or concentrate samples, for each treatment. In Exp. II, Tifton hay and ground corn samples were incubated for 48 h. The pH and ammonia nitrogen (NH3-N) concentration were measured after 0, 3, 6, 12, 18, 24, and 48 h of incubation. In Exp. I, the interaction between buffer solution and urea addition impacted the IVDMD and IVNDFD of forages (P < 0.05), with greater values being exhibited when using McDougall's buffer with urea (P < 0.05). For concentrates, the effect of buffer and urea interaction did not affect IVDMD and IVNDFD (P > 0.05). However, greater IVDMD and IVNDFD were observed for McDougall's buffer (P < 0.05), while urea addition increased IVDMD and IVFDFD estimates (P < 0.05) regardless of buffer solution used. In general, repeatability of the digestibility was better using McDougall's buffer and improved when urea was added. Urea addition also decreased the discriminatory power among samples for both buffers. In Exp. II, a buffer solution × urea addition × incubation time interaction was detected (P < 0.05) for pH and NH3-N in both Tifton hay and ground corn. Kansas buffer exhibited lower pH values with a greater decrease observed throughout incubation time when compared to McDougall's buffer. The use of Kansas buffer with urea addition was the only treatment exhibiting NH3-N accumulation throughout incubation. In conclusion, McDougall's buffer provides both better conditions for in vitro fiber digestion and greater precision in digestibility estimates, and is recommended over Kansas buffer. In spite of urea addition increases the precision of in vitro digestibility estimates, it decreases discriminatory power among samples.

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This study was conducted to evaluate the development of the mammary gland in Holstein heifers subjected to different dietary metabolisable protein (MP): metabolisable energy (ME) ratios. Twenty-five Holstein heifers (initial body weight (BW) 213±13·5 kg and initial average age 7·8±0·5 months) were divided into five treatments. The treatments were designed to provide MP:ME ratios equal to 33, 38, 43, 48, and 53 g of MP per Mcal of ME. All diets were formulated to have the same energy content (2·6 Mcal ME/kg dry matter). Actual MP:ME ratios were 36·2, 40·2, 46·2, 47·1, and 50·8 g MP/Mcal ME. The experiment was conducted in a randomised block design, while considering initial BW as a blocking factor to evaluate pre- and post-pubertal periods. Block effect was not observed for all variables evaluated; hence it was considered that the diets had the same influence both on pre- and post-pubertal phases. Dry matter and nutrient intake did not change between treatments, excepting protein intake and digestibility. Serum concentrations of insulin-like growth factor 1 increased linearly across treatments. Changes in the pixel brightness of mammary gland ultrasound images, which are associated with lipid content, were significantly influenced by MP:ME ratios in the diet of heifers that were subjected to accelerated growth rates. It is not recommended to use diets of less than 38 g MP/Mcal ME in diets to heifers allowed to gain more than 1 kg/d.

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