Kvalitativna svojstva zrelog mesa (m. triceps brachii i m. gluteus biceps) janjadi hranjene dodacima hrani

The aim of this study was to evaluate the effect of the supplementation and aging in the gluteus biceps and triceps brachii muscles of lamb. Forty-eight Santa Inês lambs, with 15 kg average initial weight were slaughtered at 32 kg average final weight, after five months of supplementation. Twenty-four animals were allocated to sixteen pastures with residual leaf area index (2.6) and unsupplemented, the other twenty-four animals were allocated to the same conditions but were supplemented. The treatments were cross factorial between rLAI (2.6) and supplemented or not, totalizing 8 treatments. In this experiment, the slaughter criterion was the age of the animals. In the gluteus biceps and triceps brachii muscles, storage for seven days increased lipid oxidation. The values​​ of cooking loss and water holding capacity increased with time of aging and were higher in the gluteus biceps, by 29.40% and 71.30%, respectively. The supplementation implies an increase in production costs, but its use provides the quantitative and qualitative characteristics favorable to the product, aiming to satisfy the consumer market. The supplementation decreased the shelf life, increasing the lipid oxidation during time of aging and affected the lightness and the hue of yellow, which may sffect consumers’ intention to purchase.Mišići triceps brachii i gluteus biceps analizirani su kako bi se ocijenio učinak dodataka prehrani na zrenje janjećeg mesa. Ukupno 48 janjadi pasmine Santa Inês imalo je početnu prosječnu tjelesnu masu 15 kg, a nakon pet mjeseci različite prehrane prosječna je tjelesna masa bila 32 kg. Životinje su razmještene na 16 pašnjaka s rezidualnim indeksom lisne površine 2,6, pod jednakim uvjetima, pri čemu su 24 životinje dobivale dodatke prehrani. Uzevši u obzir indeks lisne površine te dodatke hrani formirano je osam skupina koje su uspoređene faktorijalnom analizom. Kriterij za klanje bila je dob životinja. Povećana oksidacija lipida ustanovljena je nakon sedam dana zrenja mesa mišića triceps brachii i gluteus biceps. Vrijednosti gubitaka nastalih kuhanjem i spososbnost zadržavanja vode povećale su se s duljinom zrenja te su u m. gluteus biceps bile više, 29,40 % odnosno 71,30 %. Dodaci prehrani podrazumijevaju povećane troškove proizvodnje, ali njihova uporaba omogućuje bolje kvantitativne i kvalitativne značajke, s ciljem da se zadovolji tržište. Dodaci prehrani skraćuju rok trajanja mesa, povećavaju oksidaciju lipida za vrijeme zrenja te utječu na svjetloću i žutilo zbog čega potrošači mogu dvojiti pri kupnji mesa

Efeito de diferentes fontes de carboidratos não-fibrosos sobre o pH ruminal e digestibilidade in vitro de forragens tropicais

O presente estudo teve como objetivo avaliar os carboidratos não-fibrosos (CNF) em dietas à base de cana-de-açúcar sobre o pH ruminal e digestibilidade da forragem, e descrever as curvas de degradação dos CNF. O estudo foi composto de dois ensaios. No primeiro, três novilhos canulados no rúmen, com peso vivo de 350 ± 15 kg (Média ± DP), foram alocados em um quadrado latino (QL) 3×3, e alimentados com dietas contendo: milho moído (MM, tamanho de partículas 0,9 mm), laminado a vapor (MLV) ou polpa cítrica peletizada (PCP). Cada período tinha 14 d, sendo os primeiros 12 para adaptação e o 13º para a medição seriada do pH e o 14º para a coleta de líquido ruminal e incubação in vitro para digestibilidade da MS e FDN (DIVMS e DIVFDN) de feno de bermudagrass (Feno) e silagens de milho (SM) e cana (SC). No segundo ensaio, coletou-se fluido ruminal de um touro canulado, alimentado com silagem de milho e concentrado padrão, para digestão in vitro dos CNF em vários tempos. Esses resultados foram utilizados para ajustar as curvas de degradação dos CNF e calcular o tempo de colonização, frações alimentares e taxa de degradação. Os resultados do primeiro ensaio foram analisados em um QL 3×3. O modelo dos parâmetros de digestibilidade incluiu efeito fixo de forragem (Alimento), dieta com CNF (Dieta) e interação (Alimento × Dieta), e efeito aleatório de animal e período. O modelo para pH incluiu efeito fixo de Dieta, Tempo como medida repetida, animal e período como aleatórios. Foi considerada a probabilidade significativa de ≤ 5% (α = 0,05). As curvas de degradação dos CNF foram ajustadas pelo PROC NLIN do SAS, e parâmetros de equação comparados por intervalo de confiança. Houve interação Dieta × Tempo no pH ruminal (P = 0,04), onde o MLV diminuiu o pH comparado com PCP e MM apenas no tempo 6 h. Não houve interação Alimento×Dieta (P > 0,05) para nenhum parâmetro de digestibilidade. Houve efeito de Alimento sobre a DIVMS e DIVFDN, após 30 e 48 h de incubação (P < 0,01). A SM teve a maior DIVMS, seguido por SC e Feno, após 30 e 48 h de incubação. A SM teve a maior DIVFDN após 30 h, comparado com SC e Feno. No entanto, para DIVFDN após 48 h, a SM teve maior média, seguida da SC e Feno. O fluido ruminal de animais alimentados com MLV diminuiu a DIVMS e DIVFDN (P < 0.05) de todas as forragens, após 48 h. Resultados do segundo ensaio mostram que PCP diminuiu o tempo de colonização, fração B e aumentou a kd comparado com os dois milhos, e MLV apresentou maior kd que o MM. Em conclusão, a dieta com MLV diminuiu o pH ruminal no tempo 6 h e, consequentemente, diminuiu a DIVFDN das forragens avaliadas. Embora PCP tenha apresentado menor tempo de colonização e maior taxa de degradação da fração B, não afetou negativamente o pH do rúmen nem a digestibilidade da fibra das forragens.The present study aimed to evaluate non-fiber carbohydrates (NFC) in sugarcane-based diets on rumen pH, and forage digestibility, and to describe NFC degradation curves. The study consisted of two trials. For the first trial, three rumen cannulated steers, BW of 350 ± 15 kg (mean ± SE), were assigned in a 3×3 Latin Square (LS) design. They were fed diets containing finely-ground (0.9 mm average particle size) corn (GC), steam-rolled corn (SRC), or pelleted citrus pulp (PCP). Each period had 14 d, with the first 12 for adaptation. The 13th d was for serial measurement of rumen pH, and the14th for rumen fluid collection and in vitro incubation for DM and NDF digestibility (IVDMD and IVNDFD) of bermudagrass hay (Hay), corn (CS), and sugarcane (SS) silages. In the second trial, rumen fluid of a cannulated bull, fed corn silage and a regular concentrate, was collected for in vitro digestion of NFC for multiple time points. The incubation results were used to adjust the NFC degradation curves, and calculate lag-time, feed fractions, and degradation rate. Data from first trial was analyzed in a 3×3 LS. The model for the digestibility parameters included fixed effects of forage (Feed), diets with NFC (Diet), and their interaction (Feed × Diet), and random effect of animal and period. The model for rumen pH included fixed effect of diet, time as repeated measures, animal and period as random effects. The significance was considered at probability ≤ 5% (α = 0.05). The NFC degradation curves were adjusted using the PROC NLIN procedure from SAS, and equation parameters compared using confidence intervals. There was a Diet × Time interaction on rumen pH (P = 0.04), where SRC decreased pH compared to PCP and GC diets at the time 6 h, only. There was no Feed × Diet interaction effect (P > 0.05) for any digestibility parameter. There was a Feed effect on both IVDMD and IVNDFD, either after 30 or 48 h incubation (P < 0.01). The CS had the greatest IVDMD, followed by SS and Hay, after 30 and 48 h of incubation. The CS had the greatest IVNDFD after 30 h, compared to SS and Hay. However, for IVNDFD after 48 h, CS presented the greatest mean, followed by SS and Hay. The rumen fluid from animals fed SRC decreased both IVDMD and IVNDFD (P < 0.05) of all roughages after 48 h. Results from the second trial showed that the PCP had lower Lag Time, B fraction and greater kd compared to both corn sources, and SRC had greater kd than GC. In conclusion, the SRC diet decreased rumen pH 6 h after feeding and, consequently, decreased fiber digestibility of the tropical forage sources evaluated. Although the PCP had lower lag time, and faster rate of degradation of B fraction, it did not negatively affect rumen pH or fiber digestibility of forage

Ingestive behavior of Angus yearling steers in natural grassland subjected to fertilization and over sown of temperate species

The objective was to evaluate the ingestive behavior of Angus yearling steers grazing natural grasslands of Southern Brazil, submitted or not to the application of fertilizers: NG= natural grassland; FNG= fertilized natural grassland, and FONG= fertilized natural grassland improved with the over sown of temperate forage species. Three Angus yearling steers and a variable number of put-and-take animals were used per experimental unit, to maintain a forage allowance of 13 kg of dry matter/100 kg of body weight. Ingestive behavior of tester animals was visually assessed in four seasons of the year through instantaneous records of activity every ten minutes during the daytime period. There was no effect of pasture treatments on ingestive behavior. An interaction between seasons and periods of the day was observed for daily grazing and rumination time (P <0.05). The grazing activities were clustered at the beginning and the end of the day in summer, autumn and winter, while in spring it was similar in the 1 st three quarters of the day, with higher activity in the period close to sunset. The animals spent more time grazing in the spring despite the better quality of forage in this season. Regardless of the season, longer residence and grazing time were found in water foci areas. We conclude that grazing time on natural pastures is influenced by forage mass and forage allowance, and bite rate is influenced by the chemical composition of the sward

Digestion of feed fractions and intake of heifers fed hydrolyzed sugarcane stored for different periods

The objective of this study was to evaluate, in Nellore heifers, intake and digestibility of hydrolyzed sugarcane stored for different periods. The experimental design used was a 4 × 4 Latin square, four diets, four Nellore heifers with ruminal cannulas (initial body weight 285.4±23.08 kg and average initial age 14 months) and four periods of 21 days. The diets were composed by fresh sugarcane (time zero) or hydrolyzed sugarcane with addition of 0.5% of hydrated lime, stored for 24, 48 or 72 hours, as the unique forage. Intake and digestibility of feed fractions, nitrogen balance, microbial synthesis efficiency, total number of ruminal protozoans and ammoniacal nitrogen did not significantly change by storing sugarcane with addition of 0.5% of hydrated lime. Sugarcane pH varied quadratically for storage time, with maximum pH of 7.02 after 24 hours from lime addition. Ruminal liquid pH values were higher for heifers fed fresh sugarcane, in comparison with those fed hydrolyzed sugarcane. Sugarcane treated with 0.5% of hydrated lime stored for up to 72 hours does not change ruminal digestion to alter the amount of feed consumed by pubescent Nellore heifers. Thus, lime is a viable technology, once it allows long-duration storage and bee control on treated forage, which contributes to animal feeding logistics

Níveis de concentrado e fontes de carboidratos não-fibrosos sobre desempenho e cinética ruminal de bovinos em terminação

The objective of this study was to quantify the effect of partial replacement of finely ground corn by steam-flaked corn or pelleted citrus pulp and two concentrate levels, either 60 or 80%, on rumen pH, in vitro digestibilities of tropical forages, performance and rumen fermentation of Nellore young bulls. Three rumen cannulated Nellore steers with average BW of 350 &#177; 15 kg were assigned in a 3×3 Latin Square design. The rumen pH was measured and rumen fluid used to evaluate in vitro DM and NDF digestibilities (IVDMD and IVNDFD) of tropical forages. Moreover, a total of 108 Nellore young bulls with initial BW of 365.3 &#177; 3.12 kg, were distributed in collective pens, with 3 animals per pen, in a randomized complete block design with 6 replicates in a 3×2 factorial arrangement of treatments. The performance, carcass traits, blood parameters, feeding behavior, and sorting index were evaluated. Additionally, six rumen-cannulated steers, weighing 345.10 &#177; 14 kg were arranged in 2 6×6 non-contemporary Latin squares, in a 3×2 factorial arrangement of treatments. The rumen was manually evacuated, an aliquot of the digesta was filtered to separate solid and liquid phases. Rumen fluid samples were taken at multiple times after feeding to determine pH, short chain fatty acids and ammonia nitrogen. The steam-flaked corn decreased in vitro digestibility of the forages evaluated, but increased rate of degradation. It also increased propionic acid, but decreased ammonia compared to the other diets. It decreased NDF total tract digestibility compared to citrus pulp. The steam-flaked corn increased fat deposition, with no impact on animal performance. The citrus pulp decreased lag time and increased rate of degradation. The pelleted citrus pulp caused the bulls to sort the diet against large particles, decreasing the DMI, performance, and rumen propionic acid concentration, but increased the acetic acid, disappearance rate of NDFd, and digestibilities of DM and OM. On the other hand, the 80% concentrate diets decreased passage rate of NDF, but increased the digestibilities of OM, DM, and performance, despite the lower intake. In conclusion, the inclusion of 80% concentrate in sugarcane silage based-diets lowers intake, and increases performance, the partial replacement of ground corn by steam-flaked corn improves carcass fat deposition. And citrus pulp increases rumen pH, fiber digestibility but decreases intake, and performance of finishing young Nellore bulls.O objetivo deste estudo foi quantificar o efeito da substituição parcial de milho finamente moído por milho floculado a vapor ou polpa cítrica peletizada e dois níveis de concentrado, 60 ou 80% sobre o pH, digestibilidade in vitro de forragens tropicais, desempenho e fermentação ruminal de tourinhos Nelore. Foram utilizados três novilhos Nelore canulados no rúmen PV médio de 350 &#177; 15 kg em um delineamento de quadrado latino 3×3. O pH do rúmen foi medido e o fluido do rúmen utilizado para avaliar as digestibilidades in vitro da MS e da FDN (DIVMS e DIVFDN) de forragens tropicais. Além disso, um total de 108 novilhos Nelore com PV inicial de 365,3 &#177; 3,12 kg, foram distribuídos em baias coletivas, com 3 animais por baia, em um delineamento de blocos ao acaso com 6 repetições em um arranjo fatorial 3×2 de tratamentos. As avaliações feitas foram desempenho, características de carcaça, parâmetros de sangue, comportamento alimentar e índice de seleção de partículas. Ademais, seis novilhos canulados no rúmen, pesando 345,10 &#177; 14 kg, foram organizados em 2 quadrados latinos não contemporâneos 6×6, em um arranjo fatorial 3×2 de tratamentos. O rúmen foi evacuado manualmente, uma alíquota da digesta foi filtrada para separar as fases sólida e líquida. As amostras de fluido de rúmen foram tomadas em várias horas após a alimentação para determinar o pH, ácidos graxos de cadeia curta, e nitrogênio amoniacal. O milho floculado diminuiu a digestibilidade in vitro de forragens avaliadas, mas aumentou a taxa de degradação, ácido propiônico, mas diminuiu a amônia em comparação com as outras dietas., e a digestibilidade do trato total do FDN em relação à polpa cítrica. O milho floculado aumentou a deposição de gordura, sem impacto no desempenho. A polpa cítrica diminuiu o Lag time e aumentou a taxa de degradação, e fez com que os touros selecionassem a dieta contra partículas grandes, diminuindo o CMS, desempenho e ácido propiônico do rúmen. Por outro, lado a polpa aumentou o ácido acético, a taxa de desaparecimento de FDNd e digestibilidades de MS e MO. As dietas com 80% de concentrado diminuíram a taxa de passagem do FDN, mas aumentaram as digestibilidades da MO, MS e desempenho, apesar da menor ingestão. Em conclusão, a inclusão de 80% de concentrado em dietas à base de silagem de cana-de-açúcar reduz a ingestão e aumenta o desempenho. A substituição parcial de milho moído por milho floculado melhora a deposição de gordura de carcaça. A polpa cítrica aumenta o pH do rúmen, e a digestibilidade da fibra, mas diminui o consumo e desempenho de tourinhos Nelore em terminação

Zilpaterol hydrochloride improves beef yield, changes palatability traits, and increases calpain-calpastatin gene expression in Nellore heifers

This research aimed to evaluate the effects of the beta-agonist zilpaterol hydrochloride (ZH) on carcass traits, subprimal yield, meat quality, palatability traits, and gene expression in Nellore heifers. Zilpaterol increased Longissimus lumborum area and did not change back fat thickness, meat color, and cooking loss. Heifers fed ZH had greater hindquarter weight and carcass percentage. Muscles from hindquarter were heavier for animals fed ZH. Forequarter (% of carcass) decreased and brisket did not change with ZH supplementation. There were no differences between treatments for steak aroma, beef flavor, and off-flavor. However, tenderness and juiciness were reduced by ZH, depending on postmortem aging. Zilpaterol increased Calpain-1, Calpain-2, and calpastatin mRNA expression, with no effect of day of slaughter or ZH\ua0×\ua0Day interaction. In conclusion, ZH supplementation improved hypertrophy, meat production, and debone yield in Nellore heifers, which led to decreased tenderness and to increased mRNA expression in the calpain-calpastatin system

Replacing corn with ground or pelleted citrus pulp in diets of Nellore heifers

Citrus pulp can replace corn in feedlot diets in order to decrease metabolic problems by reducing formation of lactate ruminal. However, while eating, animals can easily select against pelleted citrus pulp due to the greater particle size of the pellet. Therefore, grinding citrus pulp pellet can be an alternative to decrease particle selectivity. This study was realized to evaluate the replacement of ground corn by pelleted citrus pulp and ground citrus pulp on animal performance, sorting index, and feeding behavior of Nellore heifers. Thirty-six Nellore heifers were randomly assigned to three treatments: control diet based on ground corn (GC), partial replacement of GC by ground citrus pulp (GCP), and partial replacement of GC by pelleted citrus pulp (PCP). . Heifers fed with the GC diet had higher final body weight (BW), average daily gain (ADG), and dry matter intake (DMI) compared with heifers fed with citrus pulp (P < 0.05). Ground citrus pulp increased DMI and fiber intake compared with the PCP group (P < 0.05). Heifers fed with PCP and GCP sorted for diet particles from 8 to 19 mm and selected particles with less than 1.18 mm (P < 0.05). Thus, the ground citrus pulp is better than pelleted citrus pulp due to higher feed intake and ADG, in consequence of lower selection index