Influence of nutritional management prior to adaptation to a feedlot diet on ruminal microbiota of Nellore cattle

ABSTRACT The objective of this study was to evaluate the effect of either a limited forage intake or concentrate supplementation prior to the adaptation to high-concentrate diets on dry matter intake, ruminal pH, bacteria, and protozoa of Nellore cattle. The experiment was designed as a two 3×3 Latin square, and six cannulated Nellore steers were used. Each experimental period was composed by three feeding phases: pre-adaptation (14 days), adaptation (12 days), and finishing (seven days) diet, in a total of 33 days per period. The steers were assigned to one of three pre-adaptation dietary treatments: control (Tifton hay fed ad libitum + mineral supplement), restriction (Tifton hay fed at 1.4% of BW + mineral supplement), and concentrate (Tifton hay fed ad libitum + 0.5% of BW of a mix of concentrate feedstuffs and mineral supplement). The adaptation period consisted of two adaptation diets, which contained 72 and 79% concentrate for six days each. The finishing diet contained 86% concentrate. During the pre-adaptation phase, restricted cattle had higher pH than concentrate-fed cattle. There was a reduction in M. elsdenii relative population in cattle from either restriction or concentrate groups. During adaptation and finishing phases, cattle from concentrate group had smaller F. succinogenes populations compared with the control group. The previous nutritional backgrounds impact ruminal microbiota during adaptation and finishing phases without causing any negative effect on ruminal pH. Feeding concentrate prior to the adaptation positively impacted the transition to high-concentrate diets and promoted increased dry matter intake.

The 2019 Brazilian survey on nutritional practices provided by feedlot cattle consulting nutritionists

This survey aimed to provide a current outlook of nutritional recommendations and management practices adopted by feedlot nutritionists in Brazil. The survey questionnaire consisted of 96 questions that included general information on nutritionists, animals, ingredients utilized in finishing diets, management and formulation practices, feeding management, and challenges associated with applying nutritional recommendations in practice. Thirty-six nutritionists, responsible for 4,671,062 animals in Brazil, responded our questionnaire. An increase in the percentage of nutritionists (38.9%) recommending 66% or more grain inclusion in the diets was observed. Fine grinding remained the preferred grain processing method by nutritionists (44.4%); however, more than 50% of nutritionists recommended high-moisture harvest and storage as the secondary grain processing method of choice. The average level of concentrate in the diets was 83.3%, which is higher compared with past surveys. The preferred fiber analysis method by 80.6% respondents was physically effective neutral detergent fiber (peNDF), and corn silage remained the main roughage source in finishing diets (69.4%). Improvements in diet mixing and distribution were also noted. While 79.0% of nutritionists' clients use a truck-mounted mixer and 69.5% of them also use programmed delivery per pen, 44.4% of the nutritionists reported that their clients use clean-bunk management. Respiratory diseases and acidosis (reported by 71.4 and 27.6% of the respondents, respectively) are among the main health problems. The present survey provides an overview of nutritional practices currently adopted by feedlot nutritionists, who played an important role on the improvement of feeding management in Brazil over the last 10 years.

Castração de bovinos Nelore na terminação em confinamento / Castration of Nellore cattle in feedlot finishing diets

O objetivo do presente estudo foi avaliar o desempenho e características de carcaça de bovinos Nelore castrados e não castrados terminados em confinamento com dieta de alto concentrado. Trinta e seis bovinos machos da raça Nelore com idade de 24 meses, provenientes de recria em sistema de pastejo contínuo, foram divididos em dois grupos de 18 animais (castrados e não castrados) com peso vivo inicial (PVi) médio de 347,5 kg ± 21,61 kg. O delineamento experimental foi em blocos casualizados, divididos de acordo com o PVi para cada condição sexual avaliada, constituindo desta forma dois tratamentos experimentais: animais castrados e animais não castrados. Cada tratamento foi composto por seis baias (3 animais/baia), sendo estas consideradas as unidades experimentais do estudo. O período de confinamento foi de 112 dias, sendo o abate realizado no 113º dia. Foram avaliados a ingestão de matéria seca (IMS), o ganho de peso diário (GPD), conversão alimentar (CA) e eficiência alimentar (EA). Além disso, foram avaliados a deposição de tecido muscular e adiposo por meio de ultrassonografia. Após o abate dos animais foram determinados o peso de carcaça quente (PCQ), o peso de carcaça fria (PCF) e rendimento de carcaça (RC). Os dados foram analisados utilizando-se o programa PROC MIXED do SAS e teste de Tukey (P ≤ 5%). Não houveram diferenças significativas para as variáveis PVi e IMS em porcentagem de PV. Já as variáveis PVf, GPD, CA e EA apresentaram efeitos significativos, tendo o grupo de animais não castrados melhor desempenho produtivo. Para as avaliações de características de carcaça foram observadas diferenças significativas para PCQ e PCF onde os animais do grupo não castrado também apresentaram melhores pesos de carcaça. Portanto, conclui-se que para sistemas de confinamento com dietas de alto teor de concentrado, a castração de bovinos Nelore não é recomendada, pois interferiu negativamente no desempenho produtivo das carcaças dos animais castrados.

The objective of the present study was to evaluate the performance and carcass characteristics of Nelore bulls and steers, finished in feedlot with high concentrate diet. Thirty-six male Nelore cattle with 24 months old, from rearing in a continuous grazing system were divided into two groups of 18 animals (castrated and non-castrated) with initial mean body weight (iBW) of 347.5 kg ± 21.61 kg. The experimental design was a randomized complete block according to iBW for each sexual condition evaluated, constituting two experimental treatments: castrated animals and non-castrated animals. Each treatment consisted of six pens (3 animals/pen), these being considered the experimental units. The feedlot period was 112-days and the slaughter was carried out on the 113th day. The dry matter intake (DMI), average daily gain (ADG), feed conversion (F:G) and feed efficiency (G:F) were evaluated. In addition, the deposition of muscular and adipose tissue was evaluated by means of ultrasonography. After slaughtering of the animals the hot carcass weight (HCW), cold carcass weight (CCW) and carcass yield (YG) were determined. The data were analyzed using thePROC MIXED program from SAS and Tukey test (P ≤ 5%). There was no significant difference for the variables iBW and DMI in percentage of BW. The fBW, ADG, F:G and G:F variables had significant effects, and the group of non-castrated animals obtained abetter productive performance. For the carcass traits evaluations, a significant difference was observed for HCW and CCW, where animals from the non-castrated group also had better carcass data. Therefore, it is concluded that for feedlot systems with highconcentrate diets, castration of Nellore cattle is not recommended because it interfered negatively in the productive performance of the castrated animals.

Castração de bovinos Nelore na terminação em confinamento / Castration of Nellore cattle in feedlot finishing diets

O objetivo do presente estudo foi avaliar o desempenho e características de carcaça de bovinos Nelore castrados e não castrados terminados em confinamento com dieta de alto concentrado. Trinta e seis bovinos machos da raça Nelore com idade de 24 meses, provenientes de recria em sistema de pastejo contínuo, foram divididos em dois grupos de 18 animais (castrados e não castrados) com peso vivo inicial (PVi) médio de 347,5 kg ± 21,61 kg. O delineamento experimental foi em blocos casualizados, divididos de acordo com o PVi para cada condição sexual avaliada, constituindo desta forma dois tratamentos experimentais: animais castrados e animais não castrados. Cada tratamento foi composto por seis baias (3 animais/baia), sendo estas consideradas as unidades experimentais do estudo. O período de confinamento foi de 112 dias, sendo o abate realizado no 113º dia. Foram avaliados a ingestão de matéria seca (IMS), o ganho de peso diário (GPD), conversão alimentar (CA) e eficiência alimentar (EA). Além disso, foram avaliados a deposição de tecido muscular e adiposo por meio de ultrassonografia. Após o abate dos animais foram determinados o peso de carcaça quente (PCQ), o peso de carcaça fria (PCF) e rendimento de carcaça (RC). Os dados foram analisados utilizando-se o programa PROC MIXED do SAS e teste de Tukey (P ≤ 5%). Não houveram diferenças significativas para as variáveis PVi e IMS em porcentagem de PV. Já as variáveis PVf, GPD, CA e EA apresentaram efeitos significativos, tendo o grupo de animais não castrados melhor desempenho produtivo. Para as avaliações de características de carcaça foram observadas diferenças significativas para PCQ e PCF onde os animais do grupo não castrado também apresentaram melhores pesos de carcaça. Portanto, conclui-se que para sistemas de confinamento com dietas de alto teor de concentrado, a castração de bovinos Nelore não é recomendada, pois interferiu negativamente no desempenho produtivo das carcaças dos animais castrados.(AU)

The objective of the present study was to evaluate the performance and carcass characteristics of Nelore bulls and steers, finished in feedlot with high concentrate diet. Thirty-six male Nelore cattle with 24 months old, from rearing in a continuous grazing system were divided into two groups of 18 animals (castrated and non-castrated) with initial mean body weight (iBW) of 347.5 kg ± 21.61 kg. The experimental design was a randomized complete block according to iBW for each sexual condition evaluated, constituting two experimental treatments: castrated animals and non-castrated animals. Each treatment consisted of six pens (3 animals/pen), these being considered the experimental units. The feedlot period was 112-days and the slaughter was carried out on the 113th day. The dry matter intake (DMI), average daily gain (ADG), feed conversion (F:G) and feed efficiency (G:F) were evaluated. In addition, the deposition of muscular and adipose tissue was evaluated by means of ultrasonography. After slaughtering of the animals the hot carcass weight (HCW), cold carcass weight (CCW) and carcass yield (YG) were determined. The data were analyzed using thePROC MIXED program from SAS and Tukey test (P ≤ 5%). There was no significant difference for the variables iBW and DMI in percentage of BW. The fBW, ADG, F:G and G:F variables had significant effects, and the group of non-castrated animals obtained abetter productive performance. For the carcass traits evaluations, a significant difference was observed for HCW and CCW, where animals from the non-castrated group also had better carcass data. Therefore, it is concluded that for feedlot systems with highconcentrate diets, castration of Nellore cattle is not recommended because it interfered negatively in the productive performance of the castrated animals.(AU)

Estimation of genetic parameters for weight traits and Kleiber Index in a Brahman cattle population

Interest in improving feed efficiency of cattle has been increasing. The residual feed intake (RFI), the most commonly used measurement of feed efficiency, is expensive and can only be used in a small number of animals. The Kleiber Index has also been proposed to measure RFI. In this study, we estimated genetic parameters for the Kleiber Index average daily weight gain and adjusted weights to obtain a more comprehensive understanding of potential responses to selection and support the development of breeding strategies. Genetic analyses were conducted on animal records from a data file with 36,505 animals recorded by ABCZ (Brazilian Association of Zebu Breeders). Restricted maximum likelihood estimates of genetic parameters were computed with Wombat software. Heritabilities ranged from 0.24 to 0.22 for adjusted weights, from 0.12 to 0.26 for Kleiber Indexes and from 0.15 to 0.22 for average daily gains. Correlations between traits ranged from -0.06 to 0.99. Results indicated that Kleiber Indexes at different ages do not constitute a viable solution for the selection of bulls and cows for Brazilian Brahman populations in terms of feeding efficiency.

Estimation of genetic parameters for weight traits and Kleiber Index in a Brahman cattle population

Interest in improving feed efficiency of cattle has been increasing. The residual feed intake (RFI), the most commonly used measurement of feed efficiency, is expensive and can only be used in a small number of animals. The Kleiber Index has also been proposed to measure RFI. In this study, we estimated genetic parameters for the Kleiber Index average daily weight gain and adjusted weights to obtain a more comprehensive understanding of potential responses to selection and support the development of breeding strategies. Genetic analyses were conducted on animal records from a data file with 36,505 animals recorded by ABCZ (Brazilian Association of Zebu Breeders). Restricted maximum likelihood estimates of genetic parameters were computed with Wombat software. Heritabilities ranged from 0.24 to 0.22 for adjusted weights, from 0.12 to 0.26 for Kleiber Indexes and from 0.15 to 0.22 for average daily gains. Correlations between traits ranged from -0.06 to 0.99. Results indicated that Kleiber Indexes at different ages do not constitute a viable solution for the selection of bulls and cows for Brazilian Brahman populations in terms of feeding efficiency.(AU)

Feedlot performance, feeding behavior and rumen morphometrics of Nellore cattle submitted to different feeding frequencies

Owing to the lack of information in the literature about the ideal feeding frequency adopted by feedlot systems, this study was designed to evaluate the effect of different feeding frequencies on performance, carcass traits, feeding behavior and rumen morphometrics of Nellore cattle. Forty-eight yearling bulls were housed in individual pens with an average initial body weight of 358.2 kg. The experiment was designed as a completely randomized block and the treatments were the feeding of cattle one, two, three, or four times daily (n = 12 per treatment). Orthogonal contrasts were used to assess linear, quadratic and cubic relationship between feeding frequency and the dependent variable. As feeding frequency increased, final body weight (p = 0.03) and average daily gain (p = 0.01; one: 0.98 kg d1; two: 0.96 kg d1; three: 1.18 kg d1; four: 1.14 kg d1) increased linearly and the feed:gain ratio decreased (p = 0.02). Also, as feeding frequency increased, hot carcass weight was affected cubically (p = 0.01; one: 246.9 kg; two: 243.0 kg; three: 263.1 kg; four: 258.1 kg). During the adaptation period dry matter intake variation was affected cubically (p 0.05; one: 16 %; two: 23 %; three: 14 %; four: 16 %). Increases in feeding frequency affected papillae height (p 0.01) and papillae surface area (p 0.01) cubically, as well as producing increases in the mitotic index (p = 0.05; one: 9 %; two: 11 %; three: 13 %; four: 13 %) and cells in proliferation (p = 0.05) linearly. Thus, Nellore yearling bulls should be fed three times daily in feedlot operations.

Feedlot performance, feeding behavior and rumen morphometrics of Nellore cattle submitted to different feeding frequencies

Owing to the lack of information in the literature about the ideal feeding frequency adopted by feedlot systems, this study was designed to evaluate the effect of different feeding frequencies on performance, carcass traits, feeding behavior and rumen morphometrics of Nellore cattle. Forty-eight yearling bulls were housed in individual pens with an average initial body weight of 358.2 kg. The experiment was designed as a completely randomized block and the treatments were the feeding of cattle one, two, three, or four times daily (n = 12 per treatment). Orthogonal contrasts were used to assess linear, quadratic and cubic relationship between feeding frequency and the dependent variable. As feeding frequency increased, final body weight (p = 0.03) and average daily gain (p = 0.01; one: 0.98 kg d1; two: 0.96 kg d1; three: 1.18 kg d1; four: 1.14 kg d1) increased linearly and the feed:gain ratio decreased (p = 0.02). Also, as feeding frequency increased, hot carcass weight was affected cubically (p = 0.01; one: 246.9 kg; two: 243.0 kg; three: 263.1 kg; four: 258.1 kg). During the adaptation period dry matter intake variation was affected cubically (p 0.05; one: 16 %; two: 23 %; three: 14 %; four: 16 %). Increases in feeding frequency affected papillae height (p 0.01) and papillae surface area (p 0.01) cubically, as well as producing increases in the mitotic index (p = 0.05; one: 9 %; two: 11 %; three: 13 %; four: 13 %) and cells in proliferation (p = 0.05) linearly. Thus, Nellore yearling bulls should be fed three times daily in feedlot operations.(AU)

Incidência de ruminite e abscesso hepático em bovinos jovens confinados alimentados com dietas contendo aditivos alimentares / Incidence of ruminite and liver abscess of feedlot bullocks fed high concentrate diets containing feed additives

O objetivo deste estudo foi avaliar o efeito da inclusão do preparado de anticorpos policlonais (PAP) e/ou de monensina sódica (MON) na morfologia das papilas ruminais, incidência de ruminites (IR) e abscessos hepáticos (AH) em bovinos jovens confinados. Foram utilizados 72 novilhos da raça Brangus, não castrados, com peso vivo inicial de 261,04 ± 34,73 kg, em 24 baias (3 animais/baia) com 6 repetições por tratamento. O delineamento experimental foi inteiramente casualizado em arranjo fatorial 2 x 2, sendo os fatores a adição ou não de MON e PAP. Após o abate foram realizadas as avaliações. No fígado tanto o percentual de AH quanto a severidade foram menores (P < 0,01) nos animais que receberam PAP em relação aos que não receberam. A inclusão de MON foi apenas eficiente em reduzir (P < 0,01) a severidade dos AH em relação ao tratamento sem o aditivo. Não houve efeito dos aditivos sobre o IR. O tratamento com MON resultou em maior (P=0,07) superfície de absorção/cm2 de parede de rúmen e maior ( P=0,10) área papilar em relação ao tratamento sem este aditivo. Número de papilas/cm2 de parede e área média das papilas não apresentaram diferenças entre tratamentos. O uso de PAP foi eficiente na redução de AH bem como a severidade, porém não foi capaz de melhorar a forma e a estrutura das papilas ruminais, como o observado com o uso de MON.(AU)

The aim of this study was to evaluate the effects of polyclonal antibodies preparation (PAP) and/or monensin (MON) on the morphology of the rumen papillae, incidence of ruminate (IR) and liver abscess in feedlot bullocks. Seventy-two bullocks Brangus (261.04 ± 34.73kg) were housed in 24 pens (3 bullocks/pen) with6 replications per treatment. The experimental design was completely randomized 2 x 2 factorial, the factors werethe inclusion or not of MON and PAP.After slaughter, the evaluations were performed. For the livers, both the percentage of abscesses and the severity of them were lower (P< 0.01) in animals fed diets with PAP than those fed MON. The inclusion of MON in the diet was only effective in reducing (P< 0.01) the severity of the abscesses in relation to treatment without this additive. There was no effect (P> 0.05) of additives on the IR. The treatment with MON had higher (P = 0.07) surface absorption/cm2 wall of the rumen and greater (P = 0.10) papillary area compared to treatment without this additive. Number of papillae/cm2 wall and average area of the papillae showed no difference among treatments. The use of PAP was effective in reducing HA as well as the severity the same, but was not able to improve the shape and structure of the ruminal papillae, as observed with the use of MON.(AU)

Incidência de ruminite e abscesso hepático em bovinos jovens confinados alimentados com dietas contendo aditivos alimentares / Incidence of ruminite and liver abscess of feedlot bullocks fed high concentrate diets containing feed additives

O objetivo deste estudo foi avaliar o efeito da inclusão do preparado de anticorpos policlonais (PAP) e/ou de monensina sódica (MON) na morfologia das papilas ruminais, incidência de ruminites (IR) e abscessos hepáticos (AH) em bovinos jovens confinados. Foram utilizados 72 novilhos da raça Brangus, não castrados, com peso vivo inicial de 261,04 ± 34,73 kg, em 24 baias (3 animais/baia) com 6 repetições por tratamento. O delineamento experimental foi inteiramente casualizado em arranjo fatorial 2 x 2, sendo os fatores a adição ou não de MON e PAP. Após o abate foram realizadas as avaliações. No fígado tanto o percentual de AH quanto a severidade foram menores (P < 0,01) nos animais que receberam PAP em relação aos que não receberam. A inclusão de MON foi apenas eficiente em reduzir (P < 0,01) a severidade dos AH em relação ao tratamento sem o aditivo. Não houve efeito dos aditivos sobre o IR. O tratamento com MON resultou em maior (P=0,07) superfície de absorção/cm2 de parede de rúmen e maior ( P=0,10) área papilar em relação ao tratamento sem este aditivo. Número de papilas/cm2 de parede e área média das papilas não apresentaram diferenças entre tratamentos. O uso de PAP foi eficiente na redução de AH bem como a severidade, porém não foi capaz de melhorar a forma e a estrutura das papilas ruminais, como o observado com o uso de MON.

The aim of this study was to evaluate the effects of polyclonal antibodies preparation (PAP) and/or monensin (MON) on the morphology of the rumen papillae, incidence of ruminate (IR) and liver abscess in feedlot bullocks. Seventy-two bullocks Brangus (261.04 ± 34.73kg) were housed in 24 pens (3 bullocks/pen) with6 replications per treatment. The experimental design was completely randomized 2 x 2 factorial, the factors werethe inclusion or not of MON and PAP.After slaughter, the evaluations were performed. For the livers, both the percentage of abscesses and the severity of them were lower (P 0.05) of additives on the IR. The treatment with MON had higher (P = 0.07) surface absorption/cm2 wall of the rumen and greater (P = 0.10) papillary area compared to treatment without this additive. Number of papillae/cm2 wall and average area of the papillae showed no difference among treatments. The use of PAP was effective in reducing HA as well as the severity the same, but was not able to improve the shape and structure of the ruminal papillae, as observed with the use of MON.

Use of feeding direct-fed microbials and monensin on feedlot performance and carcass traits of Nellore cattle / Utilização de probiótico e monensina sódica sobre o desempenho produtivo e características de carcaça de bovinos Nelore terminados em confinamento

The objective of this study was to evaluate the effect of probiotic based on lactate-producing bacteria (DBR) and sodium monensin (MON) on feedlot performance and carcass traits of feedlot Nellore cattle. The experiment was designed as a completely randomized design, replicated 6 times, in which 18 18-months-old yearling Nellore bulls (362,0 ± 30,0kg) were fed in individual pens for 84 days (1 animal/pen) in Calan gate system according to the treatments: 1) 2g of DBR; 2) 1g of DBR + 138mg of MON and; 3) 275mg of MON. The experiment lasted 84 days; the animals were both weighed and evaluated by ultrasound every 28 days. There was no effect of feed additives on final body weight and dry matter intake, expressed as percentage of body weight. The average daily gain was lower in the first 28 and 56 days of the study for animals fed MON and MON+DBR, but overall, no differences were observed between treatments were detected. Animals fed MON+DBR showed higher dry matter intake throughout the study, but lower feed conversion than those fed with DBR or MON. Animals fed MON+DBR had decreased dressing percentage than those supplemented with DBR only. In addition, animals fed only MON had thicker back fat by the end of the study. Supplementation with DBR may eventually be an alternative to replace MON.(AU)

O objetivo com este estudo foi avaliar o efeito do probiótico a base de bactérias produtoras de lactato (DBR) e da monensina sódica (MON) sobre o desempenho produtivo e características de carcaça de bovinos Nelore terminados em confinamento. Foram utilizados 18 machos, não castrados, com média de idade de 18 meses e 362,0 ±30,0kg de peso vivo inicial, divididos em três tratamentos: 1) 2g de DBR; 2) 1g de DBR + 138mg de MON e; 3) 275mg de MON, caracterizando delineamento inteiramente casualizado, com 6 animais por tratamento, divididos em 18 baias (1 animal/baia) em sistema de alimentação do tipo Calan Gate. O experimento teve duração de 84 dias, os animais foram pesados e submetidos a avaliações de ultrassonografia a cada 28 dias. Não houve efeito dos aditivos alimentares em relação ao peso vivo final e consumo de massa seca em percentagem do peso vivo. O ganho de peso diário foi menor nos primeiros 28 e 56 dias de estudo para animais que consumiram MON e DBR+MON, porém não foram observadas diferenças entre os tratamentos no período total. Animais alimentados com DBR+MON apresentaram maior consumo de massa seca durante todo o estudo, porém pior conversão alimentar que aqueles alimentados com DBR ou MON. Animais alimentados com DBR+MON apresentaram menor rendimento de carcaça que aqueles suplementados com DBR apenas e animais suplementados com MON tiveram maior espessura(AU)

Use of feeding direct-fed microbials and monensin on feedlot performance and carcass traits of Nellore cattle / Utilização de probiótico e monensina sódica sobre o desempenho produtivo e características de carcaça de bovinos Nelore terminados em confinamento

The objective of this study was to evaluate the effect of probiotic based on lactate-producing bacteria (DBR) and sodium monensin (MON) on feedlot performance and carcass traits of feedlot Nellore cattle. The experiment was designed as a completely randomized design, replicated 6 times, in which 18 18-months-old yearling Nellore bulls (362,0 ± 30,0kg) were fed in individual pens for 84 days (1 animal/pen) in Calan gate system according to the treatments: 1) 2g of DBR; 2) 1g of DBR + 138mg of MON and; 3) 275mg of MON. The experiment lasted 84 days; the animals were both weighed and evaluated by ultrasound every 28 days. There was no effect of feed additives on final body weight and dry matter intake, expressed as percentage of body weight. The average daily gain was lower in the first 28 and 56 days of the study for animals fed MON and MON+DBR, but overall, no differences were observed between treatments were detected. Animals fed MON+DBR showed higher dry matter intake throughout the study, but lower feed conversion than those fed with DBR or MON. Animals fed MON+DBR had decreased dressing percentage than those supplemented with DBR only. In addition, animals fed only MON had thicker back fat by the end of the study. Supplementation with DBR may eventually be an alternative to replace MON.

O objetivo com este estudo foi avaliar o efeito do probiótico a base de bactérias produtoras de lactato (DBR) e da monensina sódica (MON) sobre o desempenho produtivo e características de carcaça de bovinos Nelore terminados em confinamento. Foram utilizados 18 machos, não castrados, com média de idade de 18 meses e 362,0 ±30,0kg de peso vivo inicial, divididos em três tratamentos: 1) 2g de DBR; 2) 1g de DBR + 138mg de MON e; 3) 275mg de MON, caracterizando delineamento inteiramente casualizado, com 6 animais por tratamento, divididos em 18 baias (1 animal/baia) em sistema de alimentação do tipo Calan Gate. O experimento teve duração de 84 dias, os animais foram pesados e submetidos a avaliações de ultrassonografia a cada 28 dias. Não houve efeito dos aditivos alimentares em relação ao peso vivo final e consumo de massa seca em percentagem do peso vivo. O ganho de peso diário foi menor nos primeiros 28 e 56 dias de estudo para animais que consumiram MON e DBR+MON, porém não foram observadas diferenças entre os tratamentos no período total. Animais alimentados com DBR+MON apresentaram maior consumo de massa seca durante todo o estudo, porém pior conversão alimentar que aqueles alimentados com DBR ou MON. Animais alimentados com DBR+MON apresentaram menor rendimento de carcaça que aqueles suplementados com DBR apenas e animais suplementados com MON tiveram maior espessura

Feedlot performance, carcass characteristics and meat quality of Nellore and Canchim bulls fed diets supplemented with vitamins D and E / Desempenho, características de carcaça e carne de bovinos Nelore e Canchim, confinados com dietas suplementadas com vitaminas D e E

This experiment was conducted at Unesp feedlot facility, campus of Botucatu, and aimed to evaluate the supplementation of D and E vitamins on animal performance, carcass characteristics and meat quality of yearling bulls finished in feedlot. Thirty-six 7-mo-old yearling bulls, 18 Nellore (NEL) and 18 Canchim (CAC), with average initial body weight of 234.53 ± 22.15 and 248.13 ± 34.67 kg, respectively, were fed for 126 days. Nine NEL and nine CAC yearling bulls were daily supplemented with 1300 IU of vitamin E and 7.5 x 106 IU of vitamin D3 for 67 days and 10 days before slaughter, respectively. One day before slaughter, blood samples were collected for evaluation of Ca concentration. After chilling, Longissimus muscle (LM) samples were collected for analysis of shear force, myofibrillar fragmentation index, total lipids, D and E vitamins concentrations, and meat shelf life. An increased level of plasma Ca (p 0.05) of vitamins D and E on feedlot performance, carcass characteristics and meat quality.

O experimento foi conduzido no setor de confinamento da Unesp, campus de Botucatu, com o objetivo de avaliar a influência da suplementação das vitaminas D e E sobre o desempenho animal, características de carcaça e qualidade de carne de bovinos jovens confinados. Foram utilizados 36 machos inteiros, 18 Nelore (NEL) e 18 Canchim (CAC), de sete meses de idade com peso vivo inicial médio de 234,53 ± 22,15 e 248,13 ± 34,67 kg, respectivamente, os quais foram confinados por 126 dias. Nove animais NEL e nove CAC foram suplementados diariamente com 1300 UI de vitamina E e 7,5x106 UI de vitamina D3 durante 67 e dez dias antes do abate, respectivamente. Um dia antes do abate foram coletadas amostras de sangue para avaliação do cálcio plasmático. Na desossa, foram colhidas amostras do músculo Longissimus (LM) para análises como força de cisalhamento, índice de fragmentação miofibrilar, lipídeos totais, concentração de vitaminas D e E e tempo de prateleira. Foi observado aumento (p 0,05) da suplementação de vitaminas D e E sobre o desempenho, características de carcaça e qualidade da carne.

Feedlot performance, carcass characteristics and meat quality of Nellore and Canchim bulls fed diets supplemented with vitamins D and E / Desempenho, características de carcaça e carne de bovinos Nelore e Canchim, confinados com dietas suplementadas com vitaminas D e E

This experiment was conducted at Unesp feedlot facility, campus of Botucatu, and aimed to evaluate the supplementation of D and E vitamins on animal performance, carcass characteristics and meat quality of yearling bulls finished in feedlot. Thirty-six 7-mo-old yearling bulls, 18 Nellore (NEL) and 18 Canchim (CAC), with average initial body weight of 234.53 ± 22.15 and 248.13 ± 34.67 kg, respectively, were fed for 126 days. Nine NEL and nine CAC yearling bulls were daily supplemented with 1300 IU of vitamin E and 7.5 x 106 IU of vitamin D3 for 67 days and 10 days before slaughter, respectively. One day before slaughter, blood samples were collected for evaluation of Ca concentration. After chilling, Longissimus muscle (LM) samples were collected for analysis of shear force, myofibrillar fragmentation index, total lipids, D and E vitamins concentrations, and meat shelf life. An increased level of plasma Ca (p < 0.01) was observed due to vitamin supplementation, showing the action of vitamin D on the animal organism. However, there was no effect (p > 0.05) of vitamins D and E on feedlot performance, carcass characteristics and meat quality.(AU)

O experimento foi conduzido no setor de confinamento da Unesp, campus de Botucatu, com o objetivo de avaliar a influência da suplementação das vitaminas D e E sobre o desempenho animal, características de carcaça e qualidade de carne de bovinos jovens confinados. Foram utilizados 36 machos inteiros, 18 Nelore (NEL) e 18 Canchim (CAC), de sete meses de idade com peso vivo inicial médio de 234,53 ± 22,15 e 248,13 ± 34,67 kg, respectivamente, os quais foram confinados por 126 dias. Nove animais NEL e nove CAC foram suplementados diariamente com 1300 UI de vitamina E e 7,5x106 UI de vitamina D3 durante 67 e dez dias antes do abate, respectivamente. Um dia antes do abate foram coletadas amostras de sangue para avaliação do cálcio plasmático. Na desossa, foram colhidas amostras do músculo Longissimus (LM) para análises como força de cisalhamento, índice de fragmentação miofibrilar, lipídeos totais, concentração de vitaminas D e E e tempo de prateleira. Foi observado aumento (p < 0,01) do nível de cálcio plasmático pela suplementação, o que indica atuação da vitamina D no organismo animal. No entanto, não houve efeito (p > 0,05) da suplementação de vitaminas D e E sobre o desempenho, características de carcaça e qualidade da carne.(AU)

Anticorpos policlonais e monensina sódica na alimentação de bovinos jovens confinados com dietas de alto concentrado

O objetivo deste estudo foi estudar os efeitos da suplementação do preparado de anticorpos policlonais (PAP) ou monensina sódica (MON) sobre o desempenho, características de carcaça, perfil metabólico sanguíneo, flutuação da ingestão de matéria seca (IMS) e incidências de rumenites e abscessos de fígado. O delineamento experimental foi inteiramente casualizado em arranjo fatorial 2 × 2, com seis repetições por tratamento, nos quais 48 bovinos machos inteiros de cada grupo genético (GG) avaliado [Brangus (BR) ou Nelore (NE)] foram alimentados com dietas contendo MON ou PAP fornecidos diariamente nas doses de 30 e 300 mg/kg de MS, respectivamente. Os animais passaram por três fases durante o estudo: adaptação (ADAP), crescimento, e terminação. As dietas fornecidas nestes períodos continham 55, 70 e 85% de concentrado, respectivamente. Não foi observado (P > 0,05) efeito principal dos aditivos alimentares (AA) sobre a maioria das características de desempenho, com exceção à IMS em quilos e em porcentagem do peso vivo, onde bovinos recebendo MON apresentaram (P < 0,05) menores IMS. Foi observado (P < 0,01) efeito principal dos AA e dos GG sobre as concentrações de bicarbonato, total de CO2 e excesso de base no fluído extra-celular, onde bovinos recebendo PAP, e aqueles da raça BR, apresentaram maiores concentrações desses metabólitos no sangue. Animais que receberam PAP e aqueles da raça BR, apresentaram maiores (P < 0,01) valores de pH na fase de ADAP que animais suplementados com MON (7,427 vs. 7,400) e animais NE, respectivamente. Bovinos BR apresentaram (P < 0,01) maior ganho de peso diário que bovinos NE em ambas as fases, contudo conversão alimentar similar (P > 0,05). Por outro lado, bovinos NE mostraram maior (P < 0,05) incidência de lesões ruminais. Assim sendo, a suplementação de PAP pode ser uma eventual alternativa...

This study, conducted at the São Paulo State University feedlot, Botucatu Campus, Brazil, was designed to test monensin (MON) and a polyclonal antibody preparation (PAP) against rumen bacteria on feedlot performance of Brangus (BR) and Nellore (NE) cattle. The experiment was designed as a 2 × 2 factorial arrangement using repeated measures over time, replicated 6 times (4 bullocks/pen), in which 48 8-mo-old bullocks of each of two breeds (BD) evaluated were fed diets containing either MON at 30 mg?kg-1 or PAP at 300mg?kg-1 of dry matter (DM). Measures over time were taken according to the phase and level of concentrate fed during the study: 55, 70 and 85%. Phases were named adaptation (AD), growing (GR), and final (FN), respectively. No significant (P > 0.05) feed additives (FA) main effect was observed for any of the feedlot performance variables, with the exception (P < 0.05) of DM intake expressed in kg (PAP= 7.60; MON=7.24) and in % of body weight (PAP= 2.11; MON=2.03). Feeding MON led to greater (P < 0.05) subcutaneous fat deposition throughout the study, and decreased (P < 0.05) the final rib eye area (RBA). As a result a reduced (P < 0.05) RBA deposition, mainly in GR phase, it was observed when feeding MON was compared to feeding PAP. A significant (P < 0.01) FA and BD main effects were found for bicarbonate, total CO2, and base excess in extracellular fluid, where bullocks receiving PAP, and those BR cattle, presented greater concentrations of these metabolites in the blood. Likewise, BR cattle and bullocks receiving PAP had (P < 0.01) higher blood pH in the AD phase than NE cattle and bullocks fed MON (7.427 vs. 7.400), respectively. BR had greater (P < 0.01) average daily gain in GR and FN phases, but similar (P > 0.05) feed conversion was observed. On the other hand, NE bullocks presented greater (P < 0.05) incidence of rumenites. Thus, feeding PAP may...

Desempenho, avaliação ruminal e perfil metabólico sanguíneo de bovinos jovens confinados suplementados com monensina sódica ou anticorpos policlonais

Esse estudo, conduzido no confinamento experimental da UNESP ? Botucatu, foi realizado para testar anticorpos contra as bactérias ruminais S. bovis e F. necrophorum e várias cepas de bactérias proteolíticas sobre o desempenho e incidências de paraqueratose ruminal (IPR) e abscesso hepático em bovinos jovens com diferentes graus de sangue Zebu. O delineamento experimental foi inteiramente casualizado em arranjo fatorial 3X2 em parcelas subdivididas com três repetições (4 animais/baia), aonde três grupos genéticos (24 Tri-Cross (TC) - ½ Brangus, » Angus, » Nelore; 24 Canchim (CC) - ? Charolais, ? Nelore e 24 Nelores (NE)) e dois aditivos alimentares (anticorpos policlonais ? 10 ml/cabeça/dia (AP) e monensina sódica ? 30 mg/kg de dieta (MN)) foram as variáveis estudadas em três períodos de coleta de dados, correspondentes as três dietas com níveis crescentes de concentrado (73, 82 e 85%). Não houve interação (P>0,05) entre os grupos genéticos e os aditivos alimentares estudados. Animais suplementados com AP apresentaram similares (P>0,05) ganho de peso diário (GPD), ingestão de matéria seca em quilos (IMSKG), conversão alimentar (CA) e custo para ganhar um quilo de peso vivo que aqueles suplementados com MN. A ingestão de matéria seca em porcentagem do peso vivo (IMSPV) foi maior (P<0,05) para animais suplementados com AP que aqueles suplementados com MN. As IMSPV e IMSKG foram maiores na dieta de 73% de concentrado (P<0,05) para animais suplementados com AP e não diferiram entre os aditivos alimentares para as outras duas dietas (P>0,05). Conforme as dietas propostas, GPD e IMSPV diminuíram (P<0,05) e CA e IMSKG aumentaram, linearmente, durante o estudo (P<0,05). Animais suplementados com AP apresentarem menor (P=0,09) IPR que àqueles suplementados com MN. TC e CC apresentaram maiores (P<0,05) IMS e GDP e melhor (P<0,05) CA que NE. Rumens de NE mostraram, significativamente (P<0,05), maiores IPR que TC e CC

This study, conducted at the São Paulo State University feedlot, Botucatu Campus, Brazil, was designed to test antibodies against S. bovis, F. necrophorum, and several strains of proteolytic bacteria (RMT) on performance and parakeratosis and liver abscesses incidences of Bos indicus-based types (BIBT). The experiment was designed as a split plot 3X2 factorial scheme, replicated thrice (4 bulls/pen), in which 24 8-mo-old bulls (297 kg) of each of three BIBT: 3-way cross (½ Brangus, » Angus, » Nellore; TC), Canchim (? Charolais, ? Nellore; CC), or Nellore (NE) were fed one of two diets containing either monensin (MO) at 30 mg/kg of diet or RMT at 10 mL/head/d and evaluated in increasing levels of concentrate (73, 82 and 85%). There were no interactions (P>0.05) between breed type and feed additives. Bulls fed RMT had similar (P>0.05) average daily gain (ADG), dry matter intake in kilos (DMIKG), cost to gain one kilo of body weight and feed conversion (FC) as those fed MO. When analyzed as percentage of BW, bulls fed RMT consumed (P<0.05) more feed than those fed MO. DMIKG and DMIBW were higher in 73% concentrate but did not differ in the others two diets evaluated. According to diets offered, ADG and DMIBW were reduced (P<0.05) and DMIKG and FC (P<0.05) were increased as the level of concentrate in the diet got higher. Bulls fed RMT to have lesser (P=0.09) rumen parakeratosis scores than those fed MO. TC and CC had greater (P<0.05) DMI and ADG, and better (P<0.05) FC than NE. Rumens from NE bulls had greater (P<0.05) parakeratosis scores than CC and TC. Just one liver abscess was found in this study what led to conclude as no abscesses incidence. Feeding RMT enhanced intake of Bos indicus-based bulls fed 73% concentrate diet while maintaining rumen health, and permitting performance similar to that of bulls fed monensin. RMT could be an eventual substitute if monensin was really prohibited