A comparison of the economic results obtained by Holstein steer calves with different feedlot arrival body weights / Uma comparação dos resultados econômicos obtidos por bezerros Holstein com diferentes pesos vivos na entrada do confinamento

ABSTRACT: The study compared the economic results between five groups of Holstein steers with different arrival body weights (ABW) but similar ages in the feedlot. The average ABW were 105, 112, 117, 123 and 129 kg (30, 90, 87, 60, and 30 calves, respectively) with an age of 113 ± 1d. The calves were randomly distributed using an unbalanced design. The calves were weighed upon arrival at the feedlot and subsequently on days 112, 224, and 361 of the study. The calves were fed a steam- flaked corn-based diets. A receiving diet (2.21 Mcal of NEm/kg DM) was provided during the initial 112 days of feeding. From day 112 until harvest all steers received a finishing diet (2.27 Mcal of NEm/kg DM). Because two different diets were used, two partial (day 1 to day 112 and day 113 to day 361), and one full period (day1 to day 361) feeding periods were evaluated. Statistical differences between the final weights of all the groups were observed, which allowed a profit estimation, obtained by subtracting the purchase cost of calves plus the total feed cost from the revenue obtained from the sale of the steers. Overall weight gain and feed intake were higher with increased ABW, feeding efficiency was better for intermediate ABW groups (112 and 117 kg), with the calves with ABW of 112 kg being the most profitable (USD 15.8 more profit than the 117 Kg. group)

RESUMO: O estudo comparou os resultados econômicos entre cinco grupos de bezerros de raça holandesa com pesos vivos de chegada diferente, mas com idades semelhante em confinamento. Os pesos corporais médios de chegada foram 105, 112, 123 e 129 kg (30, 90, 87, 60 e 30 bezerros, respectivamente) com idade de 113 ± 1-d. Os bezerros foram distribuídos em um desenho não balanceado completamente aleatório. Os bezerros foram pesados da chegada ao confinamento e, posteriormente, nos dias 112, 22 e 361 do estudo. Os bezerros foram alimentados com dietas à base de milho floculado. A dieta de adaptação (2,21 Mcal de NEm / kg MS) foi fornecida durante os 112 dias iniciais de ração. Após 112 até o final do estudo todos os novilhos receberam a dieta de terminação (2,27 Mcal de NEm /kg MS). Diante do exposto, foram avaliados dois períodos parciais de alimentação e um período completo (1 a 112, 113 a 361 e 1 a 361 d, respectivamente). O lucro de cada grupo foi estimado subtraindo o custo de compra dos bezerros mais o custo total da alimentação da receita obtida com a venda dos novilhos. O ganho de peso geral e o consumo de ração aumentaram com o aumento do ABW, mas a eficiência alimentar foi melhor para os grupos intermediários ABW (112 e 117 kg), sendo os novilhos com ABW de 112 kg os mais lucrativos (USD 15, 8 a mais do que o grupo de 117 kg.)

Metabolizable energy equivalence of guanidinoacetic acid in corn soybean meal-based broiler diets

In this study, we evaluated how guanidinoacetic acid (GAA) addition in diets with various metabolizable energy (ME) contents affects the performance of broiler chickens. We also estimated the equivalence of GAA in ME. We distributed 1,280 one-day-old broilers in a completely randomized design with eight treatments, eight replicates, and twenty birds per experimental unit. Treatments were based on ME levels (2,775-2,875-2,975 kcal/kg; 2,850-2,950-3,050 kcal/kg; 2,925-3,025-3,125 kcal/kg; or 3,000-3,100-3,200 kcal/kg, from 1 to 7, 8 to 21, and 22 to 42 days of age) and the inclusion of GAA (0 or 600 mg/kg). Supplementation of GAA increased weight gain in broilers at an energy level of 2,908 kcal/kg and improved feed conversion ratio (FCR) at energy levels of 2,908 and 2,983 kcal/kg. There was a linear reduction in feed intake and an improvement in FCR of broilers with increasing levels of energy in diets, with and without GAA addition. Solving the equivalence equation, by applying each of the weighted average energy levels studied. indicates the GAA equivalence of 133, 103, 74, and 44 kcal/kg of diet. In conclusion, GAA supplementation improves broilers' efficiency of energy use; the average ME equivalence of 600 mg/kg of GAA is 88.5 kcal/kg.

Infestation of rabbits with just-molted adults of the cattle tick Rhipicephalus microplus: biological parameters and efficiency / Infestação de coelhos com adultos recém-mudados do carrapato-do-boi Rhipicephalus microplus

In this study, we report for the first time the successful infestation of rabbits with just-molted, unfed adults of Rhipicephalus microplus. Six New Zealand White rabbits were experimentally infested with 20 female and 20 male unfed adult ticks released into plastic chambers fixed on the shaved backs of each host. The attachment and feeding processes were successful. The biological characteristics of the ticks and the occurrence of adverse events in the tick-attachment area were studied. The average engorgement period was 10.7 days, and 33.3% of the engorged females completed the parasitic phase. The average weight of the recovered engorged females was 149.8 mg, with an average egg mass weight of 70.9 mg, a conversion efficiency index of 47.3%, and a hatching percentage of 88.31%. The adverse reactions found in the tick-attachment area were the usual inflammatory responses of the organism to infestation by these ectoparasites; however, it did not prevent the ticks from feeding and completing their life cycle. These data indicate that the infestation of rabbits with just-molted, unfed adult ticks could be a valuable, alternative animal model for rapid and economical evaluation of vaccine candidates and new molecules with acaricidal activity against Rhipicephalus microplus.(AU)

Neste estudo, relata-se, pela primeira vez, o sucesso da infestação de coelhos por carrapatos adultos recém-mudados e não alimentados. Seis coelhos brancos da Nova Zelândia foram infestados artificialmente com 20 carrapatos adultos fêmeas e 20 machos adultos não alimentados no interior de câmaras de plástico fixadas no dorso de cada hospedeiro. Os processos de fixação e alimentação dos carrapatos foram bem sucedidos. Foram estudadas as características biológicas dos carrapatos e a ocorrência de eventos adversos na área de fixação do ectoparasito. O período médio de ingurgitamento foi de 10,7 dias, e 33,3% das fêmeas ingurgitadas completaram a fase parasitária. O peso médio das fêmeas ingurgitadas recuperadas foi de 149,8 mg, com peso médio da massa de ovos de 70,9 mg, índice de produção de ovos de 47,3% e porcentagem de incubação de 88,31%. Uma resposta inflamatória usual do organismo à infestação por esses ectoparasitas foi a única reação adversa encontrada na área de fixação dos carrapatos, o que não impediu que eles se alimentassem e completassem seu ciclo de vida. Esses dados apontam que a infestação de coelhos com carrapatos adultos recém-mudados e não alimentados pode ser um modelo animal alternativo e útil para a avaliação rápida e econômica de candidatos a vacinas e novas moléculas com atividade acaricida contra Rhipicephalus microplus.(AU)

Replacing corn silage with extruded forage in sheep feeding

The objective was to evaluate levels of replacement of corn silage with extruded forage (Foragge®) in sheep feeding. Twenty adult Santa Inês ewes in maintenance, and 55.8 kg average weight were housed in metabolic cages, and the treatments consisted of 20, 40, 60 and 80% replacement of corn silage with Foragge®extruded forage with 60% Uruchloa brizanthain the diet. The design was completely randomized, with regression analysis and non-parametric analysis at 5% probability. The supply of up to 80% extruded roughage to replace corn silage increased dry matter intake and digestibility, and fecal output in dry matter (p < 0.05). Also, it increased the efficiency of ingestion, rumination and chewing activities of sheep, but did not alter urinary parameters and energy metabolites (p > 0.05). However, it reduced the concentration of uric acid (p < 0.05). Foragge®extruded roughage can replace corn silage by up to 80% with changes in intake, digestibility, fecal parameters, ingestive behavior and concentration of uric acid and urea, with no modifications in urinary parameters and energy metabolites.(AU)

A comparison of the economic results obtained by Holstein steer calves with different feedlot arrival body weights / Uma comparação dos resultados econômicos obtidos por bezerros Holstein com diferentes pesos vivos na entrada do confinamento

The study compared the economic results between five groups of Holstein steers with different arrival body weights (ABW) but similar ages in the feedlot. The average ABW were 105, 112, 117, 123 and 129 kg (30, 90, 87, 60, and 30 calves, respectively) with an age of 113 ± 1d. The calves were randomly distributed using an unbalanced design. The calves were weighed upon arrival at the feedlot and subsequently on days 112, 224, and 361 of the study. The calves were fed a steam- flaked corn-based diets. A receiving diet (2.21 Mcal of NEm/kg DM) was provided during the initial 112 days of feeding. From day 112 until harvest all steers received a finishing diet (2.27 Mcal of NEm/kg DM). Because two different diets were used, two partial (day 1 to day 112 and day 113 to day 361), and one full period (day1 to day 361) feeding periods were evaluated. Statistical differences between the final weights of all the groups were observed, which allowed a profit estimation, obtained by subtracting the purchase cost of calves plus the total feed cost from the revenue obtained from the sale of the steers. Overall weight gain and feed intake were higher with increased ABW, feeding efficiency was better for intermediate ABW groups (112 and 117 kg), with the calves with ABW of 112 kg being the most profitable (USD 15.8 more profit than the 117 Kg. group)

O estudo comparou os resultados econômicos entre cinco grupos de bezerros de raça holandesa com pesos vivos de chegada diferente, mas com idades semelhante em confinamento. Os pesos corporais médios de chegada foram 105, 112, 123 e 129 kg (30, 90, 87, 60 e 30 bezerros, respectivamente) com idade de 113 ± 1-d. Os bezerros foram distribuídos em um desenho não balanceado completamente aleatório. Os bezerros foram pesados da chegada ao confinamento e, posteriormente, nos dias 112, 22 e 361 do estudo. Os bezerros foram alimentados com dietas à base de milho floculado. A dieta de adaptação (2,21 Mcal de NEm / kg MS) foi fornecida durante os 112 dias iniciais de ração. Após 112 até o final do estudo todos os novilhos receberam a dieta de terminação (2,27 Mcal de NEm /kg MS). Diante do exposto, foram avaliados dois períodos parciais de alimentação e um período completo (1 a 112, 113 a 361 e 1 a 361 d, respectivamente). O lucro de cada grupo foi estimado subtraindo o custo de compra dos bezerros mais o custo total da alimentação da receita obtida com a venda dos novilhos. O ganho de peso geral e o consumo de ração aumentaram com o aumento do ABW, mas a eficiência alimentar foi melhor para os grupos intermediários ABW (112 e 117 kg), sendo os novilhos com ABW de 112 kg os mais lucrativos (USD 15, 8 a mais do que o grupo de 117 kg.)

Morada Nova lambs' meat production potential description through morphometric evaluation / Descrição do potencial de produção de carne de cordeiros Morada Nova por meio da avaliação morfométrica

Morada Nova breed has a low effective herd, and its white variety is in risk of extinction. The selection of individuals based on breed standard without correlation with productive aptitude is predominant today. We believe that the best way to rescue this valuable genetic resource is to describe its productive potential for commercial use. Thus, this study described the meat production potential of Morada Nova lambs through morphological and zoometric data, performance and carcass characteristics. Twenty-four non-castrated male lambs from two genetic groups were used: Morada Nova red (MNR) and crossbreed Morada Nova (red x Morada Nova white-MNF1) distributed in a completely randomized design. Univariate and multivariate analysis were used. The yields of commercial cuts and the physicochemical characteristics and qualitative measurements of the carcass were similar between the genetic groups. Seven of the 28 characteristics of the carcass were greater in MNF1 lambs. The chest height, rump height and anamorphosis index showed to be important variables in the choice of MN lambs with meat production potential. Based on factor and hierarchical cluster analysis, the Morada Nova beef morphometric index (MNBMI) was created. Both of groups have high thoracic development, ability to produce meat, weight gain, feeding efficiency and breathing capacity, infusing greater rusticity and adaptability; however, the application and validation of the developed index showed superiority for meat production in the crossed lambs. Thus, the MNF1 lambs are a sustainable option for sheep production in drylands.

A raça Morada Nova possui um baixo rebanho efetivo, e sua variedade branca está em risco de extinção. A seleção de indivíduos com base no padrão racial sem correlação com a aptidão produtiva é predominante até hoje. Acreditamos que a melhor forma de resgatar esse valioso recurso genético é descrever seu potencial produtivo para uso comercial. Assim, este estudo teve como objetivo descrever o potencial de produção de carne de cordeiros Morada Nova por meio de dados morfológicos e zoométricos, desempenho e características de carcaça. Foram utilizados 24 cordeiros machos não castrados de dois grupos genéticos: Morada Nova Vermelho (MNV) e mestiços Morada Nova (vermelho x Morada Nova branco-MNF1) distribuídos em delineamento inteiramente casualizado. Análises univariadas e multivariadas foram utilizadas. Os rendimentos dos cortes comerciais e as características físico-químicas e medidas qualitativas da carcaça foram semelhantes entre os grupos genéticos. Sete, das 28 características da carcaça, foram maiores nos cordeiros MNF1. A altura do peito, altura da garupa e índice de anamorfose mostraram-se variáveis ​​importantes na escolha de cordeiros MN com potencial de produção de carne. Com base na análise fatorial e hierárquica de agrupamento, foi elaborado o índice morfométrico da carne da raça Morada Nova (IMCMN). Ambos os grupos apresentam alto desenvolvimento torácico, capacidade de produção de carne, ganho de peso, eficiência alimentar e capacidade respiratória, infundindo maior rusticidade e adaptabilidade, porém, a aplicação e validação do índice desenvolvido mostrou superioridade para produção de carne nos cordeiros cruzados. Assim, os cordeiros MNF1 são uma opção sustentável para a produção ovina em terras áridas.

Intake, digestibility, and ingestive behavior of sheep fed with thornless Mandacaru, cactus pear genotypes Orelha de Elefante Mexicana and Miúda

This study aimed to evaluate the intake, digestibility, and ingestive behavior of sheep fed with different species of forage cacti. Fifteen sheep (17.27kg ± 1 kg) were distributed in a completely randomized experimental design with three treatments and five replicates. The treatments were diets on a dry matter basis composed of 430.9 g kg-1of thornless Mandacaru cactus (Cereus hildmannianus), 525.7 g kg-1of cactus pear cv. Orelha de Elefante Mexicana (Opuntia stricta) and 492.1 g kg-1of cactus pear cv. Miúda (Nopalea cochenillifera) in addition to Sabiá hay (Mimosa caesalpiniaefolia) (194.7 to 233.8 g kg-1), plus concentrate feed. The intake of the dry matter,organic matter, ether extract, neutral detergent fiber, total carbohydrates, non-fiber carbohydrates, total digestible nutrientsand voluntary water intake in g day-1was not differ (p > 0.05) by experimental diets. There were no differences (p > 0.05) in digestibility coefficients of the dry matter,organic matter, neutral detergent fiber, total carbohydrates, non-fiber carbohydrates, and total digestible nutrientsbetween the experimental diets. The feeding times differed (p < 0.05) between diets, with a higher value for the Opuntiadiet, while the rumination times, feeding efficiency, and rumination efficiency did not differ (p > 0.05). The cactus Cereusand Opuntiaand Nopaleahave similar nutritional value in sheep's diet.(AU)

Association of additives in supplemented grazing cattle during the finishing phase at the rainy season

The objectives were to evaluate the effects of monensin and virginiamycin, alone or combined, on supplemented Nellore cattle grazing tropical grass during the rainy season. Two experiments were conducted simultaneously to evaluate intake, digestibility, CH4 emissions, blood parameters, performance, and carcass characteristics (Exp. 1), and ruminal fermentation and relative abundance of ruminal microorganisms (Exp. 2). Animals (n = 92 Exp. 1 and n = 12 Exp. 2) were distributed in a completely randomized design and allocated in twelve paddocks composed of Urochloa brizantha (A. Rich.) Stapf. cv. Xaraés. A protein-energetic supplementation of 3 g/kg of BW per day was provided to all animals. Supplements were: without additives (WA), monensin alone at 80 mg/kg of product (MN), virginiamycin alone at 150 mg/kg of product (VM), and monensin (80 mg/kg of product) combined with virginiamycin (150 mg/kg of product; MNVM). Treatments did not affect intakes of total dry matter (DM), supplement DM, and nutrients. However, the intakes of forage DM and crude protein decreased in cattle fed MNVM compared with animals fed WA, MN, and VM. Total volatile fatty acids increased in animals fed VM. Ruminal NH3-N decreased, and pH increased in animals fed MN, VM, and MNVM. Relative abundance of total F. succinogenes and S. ruminantium decreased and R. flavefaciens increased in animals fed MN and VM at d 118. Treatments had no effect on enteric CH4 emissions. The average daily gain (ADG) and total gain were greater in cattle fed MNVM than in cattle fed MN. Combination of monensin and virginiamycin altered the rumen microbial populations but did not decrease enteric CH4 emissions. However, it decreased forage dry matter intake without altering the ADG and total weight gain, leading to an increase in feed efficiency. Results from this study indicate an advantage in including feed additives combined in the diet of supplemented Nellore cattle grazing tropical grass during the rainy season.

Sugarcane yeast (Saccharomyces cerevisiae) and ß-mannanase enzyme in broilers' diets / Levedura de cana-de-açúcar (Saccharomyces cerevisiae) e enzima ß-mananase em dietas para frangos de corte

Our objective was to evaluate the effect of supplementing ß-mannanase enzyme, with and without sugarcane yeast (Saccharomyces cerevisiae), on broiler chickens aged 1-21 days. The study used 720 one-day-old male Cobb chicks in a randomized design, with six treatments and six replications of 20 birds each. The treatments were: basal diet (BD), BD + ß-mannanase (100 g/t), 7% sugarcane yeast (SY), SY + ß-mannanase (80 g/t), SY + ß-mannanase (100 g/t), and SY + ß-mannanase (120 g/t). Zootechnical results (animal performance) were evaluated during the pre-starter (1 to 7 day-old) and starter (1 to 21 day-old) phases, as well as small intestine morphometry (duodenum, jejunum, and ileum) and diets' economic viability. Data were subjected to variance analysis using the SAS software, and the means were compared by the Student Newman Keuls (SNK) test. In the pre-starter phase, treatments with YD + ß-mannanase (80, 100, and 120 g/t) showed the best feed conversion averages. In the starter phase, chickens consuming the basal diet (BD) and BD + ß-mannanase showed better average weights, weight gains, and feed conversion rates. For intestinal morphometry, shallower ileal crypts were observed in the treatment with YD + ß-mannanase (120 g/t) compared to the basal diet, and wider ileal villi were observed in the treatment with YD + ß-mannanase (100 g/t) compared to the diet with YD + ß-mannanase (80 g/t). The thickness of the muscular wall in the duodenum was lower in chickens consuming BD compared to BD + ß-mannanase (100 g/t), higher in YD and supplementation with 100 g/t compared to 80 and 120 g/t in the jejunum, and higher in diets with ß-mannanase supplementation compared to BD and YD in the ileum. For economic viability, adding 7% sugar cane yeast, with or without enzyme, increased the average feed cost and cost index, and reduced the economic efficiency index. Based on the zootechnical results, YD + ß-mannanase (120 g/t) is recommended for the pre-starter and starter phases. However, using sugar cane yeast with or without ß-mannanase enzyme supplementation is not economically viable in the 1- to 21-day period.

Objetivou-se avaliar o efeito da suplementação da enzima ß-mananase com e sem levedura de cana de açúcar (Saccharomyces cerevisiae) para frangos de corte 1 a 21 dias de idade. Utilizou-se 720 pintos de corte de um dia de idade, machos, da linhagem Cobb, distribuídos em delineamento inteiramente casualizado com seis tratamentos e, seis repetições de 20 aves cada. Os tratamentos foram: Dieta basal (DB); DB + ß-mananase (100 g/t); DB + 7% de levedura de cana-de-açúcar (DL); DL + ß-mananase (80 g/t); DL + ß-mananase (100 g/t); DL + ß-mananase (120 g/t). Avaliou-se o desempenho zootécnico na fase pré-inicial (1 a 7) e na fase inicial (1 a 21 dias de idade), a morfometria do intestino delgado (duodeno, jejuno e íleo) e, a viabilidade econômica da ração. Os dados foram submetidos à análise da variância do programa SAS e as médias foram comparadas pelo teste de Student Newmann Keuls (SNK). Na fase pré-inicial, os tratamentos com DL + ß-mananase (80, 100 e 120 g/t) apresentaram as melhores médias de conversão alimentar. Na fase inicial, aos frangos que consumiram à dieta basal (DB) e DB + ß-mananase apresentaram peso médio, ganho de peso e conversão alimentar melhores. Para a morfometria intestinal, criptas ileais mais rasas foram observadas no tratamento com DL+ ß-mananase (120 g/t) em relação a dieta basal e vilos ileais mais largos foram observados no tratamento com DL+ ß-mananase (100 g/t) em relação a dieta com DL+ ß-mananase (80 g/t). A espessura da parede muscular, no duodeno, foi menor nos frangos que consumiram a DB em relação a DB + ß-mananase (100 g/t), no jejuno, foi maior na DL e na suplementação com 100 g/t em relação a 80 e 120 g/t e no íleo, foi maior nas dietas com suplementação de ß-mananase em relação a DB e DL. Para a viabilidade econômica, a adição de 7% de levedura de cana-de-açúcar, com ou sem enzima proporcionaram aumento do custo médio de ração e índice de custo, e redução do índice de eficiência econômica. Com base nos resultados zootécnicos recomenda-se DL + ß-mananase (120g/t) para a fase pré-inicial e inicial. Contudo, o uso de levedura de cana-de-açúcar com e sem suplementação da enzima ß-mananase não é economicamente viável no período de 1 a 21 dias.

Physiological responses, water consumption, and feeding behaviour of lamb breeds fed diets containing different proportions of concentrate

The use of adapted breeds, such as Santa Inês, is of paramount importance for regions with high temperatures because they develop efficient mechanisms for heat dissipation. Furthermore, some breeds have physiological adaptations, such as more efficient mechanisms for the digestion of fibrous foods (e.g. Rabo Largo), which can reduce the harmful effects of semiarid environments. We studied the ingestive behaviour, water consumption, and physiological parameters during feeding of two native sheep breeds fed diets containing high (700 g/kg DM; HC diet) or low (300 g/kg DM; LC diet) percentages of concentrates, based on dry matter (DM). A total of 40 uncastrated male lambs (20 Rabo Largo [breed 1] and 20 Santa Inês [breed 2], with an average body weight of 16.68 ± 2.78 kg, and 19.29 kg ± 3.28 kg, respectively), were distributed in a randomised block design in a two-by-two factorial scheme (breeds × diets) with 10 repetitions. Santa Inês lambs consumed and ruminated DM (P = 0.029 for both) and neutral detergent fibre (NDF; P = 0.001 and P = 0.004, respectively) more efficiently than RaboLargo lambs, while the latter showed an increase in respiratory rate (+19 breaths/min) and rectal temperature (+1.3 °C) compared to the Santa Inês lambs (P = 0.001). The HC diet negatively affected (P < 0.05) the feeding behaviour of the animals, reflecting the higher (P < 0.05) water consumption. The results showed that diets rich in concentrate negatively affected the thermoregulation of lambs. Santa Inês have greater feed and thermoregulatory efficiency than Rabo Largo lambs under conditions of heat stress in the feedlot.

Physiological responses, water consumption, and feeding behaviour of lamb breeds fed diets containing different proportions of concentrate

The use of adapted breeds, such as Santa Inês, is of paramount importance for regions with high temperatures because they develop efficient mechanisms for heat dissipation. Furthermore, some breeds have physiological adaptations, such as more efficient mechanisms for the digestion of fibrous foods (e.g. Rabo Largo), which can reduce the harmful effects of semiarid environments. We studied the ingestive behaviour, water consumption, and physiological parameters during feeding of two native sheep breeds fed diets containing high (700 g/kg DM; HC diet) or low (300 g/kg DM; LC diet) percentages of concentrates, based on dry matter (DM). A total of 40 uncastrated male lambs (20 Rabo Largo [breed 1] and 20 Santa Inês [breed 2], with an average body weight of 16.68 ± 2.78 kg, and 19.29 kg ± 3.28 kg, respectively), were distributed in a randomised block design in a two-by-two factorial scheme (breeds × diets) with 10 repetitions. Santa Inês lambs consumed and ruminated DM (P = 0.029 for both) and neutral detergent fibre (NDF; P = 0.001 and P = 0.004, respectively) more efficiently than RaboLargo lambs, while the latter showed an increase in respiratory rate (+19 breaths/min) and rectal temperature (+1.3 °C) compared to the Santa Inês lambs (P = 0.001). The HC diet negatively affected (P < 0.05) the feeding behaviour of the animals, reflecting the higher (P < 0.05) water consumption. The results showed that diets rich in concentrate negatively affected the thermoregulation of lambs. Santa Inês have greater feed and thermoregulatory efficiency than Rabo Largo lambs under conditions of heat stress in the feedlot.(AU)

Production, intake, and feeding behavior of dairy goats fed alfalfa via grazing and cassava

This study examined the replacement of maize and soybean meal with cassava chips and alfalfa grazing, respectively. Twelve lactating Anglo-Nubian goats were kept on a Panicum maximum cv. Tobiatã pasture. The experiment was laid out in a Latin square design in which the following diets were tested: ground maize + soybean meal, cassava chips + soybean meal, ground maize + alfalfa grazing, and cassava chips + alfalfa grazing. The evaluated variables were feed intake, daily weight gain, milk yield and composition, and feeding behavior of the goats as well as production costs. Cassava chips and grazed alfalfa influenced the intakes of dry matter, crude protein, neutral detergent fiber, and total digestible nutrients. However, milk yield, body weight, and body score did not change. There was no diet effect on the proportions of protein, solids-not-fat, somatic cell count, or urea nitrogen in the milk. Treatments influenced the levels of fat, lactose, and total solids in milk, with the highest fat levels achieved with diets containing alfalfa. Grazing, rumination, and idle times and time spent interacting with other goats were not influenced by diets. The evaluated feedstuffs improved feed efficiency and reduced production costs. Therefore, cassava chips and alfalfa can replace certain ingredients without impairing the production performance of goats, but rather improving the profit of the producer.(AU)

Productive, physiological and behavioral sheep profiles housed on facilities with different roofs in the Amazon region

The Brazilian Amazon region is characterized by high rainfall, with high temperatures and relative humidity, where sheep are raised in extensive and semi-intensive systems and some regions. This work aimed to evaluate the climatic indices of sheepfolds in the Amazon region, the productive performance, and physiological variables of Santa Inês sheep confined in sheepfolds with fiber cement (FC) and polyvinyl chloride (PC) tiles. Twenty castrated males of Santa Inês sheep were used, with a mean age of 1.5±0.2 years old and a live weight of 23±2.1 kg. The statistical design used was a completely randomized design with two roofs (FC and PC). The temperature, relative humidity of the air, temperature index of the black globe, and thermal radiation load was above the comfort zone for sheep, being higher (P < 0.05) in the sheepfold with PVC tile than FC, which contributed to the increase in respiratory rate, as a way to maintain the animals' homeotherm. Furthermore, sheep installed in the sheepfold with FC tile showed the highest weight gain, spent more time feeding, increased feeding efficiency, dry matter and fiber intake, reducing daily water intake.

Effect of sublethal concentrations of insecticides associated with NaCl and KCl on feeding behavior and mortality of Euschistus heros and Diceraeus melacanthus (Hemiptera: Pentatomidae) / Efeito de concentracoes subletais de inseticidas associados com NaCl e KCl sobre comportamento alimentar e mortalidade de Euschistus heros e Diceraeus melatacanthus (Hemiptera: Pentatomidae)

Stink bugs are important pests of highly profitable agricultural crops worldwide, and the use of insecticides remains the main strategy for their control. The objectives of this study were to evaluate the behavioral aspects of Euschistus heros and Diceraeus melacanthus through feeding after exposure to chloride solutions (NaCl and KCl), as well as the control efficacy of insecticides in combination with salt. Two bioassays were performed with stink bugs exposed to treated substrate: i) feeding preference by salivary sheath counting in a free choice test for chloride solutions, using bean pod or corn seedling as counting substrate for newly emerged E. heros and D. melacanthus adults, respectively; and ii) comparative efficiency of five synthetic insecticides associated with NaCl or KCl in the mortality of 4th instar nymphs (N4). Pre-determined sublethal (LC25) and median lethal (LC50) concentrations of commercially available insecticides (Lfn), buprofezin (Bpf), pyriproxyfen (Ppx), chlorantraniliprole (Ctn) and spinosad (Spn) were used. For each species and insecticide, the treatments were pure LC25, LC25 + NaCl 5% m/m, LC25 + KCl 5% m/m, pure LC50, and distilled water (dH2O) as the control. Corn seedlings treated with 5% NaCl saline solution had reduced salivary sheaths from D. melacanthus. Ctn LC25 (0.63 mL L-1) + 5% NaCl and pure Ctn LC50 (1.16 mL L-1) were similar and more efficient in terms of mortality of D. melacanthus N4s than any other treatment. The association of Spn LC25(0.37 mL L-1) + 5% NaCl and Spn LC50 only (0.90 mL L-1) was similar to that of E. heros N4s compared to other treatments. The insecticide concentrations used in this study have potential for stink bug pest control, thus the association of insecticides with commercially available, easy-to-find, and low-cost chloride salts may represent a good strategy for stink bug control.(AU)

Os percevejos são importantes pragas de culturas agrícolas altamente rentáveis em todo o mundo, e o uso de inseticidas continua sendo a principal estratégia para seu controle. Os objetivos deste estudo foram avaliar os aspectos comportamentais de Euschistus heros e Diceraeus melacanthus através da alimentação após exposição a soluções cloradas (NaCl e KCl), bem como a eficiencia de controle de inseticidas em combinação com sal. Dois bioensaios foram realizados com percevejos expostos ao substrato tratado: i) preferência alimentar por contagem de bainhas salivares em teste de livre escolha de soluções contendo cloreto, usando vagem de feijão ou plantulas de milho como substrato de contagem para adultos de E. heros e D. melacanthus recém-emergidos, respectivamente; e ii) eficiência comparativa de cinco inseticidas sintéticos associados a NaCl ou KCl na mortalidade de ninfas de 4º estágio (N4). Foram utilizadas concentrações subletais pré-determinadas (CL25) e letais medias (LC50) de inseticidas comercialmente disponíveis lufenurom (Lfn), buprofezina (Bpf), piriproxifem (Ppx), clorantraniliprole (Ctn) e espinosade (Spn). Para cada espécie e inseticida, os tratamentos foram CL25 pura, CL25 + NaCl 5% m/m, CL25 + KCl 5% m/m, CL50 pura e água destilada (dH2O) como controle. Plantulas de milho tratadas com a solução salina NaCl 5% apresentaram redução das bainhas salivares de D. melacanthus. Ctn CL25 (0,63 mL L-1) + 5% NaCl e Ctn CL50 pura (1,16 mL L-1) foram semelhantes e mais eficientes em termos de mortalidade de N4s de D. melacanthus do que qualquer outro tratamento. A associação de Spn CL25 (0,37 mL L-1) + 5% NaCl e Spn CL50 pura (0,90 mL L-1) foi semelhante à de N4s de E. heros em relação aos outros tratamentos. As concentrações de inseticidas utilizadas neste estudo têm potencial para o controle de pragas de percevejos, portanto, a associação de inseticidas com sais de cloreto comercialmente disponíveis, de fácil acesso e baixo custo pode representar uma boa estratégia para o controle de percevejos.(AU)

Effect of supplementation of ewes in the final third of gestation on the development of their lambs

This study examined the effect of different supplementation strategies for ewes in the last third of gestation, kept on a deferred Brachiaria brizantha cv. Marandu pasture, on their performance and the growth curve of their lambs. A total of 54 ewes, of no defined breed, with an average weight of 41.10±3.10 kg, were used in a completely randomized design, divided into three groups (18 ewes per treatment). In total, 61 lambs were born, 28 females and 33 males, with 3.70±0.55 and 3.68±0.69 kg birth weight, respectively. Treatments were as follows: multiple mixture ad libitum, concentrate supplement at 0.4% live weight (LW), and concentrate supplement at 0.8% LW. Average daily weight gain (ADG, g/animal/day) and total weight gain (TWG, kg/animal) were evaluated in ewes and lambs. Reproductive efficiency indices were measured in the ewes and biometric variables in the lambs. The ADG and TWG of ewes in the last third of gestation were higher in animals supplemented at 0.8% LW. Reproductive efficiency results were superior in ewes supplemented at 0.4% LW. The effect of ewe supplementation on lamb growth curve as estimated by the Gompertz model did not reveal differences between the curves of lambs born to ewes that received supplementation at 0.4 and 0.8% LW. However, supplementing ewes with a multiple mixture induced a reduction in the growth curve parameters of their lambs. The use of concentrated supplementation, at levels of 0.4 and 0.8% of LW, provides greater productive and reproductive performance for ewes and lambs.(AU)

Feed technologies and efficiency in cow-calf systems

This study was performed to evaluate the efficiency index of cow-calf systems, based on different feed technologies commonly employed in the Rio Grande do Sul state, southern Brazil. Hence, the efficiency of 35 cow-calf herds was evaluated by Data Envelopment Analysis (DEA). Data was collected by online survey and in-depth interviews, as well as data registers from the cow-calf systems, located in 31 municipalities. The analyzed indicators included rates of mortality, pregnancy, birth, and productivity. The feed technologies evaluated were the use of cultivated pastures during winter and summer, supplementation during winter and summer, creep feeding, deferral of natural pasture, use of grazing systems, and employee's capacitation. Approximately 80% of the evaluated farms showed low-to-medium Efficiency Index (EI; up to 0.79 in a scale of 0 to 1), 13% presented high EI, and only 7% had very high EI (above 0.95). The use of cultivated pastures with the inclusion of protein supplementation and employees' capacitation were highlighted as the main practices to increase efficiency of cow-calf systems in Rio Grande do Sul. The technologies identified as most impactful raise the EI of production systems from low to medium. Our results assist in decision-making in the use of feed technologies, pointing out a direction for the use of technologies that make breeding systems more efficient from a productive point of view.(AU)

Compensatory growth of Nile tilapia fingerlings subjected to food restriction and re-feeding at low temperatures / Crescimento compensatório de alevinos de tilápia-do-Nilo submetidos à restrição alimentar e realimentação em temperaturas amenas

This study aims to investigate the effect of different periods of fasting and re-feeding on compensatory responses in Nile tilapia fingerlings and the frequency of muscle fiber distribution. A total of 108 Nile tilapia fingerlings with initial weight of 1.64 ± 0.41 g and mean initial length of 3.60 ± 0.39 cm were used for 55 days. The fish were distributed in a water recirculation system in a completely randomized design with three treatments and four replications: Control - CO - (fish fed until apparent satiation throughout the experimental period); fasting 10 - J10 - (fish fed to apparent satiation for 15 days, followed by 10 days of fasting and re-feeding to satiation for 30 days); and fasting 15 - J15 - (fish fed to apparent satiation for 15 days, followed by 15 days of fasting and re-feeding to satiation for 25 days). Fish from the J15 treatment showed unsatisfactory results in terms of productive performance (p<0.05), such as lower final weight, apparent feed conversion, protein efficiency ratio, and survival, while fish from the J10 treatment achieved the same results as those animals kept in the CO treatment with the exception of the variables of relative weight gain and feed intake. Furthermore, food restriction directly influenced the growth of muscle fibers with a diameter smaller than 20 µm (p<0.05), and fish from the J15 treatment had the lowest frequency of fibers in this diameter class. Therefore, this study concludes that food restriction in short periods (10 days) and at low temperatures can present a compensatory growth, as they alter the process of hyperplasia and hypertrophy of muscle fibers without affecting the morphology of the fibers; however, 15 days of fasting under low temperatures do not compensate for growth and delays the hypertrophic growth of muscle fibers.(AU)

O objetivo do presente estudo é investigar o efeito de diferentes períodos de jejum alimentar e realimentação nas respostas compensatórias em alevinos de tilápias-do-Nilo, e a frequência de distribuição das fibras musculares. Foram utilizados 108 alevinos de tilápia-do-Nilo com peso inicial de 1,64±0,41 g e comprimento inicial médio de 3,60 ± 0,39 cm, durante um período de 55 dias. Os peixes foram distribuídos em um sistema de recirculação de água, em delineamento inteiramente casualizado com três tratamentos e quatro repetições: Controle - CO - (peixes alimentados até a saciedade aparente durante todo período experimental); jejum 10 - J10 - (peixes alimentados até a saciedade aparente por 15 dias, seguidos de 10 dias de jejum e realimentação até a saciedade por 30 dias); e jejum 15 - J15 - (peixes alimentados até a saciedade aparente por 15 dias, seguidos de 15 dias de jejum e realimentação até a saciedade por 25 dias). Os peixes do tratamento J15 apresentaram resultados insatisfatórios de desempenho produtivo (p<0,05), como menor peso final, conversão alimentar aparente, taxa de eficiência proteica e sobrevivência, enquanto os peixes do tratamento J10, atingiram os mesmos resultados daqueles animais mantidos no tratamento CO, com exceção das variáveis de ganho em peso relativo e do consumo de ração. A restrição alimentar influenciou diretamente no crescimento das fibras musculares com diâmetro menor que 20 µm (p<0,05), sendo que os peixes do tratamento J15 apresentaram a menor frequência de fibras nesta classe de diâmetro. Conclui-se que a restrição alimentar em curtos períodos (10 dias) e em temperaturas amenas podem apresentar um crescimento compensatório, alterando o processo de hiperplasia e hipertrofia das fibras musculares, sem afetar a morfologia das fibras, entretanto, 15 dias de jejum e sob temperaturas amenas não ocorre uma compensação no crescimento e atrasa o crescimento hipertrófico das fibras musculares.(AU)

Effect of different protein based feed on the growth of mahseer / Efeito de alimentação baseada em proteínas diferentes no crescimento de mahseer

For the proper growth of fish, it is necessary to feed the fish with a proper and balanced diet. A study was conducted to find out the effect of different protein-based diets on fingerlings of Tor putitora (mahseer). A feed with dietary protein levels of 35%, 40%, 45%, and 50% were prepared. The effect of different protein-based feed on weight gain, standard growth rate (SGR), food conversion ratio (FCR), percent weight gain, food conversion efficiency (FCE), and protein efficiency ratio (PER) was studied. An increase was observed in the growth rate with an increase in protein concentration up to 45%. The fingerlings fed a 45% protein diet shown the highest growth, followed by 50%, 40%, and 35%. The SGR value was greatest for 45% protein diet (8.56) followed by 50% and 40%, while the least values were observed for 35% protein feed (1.57). The same trend was observed for FCE. The highest PER values was observed in fishes fed 45% protein-based feed (0.65) followed by 50% (0.56), 40% (0.38) and35% (0.17). The food conversion ratio was lowest for 45% protein diet (3.41), while the greatest for 35% protein feed (16.85). It was concluded that a 45% protein-based diet was the best feed formulation for higher production of Tor putitora. However, research on the same percentage of protein diet is recommended for yearlings.

Para o bom crescimento dos peixes, é necessário alimentá-los com uma alimentação adequada e balanceada. Um estudo foi realizado para descobrir o efeito de diferentes dietas à base de proteínas em alevinos de Tor putitora (mahseer). Foi preparado um alimento com níveis de proteína dietética de 35%, 40%, 45% e 50%. O efeito de diferentes alimentos à base de proteína no ganho de peso, taxa de crescimento padrão (SGR), taxa de conversão alimentar (FCR), ganho de peso percentual, eficiência de conversão alimentar (FCE) e taxa de eficiência proteica (PER) foi estudado. Foi observado um aumento na taxa de crescimento com um aumento na concentração de proteína de até 45%. Os alevinos alimentados com dieta de 45% de proteína apresentaram o maior crescimento, seguidos de 50%, 40% e 35%. O valor de SGR foi maior para dieta com 45% de proteína (8,56), seguido de 50% e 40%, enquanto os menores valores foram observados para ração com 35% de proteína (1,57). A mesma tendência foi observada para FCE. Os maiores valores de PER foram observados em peixes alimentados com 45% de ração à base de proteína (0,65), seguido por 50% (0,56), 40% (0,38) e 35% (0,17). A taxa de conversão alimentar foi menor para a dieta com 45% de proteína (3,41), enquanto a maior para a dieta com 35% de proteína (16,85). Concluiu-se que a dieta à base de proteína de 45% foi a melhor formulação alimentar para maior produção de Tor putitora. No entanto, a pesquisa sobre a mesma porcentagem de dieta proteica é recomendada para animais de um ano.

Evaluation of nutritional and ruminal degradability potential of sandbox (Hura crepitans L. ) seeds in stabled Blackbelly sheep

This study evaluated chemical composition, in situ dry matter degradability (DMD), energy utilization, and amino acid profile of the sandbox seed meal (SSM) obtained from ground seeds of Hura crepitans trees. Two cannulated male Blackbelly sheep (initial weight of 40 kg) were fed a balanced feed ad libitum for 21 days; rumen samples of animals were collected for seven days using the nylon bag technique for degradability. The results were interpreted in reference to incubation times from 0 to 72 h, evaluating degradation kinetics with an exponential model. The SSM showed crude protein and dry matter contents of 251.1 and 931.7 g/kg, respectively. The highest DMD value was recorded from 0 to 3 h with a change rate of 41%, and the energy contained in SSM had a gradual ruminal disappearance with a maximum value of energy utilization of 14.6% after 72 h post-incubation. The most representative amino acids of SSM were glutamic (16.9%), arginine (13.0%), and aspartic (9.7%) acids. The results suggest that SSM has adequate nutritional quality and ruminal DMD for ovine feeding systems.(AU)

Influence of guava residue on tambaqui growth performance

Fruit residues represent alternative ingredients that can be included in diets of tambaqui, Colossoma macropomum. This study evaluated the growth performance of tambaqui fed diets containing different levels of guava agroindustrial residue. The experiment was based on a completely randomised design, with 105 fish randomly distributed in 15 plastic 60 L-1boxes with a water recirculation system. Feeding was carried out to apparent satiety for 45 days, using diets with 0, 50, 100, 150 and 200 g kg-1inclusion of guava residue. Biometrics were performed every 15 days. Quadratic effect (p < 0.05) was observed for daily feed intakeand apparentfeed conversion, with optimum levels of 4.86 and 6.05% inclusion of guava residue, respectively. There was no significant difference (p > 0.05) in relation to final weight, weight gain, specific growth rate, hepato-somatic index, survival rate and protein efficiency rate by the dietary treatments. The inclusion of up to 150 g kg-1of the guava agroindustrial residue in the feed did not compromise the performance of tambaqui juveniles.(AU)