ABSTRACT The aim of this study was to evaluate intake, digestibility and performance in dairy heifers fed diets containing increasing levels of babassu cake (0, 100, 200 and 300 g kg-1 dry matter - DM) as a substitute for sugarcane treated with calcium oxide. Twenty-four heifers with an initial mean weight of 190.8 + 40.8 kg were used, distributed in a completely randomised design. The dry matter intake (DMI), neutral detergent fibre intake (NDFI) and acid detergent fibre intake (ADFI), as %BW and g BW-0.75 , showed an increasing linear response. The organic matter intake (OMI) showed a linear increase of 40 g day-1, 0.017%BW and 0.66 g BW-0.75 for each 10 g kg-1 increase in babassu cake in the diet. The apparent digestibility of the dry matter (ADDM) and organic matter (ADOM) showed a quadratic response (P < 0.05), with a minimum of 493 g kg-1 DM for 150 g kg-1 DM and 526.5 g kg-1 DM for 320 g kg-1 DM as a substitute for the sugarcane, respectively. The final mean weight was not altered, presenting a value of 299.7 + 45.5 kg. Daily weight gain (DWG) showed a quadratic response, with the highest value at a substitution level of 190 g kg-1 DM. The feed conversion rate of the DM was not affected by the addition of babassu cake, with an average of 4.6 + 0.74 kg DM kg-1 in weight gain. Babassu cake can substitute hydrolysed sugarcane in heifer diets up to 300 g kg-1 DM, with the greatest weight gain seen at a substitution level of 190 g kg-1 DM.

ABSTRACT. This study aimed to evaluate cassava genotypes to identify the ones with the best nutritional values for ruminant diets. Nine genotypes were used: Amansa Burro (BGM 549), Aramaris (BGM 116), Brasília, Cambadinha (BRS Guaíra), Curvelinha, Engana Ladrão (BGM 1269), Trouxinha (BGM 1468), BRS Gema de Ovo, and BRS Dourada. A completely randomized block experimental design with nine treatments (genotypes) and three blocks (replicates) were employed. The roots were analyzed for dry matter production (DMP) in tonnes per hectare, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), starch, and in vitro dry matter digestibility (IVDMD). The multivariate analysis was carried out using Ward’s hierarchical agglomerative clustering based on Mahalanobis distance. The groups formed were evaluated by Scott-Knott test. The group formed by genotype Engana Ladrão was chosen as the best one for having the highest DMP t ha-1 and IVDMD values and the lowest NDF and ADF contents.

ABSTRACT. To gain insights into the forage morphological and anatomical characteristics in a silvopastoral system (SPS) with Bolsa de Pastor (Zeyheria tuberculosa) and palisadegrass ‘Marandu’ (Urochloa brizantha) monoculture (MONO). The SPS was established through natural regeneration of the tree species. Treatments were a SPS and MONO distributed in a completely randomized design with six replicates and repeated measures were the harvest periods. Response variables were morpho-physiological and anatomical characteristicss: green: dead material ratio, leaf blade: stem+sheath ratio, leaf area index, chlorophyll and carotenoid concentrations, proportions of non-lignified and achlorophyllous areas, lignified areas in stems, proportions of non-lignified and achlorophyllous areas, lignified and chlorophyllous areas in leaves, as well as cell length in longitudinal section of stem. Morpho-physiological patterns were altered (p < 0.05) under natural shading conditions due to higher photosynthetic efficiency in the SPS. There was no effect (p > 0.05) of the systems on anatomical patterns, proportions of non-lignified and achlorophyllous, lignified and chlorophyllous tissues, these proportions were influenced only by the periods of the year, both for stems and leaves. Cells of the internodes of the grasses of the studied systems had the same length. The SPS alters morpho-physiological characteristics of palisadegrass and increases the concentration of chlorophyll a and b.

Abstract The objective of this study was to evaluate the seasonal effect of months of the year upon the physiological and productive responses of crossbred dairy cows raised in an Amazonian climate. Twenty lactating cows were evaluated, fed on Brachiaria decumbens pasture, with free access to water and mineral supplementation. Data from climate variables air temperature (AT), relative humidity (RH), rainfall (RA) and temperature and humidity index (THI) were recorded dur ing the months of January to April 2019. The physiological data collected were: respiratory rate (RR, mov/min), heart rate (HR, beats/min), rectal temperature (RT, ºC), udder surface temperature (UST, ºC), body surface temperature (BST, ºC), dorsum surface temperature (DST, ºC), front surface temperature (FST, ºC) and rear shin temperature (RST). Milk production (MP) was also measured. There was a significant difference (P<0.05) of RST and RR with values ranging from 34.8 to 35.5°C and 32.0 to 36.2 mov/min, respectively. There were no significant difference (P>0.05) for BST, and the values for MP and THI were 3.8; 3.8; 4.6; 4.1 kg and 77.7; 79.7; 80.6; 80.1, respectively. It was concluded that there was a seasonal effect of the months of the year evaluated on the respiratory rate of animals, however, it did not change the MP and the THI. The Amazon environment is conducive to causing thermal stress in lactating cows raised on pasture, requiring the use of shading to facilitate the ability of these animals to dissipate heat.

Resumo O objetivo desse estudo foi avaliar os efeitos sazonais dos meses do ano sobre as respostas fisiológicas e produtivas de vacas leiteiras mestiças criadas em clima amazônico. Foram avaliadas 20 vacas lactantes, alimentadas com pasto de Brachiaria decumbens, com acesso livre a água e suplementação mineral. Foram registrados dados das variáveis climáticas temperatura do ar (TA), umidade relativa do ar (UR), precipitação pluviométrica (PP) e índice de temperatura e Umidade (ITU) durante os meses de janeiro a abril de 2019. Os dados fisiológicos coletados foram: frequência respiratória (FR, mov/min), frequência cardíaca (FC, bat./min), temperatura retal (TR, ºC), temperatura superficial do úbere (TSU, ºC), temperatura superfície corporal (TSC, ºC), temperatura superficial do dorso (TSD, ºC), temperatura superficial da fronte (TSF, ºC) e temperatura superficial da canela (TSCA, °C). Também foi mensurada a produção de leite (PL, kg). Houve diferença significativa (P<0,05) da TSCA e FR com valores variando de 34,8 a 35,5°C e 32,0 a 36,2 mov/min, respectivamente. Não houve diferença significativa (P>0,05) para TSC e os valores observados para PL e ITU foram 3,8; 3,8; 4,6; 4,1 kg e 77,7; 79,7; 80,6; 80,1, respectivamente. Houve efeito sazonal dos meses avaliados sobre a taxa respiratória dos animais, no entanto, isso não alterou a PL nem o ITU. O ambiente amazônico é propício a causar estresse térmico em vacas lactantes mantidas a pasto, sendo necessário o uso de sombreamento para facilitar a capacidade de dissipação de calor corporal desses animais.

ABSTRACT. This study examines the effect of adding coffee husks (CH), cacao by-product (CBP) and passion fruit by-product (PBP) (fresh-matter basis) in the silage of elephant grass cv. Napier on nutritional characteristics. The experiment was laid out in a completely randomized design with a 3 × 4 factorial arrangement represented by three additives (CH, CBP or PBP) and four inclusion levels (0, 12, 24 or 36%). Four replicates were used per treatment. The material was ensiled in experimental mini-silos that were opened 60 days later for chemical analysis of the produced silages. The dry matter content of the silages with CH and PBP included at levels greater than 25% was adequate. The silage with PBP inclusion showed the highest crude protein levels and the best results for in vitro dry matter digestibility. In the silage containing CH, the neutral detergent fiber content decreased linearly with increasing inclusion of the husks. The silage with CBP showed the lowest dry matter and crude protein levels and the highest pH. In conclusion, the inclusion of up to 36% PBP in the ensiling of elephant grass is recommended, as the resulting material has potential for use in ruminant feeding at times of forage scarcity.

RESUMO Objetivou-se determinar as medidas biométricas in vivo e na carcaça de borregos Santa Inês alimentados com resíduo de cervejaria desidratado. Foram utilizados 35 borregos da raça Santa Inês, com aproximadamente 70 dias de idade e peso corporal médio inicial de 16,00 ± 1,69 kg. O delineamento experimental utilizado foi o inteiramente casualizado, com cinco teores de inclusão do resíduo de cervejaria desidratado RCD; (0; 20; 40; 60 e 80%) adicionados à porção concentrada da dieta, com sete repetições. As rações experimentais foram compostas por feno de capim Tifton-85, farelo de soja, milho grão moído, resíduo de cervejaria desidratado nas proporções avaliadas, fosfato bicálcico e núcleo mineral. O escore da condição corporal, o perímetro torácico e a largura da garupa não foram influenciados pelas rações experimentais, bem como as medidas obtidas da carcaça, com exceção do perímetro da garupa, largura do tórax e o índice de compacidade da perna (P>0,05). Contudo, para o índice de compacidade da carcaça e a área de olho de lombo, verificou-se efeito linear decrescente à medida que o RCD foi adicionado à ração. As medidas morfométricas de altura e largura da garupa e largura do peito podem ser utilizadas como alternativa para estimar o peso corporal ao abate e da carcaça fria de borregos Santa Inês alimentados com resíduo de cervejaria desidratado, pois apresentam alta correlação com essas variáveis.

ABSTRACT The aim of this study was to determine biometric measurements in vivo and in the carcass of Santa Ines lambs fed dehydrated brewery residue. Thirty-five Santa Ines lambs were used, approximately 70 days of age and with a mean initial body weight of 16.00±1.69 kg. The experimental design was completely randomised, with five levels of dehydrated brewery residue - DBR (0; 20; 40; 60 and 80%) added to the concentrated portion of the diet, with seven replications. The experimental diets consisted of Tifton-85 hay, soybean meal, ground maize, dehydrated brewery residue in the experimental proportions, dicalcium phosphate and a mineral base. The body condition score, thoracic girth and croup width were not influenced by the experimental diets, neither were the carcass measurements, except for croup circumference, chest width and leg compactness index (P>0.05). However, there was a decreasing linear effect on the carcass compactness index and ribeye area as the DBR was added to the diet. The morphometric measurements of croup height and width, and chest width can be used as an alternative for estimating the body weight at slaughter and the cold- carcass weight of Santa Inês lambs fed dehydrated brewery residue, as they show a high correlation with these variables.

ABSTRACT. This study examined the influence of the external markers chromium oxide (CO), titanium dioxide (TD), isolated, purified and enriched lignin (LIPE®) and isolated, purified, enriched lignin in nanoparticles (NANOLIPE®) as well as the internal markers indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) in diets with inclusion of passion fruit by-product for dairy heifers on the estimation of fecal output and nutrient digestibility. Sixteen Holstein × Zebu crossbred heifers at an average live weight of 363 ± 28 kg were randomly distributed in a completely randomized design where they received diets in which Tifton 85 (Cynodon sp.) hay was replaced with passion fruit by-product (0, 12, 24 and 36%, as-fed basis). The CO, LIPE®, NANOLIPE® and iNDF markers did not differ from the total collection method (p > 0.05) in the estimation of fecal output and nutrient digestibility. The TD and iDM markers overestimated, while iADF underestimated fecal output. Under the presented conditions, we recommend using the CO, LIPE®, NANOLIPE® and iNDF markers to estimate fecal output and nutrient digestibility in diets with inclusion of passion fruit by-product for dairy heifers.

ABSTRACT This study aimed to evaluate the effect of diets containing sunflower or corn silages and concentrate based on citrus pulp or ground corn on intake, apparent digestibility, feeding behavior, microbial protein production, and production, composition, and fatty acid profile of milk from dairy cows. Eight multiparous lactating Holstein cows (586±61 kg live weight; 25.0±4.0 kg daily milk yield at 80 to 120 days in milk) were randomly assigned to a double 4 × 4 Latin square design with a 2 × 2 factorial array. The experimental diets were: sunflower silage + citrus pulp-based concentrate; sunflower silage + ground corn-based concentrate; corn silage + citrus pulp-based concentrate; and corn silage + ground corn-based concentrate. The dry matter intake was highest for diets containing sunflower silage and lowest for diets with citrus pulp. Sunflower silage provided the highest intakes of crude protein, neutral detergent fiber, and ether extract. Except for the ether extract, the type of forage and carbohydrate did not influence the apparent nutrient digestibility. The forage and carbohydrate sources did not influence the feed eating time, but animals fed sunflower silage showed decreased rumination time and chewing activity. The microbial protein production was not altered with the diets. No differences were observed for milk production or composition, except for the milk urea nitrogen and lactose concentration. The type of forage influenced the milk fatty acid profile, to which corn silage presented higher values for fatty acids up to a 17-carbon chain length. The inclusion of sunflower silage and citrus pulp, compared with corn silage and ground corn, alters dry matter intake and ingestive behavior, but maintains milk production and composition with satisfactory characteristics of the milk fatty acid profile, providing an alternative feed for dairy cows.