ABSTRACT The development of aquaculture through the cultivation of what are considered unconventional species is an option with the potential to solve the problem of food scarcity. The aim of the present study was to evaluate the zootechnical performance of juvenile Pomacea haustrum fed different commercial diets, and subjected to different levels of salinity. After seven P. haustrum spawn had hatched in the laboratory, the juveniles were randomly selected and transferred to the rearing containers. Two different commercial diets were offered: rabbit feed with a high proportion of ingredients rich in crude vegetable protein (VP), and dog food containing balanced levels of ingredients rich in crude vegetable and animal protein (MP). The selected juveniles were randomly stocked at different salinities (0, 2 and 4 parts per thousand - ppt). The experiment lasted 65 days. Twenty-one hours after the start of the experiment, 100% of the individuals reared at a salinity of 4 ppt had died. There was a significant difference (p ≤ 0.05) between the results for zootechnical performance (average final weight, weight gain, average final growth, specific growth rate, protein efficiency and apparent feed conversion) for animals reared in fresh water or at a salinity of 2 ppt, regardless of the type of diet. The origin of the protein in the diet had no significant effect on the zootechnical performance of the individuals; however, the salinity of the water impaired development of the animals in direct proportion to its concentration. scarcity P laboratory containers offered VP, VP , (VP) MP. MP . (MP) 0, 0 (0 ppt. ppt) 6 days Twentyone Twenty one 100 died p 0.05 005 05 gain rate conversion however concentration (VP (MP ( 10 0.0 00 1 0.

Summary: Biofortification is a process that increases the nutrient content in plants’ edible parts. The objective was to determine the effect of iron chelate and iron sulfathe applied through foliar and edaphic methods on the mineral, nutritional, and bioactive compound content of the Verdin bean grain. Foliar doses of 0, 25, 50 and 100 mM of iron chelate and edaphic doses of 0, 0.25 and 0.50 g per plant of iron sulfate were applied, which generated 12 treatments that were evaluated in a randomized block design in 4×3 factorial arrangement where the first factor was the foliar doses, and the second factor was the edaphic doses. The content of iron, zinc, manganese, nickel, calcium and potassium, ash, proteins, fats, fiber, total phenols, flavonoid, anthocyanins, and antioxidant capacity were determined in the grain. The individual applications of foliar and edaphic iron had significant effects (P ≤ 0.05), with the edaphic dose of 0.50 g presenting the greatest increases in iron (17.38%), nickel (20.69%), protein (10.93%), crude fiber (5.82%) and antioxidant capacity (2.84%) regarding doses without edaphic iron. The simultaneous application of edaphic and foliar iron showed statistical differences (P ≤ 0.05), presenting the greatest increase in iron (75.91%), nickel (30.61%), ash (114.69%), protein (18.14%) and crude fiber (15.34%) with the 100 mM foliar - 0.50 g edaphic combination regarding to the combination without iron. For individual and simultaneous iron applications, it was observed that increasing the foliar and edaphic doses had antagonistic effects on the zinc and fat content. The application of iron can be beneficial to increase the mineral and nutritional content, and some bioactive compounds, but care must be taken to minimize the negative effects on other nutrients and properties of the grain.

Resumen: La biofortificación es el proceso por medio del cual se puede incrementar el contenido de nutrientes en la parte comestible de las plantas cultivadas. El objetivo fue determinar el efecto del quelato y sulfato de hierro aplicado de forma foliar y edáfica en el contenido mineral, nutricional, y compuestos bioactivos del grano de frijol variedad Verdín. Se aplicaron las dosis de 0, 25, 50 y 100 mM de quelato de hierro foliar y dosis de 0, 0.25 y 0.50 g por planta de sulfato de hierro edáfico, lo que origino 12 tratamientos que se evaluaron bajo un diseño de bloques al azar en arreglo factorial 4×3 donde el primer factor fueron las dosis foliares y el segundo factor las dosis edáficas. En el grano se determinó el contenido de hierro, zinc, manganeso, níquel, calcio, potasio, cenizas, proteínas, grasas, fibra, fenoles totales, flavonoides, antocianinas y capacidad antioxidante. Las aplicaciones individuales de hierro edáfico y foliar tuvieron efectos significativos (P < 0.0001), presentando la aplicación edáfica de 0.50 g de hierro los mayores incrementos de 17.38%, 20.69%, 10.93%, 5.82% y 2.84% del contenido de hierro, níquel, proteína, fibra cruda y capacidad antioxidante con respecto a la dosis sin hierro edáfico. Pero se observaron efectos antagónicos en el contenido de zinc y grasas al incrementar la dosis de hierro. La aplicación simultánea de hierro edáfico y foliar presentó diferencias estadísticas (P ≤ 0.05), presentando el mayor incremento de hierro (75.91%), níquel (30.61%), cenizas (114.69%), proteína (18.14%) y fibra cruda (15.34%) la aplicación de 100 mM foliar y 0.50 g edáfico con respecto a la combinación sin hierro. La aplicación combinada de hierro puede ser benéfica para aumentar el contenido mineral, nutricional y algunos compuestos bioactivos; pero se debe tener cuidado para minimizar los efectos negativos en otros nutrientes y propiedades del grano.

Abstract The objective of the study was to evaluate the relationship between the preference index (IP) and synchrony (IS) of forage species from Baja California Sur. Samples of the 23 forage species of trees and shrubs were obtained to perform in situ digestibility analyzes using four Creole-Nubian goats. Collections were carried out in winter and spring of 2004, and summer and autumn of 2005. The extent of degradation per hour and total of 24 h was calculated from the amount of OM and PC degraded per hour; these data were used to calculate the IS. The seasonal PI data set was obtained from previously published information. A logistic regression model was used to explain the probability of occurrence of the IP with the IS. The regression model to explain the IP from the IS was significant and predictive for six species, being positive for Adelia virgata, Amaratus palmeri, Haematoxilon brasiletto, Lippia palmeri and Prosopis sp., and negative for Bursera microphyla. For other tree species and legumes in general, the model was significant, but not predictive, therefore, it is necessary to include other factors to fit the model.

Resumen El objetivo del estudio fue evaluar la relación existente entre el índice de preferencia (IP) y sincronía (IS) de especies forrajeras de Baja California Sur. Se obtuvieron muestras de las 23 especies forrajeras de árboles y arbustos para realizar análisis de digestibilidad in situ utilizando para ello cuatro cabras con encaste de criollas-Nubio. Se llevaron a cabo colecciones en invierno y primavera del 2004 y verano y otoño de 2005. La extensión de degradación por hora y total de 24 h se calculó a partir de la cantidad de MO y PC degradados por hora; estos datos se utilizaron para calcular el IS. El conjunto de datos del IP estacional se obtuvo de información publicada previamente. Se utilizó un modelo de regresión logística para explicar la probabilidad de ocurrencia del IP con el IS. El modelo de regresión para explicar el IP a partir del IS fue significativo y predictivo para seis especies, siendo positiva para Adelia virgata, Amaratus palmeri, Haematoxilon brasiletto, Lippia palmeri y Prosopis sp., y negativa para Bursera microphyla. Para otras especies arbóreas y las leguminosas en general, el modelo fue significativo, pero no predictivo, por lo tanto, es necesaria incluir otros factores para ajustar el modelo.

ABSTRACT Climatic conditions cause variation in the availability and nutritional quality of forages; therefore, the use of corn (Zea mays L.) silage has been proposed. However, this crop has a low protein concentration, so the combination with legumes can improve this characteristic. The objective of this study was to evaluate the nutritive value of silage in different proportions of soybean (Glycine max (L.) Merr.) and corn forage grown in a subtropical region. In Tamaulipas, Mexico, six treatments were evaluated: Soybean 100% (S100), corn 100% (C100), and soybean-corn proportions (80%-20%: S80C20; 60%-40%: S60C40; 40%-60%: S40C60, and 20%-80%: S20C80). The variables that were evaluated were: Density, pH, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, non-fibrous carbohydrates (NFC), starch, crude fat, net energy for lactation (NEL), net energy for weight gain (NEG), and metabolizable energy (ME) and mineral content. Data were analyzed as a completely randomized design with three replicates per treatment. Treatment S100 showed the highest values (p < 0.05) in CP, ADF, crude fat, NEL, and NEG. The C100 had the highest values (p < 0.05) in starch and NFC, and the lowest pH value (p < 0.05). Meanwhile, the S40C60, S60C40, S20C80 combinations showed the highest values (p < 0.05) of TDN, ENL, and ENG. In the case of the combinations, the one with the best values was S40C60. In this regard, the mean values were: CP 143 g kg-1; NEL 1.43 Mcal kg-1; and pH 3.9. According to these values, it is classified as a silage of good nutritional quality, and we recommend its use in subtropical climates.

ABSTRACT The intensification of cattle post-weaning phase in tropical pastures depends on supplementation strategies. The objective of this study was to assess the effect of increasing levels of concentrate supplement on the intake, apparent digestibility of nutrients, feeding behavior, and performance of Girolando steers on tropical pasture during the post-weaning phase in the rainy season. Forty uncastrated male Girolando steers, initially weighing 266.62 ± 32.95 kg and aged 11 mo, were allocated into four concentrate supplement levels: 0.2%, 0.3%, 0.4%, and 0.5% body weight. The steers grazed on Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster ‘Marandu’ pasture. The intakes of supplement DM, non-fibrous carbohydrates (NFC), and total digestible nutrients increased linearly (P < 0.05) with the level of supplement offered to the steers. In a similar response, the apparent digestibility of DM and NFC from the diet also rose linearly (P < 0.05). Grazing time, total feeding time, and total chewing time decreased (P < 0.05) with the increasing levels of concentrate supplementation. In contrast, the time expended on feeding at the trough, biting rate, and the time taken to ruminate each cud increased (P < 0.05) with the supplementation level. Final body weight and average daily gain increased linearly (P < 0.05) with increasing concentrate supplementation. We recommend supplying concentrate supplement at a level of 0.5% of the body weight of steers on tropical pasture during the post-weaning phase in the rainy season.

Abstract: In order to evaluate the physicochemical and microbiological composition of functional beverages obtained from chayote pulp (Sechium edule) with L-carnitine. A randomized design with four replicates per treatment was used to evaluate chemical (dry matter, crude protein, ethereal extract, fiber, and ash), physical (pH, °Brix, acidity), and microbiological (mesophilic aerobes and molds and yeasts) parameters. The treatments studied were: V1, Chayote 100% plus 500 mg of L-carnitine; V2, Chayote 75% + 500 mg of L-carnitine and 25% of distilled water; V3, Chayote 75% + 250 mg of L-carnitine and 25% of distilled water; V4, Chayote 50% + 500 mg of L-carnitine and 50% of distilled water; V5, Chayote 50% + 250 mg of L-carnitine and 50% of distilled water. The pH values at V3 gradually decreased until day 21. Crude protein and ash differed (p<0.05) in V1 and V2 compared to the other treatments. While dry matter, ethereal, and nitrogen-free extract did not differ between the variants, mesophilic aerobes, molds, and yeasts were within the ranges (<3) of acceptance according to NTE INEN 1529-6 standards. Treatment V3 showed the highest pH reduction (5.09) compared to other variants after 21 days of storage. It is concluded that including different amounts of chayote pulp with L-carnitine is a suitable alternative to obtain functional beverages for human consumption.

Resumen: Con el objetivo de evaluar la composición fisicoquímica y microbiológica de las bebidas funcionales obtenidas a partir pulpa de chayote (Sechium edule) con L-Carnitina, se empleó un diseño completamente aleatorizado con cuatro repeticiones por tratamiento se evaluaron parámetros químicos (materia seca, proteína cruda, extracto eterio, fibra y ceniza), físicos (pH, °Brix, acidez) y microbiológicos (aerobios mesófilos y mohos y levaduras). Los tratamientos estudiados fueron: V1, Chayote 100 % más 500 mg de L-carnitina; V2, Chayote 75% + 500 mg L-Carnitina y 25% agua destilada; V3, chayote 75% +250 mg L-Carnitina y 25% agua destilada; V4, Chayote 50% + 500 mg L-Carnitina y 50% agua destilada; V5, Chayote 50% + 250 mg L-Carnitina y 50% agua destilada. Los valores de pH en el V3 se redujeron gradualmente hasta el día 21. La proteína cruda y ceniza difirieron (p<0.05) en los V1 y V2 frente a los demás. Mientras que la materia seca, extracto etéreo y extracto libre de nitrógeno, no presentaron diferencia entre variantes. Los aerobios mesófilos, mohos y levaduras estuvieron dentro los rangos (<3) de aceptación según las normas NTE INEN 1529-6. El tratamiento V3 fue el que presentó mayor reducción de pH (5,09) con frente a otras variantes a los 21dias de conservado. Se concluye, que la inclusión de diferentes cantidades de pulpa de chayote con L-Carnitina es una alternativa apropiada para obtener bebidas funcionales aptos para consumo humano.

Abstract: This study compared forage yield and agronomic characteristics of 9 maize cultivars (Pioneer 30N11, Pioneer 4444, Pioneer 30K08, SC-128W, SC-166Y, SC-78Y, TWC-324W, TWC-368Y and TWC- 321W) ensiled with or without urea as for ruminants on in vitro ruminal fermentation characteristics and nutrient degradability. A factorial randomized complete block design was used. Pioneer 30N11 and Pioneer 4444 showed the greatest silage forage yield, ear weight, and plant height. The chemical composition of maize silage cultivars without urea revealed that Pioneer 30K08 had the greatest (P<0.001) crude protein (CP) content (127 g/kg), while the lowest CP content (89 g/kg) was observed with SC-78Y. CP content ranged from 118 to 156 g/kg when urea was added to the maize silage cultivars. The neutral detergent fiber, acid detergent fiber, and acid detergent lignin contents recorded the highest values (P<0.01) in TWC-324W, SC-128W and SC-78Y. Urea treatment of different cultivars affected (P<0.05) the concentrations of CP, ether extract (EE), non-structural carbohydrates (NSC), and fibers. Urea treatment increased CP and EE in all cultivars and increased or decreased truly degraded dry matter (TDDM), truly degraded organic matter (TDOM), protozoa, ammonia and methane (P<0.05). Overall, Pioneer 30N11, Pioneer 4444 and Pioneer 30K08 showed the greatest forage yield and nutritive value as a feed for ruminants.

Abstract Local brewery byproducts such as atella and tata, resulting from several fermented beverages, are used as animal feed in Ethiopia. However, there is no sufficient information on the nutritional value of those feed resources for animals. The objective of this study was to evaluate the effects of supplementing local brewery by-products on feed intake, body weight change, and economic profitability of Woyto-Guji goats fed on hay. Twenty-four yearling intact Woyto-Guji male goats were used. The experiment was conducted using a completely randomized block design. The goats were blocked into six groups of four animals based on initial body weight and randomly assigned to four different dietary treatments: hay alone (T1); hay combined with atella (T2); hay combined with tata (T3); and hay combined with an atella-tata mixture (1:1) (T4). The crude protein content of hay, atella, tata, and the atella-tata mixture used in this study were 7.35, 18.47, 17.51 and 17.86%, respectively. Dry matter intakes of 564.56 (T1), 810.27 (T2), 850.37 (T3), and 945.85 (T4) g/day, and crude protein intakes of 45.27 (T1), 104.18 (T2), 103.79 (T3), and 112.96 (T4) g/day were recorded. Total body weight gains were 2.76, 8.03, 6.15 and 9.72 Kg for the same treatments, respectively. Atella and tata, either supplemented alone or combined, increased body weight. The highest body weight gain was recorded in goats fed atella-tata mixture. All treatments had a positive net return.

Abstract This study aimed to evaluate whether bacterial inoculation improves the fermentative, microbiological, and chemical characteristics of silages of the elephant grass cv. BRS Capiaçu on different regrowth days. The experimental design was completely randomized and set up in a 3x2 factorial arrangement (three regrowth days, with and without inoculant), with four replications. There was a significant interaction between the regrowth days and inoculant on the pH, ammoniacal nitrogen (N-NH3), and effluent losses (EL) of the silages. Inoculation decreased the EL with the advance of regrowth days and increased the dry matter recovery index compared to the silages without inoculant. The population of molds and yeasts decreased when inoculation was adopted to the forage harvested after 85 d. There was a significant interaction between the dry matter (DM), crude protein (CP) and neutral detergent fiber corrected for ash and protein (NDFap) contents of the silages. Inoculation in the grass harvested after 85 d increased the DM contents of the silage. The highest CP contents were observed in the silages after 85 d. The NDFap contents of the grasses harvested after 110 and 135 d were higher than those of the grass harvested after 85 d. The NDFap contents of the silages without inoculant increased with the harvest age. The BRS Capiaçu forage silage harvested at 110 d demonstrated favorable performance for silage production. However, the influence of inoculant use was low for the characteristics evaluated.

Resumen Este estudio tuvo como objetivo evaluar si la inoculación bacteriana mejora las características fermentativas, microbiológicas y químicas de los ensilados del pasto elefante cv. BRS Capiaçu en diferentes días de rebrote. El diseño experimental fue completamente al azar y se estableció en un arreglo factorial 3x2 (tres días de rebrote, con y sin inoculante), con cuatro repeticiones. Hubo una interacción significativa entre los días de rebrote y el inoculante sobre el pH, el nitrógeno amoniacal (N-NH3) y las pérdidas por efluentes (PE) de los ensilados. La inoculación disminuyó la PE con el avance de los días de rebrote y aumentó la tasa de recuperación de materia seca en comparación con los ensilados sin inoculante. La población de mohos y levaduras disminuyó cuando se adoptó la inoculación al forraje cosechado después de 85 d. Hubo una interacción significativa entre la materia seca (MS), la proteína cruda (PC) y la fibra detergente neutro corregida por los contenidos de cenizas y proteína (FDNcp) de los ensilados. La inoculación en el pasto cosechado después de 85 días aumentó el contenido de MS del ensilado. Los mayores contenidos de PC se observaron en los ensilados después de 85 días. Los contenidos de FDNcp de los pastos cosechados después de 110 y 135 días fueron mayores que el del pasto cosechado después de 85 días. El contenido de FDNcp de los ensilados sin inoculante aumentó con la edad de cosecha. El ensilado de forraje de BRS Capiaçu cosechado a los 110 días demostró un desempeño favorable para la producción de ensilado. Sin embargo, la influencia del uso de inoculantes fue baja para las características evaluadas.

Abstract The availability of forage decreases during the dry season, so it is advisable to conserve forage and preferably it should contain high nutritional value. The present study aimed to evaluate the nutritive value of silages in different proportions of soybean and buffel grass forage under subtropical conditions. The treatments were three forage combinations: S50B50 (50% soybean forage + 50% buffel grass forage), S25B75 (25% soybean forage + 75% buffel grass forage) and B100 (100% buffel grass forage ). The variables evaluated were: crude protein (CP), neutral detergent fiber, acid detergent fiber, ether extract, and metabolizable energy. Data were analyzed based on a completely randomized design with three repetitions and Tukey’s mean comparison ((= 0.05). The S50B50 treatment presented the highest values of CP (128 vs 65 g kg-1) and EE (28 vs 21 g kg-1), compared to B100, which had the highest values of neutral detergent fiber (692 vs 513 g kg-1) and acid detergent fiber (408 vs 355 g kg-1). S25B75 and B100 treatments presented similar ME values (p> 0.05), 1.43 and 1.54 Mcal kg-1, respectively, which were surpassed by S50B50 by 15% (1.71 Mcal kg-1). Soybean and buffel grass silage could be an alternative for ruminant feeding during the dry season; in particular, the combination of 50% soybean forage and 50% buffel grass obtains the best nutrient profile.

Resumen Durante la época seca se reduce la disponibilidad de forraje, por ello es conveniente conservar el forraje y de preferencia este debe contener alto valor nutritivo. El objetivo del presente estudio fue evaluar el valor nutritivo de ensilados en diferentes proporciones de forraje de soya y pasto buffel en condiciones subtropicales. Los tratamientos fueron tres combinaciones de forraje: S50B50 (50% forraje de soya + 50% forraje de pasto buffel), S25B75 (25% forraje de soya + 75% forraje de pasto buffel) y B100 (100% forraje de pasto buffel). Las variables evaluadas fueron: proteína cruda (PC), fibra detergente neutro, fibra detergente ácido, extracto etéreo y energía metabolizable. Los datos se analizaron con base en un diseño completamente al azar con tres repeticiones y la comparación de medias de Tukey ((= 0.05). El tratamiento S50B50 presentó los mayores valores de PC (128 vs 65 g kg-1) y EE (28 vs 21 g kg-1) en comparación con B100, quien tuvo los mayores valores de fibra detergente neutro (692 vs 513 g kg-1) y fibra detergente ácido (408 vs 355 g kg-1). Los tratamientos S25B75 y B100 presentaron valores similares (p> 0.05) de EM, 1.43 y 1.54 Mcal kg-1, respectivamente; los cuales fueron superados por S50B50 en 15% (1.71 Mcal kg-1. El ensilado de soya y pasto buffel podría ser alternativa para la alimentación de rumiantes durante época de estiaje, en particular, la combinación de 50% forraje de soya y 50% pasto buffel se obtiene el mejor perfil nutrimental.

Abstract Conjugated linoleic acid is considered a functional food since its consumption improves people’s health. This compound is found in the milk of ruminant animals and is synthesized in the rumen and mammary gland using linoleic and α-linolenic acids as substrates, which are widely found in forage plants. Nevertheless, there is little information regarding the content of fatty acids in forages, particularly of native species. Therefore, the study aimed to evaluate the chemical composition and fatty acid profile of native forage shrubs that are consumed by goats under extensive grazing in northern Mexico in 2019. For this, forage shrubs consumed by goats were collected. The selected forages were determined: dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber, total lipids, and fatty acid profile. The forage shrubs consumed by the goats in the rangeland were huizache [Vachellia farnesiana (L.) Wild.], mesquite [Prosopis laevigata (Humb & Bonpl) Wild], gobernadora [Larrea tridentata (Moç. & Seseé DC)] and chaparro prieto [Vachellia constricta (Bentham Siegler & Ebinger Waif)]. Of these, mesquite (CP 148 g kg-1 DM) and chaparro prieto (CP 147 g kg-1 DM) had the best crude protein contents; likewise, mesquite had a high concentration in linoleic (14.21 g 100 g-1 total fatty acids) and α-linolenic (36.22 g 100 g-1 total fatty acids) fatty acids, so these forage shrubs can be considered in the diet of goats that aim to increase the concentration of conjugated linoleic acid in milk or meat of grazing goats.

Resumen El ácido linoleico conjugado es considerado un alimento funcional ya que su consumo mejora la salud de las personas. Este compuesto se encuentra en leche de animales rumiantes y es sintetizado en el rumen y glándula mamaria utilizando como sustratos a los ácidos linoleico y α-linolenico, los cuales se encuentran en forma amplia en plantas forrajeras. Sin embargo, existe poca información respecto al contenido de ácidos grasos en forrajes, en particular, de especies nativas. Por lo tanto, el objetivo del estudio fue evaluar la composición química y perfil de ácidos grasos de arbustos forrajeros nativos que son consumidos por cabras bajo pastoreo extensivo en el norte de México, en 2019. Para ello, se realizó una colecta de arbustos forrajeros consumidos por cabras. A los forrajes seleccionados se le determino: materia seca, materia orgánica, proteína cruda, fibra detergente neutro, fibra detergente ácido, lípidos totales y perfil de ácidos grasos. Los arbustos forrajeros consumidos por las cabras en el agostadero fueron: huizache (Vachellia farnesiana (L.) Wild.), mezquite (Prosopis laevigata (Humb & Bonpl) Wild), gobernadora (Larrea tridentata (Moç. & Seseé DC) y chaparro prieto (Vachellia constricta (Bentham Siegler & Ebinger Waif). De estos, mezquite (PC 148 g kg-1 de MS) y chaparro prieto (PC 147 g kg-1 de MS) tuvieron los mejores contenidos de proteína cruda, asimismo, mezquite tuvo una alta concentración en los ácidos grasos linoleico (14.21 g 100 g-1 ácidos grasos totales) y α-linolenico (36.22 g 100 g-1 ácidos grasos totales), por lo que estos arbustos forrajeros pueden ser considerados en dieta de las cabras que tengan el objetivo de incrementar la concentración de ácido linoleico conjugado en leche o carne de cabras en pastoreo.

ABSTRACT The effect of four harvest ages (90, 120, 150 and 180 days) on the aerial biomass yield and chemical composition of rapeseed was evaluated, as well as its use as a hay supplement for dairy cows grazing at an altitude of 3279 m. Forage yield and its chemical composition were evaluated in 16 plots, 4 per treatment, according to a randomized complete block design. The harvested rapeseed biomass was hayed and chopped to 1 cm in length, supplied daily at a rate of 3 kg per cow. Sixteen crossbred and multiparous Holstein cows were distributed in four treatments that consisted of hays made according to harvest age. Milk production per cow was recorded for six weeks. Total solids, fat, protein, and lactose were determined in the last week of the study. As rapeseed age increased, forage biomass and neutral detergent fiber (NDF) increased, and crude protein concentration decreased; however, milk production and its milk components were not affected by the supplementation of the four types of hay, except for rapeseed hay harvested at 90 days of age, which increased the milk protein content.

RESUMEN Se evaluó el efecto de cuatro edades de cosecha (90, 120, 150 y 180 días) sobre el rendimiento de biomasa aérea y composición química de la colza, así como su uso como suplemento henificado para vacas lecheras en pastoreo a 3279 msnm. El rendimiento forrajero y la composición química se evalúo en 16 parcelas, 4 por tratamiento, de acuerdo con un diseño de bloques completos al azar. La biomasa de colza cosechada fue henificada y picada a 1 cm de longitud, suministrada diariamente a razón de 3 kg por vaca. Dieciséis vacas Holstein cruzadas y multíparas se distribuyeron en cuatro tratamientos que consistieron en henos elaborados de acuerdo con la edad de cosecha. La producción de leche por vaca se registró durante seis semanas. Los sólidos totales, grasa, proteína y lactosa se determinaron en la última semana del estudio. A medida que la edad de la colza fue mayor se incrementó la biomasa forrajera y la fibra detergente neutra (FDN), y disminuyó la concentración de proteína cruda; sin embargo, la producción de leche y sus componentes lácteos no se vieron afectados por la suplementación de los cuatro tipos de heno, con excepción del heno de colza cosechada a 90 días de edad, que incrementó el contenido de proteína láctea.

ABSTRACT Livestock systems at Region Aysén del General Carlos Ibáñez del Campo depend on forage conservation during the spring-summer season, generally with low nutritional quality to animal requirements. To reduce nutrient loss, additives are commonly used, being spent brewery yeast a potential additive. Therefore, a study was carried out with the inclusion of two spent brewer’s yeast (Lager and Ale) as an additive in pasture mini silos compared to two commercial additives (SiloSolve MC™ and Josilac grass™) and mini silo without additive. It was observed that spent brewer’s yeast has a negative effect on crude protein and metabolizable energy, contents that decreased to 9.8% and 2.5%, respectively, compared to control. However, Ale yeast declined faster and maintained lower pH levels below 4.1. Spent brewer’s yeast do not improve nutritional quality, however decreased pH levels of pasture silage. Therefore, it should be noted that the effect of spent brewer’s yeasts has been insufficiently evaluated. Thus, is still a lack of trials within large scale of silage conservation and its effects on animal feed performance.

Resumen El cambio climático está reduciendo la disponibilidad de forraje para los rumiantes. Estudios previos en la Patagonia Norte Argentina demuestran la adaptación del cultivo de amaranto a estas condiciones agroclimáticas bajo riego. Sin embargo, este cultivo se utiliza como forraje en zonas marginales del mundo, dadas las destacadas cualidades productivas y nutricionales del cultivo de amaranto. El objetivo de este estudio fue evaluar la calidad nutricional del ensilado de amaranto en respuesta al oreado previo del forraje y a la adición de bacterias lácticas. El cultivo se cosechó en el estado grano lechoso y se ensiló en microsilos experimentales durante 60 días. Antes del ensilado, se llevaron a cabo diferentes tratamientos (oreado y adición de bacterias lácticas). Se evaluaron parámetros relacionados con la calidad nutricional: cenizas, proteína cruda (PC), Fibra Detergente Neutro (FDN), Fibra Detergente Ácido (FDA), digestibilidad de la materia seca (DMS) y energía metabolizable (EM). El tratamiento simultáneo de oreado y adición de bacterias lácticas antes del ensilado dio lugar a las mejores características de calidad nutricional del ensilado obtenido. Los resultados más importantes bajo estas condiciones fueron valores de proteína del 12,7%, FDN del 41,1% y FDA del 19,1%. La DMS y la EM fueron del 74% y 2,67 Mcal/kg, respectivamente. Así, el ensilaje de amaranto puede ser considerado como una alternativa forrajera conservada para la alimentación animal de la región.

Abstract Climate change is reducing forage availability for ruminants. Previous studies in Northern Patagonia, Argentina, have demonstrated the adaptation of the amaranth crop to these agroclimatic conditions under irrigation. Moreover, this crop is used as forage in marginal areas of the world, given its outstanding productive and nutritional qualities. The objective of this study was to evaluate the nutritional quality of amaranth silage in response to previous wilting and the addition of lactic acid bacteria. The crop was harvested at the milky grain stage and ensiled in experimental microsilos for 60 days. Before ensiling, different treatments (wilting and addition of lactic acid bacteria) were applied. Parameters related to nutritional quality were evaluated, including ash, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), dry matter digestibility (DMD), and metabolizable energy (ME). Simultaneous treatment with air and the addition of lactic acid bacteria before ensiling resulted in the best nutritional quality characteristics of the silage. The most significant results were protein value of 12.7%, 41.1% NDF and 19.1% FDA. The DM and ME were 74% and 2.67 Mcal/kg, respectively. Thus, amaranth silage can be considered an alternative conserved forage for animal feed in this region.

Abstract The present study aimed to produce a monosex population of all male Nile tilapia (Oreochromis spp.) using 17α-methyl testosterone and common carp testes (as a source of natural androgen). Trial was conducted into two consecutive phases, the first was fry (4-5 days old)administration with negative control (without hormone) and positive control (with hormone) feed viz., MT1:60mg/kg, MT2:70mg/kg (17α-MT), carp testis CT1:70% and CT2:80% for 30 days to reverse the sex of male fish and the second phase was nursing the fingerlings for two months on control diet (32% Crude protein).Results revealed a significant growth rate (P<0.05) in the control group where final weight (4.8±0.34ab) and weight gained was recorded as 0.66±0.03ac. In proximate chemical composition of body meat, CT2 treatment showed maximum retention of crude protein, crude fat, and ash whereas dry matter showed maximum retention in MT2 and CT1 treatments. Morphological and histological examination revealed significant difference (p<0.05) in phenotypic males of Nile tilapia fed with the highest percent in MT-treated diet (MT2) of 95±0.58a while MT1, CT2 and CT1 had males of 85±6.0b, 70±5.0b and 65±6.5b, respectively. It was concluded that synthetic androgen (17αMT) was more effective for masculinization but natural androgen scan be an alternative method to produce male tilapia population in an environment-friendly manner as they are inexpensive, eco-friendly, and radially available. These results suggested that synthetic and natural androgen supplementation in the diet plays a significant role in improving growth performance and body composition. Oreochromis spp. spp 17αmethyl αmethyl 17α methyl α androgen. . androgen) phases 45 4 5 (4- oldadministration old administration without hormone viz viz. MT160mg/kg, MT160mgkg MTmgkg MT1 60mg/kg, 60mg kg MT mg MT1:60mg/kg MT270mg/kg MT270mgkg 70mg/kg 70mg 17αMT, 17αMT αMT , (17α-MT) CT170% CT170 CT 70% 70 CT1:70 CT280% CT280 80% 80 CT2:80 3 32% 32 (32 protein.Results proteinResults protein .Results Results P<0.05 P005 P 0 05 (P<0.05 4.8±0.34ab 48034ab ab 8 34ab (4.8±0.34ab 066003ac ac 66 03ac 0.66±0.03ac meat fat treatments p<0.05 p005 p (p<0.05 MTtreated treated (MT2 95058a 95 58a 8560b b 85 6 0b 85±6.0b 7050b 6565b 65 5b 65±6.5b respectively (17αMT environmentfriendly environment friendly inexpensive ecofriendly, ecofriendly eco friendly, eco-friendly available (4 MT160mg MT160mg/kg mgkg 60mgkg 60mg/kg MT270mg 70mgkg (17α-MT CT17 7 CT1:7 CT28 CT2:8 (3 P<0.0 P00 (P<0.0 p<0.0 p00 (p<0.0 (MT 9 ( MTmg CT1: CT2: P<0. P0 (P<0. p<0. p0 (p<0. P<0 (P<0 p<0 (p<0 P< (P< p< (p< (P (p

Resumo O presente estudo teve como objetivo produzir uma população monossexuada de todos os machos de tilápia do Nilo (Oreochromis spp.) usando 17α-metil testosterona e testículos de carpa comum como fonte de andrógeno natural. O ensaio foi conduzido em duas fases consecutivas, a primeira foi a administração de alevinos (4-5 dias) com controle negativo (sem hormônio) e controle positivo (com hormônio), viz., MT1:60mg/kg, MT2:70mg/kg (17α -MT), testículos de carpa CT1:70% e CT2:80% por 30 dias para inverter o sexo dos peixes machos e a segunda fase foi amamentar os alevinos por dois meses com dieta controle (32% de proteína bruta), e analisar a taxa de crescimento (p < 0,05) no grupo controle, em que o peso final (4,8 ± 0,34 ab) e o peso ganho foram registrados como 0,66 ± 0,03 ac. Na composição química aproximada da carne corporal, o tratamento CT2 mostrou retenção máxima de proteína bruta, gordura bruta e cinzas, enquanto a matéria seca apresentou retenção máxima nos tratamentos MT2 e CT1. O exame morfológico e histológico revelou diferença significativa (p < 0,05) nos machos fenotípicos de tilápia do Nilo alimentados com o maior percentual na dieta tratada com MT (MT2) de 95 ± 0,58a enquanto MT1, CT2 e CT1 tiveram machos de 85 ± 6,0b, 70 ± 5,0 e 65 ± 6,5b, respectivamente. Concluiu-se que o andrógeno sintético (17αMT) foi mais eficaz para a masculinização, entretanto os andrógenos naturais podem ser um método alternativo para produzir população de tilápias machos de maneira ecológica, pois são baratos, ecológicos e estão disponíveis radialmente. Esses resultados sugerem que a suplementação de andrógenos sintéticos e naturais na dieta desempenha um papel significativo na melhoria do desempenho do crescimento e da composição corporal. Oreochromis spp. spp 17αmetil αmetil 17α metil α natural consecutivas 45 4 5 (4- sem hormônio hormônio, , viz viz. MT160mg/kg, MT160mgkg MTmgkg MT1 60mg/kg, 60mg kg mg MT1:60mg/kg MT270mg/kg MT270mgkg 70mg/kg 70mg MT, -MT) CT170% CT170 CT 70% CT1:70 CT280% CT280 80% 80 CT2:80 3 32% 32 (32 bruta) p 0,05 005 0 05 4,8 48 8 (4, 034 34 0,3 ab 066 66 0,6 003 03 0,0 ac corporal cinzas (MT2 9 058a 58a 60b b 6 0b 6,0b 7 50 5, 65b 5b 6,5b respectivamente Concluiuse Concluiu se 17αMT αMT (17αMT masculinização ecológica baratos radialmente (4 MT160mg MT160mg/kg mgkg 60mgkg 60mg/kg MT270mg 70mgkg -MT CT17 CT1:7 CT28 CT2:8 (3 00 4, 0, 06 (MT ( MTmg CT1: CT2: