Effects of Starch Level and a Mixture of Sunflower and Fish Oils on Nutrient Intake and Digestibility, Rumen Fermentation, and Ruminal Methane Emissions in Dairy Cows.

Four multiparous dairy cows were used in a 4 × 4 Latin square to examine how starch level and oil mixture impact dry matter (DM) intake and digestibility, milk yield and composition, rumen fermentation, ruminal methane (CH4) emissions, and microbial diversity. Experimental treatments comprised high (HS) or low (LS) levels of starch containing 0 or 30 g of a mixture of sunflower and fish oils (2:1 w/w) per kg diet DM (LSO and HSO, respectively). Intake of DM did not differ between cows fed LS and HS diets while oil supplementation reduced DM intake. Dietary treatments did not affect milk and energy corrected milk yields. There was a tendency to have a lower milk fat concentration due to HSO compared with other treatments. Both high starch level and oil supplementation increased digestibility of gross energy. Cows receiving HS diets had higher levels of total rumen VFA while acetate was lower than LS without any differences in rumen pH, or ruminal CH4 emissions. Although dietary oil supplementation had no impact on rumen fermentation, decreased CH4 emissions (g/day and g/kg milk) were observed with a concomitant increase in Anoplodinium-Diplodinium sp. and Epidinium sp. but a decrease in Christensenellaceae, Ruminococcus sp., Methanobrevibacter ruminantium and Mbb. gottschalkii clades.

Effect of Dietary Vegetable Sources Rich in Unsaturated Fatty Acids on Milk Production, Composition, and Cheese Fatty Acid Profile in Sheep: A Meta-Analysis.

A meta-analysis was conducted to analyze the effects of different dietary vegetable sources rich in unsaturated FA (UFA) on sheep cheese FA profile. This study also quantified the overall effect of feeding sheep with vegetable sources rich in UFA (linseed, flaxseed, sunflower seed, canola, olive oil, bran oil, and olive cake), on milk yield (MY) and milk composition. A literature search was conducted to identify papers published from 2000 to 2019. Effect size for all parameters was calculated as standardized mean difference. Heterogeneity was determined using I 2 statistic, while meta-regression was used to examine factors influencing heterogeneity. Effect size was not significant for MY, milk fat percentage (MFP), and milk protein percentage (MPP). Dietary inclusion of vegetable sources rich in UFA decreased the effect size for C12:0, C14:0, and C16:0 and increased the effect size for C18:0, C18:1 t-11, C18:1 c-9, C18:2 c-9, t-11, C18:2 n-6, and C18:3 n-3. Heterogeneity was significant for MY, MFP, MPP, and overall cheese FA profile. Meta-regression revealed days in milk as a contributing factor to the heterogeneity observed in MFP and MPP. Meta-regression showed that ripening time is one of the factors affecting cheese FA profile heterogeneity while the type of feeding system(preserved roughages vs. pasture) had no effect on heterogeneity. Overall, inclusion of dietary vegetable sources rich in UFA in sheep diets would be an effective nutritional strategy to decrease saturated FA and increase polyunsaturated FA contents in cheeses without detrimental effects on MY, MFF, and MPP.

Effects of inclusion of corn gluten feed in dairy rations on dry matter intake, milk yield, milk components, and ruminal fermentation parameters: a meta-analysis.

Corn gluten feed (CGF) is a co-product of wet milling that can replace energy or fiber ingredients in dairy cow rations. The present meta-analysis examines how inclusion of CGF can affect dry matter intake (DMI), milk yield (MY), milk components, and ruminal fermentation parameters. A literature search was conducted to identify papers published from 1990 to 2018. Effect size for all parameters was calculated as standardized mean difference with a 95% confidence interval. Heterogeneity was determined using Q test and I2 statistic, while meta-regression was used to examine factors influencing heterogeneity. Results indicate that feeding CGF increased the effect size for DMI and MY. No differences were observed for effect size for percentage milk fat or protein; however, increases were observed in the effect size for milk fat yield, milk protein yield, milk lactose percentage, and milk lactose yield. Ruminal fermentation parameters revealed a decrease in the effect size for pH and acetate and an increase for propionate. No differences were observed in the effect size for total VFA or butyrate. The Q test demonstrated heterogeneity (P < 0.1) for MY, MFP, and pH. The results indicate differences in forage intake between groups receiving CGF and control as an important factor contributing to heterogeneity for DMI, MFP, and pH. It can be concluded from this meta-analysis that in addition to increased DMI, inclusion of CGF in cow diets increases MY and improves milk components. Furthermore, inclusion of CGF in the diet lowers ruminal pH while decreasing acetate and increasing propionate contents.

Environmental efficiency of Saccharomyces cerevisiae on methane production in dairy and beef cattle via a meta-analysis.

The objective of the present study is to examine the effect of yeast (Saccharomyces cerevisiae) on reduction of methane (CH4) production in dairy and beef cattle using meta-analytic methods. After compilation of relevant scientific publications available from the literature between 1990 and 2016, and applying exclusion and inclusion criteria, meta-analyses of data from dairy and beef cattle were applied for the pooled dataset or for each animal category (dairy or beef). The results of meta-analysis of all three datasets (all cattle, dairy cattle, or beef cattle) suggested that effect size of yeast either on daily CH4 production or on CH4 production per dry matter intake (CH4/DMI) was not significant. The results of Q test and I2 statistic suggest that there is no heterogeneity between different studies on CH4 production and CH4/DMI. The results of meta-analysis suggest that use of yeast (Saccharomyces cerevisiae) as feed additive does not offer significant results in terms of reduction of CH4 production in dairy and beef cattle. Further research on the effects of different doses of yeast, use of yeast products, different strains, and experimental designs is warranted to elucidate the effects of yeasts on methane production in the rumen.

Effect of Aloe vera and vitamin E supplementation on the immune response of broilers / Efectos potenciales del Aloe vera y la vitamina E sobre la respuesta inmune en pollos de engorde / Efeitos potenciais da Aloe vera e vitamina E na resposta imunológica de frangos de corte

Abstract Background: herbs are among the feed supplements under investigation that could replace antibiotics to improve humoral and cellular immune response in birds. Objective: this study evaluated the potential of Aloe vera (Aloe barbadensis Miller) and vitamin E as immunostimulants on humoral and cellular immune responses in broilers. Methods: broilers were randomly assigned to three dietary treatments: a negative control (basal diet+ with no additive), basal diet + 1% Aloe vera gel in drinking water, and basal diet + 100 mg/Kg vitamin E in the feed. Antibody titers against sheep red blood cells and Newcastle disease virus were used to examine the humoral immune response, whereas cellular immune response was evaluated using the phytohemagglutinin-P tests. Results: the highest level of antibody titer against sheep red blood cells on examination days 28 and 38, and the highest response to injection of phytohemagglutinin-P on day 38 was observed in the Aloe vera gel group (p<0.05). However, the response of broilers fed Aloe vera gel was not different from those receiving vitamin E (p>0.05). In addition, the greatest antibody level against Newcastle disease virus was obtained on days 25 and 35 in the vitamin E group, with no significant difference from the Aloe vera gel group (p>0.05). Conclusion: in general, our findings demonstrated that both Aloe vera gel and vitamin E can enhance humoral and cellular immune responses of broilers, while Aloe vera gel can be used as an immunostimulant in chickens.

Resumen Antecedentes: en la industria avícola, es particularmente importante mejorar el rendimiento del sistema inmune con el objetivo de incrementar la resistencia contra patógenos. Las plantas están dentro de los suplementos alimenticios que podrían reemplazar a los antibióticos con el propósito de mejorar la respuesta inmune humoral y celular en aves. Objetivo: el presente estudio evaluó el potencial del Aloe vera (Aloe barbadensis Miller) y la vitamina E como inmunoestimulantes sobre la respuesta inmune humoral y celular en pollos de engorde. Métodos: los pollos de engorde fueron asignados aleatoriamente a tres tratamientos (dietas): un control negativo (dieta base sin aditivo), dieta base + 1% de gel de Aloe vera en el agua de bebida, y una dieta base + 100 mg/Kg de vitamina E en el alimento. Se usó la titulación de anticuerpos contra glóbulos rojos de oveja y contra la enfermedad viral Newcastle para examinar la respuesta inmune humoral. La respuesta inmune celular fue evaluada usando las pruebas de fitohemaglutinina-P. Resultados: el mayor nivel de titulación de anticuerpos contra glóbulos rojos de oveja en los días de experimentación 28 y 38, y la mayor respuesta a la inyección de fitohemaglutinina-P en el día 38 se observó en el grupo del gel de Aloe vera (p<0,05). Sin embargo, la respuesta de los pollos alimentados con gel de Aloe vera no fue diferente a la de los pollos que recibieron vitamina E (p>0,05). Además, el más alto nivel de anticuerpos contra la enfermedad viral Newcastle fue obtenida en los días 25 y 35 en el grupo que recibió vitamina E, sin diferencia significativa con respecto al grupo con gel de Aloe vera (p>0,05). Conclusión: en general, nuestros resultados demuestran que tanto el gel de Aloe vera como la vitamina E pueden mejorar la respuesta inmune humoral y celular en pollos de engorde, mientras que el gel de Aloe vera (agregado al agua) puede usarse como un inmunoestimulante en pollos de engorde.

Resumo Antecedentes: na indústria avícola, a melhoria nas respostas do sistema imunológico é importante, no sentido de aumentar a resistência contra patógenos. As ervas estão entre os suplementos que podem substituir os antibióticos na dieta com o objetivo de melhorar as respostas imunes humoral e celular. Objetivo: o presente estudo avaliou o uso potencial da Aloe vera (Aloe barbadensis Miller) e Vitamina E como imunoestimulantes sobre as respostas imunes humoral e celular em frangos de corte. Métodos: frangos de corte foram aleatoriamente distribuídos em 3 tratamentos, conforme a dieta: controle (dieta basal + sem aditivos), dieta basal + 1% de gel Aloe vera na água de bebida e dieta basal + 100 mg/Kg de vitamina E na dieta. Títulos de anticorpos contra células sanguíneas vermelhas de ovelha e o vírus da doença de Newcastle foram utilizados para avaliar a resposta imune humoral. A resposta imune celular foi avaliada através do teste da fitohemaglutinina-P. Resultados: o maior título de anticorpos contra células sanguíneas vermelhas de ovelha, aos 28 e 38 dias, e a maior resposta à injeção de fitohemaglutinina-P, aos 38 dias, foram observados no grupo recebendo o gel de Aloe vera (p<0,05). Entretanto, a resposta das aves que receberam o gel Aloe vera não foi diferente daqueles que receberam vitamina E (p>0,05). Além disso, o maior título de anticorpos contra o vírus da doença de Newcastle foi observado aos 25 e 35 dias no grupo que recebeu vitamina E sem diferença com o grupo que recebeu gel Aloe vera (p>0,05). Conclusão: em geral, nossos resultados indicam que tanto o gel Aloe vera quanto a vitamina E, podem ser utilizados para aumentar as respostas imune humoral e celular em frangos de corte, enquanto que o gel Aloe vera (adicionado à água de bebida) pode ser utilizado como um imunoestimulante em frangos.