Forages are usually inoculated with homofermentative and facultative heterofermentative lactic acid bacteria (LAB) to enhance lactic acid fermentation of forages, but effects of such inoculants on silage quality and the performance of dairy cows are unclear. Therefore, we conducted a meta-analysis to examine the effects of LAB inoculation on silage quality and preservation and the performance of dairy cows. A second objective was to examine the factors affecting the response to silage inoculation with LAB. The studies that met the selection criteria included 130 articles that examined the effects of LAB inoculation on silage quality and 31 articles that investigated dairy cow performance responses. The magnitude of the effect (effect size) was evaluated using raw mean differences (RMD) between inoculated and uninoculated treatments. Heterogeneity was explored by meta-regression and subgroup analysis using forage type, LAB species, LAB application rate, and silo scale (laboratory or farm-scale) as covariates for the silage quality response and forage type, LAB species, diet type [total mixed ration (TMR) or non-TMR], and the level of milk yield of the control cows as covariates for the performance responses. Inoculation with LAB (≥10 cfu/g as fed) markedly increased silage fermentation and dry matter recovery in temperate and tropical grasses, alfalfa, and other legumes. However, inoculation did not improve the fermentation of corn, sorghum, or sugarcane silages. Inoculation with LAB reduced clostridia and mold growth, butyric acid production, and ammonia-nitrogen in all silages, but it had no effect on aerobic stability. Silage inoculation (≥10 cfu/g as fed) increased milk yield and the response had low heterogeneity. However, inoculation had no effect on diet digestibility and feed efficiency. Inoculation with LAB improved the fermentation of grass and legume silages and the performance of dairy cows but did not affect the fermentation of corn, sorghum, and sugar cane silages or the aerobic stability of any silage. Further research is needed to elucidate how silage inoculated with homofermentative and facultative heterofermentative LAB improves the performance of dairy cows.

The first objective of this study was to examine effects of adding Escherichia coli O157:H7 with or without chemical or microbial additives on the bacterial diversity and composition of alfalfa silage. The second objective was to examine associations between the relative abundance of known and unknown bacterial species and indices of silage fermentation quality. Alfalfa forage was harvested at 54% dry matter, chopped to a theoretical length of cut of 19 mm, and ensiled in quadruplicate in laboratory silos for 100 d after the following treatments were applied: (1) distilled water (control); (2) 1 × 10 cfu/g of E. coli O157:H7 (EC); (3) EC and 1 × 10 cfu/g of Lactobacillus plantarum (EC+LP); (4) EC and 1 × 10 cfu/g of Lactobacillus buchneri (EC+LB); and (5) EC and 0.22% propionic acid (EC+PA). After 100 d of ensiling, the silage samples were analyzed for bacterial diversity and composition via the Illumina MiSeq platform (Illumina Inc., San Diego, CA) and chemically characterized. Overall, Firmicutes (74.1 ± 4.86%) was the most predominant phylum followed by Proteobacteria (20.4 ± 3.80%). Relative to the control, adding E. coli O157:H7 alone at ensiling did not affect bacterial diversity or composition but adding EC+LP or EC+LB reduced the Shannon index, a measure of diversity (3.21 vs. 2.63 or 2.80, respectively). The relative abundance of Firmicutes (69.2 and 68.8%) was reduced, whereas that of Proteobacteria (24.0 and 24.9%) was increased by EC+LP and EC+PA treatments, relative to those of the control (79.5 and 16.5%) and EC+LB (77.4 and 18.5%) silages, respectively. Compared with the control, treatment with EC+LP increased the relative abundance of Lactobacillus, Sphingomonas, Pantoea, Pseudomonas, and Erwinia by 426, 157, 200, 194, and 163%, respectively, but reduced those of Pediococcus, Weissella, and Methylobacterium by 5,436, 763, and 250%, respectively. Relative abundance of Weissella (9.19%) and Methylobacterium (0.94%) were also reduced in the EC+LB silage compared with the control (29.7 and 1.50%, respectively). Application of propionic acid did not affect the relative abundance of Lactobacillus, Weissella, or Pediococcus. Lactate concentration correlated positively (r = 0.56) with relative abundance of Lactobacillus and negatively (r = -0.41) with relative abundance of Pediococcus. Negative correlations were detected between ammonia-N concentration and relative abundance of Sphingomonas (r = -0.51), Pantoea (r = -0.46), Pseudomonas (r = -0.45), and Stenotrophomonas (r = -0.38). Silage pH was negatively correlated with relative abundance of Lactobacillus (r = -0.59), Sphingomonas (r = -0.66), Pantoea (r = -0.69), Pseudomonas (r = -0.69), and Stenotrophomonas (r = -0.50). Future studies should aim to speciate, culture, and determine the functions of the unknown bacteria detected in this study to elucidate their roles in silage fermentation.

Resumo -O objetivo deste trabalho foi avaliar os efeitos de níveis de inclusão de glicerina bruta (GB), contendo 36,20% de glicerol, na dieta de cordeiros em terminação, sobre o consumo, digestibilidade dos componentes da dieta e desempenho produtivo e econômico. Utilizaram-se 35 cordeiros machos não castrados da raça Santa Inês, com peso médio inicial de 20±2,27 kg, distribuídos em delineamento inteiramente casualizado, com cinco tratamentos e seis repetições. Os tratamentos consistiram de níveis de inclusão da GB na dieta (0, 3, 6, 9 e 12% da matéria seca), em substituição ao milho. Após 10 dias de adaptação, cinco animais foram abatidos para se obter o rendimento de carcaça inicial. Após o período de adaptação, os 30 animais restantes foram alojados em baias individuais. Quando o grupo atingiu o peso médio de 35 kg, os animais foram abatidos. Houve efeito linear decrescente dos níveis de GB sobre o consumo de MS e ganho médio diário de peso, e efeito quadrático sobre o coeficiente de digestibilidade da fibra em detergente neutro corrigida para cinzas e proteínas. Houve efeito quadrático também sobre o peso corporal final dos animais e conversão alimentar (CA). A GB contendo 36,20% de glicerol pode ser incluída na dieta de cordeiros em terminação em até 6% da MS da dieta, com otimização da CA e aumento dos benefícios econômicos.Termos para indexação: biodiesel, coprodutos, desempenho, glicerol, ovinos, ruminantes. Crude glycerin on finishing lamb dietsAbstract -The objective of this work was to evaluate the effects of crude glycerin (CG) inclusion, with 36.20% of glicerol, on finishing lamb diets on intake, nutrients digestibility, and productive and economical performance. Thirty-five intact male lambs (Santa Inês), with 20±2.27 kg of initial average body weight were randomly assigned to five treatments, with six replicates. The treatments consisted of increasing crude glycerin levels on the diet: 0, 3, 6, 9 and 12% of diet dry matter. After ten days of adaptation, five animals were slaughtered to determine initial carcass dressing. After the adaptation period, 30 animals were housed in individual pens. When the group reached average body weight of 35 kg, animals were slaughtered. The CG levels had a negative linear effect on dry matter intake and average daily weight gain, and a quadratic effect on neutral fiber detergent digestibility corrected for ash and protein. Crude glycerin levels had also a quadratic effect on body weight at slaughter and feed-to-gain ratio (FGR). Crude glycerin with 36.20% of glycerol can be included in the diet of finishing lambs up to 6% of dry matter, optimizing the FGR and promoting economic benefits.Index terms: biodiesel, co-products, performance, glycerol, sheep, ruminants. IntroduçãoA terminação de cordeiros em confinamento é uma prática que tem despertado o interesse de produtores, por possibilitar a redução das perdas de animais jovens decorrente de deficiências nutricionais e infestações parasitárias. Além disso, essa prática permite a regularidade de oferta da carne dura...

RESUMO -Objetivou-se identificar e quantificar indicadores-referência de sistemas de produção de leite no Extremo Sul da Bahia. Analisaram-se o perfil tecnológico e os indicadores zootécnicos, econômicos e de tamanho de nove empresas. Foram determinados os coeficientes de correlação dos indicadores com a taxa de remuneração do capital investido. Após a identificação dos indicadores que apresentaram correlação, foram geradas equações de regressão para cada indicador em função da taxa de remuneração do capital investido para quantificar os indicadores-referência em quatro cenários de taxa de remuneração do capital investido (4, 6, 8 e 10% ao ano). Os indicadores correlacionados e seus respectivos valores nos quatro cenários foram: produção diária de leite (456, 538, 621 e 703 L/dia); produtividade da terra (733, 1.008, 1.284 e 1.559 L/ha/ano); vacas em lactação por área (0,37; 0,45; 0,54 e 0,62 vacas/ha); produtividade por total de vacas (3,01; 3,52; 4,03 e 4,54 L/vaca/dia); relação de vacas em lactação pelo total do rebanho (24, 27, 30 e 33%); produtividade da mão-de-obra (111, 124, 137 e 150 L/dia-homem), participação do custo operacional efetivo da atividade na renda bruta da atividade (60, 57, 54 e 51%); participação do custo operacional total da atividade na renda bruta da atividade (72, 66, 60, 54%); gasto com mão-de-obra em relação à renda bruta do leite (31, 27, 22 e 18%); capital investido na atividade em relação à produção diária de leite (2.093, 1.508, 924 e 339 R$/L-dia). A identificação de indicadores-referência em sistemas reais de produção de leite, caracterizando aqueles mais diretamente correlacionados à eficiência econômica, é uma importante ferramenta de apoio gerencial e pode trazer esclarecimentos para o debate sobre a viabilidade econômica de sistemas de produção de leite.Palavras-chave: benchmark, custo de produção, gestão, rentabilidade Identification and quantification of benchmarks of milk production systemsABSTRACT -The objective of this study was to identify and quantify benchmarks of milk production systems in the region of Extremo Sul da Bahia. Technological profile and indicators of size, livestock productivity and economy of nine farms were analyzed. It were also determined the correlation coefficients between these indicators and the rate of retun. Indicators with significant correlation were regressed on rate of return in order to quantify the benchmarks with the following rates of return: 4, 6, 8 and 10% per year. Data for the four rates of return were, respectively: daily milk yield (456, 538, 621 and 703 L/day); land productivity (733, 1.008, 1284 and 1559 L/ha/year); stocking rate (0.37, 0.45, 0.54 and 0.62 cows/ha); productivity per total of cows (3.01, 3.52, 4.03 and 4.54 L/cow/day); labor productivity (111, 124, 137 and 150 L/man/day); proportion of the total effective operational cost in the gross revenue (60, 57, 54 and 51%); proportion of the total operational cost in the gross revenue (72, 66, 60 and 54%); labor cost to milk gross revenue ratio (31, 27, 22 and 18%); a...

The aim of this study was to use meta-analytical methods to estimate effects of adding exogenous fibrolytic enzymes (EFE) to dairy cow diets on their performance and to determine which factors affect the response. Fifteen studies with 17 experiments and 36 observations met the study selection criteria for inclusion in the meta-analysis. The effects were compared by using random-effect models to examine the raw mean difference (RMD) and standardized mean difference between EFE and control treatments after both were weighted with the inverse of the study variances. Heterogeneity sources evaluated by meta-regression included experimental duration, EFE type and application rate, form (liquid or solid), and method (application to the forage, concentrate, or total mixed ration). Only the cellulase-xylanase (C-X) enzymes had a substantial number of observations (n = 13 studies). Application of EFE, overall, did not affect dry matter intake, feed efficiency but tended to increase total-tract dry matter digestibility and neutral detergent fiber digestibility (NDFD) by relatively small amounts (1.36 and 2.30%, respectively, or <0.31 standard deviation units). Application of EFE increased yields of milk (0.83 kg/d), 3.5% fat-corrected milk (0.55 kg/d), milk protein (0.03 kg/d), and milk lactose (0.05 kg/d) by moderate to small amounts (<0.30 standard deviation units). Low heterogeneity (I statistic<25%) was present for yields and concentrations of milk fat and protein and lactose yield. Moderate heterogeneity (I = 25 to 50%) was detected for dry matter intake, milk yield, 3.5% fat-corrected milk, and feed efficiency (kg of milk/kg of dry matter intake), whereas high heterogeneity (I > 50%) was detected for total-tract dry matter digestibility and NDFD. Milk production responses were higher for the C-X enzymes (RMD = 1.04 kg/d; 95% confidence interval: 0.33 to 1.74), but were still only moderate, about 0.35 standardized mean difference. A 24% numerical increase in the RMD resulting from examining only C-X enzymes instead of all enzymes (RMD = 1.04 vs. 0.83 kg/d) suggests that had more studies met the inclusion criteria, the C-X enzymes would have statistically increased the milk response relative to that for all enzymes. Increasing the EFE application rate had no effect on performance measures. Application of EFE to the total mixed ration improved only milk protein concentration, and application to the forage or concentrate had no effect. Applying EFE tended to increase dry matter digestibility and NDFD and increased milk yield by relatively small amounts, reflecting the variable response among EFE types.

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Thirty non-castrated male lambs with 20±2.3 kg average body weight (BW) were randomly assigned to five treatments consisted of different dietary concentrations of crude glycerin (CG; 0, 3, 6, 9 and 12% on DM basis) to evaluate the effects on performance, carcass and meat quality traits. A quadratic effect was observed for performance (P=0.04), final BW (P<0.01) and hot carcass weight (P<0.01). No effects of CG were observed (P>0.05) on carcass pH neither on shear-force, cooking loss and ether extract content in longissimus. The inclusion of CG tended to reduce the Zn content in meat (P=0.09). The data suggests that CG (36.2% of glycerol and 46.5% of crude fat) may be used in diets of finishing lambs with concentrations up to 3% without negative effects on performance and main carcass traits. Moreover, inclusion of CG seems to not affect quality and safety of meat for human consumption.

The study was conducted to examine the effect of supplementing bentonite clay with or without a Saccharomyces cerevisiae fermentation product (SCFP; 19 g of NutriTek + 16 g of MetaShield, both from Diamond V, Cedar Rapids, IA) on the performance and health of dairy cows challenged with aflatoxin B (AFB). Twenty-four lactating Holstein cows (64 ± 11 d in milk) were stratified by parity and milk production and randomly assigned to 1 of 4 treatment sequences. The experiment had a balanced 4 × 4 Latin square design with 6 replicate squares, four 33-d periods, and a 5-d washout interval between periods. Cows were fed a total mixed ration containing 36.1% corn silage, 8.3% alfalfa hay, and 55.6% concentrate (dry matter basis). Treatments were (1) control (no additives), (2) toxin (T; 1,725 µg of AFB/head per day), (3) T + clay (CL; 200 g/head per day; top-dressed), and (4) CL+SCFP (CL+SCFP; 35 g/head per day; top-dressed). Cows were adapted to diets from d 1 to 25 (predosing period) and then orally dosed with AFB from d 26 to 30 (dosing period), and AFB was withdrawn from d 31 to 33 (withdrawal period). Milk samples were collected twice daily from d 21 to 33, and plasma was sampled on d 25 and 30 before the morning feeding. Transfer of ingested AFB into milk aflatoxin M (AFM) was greater in T than in CL or CL+SCFP (1.65 vs. 1.01 and 0.94%, respectively) from d 26 to 30. The CL and CL+SCFP treatments reduced milk AFM concentration compared with T (0.45 and 0.40 vs. 0.75 µg/kg, respectively), and, unlike T, both CL and CL+SCFP lowered AFM concentrations below the US Food and Drug Administration action level (0.5 µg/kg). Milk yield tended to be greater during the dosing period in cows fed CL+SCFP compared with T (39.7 vs. 37.7 kg/d). Compared with that for T, plasma glutamic oxaloacetic transaminase concentration, indicative of aflatoxicosis and liver damage, was reduced by CL (85.9 vs. 95.2 U/L) and numerically reduced by CL+SCFP (87.9 vs. 95.2 U/L). Dietary CL and CL+SCFP reduced transfer of dietary AFB to milk and milk AFM concentration. Only CL prevented the increase in glutamic oxaloacetic transaminase concentration, and only CL+SCFP prevented the decrease in milk yield caused by AFB ingestion.