This study evaluated the effect of two concentrate supplementation strategies on performance, metabolic profile and economic evaluation of suckling lambs and ewes in ryegrass (Lolium multiflorum) pasture. Twenty-seven ewes and 45 lambs were divided into three groups: (1) ryegrass pasture without supplementation - control (CON); (2) CON plus supplemented ewes and lambs at 1% of live weight (SEL), and (3) CON plus creep feeding supplemented lambs at 1% of live weight (CSL). Concentrate use increased (p<0.05) average daily gain (ADG) by 19.95% over CON (21.6 and 18.3% for SEL and CSL, respectively). Concentrate use contributed to minimizing forage quality fluctuation and provided greater ADG stability, mainly when ryegrass nutritional content and digestibility decreased. Blood metabolites profiles did not differ between groups, with exception of phosphorus which was higher for CON than SEL, and calcium which was higher for CSL than CON (p<0.05). Compared to CON, stoking rate values were greater to SEL (p<0.05). Compared to CSL, ewe and total stocking rate were greater (p<0.05) to SEL. Considering the control group as break even feed investment, SEL strategy had a positive economic return, while CSL showed economic losses. Concentrate use increased ADG of lambs and decrease the impact of nutrient quality changes of forage on daily gains, but must be considered that supplemental strategy used could affect negatively economic return.

Mycotoxins often contaminate cattle food, which can cause liver damage, immunosuppression, and reduced milk production. Although previous studies have shown the benefits of adsorbents in farm animals, knowledge regarding their mechanism of action is limited, especially when intoxication occurs due to naturally contaminated diets. The present study aimed to assess whether the daily oral administration of mycotoxin adsorbent bentonite clay based on aluminosilicate for 56 days, would attenuate these changes in 18 dairy cows, which were multiparous in the middle of the lactation stage, and were consuming a diet containing fumonisin B1 and B2, zearalenone, and desoxynivalenol. The animals were divided into treatment (TG, n = 9) and control (CG, n = 9) groups, and subjected to assessment of liver functions, hematological assessments, assessment of oxidative leucocyte metabolism by the tetrazolium nitroazul (NBT) technique, and physical chemical analysis of milk, every week for two months, totaling eight analyses. It was observed that the use of the adsorbent caused a reduction in the milk excretion of aflatoxin M1 (AFM1), an increase in levels of serum protein (p = 0.03) and albumin (p = 0.0001), an increase in leukocyte oxidative metabolism from day 24 of treatment(p = 0.05), and increased milk production from the day 16 of treatment (p = 0.08). There was no improvement in the physicochemical indices of the milk. It was concluded that the use of an aluminosilicate-based adsorbent was able to attenuate the effects of mycotoxins on the function of leukocytes and increase milk production.

Este trabalho objetivou verificar se o prebiótico a base de parede celular de Saccharomyces cerevisiae reduz coliformes totais, Escherichia coli e Salmonella spp da pele, fezes e da carcaça de bovinos terminados em confinamento. Para tanto, 18 novilhos, ½ sangue Angus  foram submetidos a três tratamentos diários durante 105 dias: controle (n=6),  Lev4g (dieta com 4 g de levedura por animal dia-1, n=6) ou Lev 7g ( dieta com 7 g de levedura por animal dia-1, n=6). Nos dias 29 e 90 após a entrada no confinamento, coletou-se amostras de fezes, swab de pele, água e alimento para contagem de Escherichia coli e coliformes totais e isolamento de Salmonella spp. No dia do abate, realizou-se coleta nas carcaças para identificação de Salmonella spp e quantificação de Escherichia coli, coliformes totais, mesófilos. Notou-se redução de Escherichia coli e coliformes totais nas amostras de fezes (P=0,0001 e 0,001 respectivamente) e de Escherichia coli, coliformes totais  e aeróbios mesófilos na carcaça (P=0,06; 0,10 e 0,05 respectivamente) nos grupos tratados. Houve ausência de Salmonella spp. em todas as coletas realizadas. Concluiu-se que a suplementação reduziu a excreção fecal e consequentemente, a contaminação da carcaça pela Escherichia coli, mesófilos e coliformes totais dos animais confinados, sendo uma medida sanitária benéfica e livre de resíduos para melhorar a qualidade microbiológica da carne.

Treatment of the bovine respiratory disease complex (BRDC) can elicit high bacterial resistance and stress to steers in a feedlot. Therefore, the present study aimed to evaluate three therapeutic protocols with long-acting antibiotics against BRDC naturally acquired in steers finished in feedlot. In a total of 80 animals finished in a feedlot, 18 steers showed clinical signs compatible with BRDC (mucopurulent nasal secretion, lung auscultation alteration, leukocytosis, and decrease of dry matter intake). These animals were randomly treated: marbofloxacin in a single dose (M1), marbofloxacin in two doses (M2), or ceftiofur in a single dose (C1) on Day 0. The clinical score of pneumonia, hemogram, daily food intake, and body weight were analyzed during 7 days. On slaughter day (Day 100), the body weight and frequency of lungs with pneumonia was evaluated. On Day 7, M2 showed absence of pneumonia, and M1 and C1 still showed a clinical score of mild pneumonia (P = 0.01). On day 2 and day 3 M2 showed a higher dry matter intake than others treatments (P = 0.05). C1 showed a lower body weight than others group on day 1 and 2 (P = 0.05). The C1 and M1 showed a higher pneumonia frequency than M2 (P = 0.02). The M2 slaughter weight was numerically higher than the other treatments. We conclude the marbofloxacin in two doses eliminated the pneumonia ́s clinical symptoms and allowed the animals to return the productivity earlier than other protocols.

As mycotoxins are consistent contaminants in the dairy cow diet, the use of adsorbents is recommended, although there are no ideal adsorbents. Although there are studies on this subject, few have focused on chronic natural intoxications. Here, we evaluated the effect of bentonite adsorbents associated with liver antioxidants on the health and milk production of dairy cows fed a diet containing naturally-produced fumonisin, zearalenone, and deoxynivalenol. Eighteen dairy cows (bodyweight 550 ±50 kg, 5 ± 2 years old, and 30 ± 1,25 kg/day milk production) in the middle of lactation were divided into groups: treatment (TG, n = 9, 22 g/day of supplement added to diet) and control (CG, n = 9, without supplement). A physical examination was performed, weekly over 56 days and blood was collected for liver and immune assessments. Milk was harvested to evaluate milk production and content (fat protein, somatic cell count, and lactose). The additive promoted beneficial effects on the liver from the 24th day due to a decrease in the enzymatic activities of gamma-glutamyltransferase and lactate dehydrogenase and increased serum protein and albumin levels. There were improvements in health, evidenced as fewer clinical manifestations of the disease, greater leukocyte oxidative metabolism capacity, and a lower neutrophil lymphocytes ratio. The treatment also promoted a 19% increase in milk volume. It was concluded that the additive promoted health benefits and milk production in dairy cows.