The objective of this study was to evaluate the effects of dietary supplementation of a polyherbal mixture (HM) containing saponins, flavonoids, and polysaccharides on productive performance, carcass characteristics and meat quality of lambs during the final fattening period. Thirty-six Dorper × Katahdin lambs (23.27 ± 1.23 kg body weight (BW)) were housed in individual pens and were assigned to four treatments (n = 9) with different doses of HM: 0 (CON), 1 (HM1), 2 (HM2) and 3 (HM3) g of HM kg−1 of DM for 56 days. Data were analysed as a completely randomized design using the MIXED and GLM procedures of statistical analysis system (SAS), and linear and quadratic effects were tested to evaluate the effects of the HM level. DM digestibility decreased in lambs fed HM3 (p < 0.05). There was no effect of HM on daily weight gain, dry matter intake, final BW, feed conversion, carcass characteristics, colour (L* and a*) and meat chemical composition. Meat pH, cooking loss and drip loss increased linearly (p < 0.05) when the HM dose was increased. The Warner-Bratzler shear force (WBSF) of meat was lower (p < 0.05) in lambs fed HM3. In conclusion, dietary inclusion of 3 g HM kg1 of DM improves meat tenderness. However, high doses of HM in the diet may decrease the digestibility of DM and increase the cooking loss and drip loss of lamb meat during the final fattening period.

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Funding information CONACyTA recrystallized form of enrofloxacin as dehydrate-HCl (enro-C) was assessed for bacteriological and clinical cure efficacies in Holstein-Friesian cows affected of nonsevere clinical mastitis. Treatments were enro-C susp (n = 81), treated with a pharmaceutical suspension of enro-C/quarter; group enro-C pd (n = 80) treated as above, but using enro-C powder suspended in water; group CF (n = 65), treated with ceftiofur HCl/ quarter; and group enro R (n = 66), treated with standard enrofloxacin solution (5 mg/ kg, intramuscular). Cows had a mean milk production of 31 L/day and were 2-3 lactational periods old. Treatments were administered every 24 hr for 3 days. Groups treated with enro-C exhibited statistically significant (p > .05) better clinical cure as compared to groups treated with CF or enro R (95.06%, 96.25%, 67.79%, and 57.55%, for enro-C susp , enro-C pd , CF, and enro R , respectively). In contrast, probability of bacteriological cure was not statistically different among treatments. Yet, the outstanding clinical and bacteriological cure rates obtained for enro-C for nonsevere cases of mastitis is superior to previously reported data for parenteral enrofloxacin and other antibacterial-intramammary treatments. Impact of using enro-C on the rate and pattern of bacterial resistance, somatic cell counts and milk electric conductivity, must be studied. Also, the use of enro-C for complicated cases of mastitis should be studied and milk withdrawal times must be accurately established.

OBJECTIVE To determine the concentration of tilmicosin in mammary gland secretions of dairy cows following administration of an experimental preparation once or twice during the dry period (45-day period immediately prior to calving during which cows are not milked) and to evaluate its efficacy for the treatment of cows with intramammary infections (IMIs) caused by Staphylococcus aureus at dry off (cessation of milking; first day of dry period), compared with that of an intramammary infusion of ceftiofur. ANIMALS 172 cows. PROCEDURES Milk samples were collected for microbiological culture 5 days before dry off and at calving and 15 and 30 days after calving. Cows with Staphylococcus IMIs were randomly assigned to receive an experimental preparation of tilmicosin (20 mg/kg, SC) once at dry off (n = 58) or at dry off and again 20 days later (56) or receive a long-acting intramammary preparation of ceftiofur (500 mg/mammary gland; 56) at dry off. Mammary gland secretions were collected from 5 cows in the tilmicosin-treated groups every 5 days after dry off until calving for determination of tilmicosin concentration. RESULTS Mean maximum concentration of tilmicosin in mammary gland secretions ranged from 14.4 to 20.9 μg/mL after the first dose and was 17.1 μg/mL after the second dose. The bacteriologic cure rate was 100% for all 3 treatments. Tilmicosin was detectable for 0 and 18 days after calving in the milk of cows treated with 1 and 2 doses of tilmicosin, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Administration of an experimental preparation of tilmicosin (20 mg/kg, SC) once to dairy cows at dry off might be useful for the treatment of S aureus IMIs.

Bovinos de doble propósito. Cruzamiento. Complementación.