Circadian rhythm of salivary and serum urea concentration in alpacas and sheep receiving diets with different levels of protein.

All vertebrates possess a daily rhythm, encompassing a comprehensive set of physiological, cognitive, and behavioral patterns that manifest throughout a 24-hour period. The aim of this study was to compare the effect of crude protein (CP) levels in the diet on the daily rhythm of urea in serum (US) and saliva in alpacas and sheep. Ten alpacas and ten sheep, adult, clinically healthy males, were used; they were maintained in natural light conditions and fed ad libitum with two levels of CP (16 and 7%). Blood and saliva samples were taken every 4 h for 48 h. A two-way ANOVA was conducted to analyze the parameters, including adjusted mean rhythm (MESOR), amplitude, and acrophase. It was found that both US and saliva urea exhibited circadian rhythms with a peak during the midday (10:59 - 12:16 h). The MESOR with low CP diets was higher (P < 0.05) in alpacas. The MESOR of urea levels in saliva was greater (P < 0.05) at the highest level of CP in the diet, with no differences between alpacas and sheep (P > 0.05). The amplitude was greater (P < 0.05) in alpacas and at the high level of CP compared to the low level of CP in the diet. Our findings reveal that both serum and saliva urea levels in alpacas and sheep follow a daily rhythm and the MESOR of US was higher in alpacas when they consume food with low CP content, and this difference disappears when CP levels are increased in the diet.

Effect of probiotics administration at different levels on the productive parameters of guinea pigs for fattening (Cavia porcellus).

Background: For more than 50 years, antibiotics have been used to maintain animal welfare and improve efficiency. Recently, antibiotics were found in the muscle, liver, and kidney of guinea pig carcasses put up for sale and human consumption, which is a public health issue. Probiotics are supplements of live microorganisms that, when administered in adequate doses, could replace growth-promoting antibiotics. Aim: This study analyzed the effect of the administration of an oral probiotic mixture on the guinea pigs productive performance (Cavia porcellus). Methods: Fifty male guinea pigs, weaned at 14 days of age, were distributed in a completely randomized design of five treatments with ten repetitions for each group. The treatments were CONTROL group without probiotic; PROB 1 given 1 ml of probiotic; PROB 2 with 2 ml of probiotic; PROB 3 with 3 ml of probiotic; and antibiotic growth promoter (AGP) was given 300 ppm zinc bacitracin. The microorganisms used in the probiotic were Enterococcus hirae, Lactobacillus reuteri, Lactobacillus frumenti, Lactobacillus johnsoni, Streptococcus thoraltensis, and Bacillus pumilus. Productive parameters were evaluated from weaning to 70 days of age. Results: No statistically significant difference was found between the treatments on forage dry matter intake (DMI), concentrateconcentrate DMI, or total concentrate DMI (p > 0.05). Similarly, no statistical difference was found between the treatments in terms of final weight or weight gain (p > 0.05). Regarding the feed conversion ratio (FCR), there was a significant difference between treatments (p = 0.045); the CONTROL group had the highest FCR, followed by the AGP group, with the best FCR observed in the PROB 3 group (p < 0.05). In addition, significant statistical differences were found between CONTROL and PROB 2 (p < 0.05). Likewise, a significant linear effect of increasing doses of the probiotic was found (p = 0.01), which indicated that the feed conversion was better with a higher dose. Conclusion: The treatments evaluated in this study significantly impacted the FCR in guinea pigs for fattening. Increasing doses of probiotics had a linear effect on FCR.

First Report of Hypoxylon diatrypeoides Inducing Dieback and Black Trunk Rot on Mesquite (Prosopis laevigata) in Mexico.

During 2001, branch dieback, black trunk rot, and resinosis were observed on mesquite in the biosphere reserve of Tehuacan, Mexico (18°15'N, 97°25'W) A light brown growth, which included Nodulosporium-like conidiosphores and hyaline conidia that were green in mass and ellipsoid with one end truncate developed on diseased branches. Below the conidiophores and conidia, glomerate to pulvinate stromata formed with conspicuous, black, perithecial mounds with globose perithecia. Ascospores were dark brown, unicellular, ellipsoid, nonequilateral, with narrowly rounded ends, a straight germ slit with a perispore that was dehiscent in 10% KOH, and a conspicuous coil-like, smooth epispore. Sexual reproduction was induced on sterile toothpicks in potato dextrose agar, malt extract agar, or V8 agar (with 10% calcium chloride). The fungus was identified as Hypoxylon diatrypeoides Rehm (1). Samples of mesquite branches with stromata of H. diatrypeoides were deposited in the J. H. Miller Herbarium of the University of Georgia (GAM16048). During the summer of 2002, three pathogenicity tests were performed under greenhouse conditions using three healthy young mesquite plants (25 cm high) per treatment per test. The treatments were: (i) inoculation of branches by wounding with a colonized toothpick from V8 agar, covered with mycelium and perithecia; (ii) spraying ascospores on branches previously wounded with a sterile toothpick; (iii) spraying ascospores on unwounded plants; (iv) plants wounded with sterile toothpicks; and (v) unwounded and uninoculated plants. Fifteen days after inoculation, branch dieback and black trunk rot symptoms were induced in 100% of mesquite plants inoculated with toothpicks and in 50% of wounded plants inoculated with ascospores. No symptoms were seen in the unwounded plants and control treatments. H. diatrypeoides was reisolated from the symptomatic branches. Previously, the fungus had been reported only from the Southern Hemisphere (Brazil and New Zealand), but to our knowledge, this is the first report from Mexico and the Northern Hemisphere. This is also the first evidence of its role as a plant pathogen. Reference: (1) Y. M. Ju and J. D. Rogers. A revision of the genus Hypoxylon. Mycologia Memoir No 20. The American Phytopathological Society, St. Paul, MN, 1996.