Milk production in dairy goats supplemented with different levels of ruminally protected methionine.

The objective of the study reported in this Research Communication was to evaluate graded levels of ruminally protected methionine (RPM) in dairy goat rations on milk production and live weight changes during 155 d of lactation. Twenty-five primiparous dairy goats (crosses of Toggenburg, French Alpine and Saanen; 45·4 ± 1·0 kg BW) were fed a basal diet (10·10% CP, 6·13 DP and 2·34 Mcal/kg ME) of corn silage, oat hay, alfalfa hay and concentrate (80% forage, 20% concentrate). After kidding, the treatments, which consisted of four oral doses of ruminally protected methionine (RPM) at 0, 1, 2 and 3 g/d, were randomly assigned to the goats. The experiment was conducted for 110 d with measurements of milk production and composition, body weight and dry matter intake. No treatment effects were detected in milk production and composition. However, goats with RPM showed a positive live weight changes during lactation which were improved as dose was increased (linear P < 0·01) whereas goats without RPM showed weight loss during the experiment.

Efficacy of fluralaner in 17 dogs with sarcoptic mange.

BACKGROUND: There are few licensed options for the treatment of canine sarcoptic mange. OBJECTIVE: To evaluate the efficacy of fluralaner in dogs with sarcoptic mange infestation. ANIMALS: Seventeen dogs with a diagnosis of Sarcoptes scabiei based on positive skin scrapings. METHODS: A single dose of oral fluralaner was administered according to the manufacturer's instructions. Assessments of pruritus and lesions were performed every 7 days for 1 month. RESULTS: By Day 14 post-treatment, skin scrapings from all dogs were negative for mites. At the beginning of the study there was a negative correlation between body weight of the subject and pruritus [Pearson correlation coefficient (PCC) = -0.396, P = 0.007] and a positive correlation between pruritus and lesion severity (PCC 0.755, P = 0.0001). Significant decreases in lesion size and pruritus were observed within the first 14-21 days, respectively, and improvement in these parameters continued until the end of the study at Day 28. CONCLUSION: Fluralaner was effective in eliminating scabies mites within 14 days and significantly resolved the clinical signs associated with sarcoptic mange within 21 days after a single dose.

Considerations on the use of exogenous fibrolytic enzymes to improve forage utilization.

Digestion of cell wall fractions of forage in the rumen is incomplete due to the complex links which limit their degradation. It is therefore necessary to find options to optimize the use of forages in ruminant production systems. One alternative is to use exogenous enzymes. Exogenous fibrolytic enzymes are of fungal or bacterial origin and increase nutrient availability from the cell wall, which consists of three fractions in different proportions depending on the species of forage: digestible, potentially digestible, and indigestible. The response to addition of exogenous enzymes varies with the type of forage; many researchers infer that there are enzyme-forage interactions but fail to explain the biological mechanism. We hypothesize that the response is related to the proportion of the potentially digestible fraction. The exogenous enzyme activity depends on several factors but if the general conditions for enzyme action are available, the potentially digestible fraction may determine the magnitude of the response. Results of experiments with exogenous fibrolytic enzymes in domestic ruminants are inconsistent. This, coupled with their high cost, has made their use unattractive to farmers. Development of cheaper products exploring other microorganisms with fibrolytic activity, such as Fomes fomentarius or Cellulomonas flavigena, is required.

Effects of Dietary Calcium Propionate Supplementation on Hypothalamic Neuropeptide Messenger RNA Expression and Growth Performance in Finishing Rambouillet Lambs.

The objective of this experiment was to evaluate the effects of feeding different levels concentrations of dietary calcium propionate (CaPr) on lambs' growth performance; ruminal fermentation parameters; glucose-insulin concentration; and hypothalamic mRNA expression for neuropeptide Y (NPY), agouti-related peptide (AgRP), and proopiomelanocortin (POMC). Thirty-two individually fed lambs were randomly assigned to four treatments: (1) control diet (0 g/kg of CaPr), (2) low CaPr, (30 g/kg dry matter (DM)), (3) medium CaPr, (35 g/kg DM), and (4) high CaPr (40 g/kg DM). After 42 days of feeding, lambs were slaughtered for collecting samples of the hypothalamus. Data were analyzed as a complete randomized design, and means were separated using linear and quadratic polynomial contrast. Growth performance was not affected (p ≥ 0.11) by dietary CaPr inclusion. The ruminal concentration of total volatile fatty acids (VFA) increased linearly (p = 0.04) as dietary CaPr increased. Likewise, a linear increase in plasma insulin concentration (p = 0.03) as dietary CaPr concentration increased. The relative mRNA expression of NPY exhibited a quadratic effect (p < 0.01), but there were significant differences in the mRNA expression of AgRP and POMC (p ≥ 0.10). Dietary calcium propionate did not improve lamb growth performance in lambs feed with only forage diets. Intake was not correlated with feed intake with mRNA expression of neuropeptides.