Summary Subacute rumen acidosis (SARA) represents one of the most important metabolic disorders in intensive dairy farms that affects rumen fermentations, animal welfare, productivity and farm profitability. The aim of the present study was to study the occurrence of SARA in intensive Italian dairy herds and to determine the relationship between diet composition, ruminal pH and short chain fatty acids (SCFA) concentration. Ten commercial dairy herds were investigated; twelve cows in each herd were selected randomly among animal without clinical signs of disease, with good body condition and between 5 and 60 day‐in‐milk (DIM), to perform rumenocentesis and obtain rumen fluid. Ruminal pH was determined immediately after sampling and concentration of SCFA in ruminal fluid was determined on samples after storage. An other objective of this research was to study in detail the effects of rumenocentesis on animal health: this study could confirm the extreme validity of this technique as ruminal sampling. Results were subject to anova and correlation analysis using sigma stat 2.03. The results indicated the presence of SARA in three herds (more than 33% cows with rumen pH < 5.5), a critical situation (more than 33% cows with rumen pH < 5.8) in five farms and a normal rumen pH condition in two herds. In particular, dairy herds show on average SCFA concentration of 150, 145, 123 mmol/l for low pH, critical pH and normal pH herds respectively. There were not significant differences among diet composition even if herds with SARA showed a light discordance between initially chemistry composition and residual feed. In the affected herds it was not possible to understand the exact causes of SARA. Animal management seems to be one of the most important factors in developing SARA including total mixed ration preparation.

Growth performance, forestomach development, and carcass and meat quality of veal calves fed a milk replacer diet (Control) were compared to those obtained from calves fed the same liquid diet plus 250 g x calf(-1) x d(-1) of dried beet pulp or wheat straw. Three groups of 46 Polish Friesian calves, balanced according to initial BW, were assigned to the three dietary treatments in a fattening trial, which lasted 160 d. The provision of either solid feed did not affect the milk replacer intake. However, calves' ADG was increased (P < 0.01) only by feeding the beet pulp diet. The administration of both solid feeds improved calves' health status; calves fed solid feeds required fewer iron treatments for low hemoglobin and needed less medical treatments for respiratory or gastrointestinal diseases. In comparison to the Control calves, the provision of wheat straw and beet pulp increased iron intake throughout the fattening period by 41 and 130%, respectively. However, only calves fed beet pulp showed higher levels of hemoglobin and plasma iron concentrations (P < 0.05), whereas the same blood parameters were similar between Control calves and those fed wheat straw. At slaughter, both solid feeds led to empty forestomach weights heavier than those of Controls without reducing dressing percentage. The reticulorumen was heaviest in calves fed beet pulp, whereas wheat straw promoted omasal development. The administration of beet pulp resulted in a better carcass conformation than did the Control diet or wheat straw, but it had a detrimental effect on carcass color, which was graded as the darkest (P < 0.001). Consistent with this result, meat color of calves fed beet pulp was darker than that of Control calves and those fed wheat straw, because of the higher hematin concentration measured at the muscle level. No differences in carcass and meat color were observed between Control calves and calves fed wheat straw. The administration of solid feeds for welfare purposes does not always prevent the production of veal meat fulfilling the color standards required by the market. There is not a straight-forward relationship between a solid feed's iron content and the "redness" of veal meat, which should be related to the capability of the calves to use the iron provided by the roughage.

SummaryFailure to respond to commercial limited antigen diets can occur in dogs kept on a dietary trial for the diagnosis of adverse food reaction (AFR). The aim of this study was to assess twelve canine dry limited antigen diets (eleven novel protein diets and one hydrolysed diet) for potential contamination by ingredients of animal origin not mentioned on the label. The validity of the two methods adopted for the detection of such food antigens was also evaluated. Each dietary product was analysed by microscopy analysis using the official method described in Commission Regulation EC 152/2009 with the aim of identifying bone fragments of different zoological classes (mammalian, avian and fish) and by polymerase chain reaction (PCR) for the identification of DNA of animal origin. Discrepancies between the results obtained by PCR and/or microscopy analysis and the ingredients listed on pet food packages were found. Only in two pet foods did the results of both analyses match the ingredients listed on the label. In the remaining ten samples, microscopy detected bone fragments from one or two unpredicted zoological classes, revealing avian fragments in six of ten samples followed by those of fish in five of ten and mammalian fragments in four of ten. In two samples, microscopy analysis identified a contamination that would have otherwise passed unobserved if only PCR had been used. However, PCR confirmed the presence of all the zoological classes detected by microscopy and also identified the DNA of an additional unexpected zoological class in two samples. Dogs might fail to respond to commercial limited antigen diets because such diets are contaminated with potential allergens. Both PCR and microscopy analysis are required to guarantee the absence of undeclared animal sources in pet foods. Before ruling out AFR, a novel protein home-made diet should be considered if the dog is unresponsive to a commercial regimen.

The aim of this study was to evaluate the effects of the addition of two roughage sources (wheat straw and beet pulp) to the milk replacer diet of veal calves, in order to reduce stress and improve animal welfare. We allocated 138 Polish Friesian male calves to three different feeding plans: a milk replacer diet (Control), 250 g/d of wheat straw in addition to the milk replacer, or 250 g/d of dried beet pulp in addition to the milk replacer. Within each feeding treatment, 16 calves were individually housed and 30 were kept in group pens (five calves/pen). Several behavioral, physiological, and health welfare indicators were monitored throughout the fattening period, which lasted for 160 d. Abnormal oral behavior around the meals was higher in Control calves (P< 0.01), while its lowest level was observed in straw-fed calves. At the beginning of the trial, chewing was higher in calves receiving solid feeds (P < 0.001), but the difference from the Control gradually decreased and disappeared at wk 13 for calves fed beet pulp and at wk 17 for those fed wheat straw. At the end of the fattening period, no differences among treatments were found in the frequency of chewing. Regardless of the diet, self-grooming decreased with age and no relationship was observed between this behavior and the presence of rumen hairballs. Cross-sucking was performed with low frequencies (from 4.70% at wk 2 to 1.05% at wk 23 around the meals, and even lower far from the meals) and was not affected by the provision of roughage. The time in contact with the bucket during the whole day was higher in Controls, whereas calves fed wheat straw maintained a lower level of this activity until the end of the trial (P < 0.01). The calves fed wheat straw spent more time in contact with the feed trough (P < 0.001) than those fed beet pulp and Control calves. No differences were found in cortisol curves due to the feeding treatment. In calves fed beet pulp, most hematological measures statistically differed from the other treatments, possibly in response to the higher iron intake and(or) to the higher hemoconcentration, probably due to the administration of beet pulp as dried feed. The incidence of abomasal ulcers and erosions was increased by the provision of the solid feeds, particularly by a structured fiber source such as straw. A roughage source able to satisfy calves' behavioral needs and to improve digestive processes without damaging the digestive apparatus still has to be identified.

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