How to avoid the 'Jesus multiplying bread and fish' myth and 'Münchausen baron bootstrap' legend in individual bibliometric indices: a simple bimedian method applied to Italian ASPA academic members

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Kinetics of fat and protein secretion in dairy cattle, sheep, goats and buffaloes

The negative correlations of fat and protein concentrations and milk yield, existing in all ruminants dairy species (Oftedal, 1984; Mepham, 1987), reflect a deep mechanism regulating the respective kinetics of secretion of carrier (mainly lactose which is the major responsible for the water drawn to the milk) and of fat and protein. Whereas the correlation coefficients are low (from –0.2 to – 0.4), fat and protein daily yield and milk production are positively and strongly linked (r = 0.8÷0.9). It means that more productive animals have higher fat and protein yield, but their milk has lower concentration of these components. The aim of this work is to investigate the relationships between milk, fat and protein yield in all main ruminant dairy species by using a simple mathematical model

Nutritional strategies to improve lactation persistency in dairy ewes

Milk production is largely dependent on the shape of the lactation curve. Relevant elements of the lactation pattern are the peak yield, which represents the maximum milk yield during the lactation, and the lactation persistency, which expresses the ability of animals to maintain a reasonably constant milk yield after the lactation peak. Thus, persistent animals are those that show flatter lactation curves. Several measurements of persistency have been proposed (Broster and Broster, 1984; Gengler, 1996): the rate of fall of milk yield per week or per month; combinations of parameters of mathematical functions used to model the lactation curve; the variation of test day yields throughout the whole lactation or part of it; the proportion of total milk yield achieved in a certain period (e.g. second half of lactation). However, none of the above mentioned measurements seems to be able to become the reference method (Grossman et al., 1999). For example, the definition of persistency as the rate of fall of milk yield per unit of time can be misleading if the absolute level of production is not considered. Usually curves with high peak yield show low persistency because the rate of milk yield declines faster in animals that have a fast milk yield increase after calving. Thus in this review, we will consider persistency in a broad sense, and we will analyze the nutritional and nonnutritional factors that affect and limit milk production in mid-late lactation in sheep

Transfer of aflatoxin from feed to milk and curd in Sarda ewes with different milk production level

Aflatoxin B1 (AFB1) is a toxin produced by some strains of Aspergillus growing in feedstuffs. Dairy animals fed with diet containing AFB1 excrete aflatoxin M1 (AFM1) into the milk. The carry over ratio (AFM1 excreted in milk/ AFB1 ingested) has been found lower in sheep (Battacone et al., 2002a) than in cattle (Veldman et al., 1992). Being AFM1 linked to milk proteins, its concentration in curd is higher than in milk. The AFM1 concentration in milk resulted not influenced by milk production level in cattle, therefore the total amount of AFM1 excreted in milk and, consequently, the carry-over ratio increased with milk yield (Munksgaard et al., 1987; Veldman et al., 1992). A previous study carried out on isoproductive dairy ewes showed an increase of the AFM1 concentration both in milk and in curd as the amount of AFB1 ingested increased (Battacone et al., 2002b). Aim of the present work is to study the influence of AFB1 dose and milk production level on the transfer of AFB1 from feeds to milk and curd as AFM1 in dairy ewes

La Razza bovina sarda: 2. le caratteristiche dell'allevamento

The Authors report on the results of a study concerning the Sardinian cattle; they have surveyed the demographic (geographic distribution, lifetime parameters, size and composition of herds), technical (management systems, reproductive techniques, calf raising, cow feeding) and economical (gross saleable production, net product, net income, production cost of calves) characteristics. These results were obtained with 35 herds from 2 Sardinian typical areas (Italy)

Alfalfa hay digestibility in Sardinian does

A feeding trial was carried out on ten Sardinian does. 5 does (group F) were fed with alfalfa hay and the other 5 (group C+F) with alfalfa hay + 0.6 kg of concentrate to measure the digestibility of these feeds. The digestibility was measured by marker method (lignin) and by the enzymatic method. The marker method showed that the addition of concentrate to the hay increased the OM digestibility. The second method showed similar results. The Authors calculated a regression equation between "in vivo" and "in vitro" digestibility of OM in the C+F group. The changes in lignin composition before and after the digestion were analyzed

Influenza della concimazione sul carico in pascoli della Gallura

On six different fertilization tests in pastures in Gallura (Sardinia) fertilized to a constant N (kg/ha O - 30 -60-90- 120-150) and P2O5 (O - 45-90-135- 180-225) ratio (1:1,5), the production and distribution were surveyed. The stocking rates per/ha in standard ewe and the relative allowed milk yield with held stocking rates and yield were compared; the former were determined by the cilpping method and the latter by the animal method on identicaI fields fertilized with the average N and P2O5 dose. Fertilization costs and relative functions of production were calculated

Effetto della temperatura di somministrazione e della percentuale di ricostituzione del succedaneo del latte sulla produzione di carne in agnelli a allattati artificialmente

In a trial of artificial rearing, carried out on 25 Sardinian lambs with two temperature (14 ÷ 16°C and 36 ÷ 38°C) and two concentration levels (15% and 20%), the Authors found a positive effect of higher temperature level, especially when associated with lower concentration

Technology adoption and specialized labor

Empirical evidence identifies shortages of specialized labor as one of the main obstacles to technology adoption. In this paper, we explain this phenomenon by developing a model in which firms require specialized labor to produce with a new (more efficient) technology. We assume that the cost of specializing labor increases with the efficiency gains that can be attained through the new technology. This reveals two opposing effects on the endogenous share of specialized labor. On the one hand, there is a wage effect by which efficiency gains widen the wage gap between specialized and unspecialized workers, raising the share of specialized labor. On the other hand, there is a learning effect by which efficiency gains increase specialization costs, reducing the share of specialized labor. We show the learning effect will dominate when products are sufficiently differentiated

Some bibliometric indexes for members of the Scientific Association of Animal Production (ASPA)

This study calculated several bibliometric indexes to analyze the scientific output of 363 members of the Scientific Association of Animal Production (ASPA) in Italy, based on their publications listed by ISIThompson, Web of Science database (search period from 1989 until 2006). Five main research areas were considered: AGR/17 (Animal genetics and breeding), AGR/18 (Animal nutrition and feeding), AGR/19 (Animal husbandry), AGR/20 (Poultry, rabbits and fish production) and External researcher (Ere). Position groups were: FP (Full Professor), AP (Associate Professor), Re (Researcher), EReUni (scientists working temporarily at the University or professors of an area different from AGR/17-20), and EReInst (scientists working at other institutions). Each institution was classified according to three geographical areas of Italy: North, Centre and South. Main calculated bibliometric indexes were: Ni = total number of papers published by member i over yi years; yi = number of years publishing of member i; Ci. = total number of citations of member i; IFpersonal. = Ci./Ni, Personal Impact factor of member i; Total IFjournal. = Sum of impact factor reported by the ISI-Thompson database of the journal in which a paper of member i was published (Journal Citation Reports Science Edition, 2004); Mean IFjournal. = Mean impact factor of all papers published in journals having a recognized IFjournal. by the ISI-Thompson database for member i; h = number of papers with at least h citations; m = h/y, i.e. average increase of h over the yi years publishing; and a = Ci./h2. Among the studied bibliometric indexes, Ni, Ci., Total IFjournal. and h are reliable, while IFpersonal. and Mean IFjournal. are not, to evaluate the scientific career of Animal Scientists in Italy. FP and members of AGR/17 tend to show the highest values of bibliometric indexes. Most ASPA members work in the North of Italy, which shows the highest median and highest percentage of scientists with maximum values for most bibliometric parameters. The scientific system of Animal Science in Italy has a fairly good degree of internationalization, but greater efforts should be made to increase the productivity and impact of Animal Scientists