1,721,099 research outputs found
Escrezione azotata e metabolismo energetico di suini alimentati con diete a diverso contenuto proteico e con diete a base di mais semivitreo o farinoso
No full textMeno latte se la vacca è a rischio chetosi : collaborazione SATA : speciale chetosi
No full textIl 25% delle vacche è a rischio chetosi nei primi 5-10 giorni di lattazione. Le bovine appartenenti al gruppo di aziende non a rischio chetosi presentano una produzione media di latte a inizio lattazione di 18 L capo/mungitura, contro i 17,4 L delle bovine di allevamenti a rischio
Nutritional strategies in ruminant feeding
No full textThe main mechanisms involved in N excretion and CH4 emission by ruminants are briefly summarized. While the contribution of ruminants to the global warming effect through CH4 emission seems to be exaggerated, this is not the case for N pollution: there is an urgent need for a reduction of N excretion into the environment and animal nutritionists and farmers must be aware of this. Diets fed to dairy cows or beef cattle should contain the minimum N content, but all the fermentable energy needed to maximize rumen microbial protein synthesis. Additional single rumen-protected amino acids can be satisfactorily included in low protein diets to meet metabolic amino acid requirements. Forages (preferably of medium N and high energy content) and other home-grown feedstuffs are increasingly used on cattle farms. In Italy, diets for dairy and beef cattle in the most intensive areas are mainly based on maize silage as the principal forage component and maize grain (dry or wet) as the energy concentrate supplement. The quantitative and qualitative differences between maize silage as the first, and only crop in the year and maize silage as a second crop after Italian ryegrass or a winter cereal, are discussed. The results of some studies on dietary N reduction in lactating cows and some typical diets fed in Northern Italy are also reported and commented upon
Energy and Protein Metabolism and Nutrition
No full textEnergy and Protein Metabolism and Nutrition is of increasing importance as greater efficiency and health benefits are sought in feed for animal production. Top scientists from around the world have collaborated in this book to exchange expertise and knowledge on the latest developments in the field. The topics range from tissue metabolism and regulation mechanisms to practical aspects of energy and protein nutrition and feeding. A better and deeper understanding of nutrient metabolism and nutrition can only be achieved by integrating the outcomes of scientists researching different aspects of this topic. In doing this practical outcomes are sought for the direct benefit of producers and consumers. Special topics such as the links between energy/protein metabolism and nutrition regarding food quality, nutrigenomics, environmental sustainability and animal welfare in relation to the topic are all explored. This book is a valuable resource to all researchers and industry professionals who concern themselves with animal nutrition
Trend of energy and nitrogen utilization of high fibre diets in pigs from 100 to 160 kg bodyweight
No full textScopo della ricerca è stato di indagare la capacità del suino pesante di utilizzare diete a elevato contenuto di fibra. Sono
stati utilizzati 8 suini castrati Landrace x Large White, alimentati con tre diete ad alto tenore in fibra (HF, mediamente
NDF 17,8% SS) e con una dieta di controllo (C, NDF 13,5% SS), inseriti in un disegno sperimentale a Quadrato Latino.
L’alimentazione è stata razionata, mentre l’acqua era a volontà. Ognuno dei 4 periodi includeva 21 giorni di adattamento
e 7 di digeribilità e calorimetria. Le 3 diete HF includevano crusca di frumento in scaglie o macinata e polpe di bietola
disidratate. Nei 4 periodi di digeribilità gli otto suini pesavano mediamente 105, 124, 140 e 158 kg. La digeribilità della
fibra delle diete HF è aumentata dal periodo 1 al periodo 4: 56,2, 56,6, 58,8 e 62,2% per l’NDF e 46,0, 47,1, 49,0 e 53,4% per l’ADF. Un andamento simile è stato rilevato anche per la digeribilità di sostanza secca, sostanza organica, proteine
grezze, estratto etereo ed energia. Confrontando la digeribilità media dei 4 periodi, si rileva una significativa
(P<0,05) maggior digeribilità della dieta C rispetto a quella delle diete HF per la sostanza secca (87,5 vs 84,9%), per la
sostanza organica (89,5 vs 87,0%) e per l’azoto (87,2 vs 83,4%), mentre per la fibra la tendenza si inverte senza raggiungere
differenze significative. Per le diete HF si è rilevato un incremento dell’energia persa come gas metano passando
dal periodo 1 al 4 (da 0,40 a 0,59% dell’energia ingerita, P<0,05) mentre non si sono registrate differenze significative
per il calore prodotto e l’energia ritenuta. I valori relativi a questi parametri sono risultati simili anche confrontando la
dieta C rispetto alle diete HF (media dei 4 periodi), confermando la buona capacità del suino pesante di utilizzare diete
con tenore di fibra particolarmente elevato. Passando dal periodo 1 al periodo 4 il bilancio dell’N per il trattamento HF ha
evidenziato che, a fronte di un miglioramento della digeribilità, vi è stato un aumento delle perdite di N urinario. Tale
perdita è risultata pari al 35,7% dell’N ingerito per il periodo 1 e al 51,9% per il periodo 4 (P<0,05). In valore assoluto
l’azoto escreto totale, a fronte di una riduzione dell’ingestione, è risultato simile nei 4 periodi (mediamente 0,98 g/PV 0,75).
Esprimendo i dati in percentuale dell’N ingerito, infatti, si è passati dal 54,6% del periodo 1 al 68,2% del periodo 4
(P<0,05). Questo ha portato a una deposizione proteica (N x 6.25) pari a 155 g/d nel periodo 1 e a 126 g/d nel periodo
4 (P<0,05). Al contrario, la deposizione lipidica è aumentata passando dal periodo 1 al periodo 4, rispettivamente 315,
359, 374 e 394 g/d.The aim of the experiment was to investigate the ability of the heavy pig to utilize diets rich in fibre. Eight Landrace x
Large White fattening barrows were fed 3 high fibre (HF) diets (on average 17.8% NDF on DM) and a traditional (C) diet
(13.5% NDF) in a Latin Square design. Feeding was restricted. Each of the 4 periods included 21 days adaptation and 7
days digestibility/calorimetry. The HF diets included wheat bran (coarse or milled) or beet pulp. In periods 1, 2, 3 and 4
the eight pigs weighed, on average, 105, 124, 140 and 158 kg. Fibre digestibility (%) of HF diets increased from period
1 to period 4: 56.2, 56.6, 58.8, 62.2 for NDF and 46.0, 47.1, 49.0, 53.4 for ADF. A similar trend was registered for the
digestibility of DM, OM, CP, EE and energy. Comparing the digestibility of diet C with HF diets, independently of the periods,
diet C always had significantly higher digestibility (e.g. DM=87.5 vs 84.9%) except for fibre which gave similar coefficients.
Methane energy losses increased significantly from period 1 to period 4 for HF diets (0.40 vs 0.59% of the intake
energy, IE, P<0.05), while heat production and retained energy (% of IE), did not differ significantly between periods.
Retained energy of diet C (37.1% IE) and of HF diets (35.3%) considered as the average of the four periods, were similar,
confirming that the heavy pig can utilize fibre to a good extent. Considering the N balance of treatment HF, passing
from period 1 to period 4 concomitantly with a lower faecal excretion a significantly greater urinary excretion was recorded:
35.7 and 51.9% of intake N in periods 1 and 4, respectively (P<0.05). Total N excretion was similar in the four periods
(on average 0.98 g/BW0.75). However, expressing the data as % of the intake N, total N excretion increased from period
1 (54.6%) to period 4 (68.2%) (P<0.05). As a consequence, protein deposition (N*6.25) decreased from 155 to 126
g/d from period 1 to period 4 (P<0.05). On the contrary, fat deposition increased, as expected, in the four periods: 315,
359, 374 and 394 g/d
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