13 research outputs found
Effects of extruded corn on milk yield and composition and blood parameters in lactating dairy cows
According to a 2x2 cross over design, fourteen Holstein dairy cows at 99±55 DIM were fed two diets containing 21.5% DM of either ground corn (GC) or extruded corn (EC). Performance and metabolic profile were detected during the third week of each experimental period. DMI and milk yield were not affected by dietary treatments. Milk fat and protein percentage of EC diet were significantly (P<0.10) lower than those of GC diet. Probably the higher rumen degradability of starch from EC thesis modified the synthesis of specific fatty acids leading to a milk fat depression event. Diets did not influence blood parameters, except for lower values of total protein and glucose content in EC diet-fed cows. Results suggested that the dietary inclusion of extruded corn should not be used at the tested level of substitution
Effect of the partial replacement of fish meal and oil by vegetable products on performance and quality traits of juvenile shi drum (Umbrina cirrosa L.)
A four-month growth trial was carried out in order to evaluate performance and quality traits of juvenile shi drum fedwith two isonitrogenous and isoenergetic diets having different amounts of vegetable products (Vegetable diet vs. Controldiet). Compared to the Control diet, the Vegetable diet was formulated by increasing the replacement of fish meal (14%)with soybean and cereal products, and fish oil (12%) with a mixture of vegetable oil. On June, 4 groups of 225 fish (2replicates per dietary treatment) were sorted according to live weight and reared in fibreglass tanks over a four- monthlong experimental period. Fish were hand fed to apparent satiety. Offered feed, growth parameters and feed efficiencywere recorded as productive performance. At the end of the trial (October) biometric, chemical and reological traits wereexamined to assess fish quality. The dietary treatments showed similar productive performance. The relatively high inclusionof vegetable sources led to a significant modification of body shape, mesenteric fat and viscera weight. Among qualitytraits, Vegetable diet-fed fish demonstrated a significantly lower whole body and fillet crude protein content.Yellowness value of the cooked fillet was significantly lower in the Control diet-fed fish, whereas fillet texture was similar.The results of this research showed that shi drum is a suitable candidate for Mediterranean marine aquaculture andits dietary formulation might include at least the amount of vegetable sources used in this trial
Effect of dietary fat level on carcass traits and flesh quality of European Sea Bass (Dicentrarchus labrax) from mariculture
The study aimed at evaluating the effect of the reduction of dietary fat on juvenile European sea bass nutritional value and quality traits. Fish were reared in floating cages (Trieste Gulf, Italy) from July (11) to October (10). Two isoproteic diets were compared: LF (low fat, EE = 19.4%) vs. HF (high fat, EE = 24.6%). No significantly different growth performance was observed. LF diet-fed fish were characterized by the reduction of celomatic fat (not edible fraction) and by the increase in dressing percentage. The tested dietary fat level also affected both fillet and epiaxial white muscle proximate composition, resulting in a significantly lower fillet lipid concentration in LF diet-fed fish. Dietary treatment influenced cooked fillet colour and texture probably as a consequence of the different intramuscular fat deposition. Fillet from HF-fed fish, in fact, presented higher lightness (L*) value and lower instrumental strengthness
Effect of Varying Levels of Fatty Acids from Palm Oil on Feed Intake and Milk Production in Holstein Cows
To determine the optimum feeding level of fatty acids of palm oil (PALM; Energizer RP10; 86.6% palmitic acid) on milk production, lactating cows (n = 18) were randomly assigned to a treatment sequence in replicated 4 x 4 Latin squares. Animals were assigned to squares by parity (3 multiparous and 1 primiparous squares with primiparous in the incomplete square). The 4 diets were designed to provide 0, 500, 1,000, and 1,500 g of PALM per day. Cows were fed individually with feed intake measured daily. Each period lasted 16 d with milk production and composition determined the final 2 d. Milk production, milk composition and feed intake data were analyzed using the MIXED procedure of SAS. Milk yields were 30.9, 34.0, 34.2, and 34.2 kg/ d (SEM = 1.9) for the 0, 500, 1,000, and 1,500 g levels, respectively. Milk yield was increased by the addition of PALM; however, there were no differences among the levels of PALM. Milk fat percentage was also increased from 3.44% for 0 g to 3.95% (SEM = 0.17) across all levels of PALM but there were no differences among the PALM treatments. Dry matter intakes were 23.3, 26.4, 24.7, and 23.8 kg/d (SEM = 1.4) for the 0, 500, 1,000 and 1,500 g levels, respectively. The addition of PALM increased milk yield and milk fat percentage, and no adverse effects on dry matter intake were observed
Effect of the partial replacement of fish meal and oil by vegetable products on performance and quality traits of juvenile shi drum (Umbrina cirrosa L.)
A four-month growth trial was carried out in order to evaluate performance and quality traits of juvenile shi drum fedwith two isonitrogenous and isoenergetic diets having different amounts of vegetable products (Vegetable diet vs. Control diet). Compared to the Control diet, the Vegetable diet was formulated by increasing the replacement of fish meal (14%) with soybean and cereal products, and fish oil (12%) with a mixture of vegetable oil. On June, 4 groups of 225 fish (2 replicates per dietary treatment) were sorted according to live weight and reared in fibreglass tanks over a four- month long experimental period. Fish were hand fed to apparent satiety. Offered feed, growth parameters and feed efficiency were recorded as productive performance. At the end of the trial (October) biometric, chemical and reological traits were examined to assess fish quality. The dietary treatments showed similar productive performance. The relatively high inclusion of vegetable sources led to a significant modification of body shape, mesenteric fat and viscera weight. Among quality traits, Vegetable diet-fed fish demonstrated a significantly lower whole body and fillet crude protein content. Yellowness value of the cooked fillet was significantly lower in the Control diet-fed fish, whereas fillet texture was similar. The results of this research showed that shi drum is a suitable candidate for Mediterranean marine aquaculture and its dietary formulation might include at least the amount of vegetable sources used in this trial
Valutazione del profilo aminoacidico corporeo in ombrine (Umbrina cirrosa L.) alimentate con diete a diverso rapporto lipidi/carboidrati
the objective of the study was to determine by HPLC whole body aminoacid compositions of shi drum after a 4 months long period according with two lipid/carbohydrate ratio (EE/NFE):1.0 vs !.5. Total and essential AA amount were found significantly higher in EE/NFE 1.0 fed fish as well as LYS and LEU content resulting in an higher crude protein retention. Results suggest that low dietary EE/NFE ratio increases protein feed efficiency by reduction of catabolic oxidation of almost two essential amino acid
Sensory evaluation of sea bass (Dicentrarchus labrax L.) fed two diets differing in fat content
The study aimed to evaluate sensory quality of European sea bass (IBW=304\ub130 g) fed a low fat (LF)-diet (CF=19.4%) vs. an high fat (HF)-diet (CF=24,6%) during one on-growing season (FBW: 412 vs. 407 g). After heating procedure, fish trunk were submitted to taste panel by 10 trained tasters considering appearance and physical traits. Fish fed LF-diet showed a significant higher degree of firmness and exudation than HF-fish while fillet tenderness and juiciness were higher in HF-fish. These results are due to the higher flesh lipids content in HF-fish that influenced fillet water-holding capacity and texture
Effects of triploidy on feed efficiency, morphometric indexes and chemical composition of shi drum, Umbrina cirrosa L.
Productive performances of triploid (3n) and diploid (2n) shi drum (Umbrina cirrosa L.) were evaluated over an experimental period of 76 days. Fish, selected according to body weight (196 specimens from each ploidy), were reared in tanks (two for each thesis) under the same environmental and dietary conditions. A practical extruded diet (crude protein: 43.4%; ether extract: 19.3%) was offered to fish according to a feeding rate that varied from 1% to 1.5% of live weight. Both at the beginning and at the end of the trials, samples of fish were submitted to morphometrics and chemical analysis. The final body weight and the specific growth rate of triploid fish were significantly lower than those of fish diploid. The feed efficiency of triploids showed a reduction in crude protein retention. Juvenile triploids evidenced a larger amount of coelomatic fat, and their gonads were atrophic. The whole-body proximate composition of 3n fish was characterized by a higher ether extract and a lower crude protein content than 2n fish. Triploids had higher liver lipid content; there were no significant differences in viscera proximate composition. Sum, the results showed that chromosome set manipulation in this species can reduce productive performances at a juvenile stage, influencing some morphometric traits
Effect of dietary crude fat to NFE ratio on growth, feed efficiency and quality traits in juvenile shi drum (Umbrina cirrosa)
Shi drum (Umbrina cirrosa L.) is a suitable candidate for Mediterranean (marine) aquaculture because of its very fast growth in captivity. However, nutritional requirements of this Sciaenidae are not known. Thus, two complete extruded isoproteic diets with different crude fat to N-free extract ratio (CF/NFE: L=1.0 vs. H=1.5) were tested in juvenile shi drum to evaluate productive performances and quality traits of the final product. Experimental trial was conducted over summer 2001 using 4 groups of 200 fish (IBW = 83\uf0b125 g) fed 2% BW. Growth parameters and feed efficiency were recorded and fish were submitted to morphometric, chemical and reological analysis. Considering a 4 months feeding period L-diet fed fish showed a significant greater weight gain than H-fed fish due to a higher specific growth rate (SGR) and a lower food conversion ratio (FCR). Chemical composition of whole body fish resulted in higher crude protein and lower lipids contents for animals of L-diet thesis. This suggests that the better rearing performances obtained with fish fed the low CF/NFE kind of diet are probably related to a more efficient utilization of dietary energy and/or crude protein. The main morphometric traits and textural properties of fish considered at the end of the study were not affected by dietary CF/NFE ratio
Effect of triploidy on quality traits of shi drum (Umbrina cirrosa L.) until the second rearing year
Carcass and \ua3esh morphometric, reological and chemical
traits of triploid (3n) and diploid (2n) shi drum
(Umbrina cirrosa L.) were evaluated through 7
months. Three age groups, 17-, 21- and 24-monthold
fish, were investigated. The effects of ploidy were
statistically evaluated and the weight of fish was included
in the model as a covariate because triploids
grew less than diploids. As expected, fish weight was
found to be significantly correlatedwith all the investigated
morphometric traits, but showed a negative
correlation with some chemical (pH) and colour
traits (lightness) of raw fillet. In comparison with
controls, triploid shi drums were characterized by
di\ua1erent morphological traits that involved a slender
body shape. In triploids, a reduction in condition factor,
backboneweight, dressing index and an increase
in the agility index were also recorded. When the
commercial size (i.e. over 300 g) was achieved, triploids
exhibited larger coelomatic and fillet (dorsal
whitemuscle) fat deposition than diploids. Among reological
traits, colour and texture were a\ua1ected by
ploidy; raw fillet lightness and cooked \ua3esh tenderness
were higher among triploids in all the investigated
age groups. As fish were fed with a restricted
feeding regimen, fillet fat deposition was supposed to
be limited. Thus, the effects of ploidy on reological
traits may be only partially explained by lipid fillet
amount and are supposed to bemore related to di\ua1erent
fibre muscle architecture