Dry Diet Research Articles

Evaluation of an extruded diet for adult dogs containing larvae meal from the Black soldier fly (Hermetia illucens)

Insects have experienced an increasing interest as a protein source in recent years. However, their suitability as a protein source for dogs was not yet widely investigated. Therefore, the aim of the study was to compare two extruded diets for adult dogs containing either larvae meal from black soldier fly (Hermetia illucens; HI) or lamb meal as the predominant protein source with regard to apparent fecal nutrient digestibility and the influence on fecal and immunological parameters. Twelve Beagles were used in this cross-over study and divided into two groups. The test diet with 200 g/kg HI larvae meal (HI) was compared with a control diet containing lamb meal (CON). Dogs were fed each diet for a period of five weeks. Blood samples for a complete blood count, lymphocyte phenotyping and lymphocyte proliferation tests were taken at the end of each feeding period. The latter was either mitogen- or feed antigen-induced with different protein concentrations of HI larvae meal (30–500 μg protein/mL). Fecal samples were collected for five days during each feeding period. The coefficient of the total apparent fecal digestibility (CTTAD) of macronutrients, fecal metabolites, the output and the dry matter content of the feces were analyzed. d-Glucosamine as indicator for chitin was analyzed by high-performance anion-exchange chromatography with pulsed amperometric detection in the diet and the feces. The chitinase activity was determined in the feces. The fecal output was reduced in dogs fed the HI diet (P = 0.038). The CTTAD of dry matter was higher (P = 0.002) when dogs were fed HI compared to CON (0.832 vs. 0.818) and the CTTAD of crude protein was higher (P = 0.002) when dogs received CON compared to HI (0.792 vs. 0.773). Concentrations of acetate (P = 0.011) and ammonium (P = 0.001) were higher in CON. The fecal score differed (P = 0.041) between HI (2.25) and CON (2.04), but both feeding groups had a formed and dry fecal consistency. The chitin concentration was numerically higher in the feces of dogs fed HI (92.2 g/kg DM) compared to CON (2.9 g/kg DM), the fecal chitinase activity did not differ between both diets. Complete blood counts, lymphocyte phenotyping and proliferation were not affected. In conclusion, the HI larvae meal in a dry dog diet was tolerated without adverse signs and did not affect immunological measurements compared to a commercial dry diet with lamb meal, indicating that larvae meal from HI can be considered an “alternative” protein source for dog nutrition.

Ultrastructure of Hepatocytes from Laboratory Mice Fed a Standard Dry Laboratory Animal Diet.

The significant destructive changes in ultrastructure of hepatocytes from laboratory mice kept in different vivariums in Moscow and fed with dry laboratory animal diets acquired from different domestic manufacturers that were not standardized for initial products were demonstrated using electron microscopy. Furthermore, disruption in the ultrastructure of liver parenchymal cells occurred regardless of the animal status (SPF or conventional), conditions of various vivariums, as well as the feed manufacturer. At the same time, studies on ultrastructure of liver hepatocytes from mice kept in the Charles River Laboratory facilities in Germany and fed with the Altromin Spezialfutter laboratory animal diet (GmbH & Co., Germany) that was produced using quality control of ingredients did not reveal destructive changes in the internal ultrastructure of hepatocytes. However, if these mice were later fed with the food produced in local manufactures, changes in the structure of liver cells developed after 2 months. Thus, feeding with dry diet from the domestic producers of an unspecified composition causes significant changes in the ultrastructure of hepatocytes in control animals, reflecting the development of some pathological processes in the body.

Optimal dietary lysine improves growth performance, increases protein deposition and reduces lipid accumulation in tambaqui ( Colossoma macropomum ) juveniles

The present study aimed to determine the dietary lysine requirement for tambaqui (Colossoma macropomum) juveniles, based on growth performance, whole-body composition, haematological parameters and plasma metabolites. For that purpose, an 81-day feeding trial was conducted with 150 tambaquis distributed in 15 aquariums (300 L) in a completely randomized design, with five treatments and three replicates. Five diets were formulated and crystalline l-lysine was added to obtain diets with lysine concentrations of 9.1; 11.9; 14.7; 17.5; and 20.3 g/kg dry diet. Data were subjected to one-way analysis of variance (p < .05), analyses of broken-line and second-degree polynomial regressions were combined to determine dietary lysine requirement. Fish fed 14.9 to 21.0 g/kg lysine showed higher weight gain, specific growth rate and lower feed conversion ratio, viscerosomatic index. In addition, dietary lysine levels of 15.6 and 19.4 g/kg provided higher fish whole-body deposition of protein and lower deposition of lipid respectively. There were no significant differences in haematological analysis and plasma metabolites of the fish. Thus, according to the second-order polynomial analysis of a broken-line response for weight gain, the optimum dietary lysine requirement for tambaqui juvenile was estimated to be 16.1 g/kg dry diet (5.4% dietary protein).

Effects of dietary proline on swim bladder collagen synthesis and its possible regulation by the TGF‐β/Smad pathway in spotted drum, Nibea diacanthus

Swim bladder is an ideal source of collagen production in fish for improved human health. Proline (Pro) is the main proteinogenic amino acid needed for collagen production. However, the effects of Pro supplementation on the swim bladder collagen synthesis have rarely been evaluated in fish. We determined the effects of dietary Pro supplementation on swim bladder collagen synthesis and its possible signalling pathway in spotted drum, Nibea diacanthus. A total of 450 N. diacanthus (100 ± 3.05 g) were randomly assigned into six treatments and fed with diets supplemented with different levels of Pro (0, 2.5, 5, 7.5, 10 and 12.5 g/kg of dry diet, hereafter P0, P1, P2, P3, P4 and P5, respectively) for 8 weeks. At the end, we evaluated collagen synthesis in swim bladder and the expression of genes related to TGF-β/Smad pathway in the fish. Dietary Pro levels increased significantly the contents of crude protein, total collagen (TC) and the levels of some amino acids in swim bladder than the control diet (p < .05). The optimum amount of dietary Pro inclusion in diets for swim bladder collagen synthesis in N. diacanthus was 7.6 and 7.5 g/kg based on crude protein and TC in swim bladder, respectively. Dietary Pro levels increased significantly the proline 4-hydroxylase (P4H) content in fish serum, swim bladder, muscle and liver tissues than control (p < .05). The relative expression of collagen type I alpha 1 (COL1A1), alpha 2 (COL1A2) and mothers against decapentaplegic homolog 2 (Smad2) genes in liver and swim bladder initially increased significantly as the concentration of Pro and later decreased (p < .05). Similarly, the relative expression of transforming growth factor beta (TGF-β), P4Ha2 and P4Ha3 genes in the swim bladder increased significantly as dietary Pro levels increased (p < .05). Using K-means clustering analysis, dietary proline partly promoted collagen accumulation in swim bladder through upregulation of Smad2 and TGF-βRT genes. Taken together, Pro affected the collagen metabolism in swim bladder, probably by regulating the TGF-β/Smad pathway, most likely via transient overexpression of Smad2 gene.

Effects of novel dental chews on oral health outcomes and halitosis in adult dogs.

Periodontal disease (PD) is the most common clinical condition occurring in adult dogs. The objective of this study was to evaluate the benefits of daily dental chew administration on oral health outcomes in adult dogs. Twelve adult (mean age = 5.31 ± 1.08 yr; mean BW = 13.12 ± 1.39 kg) female beagle dogs were used in a replicated 4 × 4 Latin square design consisting of 28-d periods. On day 0 of each period, teeth were cleaned by a veterinary dentist blinded to treatments. Teeth then were scored for plaque, calculus, and gingivitis by the same veterinary dentist on day 28 of each period. Breath samples were measured for malodor (volatile sulfur compounds) on days 1, 7, 14, 21, and 27 of each period. All dogs consumed the same commercial dry diet throughout the study. Control dogs were offered the diet only (CT), while treatment groups received the diet plus one of three dental chews. Two novel chews (Bones & Chews Dental Treats [BC]; Chewy, Inc., Dania Beach, FL and Dr. Lyon's Grain-Free Dental Treats [DL]; Dr. Lyon's, LLC, Dania Beach, FL) and a leading brand chew (Greenies Dental Treats [GR]; Mars Petcare US, Franklin, TN) were tested. Each day, one chew was provided 4 h after mealtime. All tooth scoring data were analyzed using the Mixed Models procedure of SAS (version 9.4; SAS Institute, Cary, NC). Halimeter data were analyzed using repeated measures using the Mixed Models procedure of SAS and testing for differences due to treatment, time, and treatment * time interaction. Data are reported as LS means ± SEM with statistical significance set at P < 0.05. DL performed at the same level as the leading brand, GR, as both resulted in lower (P < 0.05) plaque coverage and thickness scores, calculus coverage scores, and day 27 volatile sulfur concentrations compared with CT. Additionally, DL reduced (P < 0.05) volatile sulfur compounds on day 14 when compared with CT. BC reduced (P < 0.05) calculus coverage and day 27 volatile sulfur concentrations compared with CT. Our results suggest that the dental chews tested in this study may help slow the development and/or progression of PD in dogs.

Corn silage rehydrated with crude glycerin in lambs' diets.

We investigated whether the feed intake efficiency, digestibility, microbial efficiency, and nitrogen balance would be affected by inclusion of rehydrated corn grain silage with crude glycerin or water to substitute the dry corn in diets for feedlot lambs. Ten crossbred (Santa Ines×Dorper) uncastrated male lambs (25.6 ± 4.0kg body weight) were assigned in a replicated 5 × 5 Latin square design and subjected to five experimental diets, one containing dry corn and four diets containing corn grain silage rehydrated with crude glycerin in levels of 0, 75, 150, and 225 in g/kg of natural matter. The moisture of 32.5% was maintained in all silages. The inclusion of crude glycerin represented 0, 40, 80, and 120g/kg of total diet. The inclusion of rehydrated corn silage did not affect the DM, CP, EE, and ED intake. The diets with rehydrated corn silage improved the digestibility of DM, without affecting the fiber digestibility. The nitrogen losses were insignificant, resulting in the efficient use of dietary nutrients. In conclusion, corn silage rehydrated with 150g/kg NM of crude glycerin is recommended as a feed to substitute dry corn diet, as it did not influence the nutrients intake, increased the dry matter digestibility with efficient use of the dietary nutrients, improving the animal performance in the feedlot.

Effects of dietary lysine levels on growth performance, whole body composition and gene expression related to glycometabolism and lipid metabolism in grass carp, Ctenopharyngodon idellus fry

8 weeks rearing trial was designed to estimate the dietary lysine requirement, and evaluate the effects of dietary lysine on glycometabolism and lipid metabolism of grass carp fry. Six practical diets were prepared to feed 720 fish (initial weight 0.36 ± 0.00 g) with graded lysine levels (1.44%, 1.79%, 1.97%, 2.44%, 2.56% and 2.87%, dry diet). The results displayed that the final body weight (FBW), weight gain rate (WGR) and specific growth rate (SGR) were significantly improved by 2.44% dietary lysine, the same as feed intake (FI) and feed conversion ratio (FCR), compared with those of the control group (1.44% dietary lysine). Whole-body lipid contents diminished with raising dietary lysine levels from 1.44% to 2.44% and thereafter the content increased. Regarding glycometabolism, compared to the control diet, the 2.44% dietary lysine level significantly improved glycolysis by increasing glucokinase (GK) and pyruvate kinase (PK) mRNA levels, meanwhile the 2.87% dietary lysine level promoted gluconeogenesis by significantly increasing phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) mRNA levels. Glycogen synthase (GS) mRNA levels were independent of dietary treatment. For the lipolysis pathway, the 2.44% dietary lysine level caused the upregulation of hormone sensitive lipase (HSL), adipose triglyceride lipase (ATGL) and carnitine palmitoyl transferase-1 (CPT1) mRNA levels in the PPAR signaling pathway. Like the fatty acid synthase (FAS), acetyl-CoA carboxylase-1 (ACC1) and stearyl-CoA desaturase (SCD), the relative mRNA expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) related to lipid synthesis in the PPAR signaling pathway, was not remarkably influenced by dietary lysine levels. Furthermore, sterol-regulatory element binding protein-1 (SREBP1) mRNA levels in the intestine were not clearly affected among all the treatments. According to the broken-line regression analysis, based on the SGR and FCR, the optimum requirements of grass carp fry for dietary lysine were 2.39% and 2.13% of diet (6.34% and 5.65% of dietary protein), respectively. Overall, appropriate dietary lysine levels (2.44%) could improve the growth performance, reduce the whole-body lipid, promote glycolysis and lipolysis.

Coexistence between wildlife and livestock is contingent on cattle density and season but not differences in body size.

Many studies on the coexistence of wildlife with livestock have focused primarily on similar-sized species. Furthermore, many of these studies have used dietary overlap as a measure of potential competition between interacting species and thus lack the important link between dietary overlap and any negative effects on a particular species–a prerequisite for competition. Consequently, the mechanisms that drive interspecific interactions between wildlife and cattle are frequently overlooked. To address this, we used an experimental setup where we leveraged different cattle stocking rates across two seasons to identify the drivers of interspecific interactions (i.e. competition and facilitation) between smaller-bodied oribi antelope and cattle. Using direct foraging observations, we assessed dietary overlap and grass regrowth, and also calculated oribi nutritional intake rates. Ultimately, we found that cattle compete with, and facilitate, smaller-bodied oribi antelope through bottom-up control. Specifically, cattle facilitated oribi during the wet season, irrespective of cattle stocking density, because cattle foraging produced high-quality grass regrowth. In contrast, during the dry season, cattle and oribi did not co-exist in the same areas (i.e. no direct dietary overlap). Despite this, we found that cattle foraging at high densities during the previous wet season reduced the dry season availability of oribi’s preferred grass species. To compensate, oribi expanded their dry season diet breadth and included less palatable grass species, ultimately reducing their nutritional intake rates. Thus, cattle competed with oribi through a delayed, across-season habitat modification. We show that differences in body size alone may not be able to offset competitive interactions between cattle and wildlife. Finally, understanding the mechanisms that drive facilitation and competition are key to promoting co-existence between cattle and wildlife.

Homemade versus extruded and wet commercial diets for dogs: Cost comparison.

The present study aimed to verify and compare the costs of homemade diets with extruded and wet commercial diets for dogs in maintenance and consuming therapeutic diets (obesity, congestive heart failure, diabetes, hepatic encephalopathy, chronic kidney disease, and food hypersensitivity), which is important information that impacts in the choice of food by the owners. The maintenance energy requirements (MER) were estimated for adult dogs of different sizes (3 kg, 15 kg, 30 kg, and 50 kg) and the daily amounts of food intake were estimated for each type of food. The costs were calculated per day, per 1000 kcal of metabolizable energy of product and per kg of metabolic weight of the animal. Fourteen complete and balanced homemade diets were formulated, and in each proposed group, two diets with different protein sources were used. Under the conditions of the present study, it was possible to conclude that homemade diets were more expensive than dry maintenance diets and dry therapeutic diets, while commercial wet diets were more expensive in all of the scenarios.

Natural feed after weaning improves the reproductive status of Solea senegalensis breeders

The aim of this study was to evaluate the effect of long term natural feeding in the subsequent reproductive status of 4 years old cultured Solea senegalensis, and to determine if the potential changes were structural or feeding dependent. To this aim, two different feeding regimes were used from one year after weaning and during the following 3 years; 1) a commercial dry food diet and 2) a natural feeding regime. After this period, the proportion of fluent males and the evolution of maturity stages of females over a breeding season were studied. A complete sperm quality analysis assessment was carried out, including individual volumes, motility, density and curvilinear, rectilinear and mean velocities of spermatozoa. Moreover, viability and apoptosis indexes were analyzed as indicator of molecular sperm membrane integrity. Additionally, a morphological characterization of the testes during the spawning season was conducted. Finally, both groups were fed with the same commercial pellets during one year to evaluate the effect of the diet of previous years on sperm quality. The results of this study showed how feeding can improve not only sperm quality and quantity, but also the proportion of fluent males and females in advanced maturity stages. All the sperm quality parameters resulted significantly higher in the group fed with a natural diet. Moreover, the number of apoptotic cells was significantly higher in the group fed with a commercial diet. According to the morphological features of the testes, the animals fed with a natural diet presented more basal position, less protuberances and irregular edges when compared with the animals fed with commercial diet. Interestingly, the progression of the spermatogenesis determined by the proportion of germ cells and the production of spermatozoa determined by the wider of the ducts system was also significantly larger in the natural diet group.After the standardization of the diets, mean volume per male and production of total motile cells were significantly higher in the group that was previously fed a natural diet, confirming structural improvements.

Optimum dietary methionine requirement of juvenile silver pompano, Trachinotus blochii (Lacepede, 1801)

In this study, we optimized the dietary methionine requirement of juvenile silver pompano (average initial weight of 5.47 g). Six isonitrogenous and isolipidic diets (420 g/kg crude protein [CP] and 60 g/kg lipid) were formulated with different concentrations of methionine (5.1, 6.9, 9.0, 10.7, 13.1, and 15.2 g/kg dry diet) and a constant level of cysteine (5.3 g/kg). Fishes were randomly stocked in a recirculatory system for a feeding trial of 90 days. After the feeding trial, significant differences (P < 0.05) were observed in growth parameters such as weight gain (WG), specific growth rate (SGR), thermal growth coefficient (TGC), and feed utilization indices, including feed conversion ratio (FCR) and protein efficiency ratio (PER), among different treatment groups. No significant differences (P> 0.05) were observed among hepatosomatic index, viscerosomatic index, muscle ratio, condition factor, serum glucose, triglycerides, and erythrocyte count. The optimization of the fitted quadratic regression for WG, SGR, TGC, FCR, and PER based on the dietary methionine level showed that the optimum methionine requirement of silver pompano in nursery phase ranged from 11.6–11.8 g/kg dry diet (27.6–28.1 g/kg dietary CP), corresponding to a dietary cysteine level of 5.3 g/kg.

Effect of liquid feeding at different water-to-feed ratios on the morphological adaptations in the gastrointestinal tract of growing pigs

The study examined the morphology of the gastro-intestinal tract (GI) of growing pigs offered dry feed or liquid feed with differing water-to-feed ratios. Twenty male pigs were randomly allocated to one of four treatment groups; treatments included a standard dry pelleted diet (D) or the same diet soaked in water at a feed-to-water ratio of 1:1.5 (T1:1.5), 1:3 (T1:3) or 1:3 with the addition of lactic acid to adjust the feed to pH 4 (T1:3[4]). Animals were humanely slaughtered after 6 weeks to enable sampling and histological examination (light, scanning electron (LSEM) and binocular dissection microscope) of the GI tract. Samples were taken at the 2% position (duodenum), the 20% position and 50 % position (jejunum) along the small intestines (SI). Liquid-fed pigs were heavier (P &lt; 0.05) and exhibited improved feed conversion ratios (FCR) when compared to D animals. These differences in live weight were attributed to alterations in the weight and volume of the stomach and SI, which were also heavier and larger in liquid-fed pigs (P &lt; 0.05). However, these differences were no longer apparent when intestinal weights and stomach volumes were adjusted for animal live weight. Differences in villus type between the treatments were noted throughout, particularly in the duodenum and proximal jejunum sections. Mean villus height was taller in all liquid-fed animals when compared to D pigs (P&lt;0.05); this was particularly apparent in T1:1.5 and T1:3[4] pigs. There were no differences in crypt depths between treatment groups at the 2% and 20 % positions, but at the 50 % position the T1:1.5 group crypts were deeper (P &lt; 0.05) than those in the D and T1:3 pigs. It is concluded that liquid feeding alters the morphology of the GI tract, which may in part, explain the differences in growth performance observed between liquid and D fed pigs. The inclusion of organic acid in the diets of T1:3[4] pigs appeared to exert an effect on villus height and crypt depth when compared to those pigs receiving the T1:3 diet

Chronic kidney disease in cats alters response of the plasma metabolome and fecal microbiome to dietary fiber.

The objectives were to determine the effects of feeding different fiber types to healthy cats and cats with chronic kidney disease (CKD) on plasma metabolites and the fecal microbiome.MethodsA cross-over study within a split-plot design was performed using healthy (n = 10) and CKD cats [IRIS Stage 1 and 2; n = 10]. Cats were fed dry Prescription Diet® k/d® Feline with chicken, during a pre-trial period and then randomly assigned to two fiber treatments for 4 weeks each. Treatment foods were formulated similar to pre-trial food, with the exception that they contained 0.500% betaine, 0.586% oat beta glucan, and either 0.407% short chain fructooligosaccharides (scFOS) fiber or 3.44% apple pomace. Both foods had similar crude fiber percent (2.0 and 2.1% for scFOS and apple pomace, respectively) whereas soluble fiber was 0.8 and 1.6%, respectively.ResultsPlasma metabolites separated cats based on health status. At baseline, cats with CKD had significantly higher circulating concentrations of creatinine, urea, and some microbial and host tryptophan metabolites including several indole sulfates and kynurenate. Healthy cats had higher concentrations of the antioxidant α-tocopherol after consuming apple pomace; alternatively, they had higher concentrations of inflammatory sphingolipid metabolites after consuming scFOS, but not after consuming apple pomace. The CKD cats had higher concentrations of the more oxidized glutathione metabolites after consuming apple pomace compared with scFOS, as well as higher concentrations of inflammatory sphingolipid metabolites after consuming apple pomace, but not scFOS. After consuming scFOS, CKD cats had lower concentrations of the phenolic uremic toxins guaiacol sulfate and 4-vinylphenol sulfate compared with after consuming apple pomace. At baseline, there were five significant microbiota OTU differences in CKD cats compared with healthy cats. Overall, the OTUs in CKD cats were more resistant to change after feeding either fiber source. Counts of an unclassified genus in the family S24-7 in the order Bacteroidales (OTU 100296), were lower in CKD cats compared with healthy cats at baseline (P = 0.001), but increased after consumption of food containing scFOS (P = 0.006). Linear regression analysis showed that this genus had significant negative correlations with several microbial uremic toxins. None of the baseline differences in OTUs between healthy and CKD cats changed after CKD cats consumed food containing apple pomace.ConclusionsHealth status impacts the influence of dietary fermentable fibers on the feline plasma metabolome and fecal microbiome. A more readily fermented fiber such as scFOS is preferable to apple pomace as a fiber source for cats with CKD.

Effects of crude protein and sodium intake on water turnover in cats fed extruded diets.

The comprehension of strategies to increase urine production may be important, especially in kibble diets to prevent urolithiasis in cats. The effects of increasing amounts of crude protein (CP) and sodium on the water turnover of cats were evaluated using the water balance (WB) method and the deuterium dilution technique. The study followed a randomized block design, with three blocks of eight cats, two cats per food type in each block, and six cats per food. Four extruded diets with different amounts of CP and sodium were evaluated (on DM basis): 28% CP and 0.58% sodium; 39% CP and 0.64% sodium; 52% CP and 0.76% sodium; and 64% CP and 0.87% sodium. Cats were individually housed in cages for 8days to measure WB, urea excretion, and faecal and urine characteristics. Deuterium oxide was used to evaluate water turnover, and during the period cats were housed in a collective cattery. The data were analysed by an F test, and the means were compared by polynomial contrasts. The ɑ level of significance was set at 0.05. The methods were compared by Pearson correlation, and Bland and Altman analysis. The increase in the CP content elevated linearly the renal excretion of urea (p<.001), and, together with the higher sodium intake, elevated the renal solute load, which resulted in a linear increase in urine production and water intake (p<.01). The urine density, metabolic water, and faecal and insensible water losses did not differ (p>.05). The water flux increased linearly when using the deuterium method (p<.001), but the obtained values were 20.85±11.11ml/cat/day higher than those verified using the WB method (p=.001). Higher CP and sodium amounts in dry diets increased the urine production and water consumption of cats, and this can be explored as a possible option to increase urination.

Growth performance and apparent total tract nutrient digestibility of limit-fed diets containing wet brewer's grains to Holstein heifers.

The objective of this study was to evaluate the growth performance and apparent total tract nutrient digestibility of Holstein heifers limit-fed diets containing different amounts of wet brewer’s grains (WBG). A 12-wk randomized complete block study was conducted using 30 yearling Holstein heifers [378 ± 27 d of age, and body weight (BW) of 357.8 ± 27.6 kg (mean ± SD)]. Treatments were 0%, 10% and 20% of WBG on a dry matter (DM) basis and diets were formulated to be limit-fed for dry matter intake (DMI) at 2.35% of BW and provided 15% crude protein (CP) and 2.27 Mcal metabolizable energy/kg of DM. Dry matter intake was recorded daily, while BW and skeletal measurements were measured every 2 wk. During week 12, fecal samples were collected directly from the rectum over four consecutive days and composited by heifer to determine apparent total tract nutrient digestibility using acid detergent insoluble ash as a marker. Data were analyzed using the MIXED procedure of SAS. Dry matter intakes, BW, and average daily gain were not different among treatments (P = 0.2, P = 0.4, and P = 0.6, respectively). Dry matter intakes ranged from 8.6 to 9.0 kg/d. Average BW were 404.4, 411.5, and 409.3 kg for heifers fed the 0%, 10%, and 20% WBG diets, respectively. Average daily gains were 1.03, 1.04, and 0.96 kg/d for heifers fed the 0%, 10%, and 20% WBG diets respectively. Skeletal measurements and body condition scores (BCS) were not different among treatments except for the change in heart girth (P < 0.01) and initial BCS (P < 0.01). Apparent total tract digestibilities of DM, organic matter, CP, fat, and hemicellulose were greater or tended to be greater in heifers fed 0% and 20% WBG treatments than heifers fed 10 % WBG (P = 0.04, P = 0.04, P = 0.06, P = 0.06, and P = 0.01, respectively). Neutral detergent fiber, acid detergent fiber, and fat digestibilities were similar among treatments (P = 0.2, P = 0.3, and P = 0.3, respectively). During the digestibility phase, DMI tended to be greater (P = 0.08) for the 10% WBG treatment. These results demonstrate that limit-feeding heifers with diets containing up to 20% WBG could replace soybean- and corn-based concentrates in diets without adverse consequences to the heifer growth performance.

Effects of dietary Sargassum horneri on resisting hypoxia stress, which changes blood biochemistry, antioxidant status, and hepatic HSP mRNA expressions of juvenile black sea bream Acanthopagrus schlegelii

Aquatic hypoxia is a frequent event and a complex set of physiological and biochemical alterations are employed to cope with this environmental stress in fish. This study aimed at evaluating the protective effects of Sargassum horneri on hypoxia stress in black sea bream Acanthopagrus schlegelii. Four hundred and eighty fingerlings with approximate mean body weight of 12.0 ± 0.1 g were randomly distributed into four experimental groups in triplicate. Each group was stocked with 40 fish and fed with isonitrogenous (42% crude protein) and isolipidic (12% crude lipid) experimental diets containing either 0% (control), 3%, 6%, or 9% S. horneri in the feed. At the end of 8 weeks of experimental feeding, fish were exposed to hypoxia (dissolved oxygen 2.5 mg L−1) conditions for 12 h and subsequent recovery to normoxia (dissolved oxygen 7.2 mg L−1). Fish samples were collected after hypoxia stress at 0, 6, 12 h, and 12 h recovery to normoxia, respectively. Hypoxia stress caused a significant increase in the serum concentrations of cortisol, glucose, and lactate at 6 h after hypoxia, as well as the activities of hepatic superoxide dismutase (SOD) and MDA content at 12 h after hypoxia compared with 0 h after hypoxia. Moreover, the fish exhibited a significantly higher level in the mRNA expressions of hepatic Cu/Zn-SOD, HSP70, and HSP90 at 12 h after hypoxia. However, dietary S. horneri supplementation could significantly improve antioxidant capacity and resistance against hypoxia stress, particularly in the 6% S. horneri group. Therefore, the optimal dietary S. horneri level based on increasing the resistance of hypoxia for juvenile black sea bream in the present study was estimated to be approximately 6% dry diet.

Dietary lysine requirement of juvenilePseudobagrus ussuriensis

An 8‐week feeding trial was conducted to determine dietary lysine requirement of juvenile Pseudobagrus ussuriensis (initial body weight: 0.60 g). Six isonitrogenous (crude protein, 400 g/kg) and isolipidic (crude lipid, 50 g/kg) diets were formulated to contain graded levels of dietary lysine (12.8, 19.9, 26.5, 34.0, 40.8 and 44.1 g/kg dry diets, respectively). The results indicated that weight gain, specific growth rate, productive protein value and protein efficiency ratio increased, while feed conversion ratio decreased with increasing dietary lysine level up to 34.0 g/kg dry diet and then levelled off. Fish fed diet with 12.8 g/kg lysine had the lowest lysine content (58.6 g/kg dry matter) in muscle, while fish fed diet with 34.0 g/kg lysine had the highest value (61.6 g/kg dry matter; p < .05). Broken‐line analysis on the basis of weight gain showed that the optimal dietary lysine requirement for maximum growth of juvenile Pseudobagras ussuriensis is 33.5 g/kg dry diet (82.4 g/kg dietary protein). Quadratic regression analysis of protein efficiency ratio against dietary lysine levels indicated that the optimal dietary lysine requirement of juvenile Pseudobagras ussuriensis is 36.4 g/kg dry diet (89.5 g/kg dietary protein).

Influence of two different feeding strategies in the dry period on dry matter intake and plasma protein peroxidative and antioxidative profile during dry period and early lactation

BackgroundDairy cows undergo dramatic changes in endocrine and metabolic status around parturition and in early lactation. Meeting the nutritional requirements of transition dairy cows is important for animal health, production and animal wellbeing. Dry cow feeding and managing play an essential role in this. The changes in metabolism of periparturient cows also lead to a rise in the production of oxidising agents, leading to oxidative stress. The relationship between dry cow diet composition and oxidative stress has received little research attention so far. In the present study, the influence of two different dry cow feedings (single diet with medium energy content over the whole dry period versus traditional two-phase diet with a low-energy “far-off” ration and a high energy “close-up” ration) on dry matter intake, energy intake and plasma protein peroxidative and antioxidative profile was investigated.ResultsThe examined parameters revealed a dynamic profile within the experimental period. Dry matter intake (DMI) did not differ between groups. However, there was a time and a group x time interaction effect: Group 1 (“one-phase”) had a very constant DMI with a slow and even decrease until calving. In Group 2 (“two-phase”), an initial increase in DMI two weeks antepartum (a.p.) was followed by a sharp drop at week 1 a.p.. The highest total antioxidant capacity and sulfhydryl residue concentration was noted at partus. In contrast, concentration of formylokinurenine and bityrosine bridges as representatives of protein peroxidation were lowest at parturition. The time course of formylokinurenine and bityrosine bridges showed parallels to the DMI. The contents of sulfhydryl groups, formylokinurenine and total antixoxidant capacity did not differ between groups. In contrast, concentration of bityrosine bridges was always higher in Group 2 compared with Group 1 and these differences were statistically significant at week 3 a.p., week 2 a.p., week 1 a.p. and at parturition.ConclusionThe results of our study suggest time-related changes of pro- and antioxidative plasma parameters. Different dry cow feeding affected antepartal DMI. Furthermore, DMI and diet compositions seemed to have an influence on plasma protein peroxidative profile and activity of antioxidative defence.

Micro-algal astaxanthin could improve the antioxidant capability, immunity and ammonia resistance of juvenile Chinese mitten crab, Eriocheir sinensis

Green alga Haematococcus pluvialis is an important source of natural astaxanthin (Ast), which have been shown to be beneficial for the color formulation, survival, antioxidation, immunity and stress resistance of many crustacean. This study was conducted to investigate the effects of dietary supplementation of H. pluvialis meal on growth, antioxidant status, ammonia resistance, color parameters, and carotenoids composition of juvenile Chinese mitten crab Eriocheir sinensis. Five diets were formulated to contain 0, 30, 60, 90 and 120 mg/kg dry diets of natural Ast (defined as Diet 1–5) using H. pluvialis meal as astaxanthin source. The results showed that: (1) Although all treatments with Ast supplementation had the relatively higher growth performance and survival than the control (Diet 1 treatment), no significant differences were found on growth performance, feed conversion ratio and hepatosomatic index among all treatments. (2) The highest total antioxidant capacity (T-AOC) in hepatopancreas and hemolymph were observed in Diet 4 and 3 treatments respectively, while the lowest malondialdehyde (MDA) contents in hepatopancreas and hemolymph were also found in these two treatments. Furthermore, the significantly positive relationships were detected on acid phosphatase (ACP) activities and dietary Ast contents for hepatopancreas and hemolymph. (3) Diet 3 treatment had the highest mRNA levels of EsLecA, EsTrx, and EsPrx6 in hepatopancreas, while both Diet 3 and 4 treatments reached the peaks for mRNA expression levels of EsMyd88 and EsHc, respectively. (4) The stress test with ammonia-N indicated Diet 1 treatment had the highest mortality among all treatments, and the lowest mortality was found on Diet 3 treatment during the stress test. (5) Dietary Ast significantly improved the redness (a*) of carapace and hepatopancreas, which were consistent with the Ast contents in these tissues from the different treatments. Ast concentrations in carapace reached the plateau for Diet 3 treatment while hepatopancreatic Ast concentration kept increasing with elevating dietary Ast contents. In conclusion, natural astaxanthin could enhance the antioxidative capability, non-specific immunity, tissue Ast contents and stress resistance to ammonia-N, and these results suggested the optimal diet micro-algal astaxanthin was around 60 mg/kg for juvenile E. sinensis.

Effect of Dry-Period Diet on the Performance and Metabolism of Dairy Cows in Early Lactation.

Simple SummaryIn dairy cows, the management of the dry period should optimize milk production and limit impact on metabolic health. In early lactation, there is little information on the effect of the dry-period diet composition on the production and composition of milk and the blood metabolites. The aim of this study was to compare the effects of different dry-period diets on the blood metabolites of dairy cows during the peripartum period and the milk yield and fatty acid profile at onset of lactation. This study showed that different dry-period diets can be used without impact on milk production and composition when these diets cover the needs of dairy cows. However, blood metabolites were more sensitive to the diet offered during the dry period. In early lactation, a dry-period diet based on corn and grass silages allowed a smooth transition with better rumen and liver function parameters.The objective of this work was to observe the effect of three different dry-period diets on blood metabolites (p = 9) and the production and fatty acid (FA) profile of milk (p = 19) in the peripartum period. In this study, 32 Holstein dairy cows, during their dry period, were divided in 3 different diet groups, as follows: the CONC diet (n = 11) was based on concentrate meal and straw, the CORN diet (n = 11) was based on corn silage, and the MIXED diet (n = 10) was based on corn and grass silages. According to our results, the variations of C18:2n-6, C18:3n-3, non-esterified fatty acid (NEFA), NEFA/cholesterol ratio, and albumin were significantly (p < 0.05) different, according to the dry diet. The dry-period diet also had a significant effect on the concentrations of urea and vitamin B12 in the blood. In early lactation, this work showed that blood metabolites were more sensitive to changes in the dry diet than the production and FA profile of milk.