Crude Protein Basis Research Articles

Evaluating Fecal DNA Metabarcoding to Estimate the Dietary Botanical Composition of Goats

Improved techniques are needed to estimate the dietary species composition of grazing animals. The fecal DNA metabarcoding technique has been proposed as a noninvasive method to determine dietary species composition. However, studies suggest that it is more effective to qualitatively estimate species composition of wild and domestic animals than for accurately quantifying diet composition. The technique, using the trnL barcode, was evaluated with 10 individually penned goats, which were fed hand-harvested plant materials that were collected fresh each morning before known amounts of each type of plant materials were fed and completely consumed by the goats. Goats were fed at 3% of their body weight on a DM basis. Broadleaf plant materials fed were Russian olive (Elaeagnus angustifolia), silver buffaloberry (Shepherdia argentea), western snowberry (Symphoricarpos occidentalis), and wormwood sage (Artemisia absinthium) plus a mixture of predominantly smooth bromegrass (Bromus inermis), which also included small amounts of other grasses such as Kentucky bluegrass (Poa pratensis) and forbs such as leafy spurge (Euphorbia esula). Estimates of the dietary composition of the goats were different (P ≤ 0.04) from those of their known dietary composition, except for wormwood sage when expressed on a crude protein basis (P = 0.98), regardless of whether known composition was expressed on a dry matter or crude protein basis. Therefore, we conclude that the fecal DNA metabarcoding technique for estimating the dietary composition of goat diets is useful qualitatively but needs further development to be a better quantitative technique.

Effects of Fishmeal Substitution with Mealworm Meals (Tenebrio molitor and Alphitobius diaperinus) on the Growth, Physiobiochemical Response, Digesta Microbiome, and Immune Genes Expression of Atlantic Salmon (Salmo salar).

A 12-week growth trial was conducted to assess the effects of mealworm meals, as a substitution for fishmeal, on the growth, physiobiochemical responses, digesta microbiome, and immune-related genes expression of Atlantic salmon (Salmo salar). Twenty Atlantic salmon parr (38.5 ± 0.1 g, initial weight) were stocked into each of 16 tanks in a recirculating aquaculture system. A fishmeal-based diet (100% FM) was used as the control treatment and was compared with three test diets where: (1) fishmeal was partially (50%) replaced with defatted mealworm meal, Tenebrio molitor (50% DMM), (2) fishmeal was fully replaced with defatted mealworm meal (100% DMM), and (3) fishmeal was partially replaced with whole lesser mealworm meal, Alphitobius diaperinus (50% WMM). All substitutions were done on a crude protein basis. Each of the four experimental diets was evaluated in quadruplicate tanks as part of randomized design. The results indicated that Atlantic salmon showed high survival (greater or equal to 98.8%), and no significant difference in final growth, feed efficiency, feces stability and condition indices. Hepatosomatic index was lower in fish fed 100% DMM and 50% WMM when compared to fish fed the control diet (100% FM). Whole-body proximate and amino acid compositions were not statistically different between treatments, while essential fatty acids, including linolenic, eicosapentaenoic acid, and homo-a-linolenic, were lower in fish fed 100% DMM. Plasma parameters (total protein, alanine aminotransferase, alkaline phosphatase, and total iron-binding capacity), hepatic peroxide, and antioxidant enzymes were not significantly affected by dietary substitutions, whereas plasma immunoglobulin M showed significantly higher levels in fish fed 50% DMM and 100% DMM when compared to fish fed the control diet (100% FM). The inclusion of mealworm meals significantly impacted the overall microbiome composition but not the richness and evenness of the salmon digesta microbiomes compared to control. The most common genus in all treatments was Pseudomonas, which has been previously shown to have both commensal and pathogenic members. The relative expressions of growth (IGF-I) and protein synthesis (TIPRL) were not significantly different between the treatments, whereas immunoglobulin genes (IgM, IgD, and IgT) were significantly upregulated in fish fed the DMM diets when compared to fish fed the control diet. Overall, this study suggests that the mealworm meals tested could be suitable alternatives to fishmeal in the diet of Atlantic salmon.

Dietary Valine Requirement of Juvenile Olive Flounder (Paralichthys olivaceus).

This study was conducted to estimate dietary valine (Val) requirement for juvenile olive flounder (Paralichthys olivaceus). In a feeding trial, a total of 540 fish (initial body weight: 23.0 ± 0.2 g) were stocked into 18 tanks (210 L). Six experimental diets containing graded levels of Val (4, 8, 12, 16, 20, and 24 g/kg, dry matter basis) were fed to the fish in triplicate groups for 13 weeks. The lowest growth, feed utilization, and survival were observed in 4 g/kg Val group (P < 0.05). Dietary Val deficiency resulted in significant decreases (P < 0.05) in whole-body protein and Val concentrations, hepatosomatic index, condition factor and plasma protein and cholesterol levels. Nonspecific immunity and antioxidant activities were significantly lower (P < 0.05) in 4 g/kg Val group than in other groups. Dietary Val deficiency upregulated the expression of proinflammatory cytokines and downregulated the expression of anti-inflammatory cytokines and intestinal tight junction protein (occludin) (P < 0.05). Mucosal fold height and submucosa and muscularis thickness of fish intestine were significantly lower (P < 0.05) in fish fed 4 g/kg Val diet. Relatively lower lipid droplet in hepatic cell was observed in 4 g/kg Val group. Our findings suggested that dietary Val requirements for juvenile olive flounder would be 17.7-18.9 g Val/kg (35.4-37.8 g/kg on the basis of crude protein), estimated by quadratic regression analysis based on the weight gain, protein efficiency ratio, and protein retention efficiency.

Nutritional value of torula yeast as an alternative protein feedstuff for hybrid Striped Bass (White Bass × Striped Bass)

AbstractObjectiveTwo separate trials were conducted to evaluate the digestibility of a novel alternative ingredient, enhanced torula yeast (TY) Cyberlindnera jadinii, in diets for hybrid Striped Bass (HSB; White Bass Morone chrysops × Striped Bass M. saxatilis) and to evaluate graded inclusion levels of this product when replacing soybean products.MethodsIn trial 1, the digestibility of TY was determined by testing a reference diet and a TY diet (reference and TY ingredient at an 80:20 ratio). A total of 90 fish were fed the experimental digestibility diets for 21 days, and fecal samples were collected using the stripping technique. In trial 2, a comparative feeding trial evaluated the replacement of soybean meal by TY on a crude protein basis at 50, 100, 200, and 300 g of TY/kg of experimental diet. A total of 150 HSB (18.6 ± 0.21 g/fish [mean + SE]) were distributed among fifteen 110‐L glass aquaria. Each diet was fed to triplicate groups of fish for 9 weeks.ResultIn trial 1, apparent digestibility coefficients for protein, lipid, organic matter, and energy of TY were 0.97, 0.98, 0.75, and 0.75, respectively. The availability of essential amino acids also was generally high, ranging from 0.74 to 0.99. For trial 2, a second‐order polynomial regression indicated that the optimal inclusion levels of TY in diets were 102, 112, and 109 g/kg for weight gain, feed efficiency, and protein conversion efficiency, respectively. However, the muscle yield linearly decreased with the graded inclusion levels of TY. Linear increases in intraperitoneal fat, hepatosomatic index, and whole‐body lipid were observed as the inclusion of TY increased in the diet.ConclusionIn conclusion, nutrients from TY were well utilized by HSB, and it can replace soybean products without affecting growth performance, with the optimal TY inclusion level being 102–112 g/kg of diet.

Production effects of extruded soybean meal replacing canola meal in the diet of lactating dairy cows

This study investigated the effects of extruded soybean meal (ESBM) in comparison with canola meal (CM) fed on an equivalent crude protein (CP) basis on lactational performance and ruminal fermentation of dairy cows. Following a 2-wk covariate period, 48 Holstein cows averaging (±SD): 146 ± 46 d in milk (DIM) and 43 ± 7 kg/d milk yield (MY) were assigned 1 of 2 treatment diets in a randomized complete block design experiment, which included a 2-wk period for dietary treatment adaptation before experimental data were collected. Following the adaptation period, samples and experimental data were collected for a total of 7 wk. Cows were blocked based on parity, DIM, and MY. Treatment diets contained 15.8% CM (containing 41.2% CP) or 13.2% ESBM (with 48.7% CP) of total mixed ration dry matter (DM), with similar inclusion of other feed ingredients. The CM diet was supplemented with canola oil, whereas the ESBM diet was supplemented with soybean hulls to achieve similar ether extract and neutral detergent fiber contents between the diets. Urea and rumen-protected Met and Lys were added to both diets to meet or exceed cow recommendations. Whole-ruminal digesta samples were collected from 10 (5 per treatment) ruminally cannulated cows. Eight cannulated cows were removed during the last week of the experiment to participate in another study. Treatment did not affect DM intake and MY or energy-corrected MY of the cows. Energy-corrected MY, apart from experimental wk 5, was similar between treatments. Apart from experimental wk 3 and 7, milk fat concentration and yield were greater for cows fed ESBM compared with CM. In multiparous cows only, milk true protein yield was greater for cows fed CM compared with ESBM. Ruminal concentration of total volatile fatty acids and the molar proportion of acetate were greater for ESBM, and propionate and valerate were greater in cows fed CM. Acetate to propionate ratio was greater for cows fed ESBM versus CM diet. Compared with the CM diet, the ESBM diet increased plasma concentrations of Ile, Leu, and Phe but not the sum of essential AA. Apparent total-tract digestibility of acid detergent fiber was greater in cows fed ESBM relative to CM. In this experiment, CM and ESBM included on an equal CP basis in the diet of dairy cows, resulted in similar DM intake, MY, and feed efficiency.

Effect of dietary Marula (Sclerocarya birrea caffra) nut meal on the growth performance, carcass traits and meat quality of Dorper lambs

Use of Marula nut meal (MNM) to replace Soyabean meal (SBM) as a dietary protein source in lamb fattening diets by determining effects on growth performance, carcass yield and meat quality was evaluated. MNM replaced SBM on a crude protein (CP) basis, in five diets, at 0%, 25%, 50%, 75% and 100%, respectively. Forty 112-day old entire male Dorper lambs (average body weight: 22.1 ± 3.3 kg) were randomly allocated to the diets and fed ad libitum for 63 days. Weekly and final body weight (FBW), body weight gain (BWG), average daily gain (ADG), daily feed intake (FI) and feed conversion ratio (FCR), warm and cold carcass weight, dressing percentage, meat (physical and chemical attributes) quality were determined. Dietary MNM caused no significant difference in FBW, BWG, ADG, FI, FCR, carcass weight and the meat’s physical attributes compared to SBM. At 25% and 100% dietary substitution of SBM (CP basis), MNM significantly (P < 0.05) reduced meat protein content. Feeding MNM-based diets produced meat with higher fat content compared to the control SBM diet (P < 0.05). The meat’s total monounsaturated fatty acid content, dominated by oleic acid, increased with increasing dietary MNM. At 100% substitution of SBM, dietary MNM produced meat with the highest (P < 0.05) oleic acid content. The results obtained in the study showed that MNM can replace SBM in lamb fattening diets without compromising growth performance, feed utilisation efficiency, carcass yield and physical attributes of meat. MNM can potentially be utilised to improve lamb quality by increasing its oleic acid content.

Economic outcomes for transitioning to organic forage production

AbstractResearch on the use of forages to transition cropland to organic production is limited. Our objective was to determine the cost of transitioning from conventional to organic production using perennial and annual forage systems. The study was conducted at the Middle Tennessee AgResearch and Education Center, in Spring Hill, TN. Five forage treatments were compared: tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] monoculture, bermudagrass [Cynodon dactlyon (L.) Pers.] monoculture, tall fescue and alfalfa (Medicago sativa L.) mixture, bermudagrass and alfalfa mixture, and an annual rotation of a cool‐season mixture, including winter wheat (Triticum aestivum L.) and winter pea (Pisum sativum L.), and a warm‐season mixture of sorghum–sudangrass [Sorghum bicolor (L.) Moench × S.orghum sudanese (Piper) Stapf] and cowpea [Vigna unguiculata (L.) Walp.]. Perennial forages were established in 2017 and 2018 following orchard removal and a fallow period. Regular production measurements began in 2019 when the plots achieved full organic certification status. Tall fescue had the lowest cost for the overall transition period. However, on a cost per unit of dry matter (DM) forage mass and on a cost per unit of crude protein (CP) basis, all treatments were similar, with a range between US$0.02 and $0.03 lb–1 for DM forage mass and between $0.15 and $0.20 lb–1 for CP, except for the more costly bermudagrass monoculture that was $0.06 lb–1 DM forage mass and $0.40 lb–1 CP. Given the lack of a premium during the transition period, tall fescue was the most cost‐effective transition forage.

Lactational performance, enteric gas emissions, and plasma amino acid profile of dairy cows fed diets with soybean or canola meals included on an equal protein basis

This study investigated the effects of feeding solvent-extracted canola meal (CM), extruded soybean meal (ESBM), or solvent-extracted soybean meal (SSBM) on an equivalent crude protein basis on performance, plasma AA profiles, enteric gas emissions, milk fatty acids, and nutrient digestibility in lactating dairy cows. Fifteen Holstein cows (95 ± 20 d in milk) were used in a replicated 3 × 3 Latin square design experiment with 3 periods of 28 d each. Treatments were 3 diets containing 17.1% CM, 14.2% ESBM, or 13.6% SSBM (dry matter basis). Vegetable oil was added (canola oil for CM or soybean oil for SSBM) to equalize the ether extract concentration of the diets. Rumen-protected Met was supplemented targeting digestible Met supply of 2.2% of metabolizable protein in all diets. Canola meal increased dry matter intake (DMI) by 5.9 and 8.9% in comparison with ESBM and SSBM, respectively. Milk urea nitrogen was lowest in CM, followed by SSBM, and was highest for ESBM. No differences were observed in feed efficiency, energy-corrected milk yield, and milk composition or component yields among treatments. Cows fed CM emitted less enteric CH4 per kg of DMI compared with both ESBM and SSBM, but CH4 emission intensity (CH4 per kg of energy-corrected milk) was similar among treatments. In summary, replacement of ESBM or SSBM with CM, on an equal crude protein basis, in the diet of lactating dairy cows enhanced DMI, but yields of energy-corrected milk and milk components and feed efficiency were similar among treatments.

Effects of dietary inclusion of GuarPro F-71 on the growth performance and nutrient metabolism in young growing pigs

Using alternative feedstuffs can be a feasible measure to reduce swine production cost. GuarPro F-71 (GP71), a newly developed guar meal product, is considered as a potential protein source for pigs. This preliminary study was conducted to evaluate the effects of GP71 inclusion in feed on growth performance and nutrient metabolism of growing pigs. Sixty crossbred barrows (31.9±1.84 kg body weight (BW)) were allotted to one of five dietary treatments in a completely randomised experiment design, with four pens/treatment and three pigs/pen. Diet 1 was a maize- and soybean-based basal control diet formulated to meet NRC recommendations. GP71 was used to replace 25, 50, 75, and 100% soybean meal in diet 1 (on an equivalent crude protein (CP) basis) to generate diets 2, 3, 4, and 5, respectively. Crystalline amino acids were used to balance the essential amino acid concentrations across the five diets. Inclusion of GP71 quadratically reduced average daily feed intake (ADFI) (P=0.01) with no observed clinical signs of unhealthiness of pigs. The blood plasma concentrations of six metabolites, including urea nitrogen, total protein, albumin, glucose, total cholesterol and total triglycerides, were not affected (P&gt;0.30), indicating that the pigs’ metabolic utilisation of nutrients was not compromised. The cubic effect (P&lt;0.05) of dietary GP71 inclusion on G:F ratio suggested that the level of soybean meal replacement (up to 75% soybean meal) did not negatively affect feed efficiency in pigs. In short, the feed intake reduction due to the dietary GP71 inclusion was, if not solely, responsible for the average daily gain (ADG) and final BW reduction. This study suggested that using GP71 to replace soybean meal up to 75% (on an equivalent CP basis) can negatively affect ADFI and ADG, but not feed efficiency, in growing pigs. The reasons for the ADFI and ADG reduction need to be understood in future research.

Sunflower meal as an alternative protein source to replace soybean meal in the diet of GIFT strain of Nile tilapia Oreochromis niloticus

The main objective of the study was to investigate the effect of partial replacement of soybean meal (SBM) protein with sunflower meal (SFM) protein on growth performance, feed utilisation, survival and body composition of GIFT tilapia. Fish weighing between 1.03±0.01 and 1.19±0.02 g were stocked in in plastic troughs (50 l) at a stocking rate of 15 fishes per trough. Percent replacement of SBM by SFM on the basis of crude protein was 0% (control), 10% (SFM10), 20% (SFM20) and 30% (SFM30). Diets were fed to fish at the rate of 5% of the total fish biomass, daily for a period of 60 days. Fish fed with SFM 20% and SFM 30% sunflower meal had best performance in terms of weight gain, specific growth rate, protein efficiency ratio, feed efficiency ratio and feed conversion ratio (p&lt;0.05). Analysis of fish whole body composition revealed that with increasing dietary SFM levels, whole body protein, ash and moisture contents showed significant difference among dietary treatments (p&lt;0.05). Fish fed with SFM 30 diet showed the best growth performance compared to fish fed with the control diet.

Bioprospecting Cultivated Tropical Green Algae, Caulerpa racemosa (Forsskal) J. Agardh: A Perspective on Nutritional Properties, Antioxidative Capacity and Anti-Diabetic Potential.

Caulerpa racemosa (Forsskal) J. Agardh is a green seaweed used as food and folk medicine since ancient times in the Indo-Pacific region, particularly in southeast Asia. In this study, the proximate nutrient composition, phytochemical, anti-oxidant and anti-diabetic properties of sea grape C. racemosa collected from culture fishponds in Johor, Malaysia were analysed. The contents (dry weight basis) of carbohydrate, crude protein, crude lipids, ash and caloric value obtained were 33.42 ± 1.34%, 20.27 ± 0.14%, 4.20 ± 0.32%, 28.25 ± 0.27% and 2544.67 ± 7.04 cal g−1, respectively. The amino acid score (AAs) and biological protein value (213.43 mg g−1) indicated that C. racemosa presented a better protein quality. The most abundant fatty acids were C16:0 (palmitic acid: 63.27%), followed by C18:1 (oleic acid: 5.80%), and C18:2 ῳ6 (linoleic acid: 5.33%). The analysis of the ash content indicated that essential minerals and trace elements, such as Ca, Fe, and Mn, were present in the seaweed. The total phenolic content (TPC) and total flavonoid content (TFC) observed in the ethyl acetate extract were 17.88 ± 0.78 mg GAE g−1 and 59.43 ± 2.45 mg QE g−1, respectively. The ethyl acetate extract of C. racemosa demonstrated notable anti-diabetic activity in diabetic induced rats. The low (100 mg kg−1) and high (200 mg kg−1) doses of cultivated C. racemosa extract exhibited a significant decrease (p < 0.05) in blood glucose levels while preventing weight loss, reducing plasma AST, ALT levels as a sign of hepatoprotective effect and recording albumin levels similar to positive control in diabetic induced rats. The results support the usefulness of cultivated C. racemosa as a potential functional food.

Intrinsic tannins affect ensiling characteristics and proteolysis of Neolamarckia cadamba leaf silage by largely altering bacterial community

The mechanism that tannins alter microbial community to inhibit proteolysis and enhance silage quality is unclear. Neolamarckia cadamba leaf (NCL; rich in tannins) were ensiled alone or with addition of polyethylene glycol (PEG, tannins inactivator), and then fermentation quality, proteolysis activity and bacterial community were investigated during ensiling (Day 3, 7, 14 and 30). As a result, PEG addition increased lactic acid (1.09% vs 2.03%, on dry matter basis) and nonprotein-N (13.65% vs 17.59%, on crude protein basis) contents but decreased ammonia-N content (9.21% vs 2.29%, on crude protein basis) in NCL silage. Meanwhile, the dominant microbiome shifted from Cyanobacteria (60.92%–81.50%) to Firmicutes (48.96%–88.67%), where the unclassified genus (80.95%–85.71%) was substituted by Leuconstoc (42.03%–55.55%) and subsequently Lactobacillus (65.98%–82.43%). This study suggests that the intrinsic tannins inhibit lactic acid fermentation and protein degradation in NCL silage.

The effect of dietary Marula nut meal on the physical properties, proximate and fatty acid content of Japanese quail meat

Soyabean meal (SBM) is the major dietary protein source for the poultry industry in sub-Saharan Africa. Due to inadequate local soyabean production, alternative protein sources are required. Two hundred 9-day old Japanese quail chicks were randomly allocated to grower diets wherein Marula nut meal (MNM) substituted SBM on a crude protein (CP) basis at 0%, 25%, 50%, 75% and 100% and fed for 4 weeks, followed by being fed on similarly formulated finisher diets for 2 weeks, and thereafter they were humanely slaughtered and dressed. Initial pH (pHi) and ultimate (pHu), colour, thawing loss (TL), cooking loss (CL), tenderness, proximate and fatty acid (FA) composition of the breast and thigh meat were determined. The results showed that pHi and pHu of meat from carcasses of quail fed diet 1 was lower, but had lighter and less red meat than that from counterparts fed diet 5 (P < 0.01). Dietary MNM had no effect (P>0.05) on TL, CL and tenderness of the meat. The ash content of the meat increased with an increase in dietary MNM, but its CP and fat decreased (P < 0.05). In addition, the total saturated FA content of meat from birds fed diet 4 was lower (P < 0.05) than other counterparts. Meat from birds fed diets 1 and 2 had a lower oleic acid (OA) content in comparison to meat from birds fed diets 3, 4 and 5. MNM can potentially be utilised in quail feeds without compromising the physical and proximate properties of the meat. Also, it can be used to produce lean but OA-rich meat with possible potential health benefits to consumers.

Effect of dietary substitution of maize meal with finger millet meal on fat deposition on broiler meat

The aim of this study was to investigate the effect of a finger millet-based broiler feed on the meat quality of chicken. Proximate nutrient composition was analyzed on the finger millet meal and a feed formulated with finger millet as the main energy source. The feed was formulated on percent crude protein (CP) basis using Pearson square method. An experiment was designed and conducted on Ross Hybrid chickens to determine the effect of the feed on lean tissue development. A two-tailed t-test statistical analysis was conducted at a significance level of 5% to determine the effect of the feed on fat deposition and lean tissue development in broiler muscle. The finger millet feed increased mean lean tissue mass by 3.47%. This study showed that use of finger millet feed reduced the fat deposition and favored protein deposition in broiler muscle (increased leanness). This study also showed that finger millet feed significantly enhanced broiler growth performance. We concluded that finger millet has the potential to replace maize meal in broiler feed formulation in order to produce lean and healthier meat for consumers.

Replacing alfalfa hay with triticale hay has minimal effects on lactation performance and nitrogen utilization of dairy cows in a semi-arid region of Mexico

In the semi-arid highlands of central Mexico, triticale (× Triticosecale L.) is emerging as an alternative, less water-demanding forage crop than alfalfa for dairy cattle. Studies reported here were aimed at evaluating triticale hay (TH) relative to alfalfa hay (AH) for lactating cow performance, apparent digestibility, N partition, and ruminal degradation kinetics of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF). Study 1 was conducted on a privately owned farm. Four barns were used to conduct 4 replicated 3 × 3 Latin squares (1 barn = 1 square), where each barn included 3 pens (experimental units) receiving 1 of 3 dietary treatments. Each pen had 62 Holstein dairy cows. All diets included a forage-to-concentrate ratio of 42:58 (DM basis), which is typical for intensive dairy farms of the region. Dietary treatments were formulated to replace AH with TH on a CP basis, and included (DM basis) 15.1% AH and 0% TH, 9.0% AH and 7.4% TH, and 0% AH and 16.4% TH. Diets were iso-energetic (1.64 Mcal of net energy for lactation/kg of DM) and iso-nitrogenous (17.9% CP). Pen-level DM intake and milk production were from all cows in the pen, but pen-level milk composition, apparent digestibility, and N partitioning were from 8 cows (observational units) randomly selected in each pen. Orthogonal contrasts were used to determine linear and quadratic effects of increasing TH from 0 to 7.4, and 16.4% of dietary DM. Although DM intake was not affected, there was a tendency for CP intake to decline linearly and for NDF intake to increased linearly as TH replaced AH in the diet. Milk production declined linearly by 0.077 kg/d for each additional percentage unit of TH in the diet, which amounted to a 3.5% decline when TH replaced AH entirely. However, no effect was observed on energy-corrected milk production because of a compensatory linear effect of increasing milk fat concentration with the incorporation of TH in the diet. Total-tract NDF digestibility tended to increase linearly by 18.5%, but no differences were detected for urinary urea-N excretion and for N utilization estimated as milk N/(fecal N + urinary N + milk N). Study 2 was an in situ trial conducted to determine the degradation kinetics of AH and TH used in study 1. In spite of differences in degradation kinetics parameters for DM, CP, and NDF, only NDF effective ruminal degradation tended to be greater for TH than AH. Replacing AH with TH at the level typically found in intensive dairy farms of the semi-arid regions of Mexico had minimal effects on milk production and N utilization.

Nutrient Composition, Glucosinolate and Vinyl-Oxazolidine-Thione Profiling of Indian Rapeseed (&lt;i&gt;Brassica juncea&lt;/i&gt; Coss.) Meal

Presence of antinutritional factor(s) in any feedstuff impedes effective nutrient utilization by animals, besides causing specific adverse effects. This study includes eighteen different batches of Indian rapeseed ( Brassica juncea Coss.) meal (RSM) sampled over a period of nine months for their evaluation in terms of nutrient composition, glucosinolate (GL) and vinyloxazolidine- thione (VOT) concentrations. Results showed that RSM contained a mean value (on dry basis) of crude protein (36.7%), ether extract (1.1%), ash (7.6%), crude fibre (10%), neutral detergent fibre (25%), acid detergent fibre (16.5%), hemicellulose (8.6%), total carbohydrates (54.7%), non-fibrous carbohydrates (29.7%), total digestible nutrients (77.9%) and metabolizable energy (11.7 MJ/kg). Furthermore, antinutritional factors like GL (μmol/g) and VOT (mg/g) are presented to be in the range of 36.2–72.2 (mean: 52) and 0–3.2 (mean: 1.0) respectively. Based on the species-wise tolerance limit for GL, the optimum inclusion level of RSM recommended for ruminants, pigs, rabbits, rats, poultry and fish is 15.6%, 1.5%, 13.5%, 1%, 10.4% and 6.9% respectively. Results of the present study are expected to maximize precision ration balancing for enhanced nutrient utilization whilst also curtailing any possible adverse effects of GL and VOT on production performance of animals.

Validation of processed animal proteins (mono-PAPS) in experimental diets for juvenile gilthead sea bream (Sparus aurataL.) as primary fish meal replacers within a European perspective

Experimental diets were formulated to evaluate a “pure” poultry meat meal (PMM) source in diets formulated for juvenile gilthead sea bream (Sparus aurata L.). The digestible protein contribution of fish meal in a control diet was substituted by 25%, 50% and 75% of a processed poultry meat meal (PMM) on a digestible crude protein (DCP) basis and by 5% and 10% for an enzyme‐treated feather meal (EFM) and also a spray‐dried haemaglobin meal (SDHM), respectively. In a consecutive trial, diets were designed to assess the value of a “pure” (defatted) poultry protein substituting the fish meal (FM) protein content. Experimental diets included: a control diet, two test diets where 75% of FM was replaced by a full‐fat PMM (PMM75) or a defatted grade of PMM (dPMM75) and two test diets where 50% of FM was substituted for defatted PMM (dPMM50) or a 50:50 blend of soya bean meal and defatted PMM (SBM/dPMM) to produce a composite product. This soya bean/dPMM blend was tested to enhance the nutritional value of this key plant ingredient commonly employed in sea bream diets that can be deficient in specific amino acids and minerals. In the first trial, gilthead sea bream grew effectively on diets containing up to the 75% replacement of FM attaining a mean weight of 63.6 g compared to 67.8 g for the FM control fed group. For the consecutive trial, the fishmeal‐based control diet yielded the highest SGR followed by dPMM50 and SBM/dPMM blend inclusion but was not significant. Carcass FA profiles of gilthead sea bream conformed to the expected changes in relation to the dietary FA patterns, with the 18:1n‐9 representative of the poultry lipid signature becoming more apparent with PMM inclusion. The ratio of n‐3/n‐6 fatty acids was greatly affected in sea bream fed the full‐fat PMM at 75% inclusion due to fish oil exclusion. Defatted dPMM, however, allowed more of the fish oil to be used in the diet and reducing this latter effect in sea bream carcass, hence restoring the higher total omega‐3 HUFA fatty acids namely EPA and DHA and n‐3/n‐6 ratio. It is concluded that poultry meat meal can be modestly incorporated into formulated diets for sea bream and can be used in conjunction with soya bean meal without any fundamental changes in performance and feed efficiency.

Effects of Dietary Ximenia caffra Meal on Nutrient Intake, Digestibility, Nitrogen Balance and Growth Performance in Sprague Dawley Rats Modelling Monogastrics.

The sub-saharan livestock feed industry depends on imported soyabean meal (SBM) as a dietary protein source in feeds thus making livestock production costly. This calls for the search and development of local dietary protein sources. Using Sprague Dawley rats to model monogastric animals, this study evaluated the potential of Ximenia caffra kernel meal (XCKM) to substitute SBM as a dietary protein source in feeds. Five diets were formulated wherein XCKM replaced SBM on a crude protein basis at 0, 25, 50, 75 and 100%. In the digestibility trial, 20 adult male SD rats were randomly assigned to the 5 diets. After a 12-day adaptation period feed and nutrient intake, faeces and urine output were determined over a 5-day collection period. Apparent Total Tract Digestibility (ATTD) of nutrients and nitrogen absorption and retention were determined. In the growth trial, 40 weanling male SD rats were randomly assigned to the five dietary treatments and fed for 38 days. The rats were weighed twice weekly. Following euthanasia, gastrointestinal viscera were harvested and their macro-morphometry determined. Linear growth was determined from tibiae and femora indices. In adult rats dietary XCKM had no (p>0.05) effect on ATTD of nutrients. At 100% substitution of SBM, XCKM increased (p<0.05) faecal nitrogen loss while at 75% substitution level it increased (p<0.05) nitrogen retention. In growing SD rats, although dietary XCKM had no effect (p>0.05) on the terminal body and empty carcass mass and viscera macro-morphometry, at 100% SBM substitution, it significantly compromised (p<0.05) body mass gain and average daily gain. Femora and tibiae mass and seed or index significantly decreased (p<0.05) with increased dietary XCKM. The XCKM could replace SBM as a dietary protein source in adult SD rat feeds without compromising ATTD digestibility of nutrients and nitrogen utilization thus it could be speculated that XCKM can be utilized as a dietary protein source in feeds of mature monogastrics. Caution must be exercised in using XCKM in grower rat diets as its use at higher inclusion levels compromised growth performance and long bone health.

Nutritional value of detoxified Jatropha curcas seed cake protein isolates using rats as an animal model.

A bioassay study was conducted to investigate the effects of substituting casein with graded levels of detoxified Jatropha curcas seed cake protein isolates (JPI) as a protein source on the growth performance, feed efficiency ratio (FER) and its protein values using rats as an animal model. Thirty 21-day-old male Sprague–Dawley weaned rats were randomly divided into 5 groups, each group with 6 replications (n = 1). Each group consumed one of the following diets: protein-free, casein (CAS) and JPI diets (JPI20, JPI40 and JPI60; different levels of JPI to replace the casein at concentrations of 20%, 40% and 60% on crude protein basis). Feed intake and protein intake showed no difference among the rats fed JPI20, JPI40 and CAS diets (P > 0.05). However, these parameters were lower in the rats fed JPI60 than in rats fed CAS (P < 0.05). The rats fed diets containing JPI had lower body weight gain, protein efficiency ratio and net protein retention than those fed CAS diet (P < 0.05). When the level of JPI used to replace the casein was lower than 40%, protein efficiency ratio (PER) was close to or higher than 2.0, which suggests that JPI could be viewed as a high-quality protein. Inclusion of JPI in the diet decreased alkaline phosphatase activity. The values were significantly lower in rats fed JPI20 and JPI40 than in rats fed CAS (P < 0.05). No histopathological changes were observed in livers and kidneys in the rats fed JPI diets. The results demonstrate that JPI could be used as an efficient protein source at a level of no more than 40% of dietary protein source.

Investigating Common Carp (Cyprinus carpio) as a Novel Feed Ingredient for Diets of Farmed Carnivorous Fish

Over 60% of natural fish stocks are either fully‐exploited or overexploited. This declining productivity has led to the rapid growth of the aquaculture industry, or the farming of fish. All fish require a certain level of protein from marine sources, most often provided in the form of fishmeal. Fishmeal is produced using species from the low end of the food chain, such as menhaden or sardine, which usually have low market value. Carnivorous species, such as salmon and trout, are particularly popular in Western markets, but also demand relatively more wild inputs than omnivores/herbivores. While species of the latter, such as carp and catfish, are popular in Asia, they maintain low commercial value in North America. Carp was thus investigated as a source of fishmeal for the growth of a carnivorous species, Rainbow Trout (Oncorhynchus mykiss). Fish were grown in three separate treatment groups, each being fed either a commercial sinking pellet, a unique pellet with commercial herring meal, or a unique pellet with carp meal. Upon determination of crude protein and energy content of the carp meal, diets were balanced on a crude protein and digestible energy basis. Pellets were made using a meat grinder. Trout were fed pellets with an increasing carp meal:herring meal ratio, and palatabilty was determined using the amount of pellets consumed (g) per mean mass of rainbow trout group (g).