Dietary Crude Protein Research Articles

Effect of Temperature and Humidity on Milk Urea Nitrogen Concentration.

This study investigated the effect of ambient temperature and humidity on milk urea nitrogen (MUN) concentration in Holstein cows. Meteorological data corresponding to the dates of milk sampling were collected over six years. A linear mixed-effects model including a random effect term for cow identification was used to assess whether temperature and humidity were predictive of MUN concentration. Age, days in milk, temperature humidity index (THI), ration, milk yield, parity and somatic cell count were also evaluated as main effects in the model. A general linear model including all variables as random effects was then fitted to assess the contribution of each variable towards the variability in MUN concentration. Maximum daily temperature and humidity on the sampling day were positively associated with MUN concentration, but their interaction term was negatively associated, indicating that their effects were not independent and additive. Variables that contributed the most to the variability of MUN concentration were dietary crude protein (21%), temperature (18%) and other factors (24%) that were not assessed in the model (error term). Temperature has a significant influence on urea nitrogen concentration and should therefore always be considered when urea nitrogen concentration data are used to make inferences about the dietary management of dairy cows.

Reducing dietary crude protein in broiler diets positively affects litter quality without compromising growth performance whereas a reduction in dietary electrolyte balance further improves litter quality but worsens feed efficiency

Reducing crude protein (CP) in broiler feed is a nutritional strategy that allows to partially reduce dietary soybean meal (SBM) inclusions to reduce feed costs, with proven benefits. In addition, reduction of dietary CP leads to a lower dietary electrolyte balance (dEB) due to the concomitant reduction of potassium (K). The aim of the present study is therefore two-fold: 1) to evaluate the potential of reduction of dietary CP until performance drops (1, 2 or 3 % points of reduction) and 2) to combine it with a reduction of dEB (by reducing dietary K) to validate the benefit of reduced dEB/K on litter quality without compromising performance. In total, 9100 male Ross 308 chicks were randomly allotted to 35 pens of 260 broilers. They were fed 5 dietary treatments from 10 to 20d and 20–30d.There was a “positive control” diet (CONTROL; 20.7 % CP in grower, 19.5 % CP in finisher) and 3 levels of dietary CP reduction by 1 % (CP-1 %), 2% (CP-2 %) and 3 % (CP-3 %), all diets formulated to respect at least the ideal AA profile for indispensable AA. In addition, an extra diet called “negative control” (NC CP-3 %) was formulated to have the same ingredient composition as the CP-3 % diet but with lower K and dEB level. Reducing dietary CP as low as 3 % points and maintaining AA and dEB levels resulted in similar or better production performance from 10 to 30d for weight gain, feed intake, feed conversion ratio (FCR) and carcass traits, reduced daily water intake and water-to-feed ratio, excreta N and moisture as well as lower litter moisture and footpad lesions (FPL). Reducing dEB level at − 3 % CP (negative control) increased feed intake and FCR but reduced water intake, water-to-feed ratio, and FPL. It is therefore possible to feed broilers with lower CP diets without compromising performance, with clear benefit on litter quality. As reducing dietary CP is often associated to reduced dietary K, due to lower SBM inclusion, the extent of reduction of K and the control of dEB by Na, Cl and K need to be further explored, especially on litter quality, to facilitate the adoption of low protein diets in practice.

Effect of Reduced Crude Protein Level on Fecal Nitrogen Excretion and Blood Profile in Finishing Pigs

The purpose of this experiment was to evaluate the effects of a low-protein diet on the selected variables of protein and energy metabolism in the blood serum as well as on the indicators of fermentation in the faeces (fecal crude protein, ammonia, pH, volatile fatty acids, and dry matter). Twelve finishing pigs (initial body weight: 64.6 ± 3.35 kg) were randomly divided into two groups and fed basal diets with crude protein (CP) levels of 13.6% and 15.4%, respectively. The Lysine, Methionine, Threonine, and Tryptophan levels in the 13.6% CP group were the same as those in the 15.4% CP group after the addition of four crystalline amino acids—Lysine, Methionine, Threonine, and Tryptophan to the diet. The blood and faeces samples were taken from the cranial vena cava and from the rectum at the end of the study period (44 days). The results showed that with the decrease in dietary CP level from 15.4% to 13.6% (a decrease of 1.8%), the fecal crude protein, the fecal ammonia, as well as the blood urea level decreased in the experimental group compared to the control group (P< 0.05 and 0.01, respectively).

Effect of antibiotics and low-crude protein diets on growth performance, health, immune response, and fecal microbiota of growing pigs.

This study aimed to investigate the effects of diets with and without antibiotics supplementation and diets with 18.5% and 13.0% crude protein (CP) on growth performance, carcass characteristics, disease incidence, fecal microbiota, immune response, and antioxidant capacity of growing pigs. One hundred and eighty pigs (59-day-old; 18.5 ± 2.5 kg) were distributed in a randomized complete block design in a 2 × 2 factorial arrangement, nine replicates, and five pigs per pen. The factors were CP (18.5% or 13.0%) and antibiotics (none or 100 mg/kg tiamulin + 506 mg/kg oxytetracycline). Medicated diets were fed from days 59 to 73. After that, all pigs were fed their respective CP diets from 73 to 87 days. Data were analyzed using the Mixed procedure in SAS version 9.4. From days 59 to 73, pigs fed antibiotics diets had higher (P < 0.05) average daily feed intake (ADFI), average daily weight gain (ADG), gain to feed ratio (G:F), compared to the diets without antibiotics. From days 73 to 87 (postmedicated period), any previous supplementation of antibiotics did not affect pig growth performance. Overall (days 59 to 87), pigs-fed antibiotics diets had higher (P < 0.05) G:F compared to pigs-fed diets without antibiotics. In all periods evaluated, pigs fed 18.5% CP diets had higher (P < 0.05) ADG and G:F compared to pigs fed 13.0% CP. Pigs fed the 13.0% CP diets had lower (P < 0.05) fecal score and diarrhea incidence than those fed 18.5% CP. Pigs fed 18.5% CP diets had improved (P < 0.05) loin area compared to pigs-fed diets with 13.0% CP. At 66 days of age, pigs-fed antibiotics diets had lower (P < 0.05) alpha diversity estimated with Shannon and Simpson compared to the pig-fed diets without antibiotics. At family level, pigs fed 18.5% CP diets had higher (P < 0.05) relative abundance of Streptococcaceae, and lower (P < 0.05) relative abundance of Clostridiaceae at days 66 and 87 compared with pigs fed 13.0% CP. Pigs-fed antibiotics diets had lower (P < 0.05) immunoglobulin G and protein carbonyl concentrations at day 66 compared to the pigs-fed diets without antibiotics. The reduction of dietary CP from 18.5% to 13.0% reduced the growth performance and loin muscle area of growing pigs, although it was effective to reduce diarrhea incidence. Antibiotics improved growth performance, lowered diarrhea incidence, improved components of the humoral immune response, and reduced microbiota diversity. However, in the postmedicated period, we found no residual effect on the general health of the animals, and considering the overall period, only G:F was improved by the use of antibiotics.

Effects of dietary protein content and crystalline amino acid supplementation patterns in low protein diets on intestinal bacteria and their metabolites in weaned pigs raised under Different sanitary conditions.

The objective of this experiment was to investigate the effects of dietary crude protein (CP) content and crystalline amino acids (CAA) supplementation patterns in low CP (LCP) diets on intestinal bacteria and their metabolites in weaned pigs raised under clean (CSC) or unclean sanitary conditions (USC). One hundred forty-four piglets (6.35 ± 0.63 kg) were assigned to one of six treatments in a 3 × 2 factorial arrangement based on CP content and sanitary conditions in a randomized complete block design to give eight replicates with three pigs per pen over a 21-d period. Diets consisted of a high CP (HCP; 21%) and two LCP (18%) diets supplemented with 9 CAA (Lys, Met, Thr, Trp, Val, Ile, Leu, His, and Phe) or only six CAA (Lys, Met, Thr, Trp, Val, and Ile) to meet the requirements. The CSC room was washed weekly, whereas the USC room had sow manure spread in the pens from the beginning of the study and was not washed throughout the experiment. Jejunum and colon digesta were sampled on day 21. Both jejunum and colon digesta were analyzed for ammonia nitrogen, short-chain fatty acids, and biogenic amines but only colon digesta was analyzed for microbiome composition (16s rRNA sequencing on MiSeq). Data were analyzed using R software for 16S rRNA and the MIXED procedure of SAS for microbial metabolites. Sanitation, CP content, and CAA supplementation patterns did not affect the diversity of colonic bacterial composition in weaned pigs. Pigs raised under USC had greater (P < 0.05) jejunal ammonia nitrogen concentration than those raised under CSC. Pigs fed LCP diets had reduced (P < 0.05) jejunal ammonia nitrogen concentration compared to those fed the HCP diet. Interactions between sanitation and dietary CP content were observed (P < 0.05) for: (1) jejunal acetate and (2) colonic spermidine and spermine, whereby (1) acetate concentrations decreased from NCP to LCP in pigs raised under the CSC but those concentrations increased under the USC, and (2) spermidine and spermine concentrations increased in LCP diets compared to HCP diet under USC, unlike CSC which did not show any difference between HCP and LCP. In conclusion, reducing dietary CP lowered ammonia nitrogen content regardless of sanitation and increased microbial metabolites in weaned pigs raised under USC. However, LCP diets with different CAA supplementation patterns did not affect bacterial diversity in weaned pigs, regardless of the hygienic conditions where the animals were housed.

Meta-analysis of the relationship between dietary condensed tannins and methane emissions by cattle

Using condensed tannins (CT) in ruminant nutrition yields many benefits, especially regarding better dietary protein utilization and decreased methane (CH4) emission by altering ruminal fermentation kinetics. A meta-analysis was conducted to develop and analyze a database from published studies and verify the effects of CT inclusion on enteric CH4 emission by cattle, nutrient digestibility and ruminal parameters, and their interactions. The study aimed to develop regression equations based on the significant components and their interactions to target a specific ruminal CH4 mitigation when correctly associating CT inclusion level and diet composition. A database was developed from 40 published studies that measured cattle CH4 emission using in vitro or in vivo methods and reported the source and inclusion levels of CT as well as typical diet characteristics, including crude protein (CP), organic matter (OM), neutral detergent fiber (NDF), and ether extract (EE). Other related parameters were also included in the database when reported, such as dry matter intake (DMI) and digestibility, OM digestibility, NDF digestibility, and ruminal parameters, including pH, ruminal ammonia nitrogen, total volatile fatty acids (VFA), acetate, propionate, butyrate, and the acetate-to-propionate ratio. The meta-analysis was conducted by multiple linear regression, using the nlme package of R 4.2.1, in which studies were assumed as random variables affecting the intercept and slopes. The CH4 emission, expressed in L/kg of DMI, decreased with increasing levels of dietary CT when in vitro and in vivo were analyzed together (P < 0.001) or in vivo alone (P < 0.001). Total VFA concentration (P = 0.049), propionate (P = 0.042), and butyrate (P = 0.047) increased with increasing levels of dietary CT on in vitro + in vivo methods, suggesting improved fermentability. When analyzing all chemical components of the diet, OM (P = 0.043) and CP (P = 0.010) decreased CH4 production with in vitro methods, EE decreased CH4 production on in vivo method (P = 0.001), while dietary NDF increased CH4 production on in vitro + in vivo (P = 0.016), and also separately for in vivo (P = 0.058) and in vitro method (P = 0.022). There was an interaction between CT and CP for in vivo experiments (P = 0.010): CH4 = 35.64 – 6.87 ×CT – 0.49 ×CP + 0.33 ×CT*CP. Across many experiments, increasing the level of dietary CT led to a decrease in ruminal CH4 concentrations for in vitro and in vivo fermentation conditions and an increase in molar proportions of propionate, butyrate, and total VFA, indicating that it is an efficient natural alternative to reduce environmental impacts of ruminant production systems possibly. Our meta-analysis identified diet components that significantly affect enteric CH4 emissions by cattle and developed a prediction model based on these components, including OM, CP, NDF, and EE. The in vivo CH4 method showed that an interaction between CT and CP diet content affects CH4 emissions. Future research and meta-analysis must focus on CT biological activity along with percent content to dictate ideal diet inclusion to suppress CH4 emissions without depressing animal performance.

The effect of supplementation of essential amino acid combinations in a low crude protein diet on growth performance in weanling pigs.

The present study investigated the impact of providing different supplemental essential amino acids (EAA) in a low crude protein (CP) diet on growth performance in weanling pigs. A total of 324 mixed-sex 24-d weaned piglets (initial BW 6.9 ± 0.34 kg) were used in a 27-d growth trial with six dietary treatments immediately post-weaning. The first two treatments were a control standard CP (19%) diet (positive control; PC) and a negative control (NC) diet with low CP (16%) and reduced Ile, Leu, and histidine levels. The rest of the treatments had low CP with varied EAA types and levels; T1 had similar Ile, Leu, and His levels as PC but with low CP (16%), while T2 had low CP and 10% higher His, Thr, Trp, and Met+Cys compared to PC. The T3 was a low CP diet with 10% supplemental Leu, Ile, and Val compared to PC, while T4 was a low CP diet with 10% supplementation with all the EAA except Lys compared to PC. The initial body weight (BW) was not statistically different (P > 0.05) among the treatments. Also, on d 6, no statistical differences in BW were observed among the treatments. The average BW recorded on d 13, 20, and 27 showed significant treatment differences where the PC had consistently higher BW than all the other treatments (P < 0.05). The average daily gain (ADG) of the PC was higher than the rest of the treatments. Between d 13 and 20, the average daily feed intake (ADFI) for PC was not different from NC and T1 (P > 0.05), but compared to T2, T3, and T4, the PC treatment showed a high ADFI (P < 0.05). Overall (d 0-27), the ADFI for PC was not different from T1 and was significantly higher than all other treatments. Overall, results showed that the gain to feed (G:F) ratio was higher (P < 0.05) for PC compared to other dietary treatments. In summary, although the treatments (T1-T4) consisted of varying levels of EAA above the recommended requirement levels for optimal performance, we did not see a significant impact on growth performance improvement, which may indicate that the targeted EAA (His, Val, Thr, lle, Leu, Trp, and Met) may not have been limiting in these diets. On the other hand, the phenylalanine (Phe) requirement may be limited in the current formulations, or perhaps the EAA: total N ratio in T1, T2, T3, and T4 may have been too high, resulting in the inefficiency of EAA utilization for growth.

Effects of crude protein and neutral detergent fiber percentages in the diet of Japanese Black steers on rumen fluid properties, blood biochemical properties, and carcass characteristics.

The effects of crude protein (CP) and neutral detergent fiber (NDF) percentages in the diet of Japanese Black steers on rumen fluid properties, blood biochemical properties, and carcass characteristics were examined. Twelve 13-month-old Japanese Black steers were used for this study and slaughtered at 30 months of age. Steers were assigned to a control group (n = 6) and test group (n = 6) and were fed a concentrate containing 12.9%-13.9% CP and 26.5%-29.8% NDF or 9.1%-9.6% CP and 29.9%-31.2% NDF, respectively. Lipopolysaccharide activity levels in rumen fluid were lower in the test group than in the control group. Plasma urea nitrogen concentration and activities of aspartate aminotransferase and γ-glutamyltransferase remained lower in the test group than in the control group. In contrast, plasma vitamin A concentrations remained higher in the test group than in the control group. Carcass characteristics did not significantly differ between the two groups. These results suggest that dietary CP and NDF percentages in feed for Japanese Black steers older than 13 months of age affected rumen fluid properties and blood biochemical properties, indicating a reduced load on the liver with a small effect on carcass characteristics.

Effects of sustainable agronomic intensification in a forage production system of perennial grass and silage corn on nutritive value and predicted milk production of dairy cattle.

The objectives were to determine the effects of incrementally applied improved nutrient management, alternative cropping practices, and advanced production technologies in a dual forage system of perennial grass and silage corn on nutrient composition and in vitro ruminal fiber digestibility of the forages and, using these data as inputs into the Cornell Net Carbohydrate and Protein System, to predict milk production, indicators of nitrogen (N) utilization, and N excretion of dairy cattle. Farm management systems (farmlets) included a conventional system with whole manure slurry broadcast to a late maturing corn hybrid and grass harvested with 5 cuts per year (F1); improved nutrient management with a separated manure system where the sludge was applied to corn and the liquid was applied to grass (F2); improved nutrient management and alternative cropping practices with separated manure, an early maturing corn hybrid interseeded with a relay winter cover crop, and grass harvested with 3 cuts per year (F3); and improved nutrient management and alternative cropping practices combined with advanced production technologies that included irrigation and a nitrification inhibitor (F4). The field trial was a randomized complete block design over 2 yr with 4 blocks each divided into grass and corn, 4 subplots within each block for each crop, and 2 replicates within each subplot. Diets were formulation with 60% forage and 40% concentrate where the grass and corn as silage was proportional to yield for land allocations of grass and corn of 80:20, 60:40, 40:60, and 20:80. Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc.). The intensified management systems (F2, F3, and F4) increased the crude protein (CP) concentration of corn with no effects on starch concentration [32.1% dry matter (DM)] compared with the conventional system (F1). Decreasing cuts of grass from 5 to 3 reduced the CP concentration in the spring harvest (15.8% vs. 12.5% DM), and increased fiber concentration and reduced digestibility in the spring, summer, and fall harvests. A common concentrate was formulated for the conventional farmlet and then combined with the forages for each farmlet within each land allocation. Forages grown under intensified management to improve N capture increased the CP concentration of the diets. However, reducing the number of cuts of grass from 5 to 3, combined with the corn and relay crop to increase yield, reduced milk production across all land allocations. To complement the nutritive value of the forages grown under each management system and land allocation, the concentrates were reformulated, which reduced dietary CP, improved the indicators of N utilization (e.g., milk urea N and milk N efficiency), reduced N excretion, and improved milk yield with no differences among the farmlets. Increasing land allocated to corn supported higher milk yield at lower dietary CP concentrations (16.5% vs. 15.4% DM) with improved milk N efficiency and lower N excretion. Intensified agronomic management increased the CP of the combined forages decreasing the need for supplemental CP in the concentrate and could reduce the importation of feed N to the farm.

The Effects of Yucca Schidigera Extract and Multi-carbohydrase in Different Crude Protein Diets on Growth Performance, Nutrient Digestibility, Carcass Parameters and Excreta Noxious Gas Contents in Broilers

The scarcity and increase in the price of animal feeds have attracted the attention of nutritionists to address this issue. The inclusion of plant extracts and enzymes to protein-reduced diet could be a feasible strategy to reducing the feed cost. Therefore, the purpose of this study was to assess the impacts of Yucca schidigera extract and multi-carbohydrase in low crude protein (CP) diets of broiler on growth performance, nutrient digestibility, carcass metrics, and noxious gas levels in the excreta. A total of 480, 1-d-old ROSS 308 were randomly allocated into 4 dietary treatments, six replication, and 20 birds/cage. Phase 1, T1(CP 21%, ME 2,969 kcal/kg); T2 (CP 19%, ME 2,863 kcal/kg + 0.02% Yucca); T3 (CP 17%, ME 2,865 kcal/kg + 0.02% Yucca); T4 (CP 17%, ME 2,861 kcal/kg + 0.02% Yucca + 0.1% multi-carbohydrase). Phase 2, T1 (CP 19%, ME 3,086 kcal/kg); T2 (CP 17%, ME 2,977 kcal/kg + 0.02% Yucca); T3 (CP 15%, ME 2,978 kcal/kg + 0.02% Yucca); T4 (CP 15%, ME 2,978 kcal/kg + 0.02% Yucca + 0.1% 0.1% multi-carbohydrase). Although the addition of YS and multi-carbohydrase to the low CP diets on the growth performance did not improve, it revealed the positive result on the nutrient digestibility, carcass parameters, and noxious gas emission. Overall, broilers supplemented with YS 0.02% and multi-carbohydrase (0.1%) demonstrated the best production performances compared to the other treatment groups. Thus, a combination of YS and multi-carbohydrase could be added to the diets with low CP to boost broiler production performance.

Effects of Aspergillus oryzae prebiotic on dietary energy and nutrient digestibility of growing pigs.

The objective of this study was to determine the effects of Aspergillus oryzae prebiotic (AOP) on nutrient digestibility in growing pigs fed high-fiber diets. Eighteen growing barrows (initial body weight = 50.6 ± 4.9 kg) were surgically equipped with a T-cannula at the distal ileum. Corn and soybean meal-based diets were formulated with fiber from cereal grain byproducts corn (distillers dried grains with solubles, DDGS), rice (rice bran, RB), or wheat (wheat middlings, WM) to meet or exceed all nutrient requirements for 50 to 75 kg growing pigs. Three additional diets were formulated to contain 0.05% AOP supplemented at the expense of corn in the DDGS diet (DDGS + AOP), RB diet (RB + AOP), and WM diet (WM + AOP). All diets contained 0.5% of titanium dioxide as an indigestible marker. Pigs were allotted randomly to a triplicated 6 × 2 Youden square design with six diets and two successive periods. Ileal digesta and fecal samples were collected for 2 d after a 21-d adaptation period, and dry matter (DM), gross energy (GE), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), and ash were analyzed to calculate apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD). Standardized ileal digestibility (SID) of amino acids (AA) was calculated by correcting AID with basal endogenous AA losses from the same set of pigs. Pigs fed the DDGS+AOP diet had greater (P < 0.05) AID of EE compared with those fed the DDGS diet. However, supplementation of AOP did not (P > 0.05) affect AID of GE, DM, CP, NDF, ash or SID of AA of any high-fiber diet. Supplementation of 0.05% AOP increased (P < 0.05) ATTD of DM, GE, CP, NDF, and ash in DDGS, RB, and WM diets. Diet digestible energy was 35 kcal/kg greater (P < 0.05) in pigs fed AOP supplemented diets compared with those fed diets without AOP. In conclusion, supplementation of AOP increased ATTD of nutrients and energy value in high-fiber diets containing DDGS, RB, or WM.

Effects of feeding fodder beet or kale in winter to dams and their heifer offspring on the heifer growth and production

Context Fodder beet (FB) is a widely used winter feed in New Zealand’s southern regions due to its high yield, consistent quality, and environmental benefits. However, FB is low in crude protein, phosphorus and fibre, and a survey showed that many dairy farmers were concerned that feeding FB may have negative impacts on lifetime performance. Aim To determine whether winter feeding FB or kale (Ka) to dairy cows, and then their heifer offspring at 1 and 2 years old, affects the heifer performance from birth until the end of their first lactation. Methods In June–August 2017, pregnant dairy cows were fed FB or kale over winter and then 140 of the resultant heifer offspring were divided into four treatment groups at 9–11 months old according to their dam’s winter diet and offered either FB or kale, with pasture baleage. The groups were as follows (dam crop–heifer crop): FB–FB, FB–Ka, Ka–FB, Ka–Ka. The heifers’ subsequent performance (growth, stature, milk production, and reproduction) was measured to the end of their first lactation (May 2020), and blood mineral status was monitored from May 2018 to May 2019. This observational study has its limitations, but is useful for generating hypotheses to test in more controlled research. Key results Heifers grazing FB in winter (June–August) 2018 had lower blood plasma urea and phosphate concentrations than did heifers grazing kale, despite similar dietary crude protein contents. Treatments had no effect on milk production. However, the heifer liveweights were affected and there was an indication of poorer reproductive performance. The FB–FB heifer treatment group had a lower average liveweight than the FB–Ka heifers from 1 to 2.8 years old. Conclusions Although no impact on milk production for the first lactation was observed, the key results suggest possible negative impacts of feeding heifers FB during winter, particularly if their dam also wintered on FB. Implications The combined effects of FB dam and heifer winter diets on lifetime productivity warrant further investigation to help develop sustainable FB feeding systems. When feeding FB, we recommend that farmers test their crops and supplements to ensure that sufficient nutrition, in particular protein and phosphorus are provided.

Effect of level of metabolizable energy on the breast and wing weight of local chickens: A meta-analysis

The purposed of this study was to determine the effect of dietary energy and protein balance on the wing weight and breast weight of native chicken using meta-analysis technique. This study used meta-analysis technique to integrate 116 data from 8 articles that contain information about effect of energy and protein balance rations on wings weight and breast weight of local chicken. The meta-analysis technique begins with collecting data from several scientific publications that contain energy and protein levels. The data was tabulated in the form of database with the help of Microsoft excel and in this tabulation process the units of each data were equalized tabulated and analysed using SAS. The results of this study concluded that it took 17.04% of dietary crude protein to produce a minimum breast weight of 151.96grams and 2953.31 kcal/kg to produce 122.66grams of breast weight, as well as 17.43% of raw proteins to make a minimum wing weight of 88.25gram and 2970 kcal / kg to produce an 89.53gram of wing. In conclusion protein requirements and energy metabolism, each pile showed varying results. The existence of this diversity is influenced by genetic and environmental factors.

Growth performance and carcass traits of indigenous Nigerian guinea fowl fed on different dietary protein levels.

This work examined the results of different dietary protein levels on indigenous Nigerian guinea fowl growth performance and carcass yield. One hundred and eight unsexed indigenous keets were randomly assigned to three treatments with experimental diets containing 22%, 24%, and 26% crude protein (CP) in a completely randomized design, with 3 replicates with 12 keets in each replicate. The parameters were measured, including proximate composition, feed intake, growth rate, feed conversion ratio (FCR), and carcass yield. The birds fed diets containing 24% CP gained the most body weight at 619.83 gm and had the highest FCR of 3.45. The presence of CP had an impact that was significant (p < 0.05) on most carcass traits and prime cuts but not on gastrointestinal tract weight, head weight, dress percentage, or organ yield. The study concluded that the dietary CP level of 24% was optimal for body weight gain and carcass yield.

Limiting amino acids supplementation in low crude protein diets and their impacts on growth performance and carcass composition in Labeo rohita (rohu) adult fish.

Ninety days study was conducted in hapas installed in earthen ponds. Fish of an average initial weight (220g) were evenly distributed in triplicate groups within fifteen hapas. Five experimental diets labeled as T1 (25% CP and NRC recommended amino acid level) as control diet, T2 (with 2% low protein and 5% amino acid supplementation), T3 (with 2% low protein and 10% amino acid supplementation), T4 (with 4% low protein and 10% amino acid supplementation) and T5 (with 4% low protein and 20% amino acid supplementation) were prepared. Fish were fed with @3% of their body weight twice a day at 10.00 & 16:00 hour. Significantly higher percent weight gain (420.18 ± 66.84a) and specific growth rate (13499.33±1273.54a) along with improved feed conversion ratio (1.29 ± 0.09b) and hundred percent survivals were recorded during the trial. Furthermore proximate analysis of meat showed significant improvement in the crude protein level (81.77 ± 0.19a) served with diet containing 20% limiting amino acids mixture. Therefore, limiting amino acids can be a source of cost effective feed and use safely in L. rohita diet.

Incaptive culturing of Goldfish and Koi carp in Punjab, Pakistan

This study observed the captive culture of Carassius auratus and Cyprinus carpio in the Potohar region, Punjab, Pakistan. Captive culturing of both species was conducted up to one-month post hatchlings. The sample size was 180 (90 goldfish and 90 koi carp) and kept in cemented raceways under optimum conditions. The study period was from October 2019 to April 2020. The natural breeding season for Carassius auratus and Cyprinus carpio was from 25th January to 5th February and the end of February to 11th March, respectively. The induced breeding duration for goldfish and koi carp was from 6th to 25th February and for koi carp from 12th to 30th March, respectively. For artificial breeding, the synthetic hormone Ovaprim C was injected intra-peritoneally at 0.5 ml/kg and 0.1 ml/kg body weight of females and males, respectively. Both the species were fed a 30% crude protein diet. Hydrilla plants were used for the adhesion of eggs. The female to male ratio was 2:3. Approximately 4500 to 5000 eggs of goldfish and 17000 to 18000 eggs of koi carp were laid. Fertilization, hatching, and survival rates observed for both were approximately 74%, 57% and 42.5%, respectively.

EFFECT OF PROBIOTIC SUPPLEMENTATION AND VARYING DIETARY PROTEIN LEVELS IN CREEP FEED ON GROWTH PERFORMANCE OF SALT RANGE LAMBS

Main aim of this work was to findout the influence of probiotic supplementation and suitable dietary protein level in creep feed for optimum growth performance of Salt Range lambs. Lambs (n ₌ 16; Age ₌ 30±10 days) were chosen and divided into four equal groups. Four dietary treatments; diet-1 (CP 18% with no probiotic), diet-2 (CP 18% with probiotic), diet-3 (CP 20% with noprobiotic) and diet-4 (CP 20% with probiotic) were randomly allocated to lambs under Completely Randomized Design. The raw data were analyzed through ANOVA technique using SAS 9.3 software. The growth performance was determined in terms of average daily gain, average daily feed intake, feed conversion ratio, feed cost per kg gain and blood parameters; hemoglobin, blood glucose, blood urea and blood cholesterol. Results indicated that average daily gain of lambs fed diets having 20% proteinwith and without probiotic supplementation are not different (P&gt;0.05), whereas average daily gain of lambs fed 20% protein was found higher (P&lt;0.05) than of those fed 18% protein with and without probiotic supplementation. Average daily feed intake was found higher (P&lt;0.05) in diet-3 than diet-2 but remained not different in animals fed diet-1 and diet-4. Lambs fed dietary protein 20 percent were found more efficient (P&lt;0.05) in terms of feed conversion ratio than that of 18 percent protein. Bloodparameters were found not different by various dietary treatments. It was inferred that creep feed with probiotic supplementation couldn’t influence growth but higher dietary crude protein 20% in creep feed improved growth performance of Salt Range lambs in pre-weaning phase.

Effect of age and dietary crude protein level on nitrogen excretion in Holstein bull calves

The aim of the present study was to investigate the effect of age and dietary crude protein (CP) level on nitrogen (N) excretion in Holstein bull calves. Thirty-six Danish Holstein bull calves were divided into 4 age groups; 12, 22, 32, and 42 weeks old (W12, W22, W32, and W42), respectively, with 9 animals per group. Within age group, calves were blocked in groups of 3 according to age and weight, and randomly assigned to the dietary treatments in a 3 × 3 Latin square design. The dietary treatments consisted of 4 diets in total, with CP concentrations of 10.9, 14.1, 16.9, and 20.2%, of which the 3 diets with the highest CP concentrations (i.e. 14.1, 16.9, and 20.2%) were provided to W12 and W22 calves, whereas the 3 diets with the lowest CP concentrations (i.e. 10.9, 14.1, and 16.9%) were provided to W32 and W42 calves. The experiment was divided into 3 periods, all lasting for 2 weeks in which the first 11 days were used as adaptation, while the last 3 days were used for sampling and recording. Feed and water intake were recorded daily, and feces and urine samples were collected and analyzed for chemical composition. Intake of DM increased for all age groups with greater dietary CP level (P < 0.01), and was greatest in the oldest bull calves (P < 0.01). Urinary N excretion was positively correlated with N intake (P < 0.01) and age of the calves (P < 0.01). Fecal output of N increased with increasing dietary CP level (P = 0.05), but might mainly be explained by the greater feed intake observed with increasing CP level in the diet. When increasing the dietary CP level, the proportion of N intake excreted in urine increased (P < 0.01), whereas the proportion of N intake excreted in feces decreased (P < 0.01). In addition, the proportion of N intake excreted in urine was greatest in the oldest bull calves (P < 0.01). Furthermore, simple prediction equations for N excretion in urine and feces, respectively, were established and considered reliable proxies for N excretion in Holstein bull calves for application on farm.

In Vitro Rumen Fermentation and Post-Ruminal Digestibility of Sorghum-Soybean Forage as Affected by Ensiling Length, Storage Temperature, and Its Interactions with Crude Protein Levels.

The study aimed to evaluate the effects of ensiling length, storage temperature, and its interaction with crude protein (CP) levels in sorghum−soybean forage mixtures on in vitro rumen fermentation and post-ruminal digestibility of nutrients. The dietary treatments consisted of fresh forages (d 0) and silages of sorghum and soybean stored indoors or outdoors for 75 and 180 d with additional ingredients to make two dietary CP levels, 90 and 130 g/kg dry matter (DM) and a forage-to-concentrate ratio of 80 to 20. An in vitro procedure was conducted using the ANKOM RF technique to study rumen fermentation. The dietary treatments were incubated in duplicate for 8 and 24 h in three runs. After each incubation time, in vitro rumen fermentation parameters were measured, and the protozoa population was counted using a microscope. Post-ruminal digestibility was determined using the pepsin and pancreatic solubility procedure. Cumulative gas production (GP) increased quadratically with ensiling length (8 h, p < 0.01; 24 h, p = 0.02), and the GP differed between CP levels at both incubation times (p < 0.01). However, total short-chain fatty acid (SCFA) concentrations in rumen inoculum increased quadratically with ensiling length (p < 0.01; for both incubation times), and interaction between ensiling length and CP levels was observed in proportions of acetate and propionate after 24 h of incubation (p < 0.01; for both incubation times). Similarly, an interaction between ensiling length and CP levels was found in the proportion of valerate after 24 h of incubation (p < 0.01). There was a quadratic response to ensiling length in the NH4−N concentration after 8 h (p < 0.01) and 24 h (p < 0.05), and the CP level also differed (p < 0.01) at both incubation times. The ciliate protozoa count after 24 h was higher in low CP diets than in high CP diets (p = 0.04). The amount of CP in the undegraded substrate at both incubation times differed between CP levels (p < 0.01; for both incubation times). An interaction effect between ensiling length and storage temperature after 8 h (p = 0.02) and 24 h (p < 0.01) was observed for intestinal CP digestibility. The effect of CP levels on intestinal CP digestibility differed after 8 h (p < 0.01) and 24 h (p < 0.01). In conclusion, increasing ensiling length beyond 75 d reduced CP digestibility, and additional CP inclusion did not ameliorate this.

Production performance of Holstein cows at 4 stages of lactation fed 4 dietary crude protein concentrations.

Dairy cow responses to dietary crude protein (CP) may depend on stage of lactation. The primary objective of this study was to evaluate the effects of 4 concentrations of dietary CP on dry matter intake (DMI), production performance, net energy for lactation (NEL) output in milk, feed efficiency (FE: milk NEL/DMI), and nitrogen use efficiency (100 × milk protein-N/N intake) when fed to cows grouped as early, mid-early, mid-late, and late lactation. Our secondary objective was to determine the range of CP concentration at which production responses were not negatively affected across days in milk (DIM). Multiparous Holstein cows (n = 64) were stratified by DIM [initial average ± standard deviation: 86 ± 14.9 (early), 119 ± 10.0 (mid-early), 167 ± 22.2 (mid-late), and 239 ± 11.1 (late)] and then randomly assigned within DIM group to receive 1 of 4 total mixed rations containing 13.6, 15.2, 16.7, and 18.3% CP (dry matter basis) according to a 4 × 4 factorial arrangement of treatments. Cows were individually fed a covariate diet for 14 d, followed by 56 d of treatment diets. Milk yield and DMI were recorded daily and milk components were analyzed weekly for 2 consecutive days at 3 daily milkings. Data were analyzed using a categorical mixed-effect model to evaluate the effects of CP concentration and DIM using linear, quadratic, and cubic contrasts, and their interactions. Additionally, a mixed-effect cubic regression model was fit with DIM, dietary CP concentration, and their interaction as continuous independent variables. Dietary CP concentration deemed optimal across DIM was determined as the range of CP for which the dependent responses did not differ from the predicted maximum. With advancing stage of lactation, DMI, milk NEL output, and FE decreased linearly (from 30.4 to 28.4 kg/d for DMI, from 33.2 to 23.3 Mcal/d for NEL output, and from 1.09 to 0.82 Mcal milk NEL/kg DMI for FE for early and late lactation cows, respectively). Responses to dietary CP concentration were linear, quadratic, and cubic with the greatest values observed when cows were fed the 16.7% CP diet across DIM (30.8 kg/d, 31.0 Mcal/d, and 1.01 Mcal/kg for DMI, milk NEL output, and FE, respectively). There was an interaction between dietary CP concentration and stage of lactation for DMI, milk NEL output, milk component yield, and FE, which was due to the decline in response to additional CP as lactation progressed. Compared with the 16.7% CP diet, feeding the 18.3% CP diet decreased milk NEL 0.81 and 5.3 Mcal/d for early and late lactation cows, respectively, indicating that feeding a higher CP concentration in late lactation had a negative effect on cow performance. Nitrogen use efficiency declined linearly with increasing CP concentration and DIM. Regression analysis suggested that dietary CP ranging from 16.3 to 17.4% maintained production in early and mid-early lactation. However, dietary CP could be reduced to between 15.7 and 17.1% in late lactation. This research suggested that there are distinct ranges of dietary CP concentrations that maintain cow performance at each stage of lactation.