Increase In Crude Protein Content Research Articles

Connection of protein and amino acid content of forage and medium quality winter wheat varieties

We analysed the crude protein content, amino acid content, amino acid composition of four forage and milling III. quality winter wheat varieties (Magor, Hunor, Róna and Kondor) from their samples from five following years (2003, 2004, 2005, 2006, 2007). We found that quantity of essential and non-essential amino acids rose with increase in crude protein content. On examination of protein amino acid composition in relation to crude protein content we found that the crude protein content increased the quantities of the non-essential amino acids also rose, while those of the essential amino acids decreased as the lysine, the limiting amino acid of wheat. We also established that, as crude protein content increased, the biological value of the protein decreased.

Connection of crude protein content and amino acid content of forage and medium quality winter wheat varieties in the relation of quantity and quality

We analysed the crude protein content, amino acid content, amino acid composition of four forage and milling III. quality winter wheat varieties (Magor, Hunor, Róna and Kondor) from their samples from five following years (2003, 2004, 2005, 2006, 2007). We found that quantity of essential and non-essential amino acids rose with increase in crude protein content. On examination of protein amino acid composition in relation to crude protein content we found that the crude protein content increased the quantities of the non-essential amino acids also rose, while those of the essential amino acids decreased as the lysine, the limiting amino acid of wheat. We also established that, as crude protein content increased, the biological value of the protein decreased.

Processing Effects on the Nutritional and Anti-Nutritional Contents of African Locust Bean (Parkia biglobosa Benth.) Seed

2 Abstract: African locust bean (Parkia biglobosa Benth.) seeds with thin layers of pulp material were processed by soaking in water for 12 h, washing to depulp the seeds and boiling in water for 8 h to dehull the seeds. The dehulled seeds were boiled again for 30 min to produce the processed substrate which were fermented for 72 h. Mechanically dehulled bean seeds were obtained from depulped bean seeds with a pair of pliers. Proximate compositions of the samples were determined for crude protein, ether extract, ash and total carbohydrate content. The presence and levels of trypsin inhibitors, tannin and phytic acid were determined. Fermentation gave rise to significant increase in crude protein content. The ether extract was significantly increased by soaking and boiling, this was further increased by fermentation at 72 h. The ash content decreased significantly by soaking and boiling. Also the total carbohydrate content decreased significantly by soaking and boiling, this was further decreased by fermentation at 72 h. In all the anti- nutritional factors evaluated, soaking and boiling significantly reduced the levels of anti-nutritional factors, fermentation at 72 h led to further reduction in the levels of anti-nutritional factors. The reduction in content of trypsin inhibitors activity at 72 h fermentation was greater than the other anti-nutritional factors with a total reduction level of 89.0%.

Effect of Fermentation, Malt-Pretreatment and Cooking on Antinutritional Factors and Protein Digestibility of Sorghum Cultivars

Two sorghum cultivars namely, Mugud (low tannin) and Karamaka (high tannin) were used in this study. The flour of the seeds of both cultivars was mixed with 5% malt. Then the flour with or without malt was fermented for 16 h. Samples were taken every 2 h during fermentation to study changes in pH, total acidity, crude protein and dry matter. Fermentation of the flour with or without malt resulted in an increase in crude protein content and total acidity for both cultivars. Moreover, the fermented flour with or without malt was cooked to study changes in phytate, tannins and in vitro protein digestibility of the cultivars. A highly significant (P < 0.05) reduction in antinutritional factors (phytate and tannins) was observed for malted and fermented flour compared to the fermented dough. Cooking significantly (P < 0.05) reduced the in vitro protein digestibility of the treated cultivars but the extent of the reduction is lower in malted samples. Fermentation alleviates the adverse effect of cooking on sorghum protein digestibility after addition of malt. Results obtained revealed that addition of malt followed by fermentation is a useful method to improve the nutritional value of sorghum even after cooking.

Effect of second pond dairy effluent applied in spring to silage regrowth of perennial ryegrass based pasture in southern Australia. 2. Changes in nutritive characteristics and mineral content

The 2-pond effluent systems used by the majority of dairy farmers in southern Australia result in the collection of liquid effluent in an aerobic second pond. This liquid effluent contains a wide range of nutrients that have the potential to significantly affect the nutritive characteristics and mineral content of forages. The effect of applying second pond dairy effluent to perennial ryegrass based pasture following harvesting for silage over a 3-year period was measured. Effluent was applied at 6 rates: 0, 15, 30, 45, 60, and 75 mm following a spring silage harvest each year, with changes to nutritive characteristics and mineral content determined at each subsequent grazing. Analysis of the effluent applied showed that on average, over the 3 years of application, the effluent contained 31, 454, 20, and 149 kg/ML of phosphorus (P), potassium (K), sulfur, and nitrogen, respectively. In addition, the effluent contained 152 kg/ML of calcium (Ca) and 225 kg/ML of magnesium (Mg). Changes in nutritive characteristics as a result of effluent application were primarily restricted to the first grazing after application. The metabolisable energy content of herbage at the first grazing in Years 1 and 2 was unaffected by effluent application; however, in Year 3 there was a linear increase of 0.0051 MJ/kg dry matter (DM).mm of applied effluent. In contrast, effluent application had a positive linear effect on pasture crude protein (CP) content at the first grazing in all years. In Year 1, CP content increased by 0.083%/mm of applied effluent, while for Years 2 and 3 the increases in CP content were 0.044 and 0.029%, respectively. In all years, there was a negative linear effect on water-soluble carbohydrate content at the first grazing after effluent application. For Years 1, 2, and 3, responses were –0.138, –0.066, and –0.022%/mm applied effluent, respectively. The P content of pasture was higher at the first grazing following effluent application at rates of 60 and 75 mm in each year compared with the control and the 15 mm application rate. Potassium concentrations were increased with effluent application at rates of 45, 60, and 75 mm in all 3 years in comparison with the control at the first and second grazing after application. In Year 1, Mg content of the pasture was lower for the control, 15, and 30 mm treatments than for the 2 highest application rates at the first grazing after application. This experiment has highlighted the potential of using second pond dairy effluent following pasture harvesting for silage to maintain the CP content of pasture in late spring. The high mineral content of effluent led to increases in the concentration of several these minerals and, while the ratio of K to (Ca + Mg) was substantially increased, it is unlikely that effluent application in late spring and the concomitant increases would lead to animal metabolic problems. Coupled with the observed increases in DM yield, the increase in CP content provides greater flexibility in feeding options to bridge feed shortfalls before summer forage crops becoming available on dryland dairy farms in southern Australia.

Effect of second-pond dairy effluent on turnip dry matter yield, nutritive characteristics, and mineral content

Dairy farms in southern Australia generally use a 2-pond system to manage dairy shed effluent. This system consists of a deep anaerobic first pond and a shallow aerobic second pond. The liquid in the second pond contains a range of nutrients that may have agronomic benefits for forages. The effect of applying second-pond dairy effluent to a summer turnip (Brassica rapa L.) crop over 3 consecutive summer periods was measured. Effluent was applied at 6 rates, 0, 15, 30, 45, 60, and 75 mm, approximately 6–8 weeks after turnips were sown each year. Turnips were assessed for dry matter (DM) accumulation, nutritive characteristics, and mineral content. In addition, total annual production for years 1 and 2 was calculated by including the DM accumulation from annual ryegrass grown from autumn to spring each year. Concentrations of nutrients within the effluent as an average over the 3 years were 31, 454, 20, and 149 kg/ML for phosphorus (P), potassium (K), sulfur (S), and nitrogen (N), respectively. In addition, effluent also contained 152 kg/ML of calcium (Ca), 225 kg/ML of magnesium (Mg), and 529 kg/ML of sodium (Na). Soil pH was generally unaffected with effluent application, while soil EC and total soluble salt (TSS) content increased with effluent addition. In the first year, application of effluent at 15 mm and higher resulted in increases in available K; however, in subsequent years, rates of 45 mm and higher led to an increase in available K, while for the control and lower effluent rates there was a marked decline in K status. In all years there was a linear increase (P &lt; 0.05) in leaf, root, and total DM yields with applied effluent. For leaf, responses were 19, 50, and 26 kg DM per mm applied effluent and for roots, 10, 39, and 25 kg DM per mm applied effluent for years 1, 2, and 3, respectively. In years 2 and 3, turnip leaf crude protein (CP) content increased (P &lt; 0.05) in a linear manner at rates of 0.046 and 0.044% per mm applied effluent, respectively. There was also a linear increase (P &lt; 0.05) in turnip root CP in years 2 and 3 of 0.033 and 0.021% per mm applied effluent, respectively. In all years there was a linear increase (P &lt; 0.05) in leaf K content, while for root K there was a quadratic trend (P &lt; 0.05) for year 1 and a linear increase (P &lt; 0.05) for years 2 and 3. The results from this study indicate that the use of dairy effluent can increase DM yield and improve the nutritive value of turnips through an increase in CP content. The data also indicate that this effect can be maintained over consecutive years, which in turn may provide greater flexibility for returning effluent to farm land. While results appear to indicate that the primary responses are due to N, further work is required to determine the effects of water and other nutrients within dairy effluent.

The effect of concentrate crude protein content and feeding strategy of total mixed ration on performance of primiparous dairy cows

The effect of total mixed ration (TMR) with constant (TMR1) or decreasing (TMR3) proportion of concentrate in dry matter (DM) and with different crude protein (CP) content of concentrate (170 or 200 g/kg DM) on the performance of 51 first parity Ayrshire cows was studied. On TMR1 diet the forage to concentrate ratio in DM was 55:45 throughout the lactation. On TMR3 the forage to concentrate ratio was 45:55, 55:45 and 65:35 during the lactation days 0–100, 101–200 and 201–305, respectively. There was no significant interaction between feeding strategy (TMR1 or TMR3) and CP content of the concentrate on the performance parameters studied. Feeding strategy had no effect on energy corrected milk (ECM) production (26.6 vs. 27.1 kg/day), milk composition, DM intake (18.0 vs. 18.2 kg/day) or post partum development of the body condition score of the cows. The higher CP content of the concentrate increased ( P<0.05) the milk (24.8 vs. 26.2 kg/day) and milk protein yield (871 vs. 922 g/day) and tended to increase ( P=0.13) the ECM yield (26.3 vs. 27.4 kg/day). Milk composition was not affected by the CP content. DM intake was higher in early and mid lactation but not in late lactation when CP content of the concentrate was 200 g/kg DM compared to 170 g/kg DM. Increase in CP content of the concentrate decreased the protein conversion efficiency (milk protein/CP intake) in early and mid lactation but not in late lactation. It can be concluded that there is no advantage to primiparous cows of adjusting the forage to concentrate ratio in TMR with progressing lactation. Results also showed that the primiparous cows benefited from the protein content of the concentrate higher than 170 g/kg DM.

The influence of modified 14-3-3 protein synthesis in potato plants on the nutritional value of the tubers

The recently created six transgenic potato genotypes with overexpressed or underexpressed P14-3-3a (29G) and P14-3-3c (20R) isoforms of 14-3-3 protein were field-trialled (1998–2001). The contents of protein, starch, reducing sugars, sucrose and lipids were determined in the transgenic and control tubers harvested from the field. The obtained results showed a significant increase in crude protein content in potatoes with repression of P14-3-3c isoform and in potatoes with blocked P14-3-3a synthesis in comparison to the control line. A stable increase in lipid content of potatoes with overexpression of 14-3-3 protein from Cucurbita pepo in the field trials was observed. The variability of the investigated genotypes, in respect to the nutritional components, was statistically analysed using discriminant function and cluster analyses. The dominant influence of the variability of the genotypes exerted significant differentiation of protein, lipid and starch contents. These components showed the greatest discriminant power in the variability of genotypes. These results confirm the suggestion that 14-3-3 protein co-ordinates primary metabolite synthesis in plants.

Influence of dehulling of rape seeds on chemical composition of meal

The aim of this work was to determine the effectiveness of dehulling of rape seeds with the objective of raising nutritive value of meal. The study was carried out on three Polish varieties of winter rape seeds and their fractions, size >2.0–2.5 mm (large) and 1.6–2.0 mm (small). Content of hull and chemical composition of seeds, hull and embryo were determined. Dehulling of rape seeds by definite deformation method and separation pneumatically was undertaken and the chemical composition of resultant fractions was determined. No significant differences ( P≤0.05, n=6) in content of protein and crude fibre in seeds depending on variety were observed. The lowest content of hull (138 g kg −1) was from large seeds of the variety Polo. Large seeds show significantly higher ( P≤0.05, n=18) mass of 1000 seeds (5.79 g) and contained more oil (2.5%), crude protein (2.6%), less hull (8.8%) and crude fibre (3.1%) but also more glucosinolates (by 10.4%). Significant differences ( P≤0.01, n=9) in chemical composition (dry matter, oil, crude protein, crude fibre, tannic acid, condensed tannins, phytates, iron, copper and zinc) between hull and embryo were observed. The composition of hull and embryo was independent on size of seeds (at the 95.0% confidence level). Dehulling increased content of protein (to 439 g kg −1), glucosinolates (20.3 μM g −1), tannic acid (22.0 g kg −1), phytates (49.1 g kg −1) and zinc (63.3 mg kg −1) in meal and decreased content of crude fibre (67 g kg −1), condensed tannins (179 mg catechin × 10 −2 g −1), iron (83.8 mg kg −1) and copper (5.7 mg kg −1). In the experimental conditions ( n=6) dehulling of seeds reduced the meal fibre content from 124 to 72 g kg −1 (on oil-free dry matter basis) and increase of crude protein content from 388 to 437 g kg −1. The compositions of fraction overflow (dry matter, crude fibre, tannic acid) and underflow (crude protein, glucosinolates) depended on size of seeds (at the 95.0% confidence level).

Effect of rate and time of nitrogen application from autumn to midwinter on perennial ryegrass - white clover dairy pastures in western Victoria. 2. Pasture nutritive value

Field experiments were carried out at 2 sites to study the effects of time and rate of nitrogen (N) application from autumn to midwinter on the nutritive value of perennial ryegrass–white clover dairy pastures in western Victoria. Nitrogen (0, 15, 25, 30, 45, and 60 kg/ha) was applied in mid-April, early May, mid-May, early June, and mid-June during 1996 onto a pasture which had been grazed and topped to a uniform height of 5 cm prior to imposition of treatments. Pasture samples to a height of 5 cm were collected when perennial ryegrass in the 45 kg N/ha treatment reached the 3-leaf stage of development. Samples were analysed for metabolisable energy (ME), crude protein (CP), neutral detergent fibre (NDF), and water-soluble carbohydrates (WSC). Increasing rates of N gave rise to a curvilinear (Site 1) and linear (Site 2) increase in pasture ME and CP content. The actual response of 0.007 MJ/kg DM. kg N at 45 kg N/ha was the same at both sites, regardless of N application time, and corresponded to an increase of 0.32 MJ/kg DM. At Site 1 the actual increase in CP content at 45 kg N/ha (0.067% per kg N applied) was the same for all application times and corresponded to an increase in CP content of 3%. For Site 2, the increase ranged from 0.040% (mid-April) to 0.098% (mid-May) per kg N, corresponding to a pasture CP content increase of 1.8 to 4.4% at 45 kg N/ha, respectively. The application of N gave rise to a curvilinear (Site 1) and linear (Site 2) decrease in pasture NDF. For Site 1 at 45 kg N/ha, the actual decrease ranged from –0.04% (early May) to –0.10% (mid-May) per kg N, corresponding to a pasture NDF content decrease of 1.69 to 4.61%, respectively. At Site 2, the actual decrease in NDF content (–0.04% per kg N applied) was the same for all application times and corresponded to a decrease of 1.58% at 45 kg N/ha. Apart from some exceptions, increasing rates of applied N gave rise to a linear (Sites 1 and 2) decrease in pasture WSC content. For Site 1, the change in pasture WSC content ranged from 0.007% (early May) to –0.032% (mid-June application) per kg N, corresponding to a change in pasture WSC content of 0.32 to –1.44% at 45 kg N/ha, respectively. At Site 2, the change in WSC content ranged from 0.0004% (mid-April) to –0.076% (mid-May) per kg N, corresponding to a change in pasture WSC content of 0.02 to –3.42% at 45 kg N/ha, respectively. In this study, N application had a positive effect on the nutritive value of dairy pastures in the autumn to midwinter, in western Victoria. This is particularly important for the provision of quality feed during this period as the majority of dairy herds in the region are calving at this time. Thus, the provision of an increased quantity of higher quality feed may lead to a reduction in the requirement for purchased feeds.

Effect of Top Dressing at Booting Stage on Crude Protein Content of Wheat in Kyushu District.

九州地域のコムギ粗タンパク質含有率を増加させる手段として, 基肥及び1回目追肥の量を通常施肥量の72%に減じ, その分を穂孕み期に2回目の追肥として施す施肥法の有効性を調べた. 異なる粗タンパク質含有率を持つ16品種を用いた2ヵ年の試験で, 穂孕み期追肥区は対照区と比較し, 成熟期が全品種平均で約半日遅延し, 千粒重, リットル重が有意に増加した. 穂孕み期追肥に伴う千粒重の増加と粉の明るさの増加, リットル重の増加と製粉歩留の増加とは有意な正の相関関係が見られた. 子実収量に対する影響は年次および品種により異なった. 試験2年目の穂孕み期追肥により, 硝子率の増加がみられたが, 粒および粉品質の低下には結びつかなかった. 子実及び粉粗タンパク質含有率は有意に増加し, 粗タンパク質収量(子実収量×子実粗タンパク質含有率)も2年目に多くの品種で増加した. 一方, 子実および粉灰分含有率は有意に低下した. 粉の白さ, 明るさに対する穂孕み期追肥の効果は品種により異なった. しかし, 粉粗タンパク質含有量の増加した品種の多くは, 粉の明るさが低下した. 品種間の比較から, 穂孕み期追肥の粉粗タンパク質含有率, 粉灰分含有率への効果について, 粗タンパク質含有率の高い品種グループと低い品種グループ間での差異は見られなかった. 以上から穂孕み期追肥は, 九州地域におけるコムギの, 粗タンパク質含有率を増加させる手段として, 有効であることが判明した.

Utilization of cassava peels as substrate for crude protein formation

Mash prepared from cassava peels was inoculated with either Sacchromyces cerevisiae or Candida tropicalis and then left to ferment for 7 days. Chemical analysis of the fermented mash showed substantial increase in crude protein content and decrease in carbohydrate content of the mash. The results also revealed slight increases in the ash, fibre and lipid content of the fermented mash. It was further observed that, when the mash was supplemented with inorganic nitrogen sources (urea, ammonium sulfate or sodium nitrate) before commencement of fermentation, the amount of crude protein formed was almost doubled. This enhanced crude protein production was highest in the mash supplemented with urea. Temperature of 30 degrees C, pH of 5.5 and moisture concentration of 130% were found to be optimum for crude protein formation by the organisms growing on the mash.

In vitro degradation of wheat straw treated with neem ( Azadirachta indica) seed kernel cake water extract

The wheat straw was treated with different volumes of neem ( Azadirachta indica) seed kernel cake water extract (NSKCWE) for up to three weeks at ambient temperature in sealed polythene bags. There was a gradual increase in crude protein content with the increasing volume of extract in the premix and also with the increasing time of fermentation, in comparison to that of the control. The in vitro degradation study indicated that the total volatile fatty acids (TVFA) and in vitro dry matter digestibility (IVDMD) increased with the increasing volume of NSKCWE in the premix but decreased with the increase in the treatment period. The results showed that treatment of wheat straw with NSKCWE for the shortest time period (0 days) was the best among all the treatments.

Preservation of Alfalfa Hay with Urea

Urea was evaluated as a preservative for high-moisture alfalfa hay through trials designed to represent a forage producers use of the treatment. A device was developed to meter and distribute granular or powdered urea into hay at baling. When compared to untreated high-moisture hay, urea treatment provided a small reduction in heating during storage with a slight improvement in hay appearance and a reduction in spore numbers on hay following storage. When compared to untreated dry hay, urea treated high-moisture hay had much greater heating and loss during storage with greater fiber and fiber-bound protein contents following storage. The only consistent improvement provided by urea was an increase in crude protein content due to the nitrogen added through urea. The small benefit obtained would not justify the use of urea as a preservative of alfalfa hay.

Mineral utilization of malted sorghum and corn with added crayfish in rats.

Forty adult rats were used to study the mineral balances of malted and unmalted wet- or dry-milled sorghum and corn combined with crayfish and fed rats for 12 days. Five out of the twelve days were for adjustment and the rest for balance period. These mixtures each was calculated to provide 1.6 g N daily for the entire study period. Malting and wet milling produced increases in crude protein content of the cereal grains. However, the increases were much more evident in sorghum. Wet milling caused increases in calcium retention in corn groups. It produced the same effect on phosphorus balance only in sorghum groups. On the other hand, it produced positive iron balances only in unmalted corn and malted sorghum groups. The results suggest improved mineral nutriture due to malting except for the Fe retention of the MDC:CR group.

Intercropped Corn-Soyabean Density Studies. II. Yield Composition and Protein

SUMMARYIf corn-soyabean intercrops are to replace corn grown alone, maintenance of yield and improvements in forage quality are important. Total yields and inter-crop competition in corn-soyabean intercropping experiments have been discussed previously (Putnam et al., 1985). In Part II yield composition, components and protein content are presented for intercrops of varying planting patterns and corn densities. Most intercrop patterns produced more forage than sole crops compared at the same yield ratio of corn-soyabean as in the intercrop harvested mixture. At high plant density ear yields in the intercrop were increased while in sole crops they were reduced or unaffected. The increase was a result of an increased number of ears, weight per ear and kernel, and number of kernels per row in the intercrops. Increases in crude protein content over sole crop corn of 11–51% were shown for the various intercrop treatments. Crude protein yields in the intercrops were greater than either sole crop in 1981 and greater than corn and similar to soyabean in 1982, and greater than the crude protein yields expected from an equal planted area of sole crop corn and soyabean in both years. Intercrop forage quality was improved over sole corn both by the addition of protein from soyabean pods and an increased ear: stover ratio of the intercropped corn.

Causal Analysis of the Difference in Crude Protein Content of Barley Kernels between Two-rowed and Six-rowed Forms

TAKAHASHI, HAYASHI and MORIYA (1975) have demonstrated in their studies with a large number of V-v isogenic line pairs that the two-rowed strains were about two percent higher in general in crude protein content of the grain than the corresponding six-rowed strains. This study was planned to approach the underlying cause of the difference in crude protein content (%) between two types of isolines. In the first experiment change of crude protein content with the progress of the kernel growth was investigated using a six-rowed late cultivar (Kikai Hadaka) and a two-rowed early cultivar (Seijo 17). Seed samples were taken from 17 days after anthesis to maturity at 6-day intervals. The result indicated that percentage of crude protein accumulated in the kernels was not so much different between varieties at any stage of kernel growth (Fig. 1). Next, crude protein content of the central and lateral kernels was compared in the second experiment with three six-rowed varieties, which showed no appriciable difference existing between central and lateral kernels (Table 2). Finally, effects of removing lateral kernels of six-rowed strain at different times of kernel growth on final protein content of central kernel was studied in the third experiment. Three pairs of V-v isogenic paired lines (KA-26, KT-16 and GT-17) which had been produced by TAKAHASHI et al. were used. The removal of lateral kernels was made firstly on one or two days before anthesis, and repeated five times at 5-day intervals after anthesis (from 5th to 25th days). In KA-26 and KT-16, one-half of the spikes within plant was used for treatment and remaining half for untreated control. In GT-17, treatment was made within population regardless of the plant. The removal of lateral kernels resulted generally in an increase in crude protein content of remaining central kernels, and the increasing effect of the removal was most evident when the treatment was made before anthesis (Figs. 2 and 3). However, the increase of crude protein content became smaller and smaller with the later date of the treatment, and the treated spikes reached the same crude protein percent as the intact plot on 25th day after anthesis. Removal of laterals affected a little on 1000 kernel weight. From this study, the cause of difference of protein content between two-rowed and six-rowed isolines may be explained as follows : Protein is mainly synthesized in leaves from nitrogen absorbed from the roots, and is distributed almost uniformely to central and lateral kernels in intact six-rowed spike. But when lateral kernels have been removed from the spike, the protein which ought to be allotted to the lateral kernels will be distributed to and accumulated excessively in the central kernels. Consequently, if so-called source size is not different between two-rowed and six-rowed types, crude protein percent of the kernels will be higher in two-rowed type with small size of so-called sink than those of six-rowed ones.

Factors affecting genotypic and environmental variance for crude protein content in cereals

The effects of N fertilizer, irrigation and location on genotypic and environmental variances of barley and wheat varieties were studied in a series of trials. Genotypic variance for crude protein content, as well as for grain yield, tended to be higher under high N fertilizer rate (80 kg N/ha). The effect of N fertilizer rate on environmental variance varied with variety and location. Increase in crude protein content resulted in decrease in environmental variance for only a few of the varieties tested. The effect of quantity of irrigation water on genotypic and environmental variance for crude protein content was small.

Effect of Diet Protein Level on Weight Gains of Early Weaned Beef Calves

Forty-eight Angus and Polled Hereford calves were weaned at an average of 48 days of age. Calves were group-fed in dry lot four diets ad libitum which contained 14.5, 18.9, 23.7 and 28.5% crude protein (diets 1, 2, 3 and 4, respectively) with each diet having approximately 14% crude fiber on a dry matter basis. After a 12-day preliminary period, calves were fed for three periods of 6, 6 and 5 weeks. Differences in daily gain due to diet were significant (P<.05) only for Angus. Period effects on daily gain were significant (P<.05) for Angus and P. Hereford males. Angus males gained significantly (P<.01) faster than P. Hereford males and P. Hereford males gained significantly (P<.01) faster than P. Hereford females. Breed-sex × diet interaction did not (P>.05) affect daily gains. Age of calf at weaning was associated with increases in daily gains of .0083 kg (P<05) for Angus and .0099 kg (P<.01) for P. Hereford males per day increase in age. Results of apparent digestibility indicated an increase (P<.05) in the digestibility of crude protein for each increase in crude protein content of the diets. Nitrogen retention of diet 1 was significantly (P<.05) lower than the other diets with the other three diets not differing significantly although the trend showed an increase in nitrogen retention with increases in protein content of the diets. Comparison of daily gain response from the various diets was made with those expected from N.R.C. protein requirements.

The effect of quantity, source and time of application of nitrogen fertilizers on the yield and quality of Andropogon gayanus at Shika, Nigeria

SUMMARYExperiments made at Shika, Nigeria, over a period of 3 years showed that the drymatter response of Andropogon gayanus to applied N was curvilinear over the range 0–896 kg N/ha, with maximum yields being obtained at an application rate of about 500 kg N/ha. However, the highest return of dry matter per unit of fertilizer applied (14·4 kg D.M./kg N) occurred at 28 kg N/ha and there was only a modest increase in crude-protein content as N was increased, reaching a maximum of 10·5% at the highest level of N. Also, at both high and intermediate levels of N, A. gayanus was replaced by less desirable grasses.May, the beginning of the rainy season, was found to be the most efficient time to apply N, although reasonable dry-matter responses were obtained by applying N in the dry season. ‘Nitro-chalk’ and calcium nitrate were more efficient sources of N than urea, sodium nitrate and, in the long term, ammonium sulphate.