Supplemental Protein Source Research Articles

Supplementation of Cassava Hay and Stylo 184 Hay to Replace Concentrate for Lactating Dairy Cows

Sixteen multiparous Holstein-Friesian crossbred cows in mid-lactation were blocked according to days in milk (DIM) and previous lactation and randomly assigned according to a Randomized Complete Block (RCB) design with four replications to receive four dietary treatments. The dietary treatments consisted of T1: No cassava hay (CH) or stylo 184 hay (SH) supplementation, supplementation of concentrate to milk yield at 1:2 (control), T2: Supplementation of 1 kg of CH/hd/d, supplementation of concentrate to milk yield at 1:2, T3: Supplementation of 1 kg of CH+SH/hd/d, supplementation of concentrate to milk yield at 1:2, T4: Supplementation of 2 kg of CH+SH/hd/d, supplementation of concentrate to milk yield at 1:3. All animals received Ruzi grass from a cut-and-carry system as roughage source. The feeding trial lasted for 9 weeks. The results revealed that DMI of concentrate of supplemented treatments were significantly lower (p<0.05) than those in the control, but there was no significant difference between T2 and T3. There was no significant difference in forage DM intake between the control and supplemented treatments. CP and NDF digestibility of supplemented treatments were significantly (p<0.05) greater than the control and there were no significant differences among supplemented treatments. Milk yield and 3.5% FCM (14.3, 14.5, 14.7 and 14.8; 13.9, 14.3, 14.3 and 14.6 kg/hd/d, respectively) were not significantly different among treatments. Milk protein percentage of supplemented treatments was significantly (p<0.05) higher than the control, but there were no significant differences among supplemented treatments. There was no significant difference in milk fat percentage between the control and supplemented treatments. However, milk fat percentage tended to be higher for supplemented animals as compared to the control group. There were also no significant differences in lactose, solids-not-fat and total solids percentages among treatments. Cows in supplemented treatments gave incomes over supplement cost (IOSC) of 2.72, 2.74 and 2.93 US$/hd/d, respectively which were greater than for cows on control treatment. Furthermore, IOSC were greatest for cows in T4 as compared to other treatments. Based on this study it was concluded that, feeding cassava hay solely or in combination with stylo 184 hay as a supplemental protein source could be a potential valuable strategy in small-holder dairy farming systems in the tropics. This strategic supplementation significantly reduced concentrate use, which resulted in improved milk yields and milk quality for the supplemented cows. Moreover, it resulted in higher economical returns through increased productivity and lower ratios of concentrate to milk yield, from 1:2 to 1:3. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 5 : 670-677)

Effects of supplemental protein sources during the grazing period on performance, ruminal characteristics and blood constituents in early weaned growing Wagyu steer calves

ABSTRACTWe investigated the effects of grazing and supplemental protein sources during the grazing period on growth performance, ruminal characteristics and blood constituents in 15 growing Wagyu steer calves weaned at 3 months of age. Each animal was allotted one of three treatments: (1) GSBM, soybean meal (SBM) supplemented as a protein source during a grazing period; (2) GCGM, corn gluten meal (CGM) supplemented as a protein source during a grazing period; or (3) NG, no grazing, in which steers were fed hay and GSBM concentrate only. The estimated rumen undegradable protein (RUP) concentration of CGM was higher than that of SBM. High RUP supplementation during the grazing period did not influence feed intake or growth performance. Compared with the NG treatment, the average daily gain in GSBM and GCGM calves was significantly depressed (P &lt; 0.05). Bodyweight/withers height ratio in the NG calves tended to be greater than in the GSBM and GCGM calves. Final paunch girth/heart girth ratio in the GSBM and GCGM calves was significantly greater (P &lt; 0.05) than in the NG calves. Supplementation with CGM did not influence ruminal ammonia nitrogen and blood constituents. These results indicate that CGM supplementation during the grazing period did not enhance the growth of Wagyu calves because the CGM diet probably did not elevate the metabolizable protein supply to the grazing calves above that of the SBM diet in our conditions.

Effects of level and source of supplemental protein in a concentrate-based diet on growth performance of Boer × Spanish wether goats

Boer×Spanish wether goats (50; 26.8±4.04 kg initial BW and 7 months of age) were used in a 27 week experiment to determine effects of two levels of CP (13 and 19%) and five protein sources varying in ruminal degradability (blood, corn gluten, feather, fish and soybean meals). Diets were 70% concentrate, had a ratio of ruminally degraded intake protein (DIP) to total digestible nutrients (TDNs) of at least 0.09 and were formulated to maximize ruminally undegradaed protein from supplemental protein sources. There were no interactions between dietary CP level and supplemental protein source. Voluntary DM intake (1043, 1089, 1153, 1086 and 1112 g per day; S.E.=74.4), ADG (136, 134, 143, 145 and 138 g per day; S.E.=9.8) and gain efficiency (ADG:DM intake) (131, 124, 125, 136 and 128 g/kg for blood, corn gluten, feather, fish and soybean meals, respectively; S.E.=5.7) were similar between CP levels and among sources of supplemental protein. In summary, with a dietary concentrate level of 70% and at least 13% CP, differences in amino acid profiles among blood, corn gluten, feather, fish and soybean meals did not impact rate or efficiency of growth by Boer×Spanish wethers.

Growth performance, carcass quality, meat quality and fatty acid composition of pigs fed diets

Two hundred gilts and 200 barrows, housed within sex in pens of 25, were randomly allotted to two replications of four dietary treatments to determine the effects of incorporating 30, 20, 10 or 0% extruded soybeans (ESB), displacing a commercial protein supplement, in barley-based grower and finisher diets for pigs. Growth, feed intake and carcass quality of the pigs, and meat quality and fatty acid composition of the pork from a random subset of the pigs on test were determined. No sex × diet interactions were observed. ESB inclusion rate had no effect on growth rate; however, per-pen feed consumption decreased numerically with increasing ESB resulting in an improvement in feed efficiency. The 30% ESB inclusion rate increased carcass fat content (P &lt; 0.05) compared with the control, whereas lean content was unaffected. Meat colour and marbling score were similar across all treatments whereas fat and lean firmness was reduced by the 30% ESB inclusion rate (P &lt; 0.05) compared with all other treatments. Increasing ESB in the diet altered the fatty acid content of the pork by decreasing the amount of short-chain saturated and monounsaturated fatty acids and increasing the amount of long-chain polyunsaturated fatty acids (PUFA). The results of this study indicate that ESB can be used as the sole source of supplemental protein in barley-based diets for pigs with no detrimental effects on performance and minimal negative effects on carcass and meat quality. Alteration of fatty acid content of pork from feeding ESB has both positive and negative implications for consumer acceptance by increasing PUFA content while concomitantly increasing the risk of premature oxidation. Key words: Extruded soybeans, pigs, pork, growth, fatty acids, meat quality

Effects of Fertilizer Phosphorus on Yield Traits of Dekoko (Pisum sativum var. abyssinicum) Under Field Conditions

AbstractCool‐season food legumes (CSFLs) are important supplementary protein sources and soil fertility restorers for subsistence farmers in Ethiopia. Yields of CSFLs, however, are limited by low soil fertility, as they are grown in poor soils, often without fertilizer. Dekoko (Pisum sativum var. abyssinicum) is one of the CSFLs cultivated in Tigray, Northern Ethiopia. It is highly appreciated by the local people for its taste. This paper reports on the effect of phosphorus (P) on the yield and nutrition value of Dekoko under field conditions, and compares the results with those obtained for Ater (Pisum sativum var. sativum). The experiment was conducted in the 1998 and 1999 growing seasons. Three rates of P equivalent to zero, 30, and 60 kg ha−1 P2O5 were tested. Biomass, leaf area index, branches/plant, pods/m2 and yield responded positively while seeds/pod and seed weight were not significantly affected by P. Tissue P contents in shoots and roots increased with an increase in P application rate, while P in the nodules was not affected. Crude protein (CP) content increased from 24.9 % of dry matter (DM) at P0 to 26.2 % at P2, and from 24.3 % at P0 to 25.2 % at P2, in Dekoko and Ater seeds, respectively, while total sugars decreased with an increase in P application rate. Cysteine in Dekoko and asparagine and threonine in both varieties decreased, while lysine and other amino acids were not significantly affected by P. P improved seed yield and CP content without greatly affecting the amino acid profile of Dekoko, when compared with that of the FAO/WHO (1991, Protein Quality Evaluation. Food and Nutrition, Paper 51. FAO/WHO, Rome) standard pattern of amino acid for children 2–5 years of age. Thus, improving yield through fertilization may help to improve nutritional quality and household food security for subsistence farmers.

EFFECTS OF STACHYOSE ON PERFORMANCE, DIARRHOEA INCIDENCE AND INTESTINAL BACTERIA IN WEANLING PIGS

A three-week trial was conducted to evaluate the effects of the oligosaccharide stachyose on performance, diarrhoea incidence and intestinal bacterial populations in weaned pigs (7.96±0.2kg). A total of 144 crossbred (Landrace × Large White × Duroc) pigs weaned at 28 days were allotted to one of four treatments with six pens per treatment and six pigs per pen. The experimental diets were based on maize, dried whey and whole-fat milk and were supplemented with 0, 1 or 2% stachyose. A fourth diet contained no milk but instead contained 20% soybean meal to provide 0.78% stachyose and 0.21% raffinose. Inclusion of 1 or 2% stachyose in the diet depressed growth compared with pigs fed the control diet. Pigs fed the soybean meal diet gained weight at a rate similar to pigs fed the diet containing 1% added stachyose. Diarrhoea incidence was highest for pigs fed the soybean meal diet and lowest for pigs fed the control diet, with pigs fed the diets containing stachyose being intermediate. Pigs fed 1% stachyose had more lactobacilli in the ileum as well as more bifidobacteria in the caecum and colon than control pigs. They also had fewer enterobacteria in the colon. In contrast, pigs fed the diet containing 2% stachyose had fewer lactobacilli and bifidobacteria in the jejunum, ileum and caecum than did control pigs. Volatile fatty acids in the ileum, caecum and colon were highest for pigs fed 1% stachyose and lowest for pigs fed 2% stachyose. Volatile fatty acid concentrations were not significantly different between pigs fed the soybean meal diet and those fed the control. The overall results of this experiment indicate that the oligosaccharide stachyose had a negative effect on pig performance and its presence may partially explain the poorer performance observed when soybean meal is used as the sole source of supplemental protein in cereal-based diets fed to weaned pigs.

Physicochemical traits of Dekoko (Pisum sativum var. abyssinicum) seeds.

Dekoko (Pisum sativum var. abyssinicum) has high appreciation for its taste and obtains a premium price in local markets compared to Ater (Pisum sativum var. sativum). However, data on the physicochemical traits of Dekoko seeds were lacking. This paper reports on the physicochemical features of Dekoko and compares the results with that of Ater. Seed weight and seed volume were 36 and 30%, respectively, higher in Ater, while water absorption, percent seed swelling, and percent husk were higher in Dekoko. Cooking time was shorter for Dekoko than Ater seeds. Decortication reduced cooking time on average by 39 and 45 min in Dekoko and Ater, respectively. Cotyledon flour of Dekoko contained 251 g crude protein, 19 g fat, 31.7 g total sugars, 370 g starch, and 130 g neutral detergent fiber per kilogram DM. These traits were significantly higher in Dekoko than in Ater, except for starch, which was higher in the latter. Arginine, asparagine, and glutamine occurred in larger proportions, and collectively contributed about 39% to the total amino acids in both varieties. Lysine contributed about 7%, while sulfur containing amino acids constituted about 3.0 and 2.3% of the total amino acids in Dekoko and Ater, respectively. Ca and Mg were higher in Ater, while P was higher in Dekoko. Based on the observations it was concluded that Dekoko is a suitable supplementary protein source for a cereal-based diet.

Peas ( Pisum sativum L.) as an alternative protein source in lamb diets: growth performances, and carcass and meat quality

Thirty weaned Barbaresca lambs were divided into three groups and fed diets that differed in their protein supplement source; the main protein source was soybean meal in SBM diet treatment, totally or partially replaced by peas in P39 and P18 diet treatments, respectively. Soybean meal and peas were present in the diets in the following proportions (on as fed basis): 16:0% (SBM), 0:39% (P39), 9:18% (P18).The diets were of different crude protein content: higher in SBM diet (16.96% DM) than in P39 (14.27% DM) and P18 (15.37% DM). Soluble protein was higher in P39 diet than in the other treatments (36.2, 27.4 and 23.14% CP in P39, P18 and SBM treatments, respectively) while the B 2-protein fraction was lower. The NDF-bound nitrogen was 17.36, 16.87 and 15.06% of crude protein in P39, P18 and SBM diet, respectively. The NDF content was similar among the diets. Growth and slaughter performances were similar among groups (250 g per day versus 219 and 218 g per day respectively in P18, P39 and SBM groups). Carcass fatness was comparable among treatments. Meat pH, colour parameters and cooking losses were comparable among groups. Drip losses were significantly higher ( P<0.001) in meat from P39 and P18 than from SBM group. In the present trial, the replacement of soybean meal with peas did not significantly affect growth and slaughter performances and preserved meat quality.

Digestibility and dry matter intake of diets containing alfalfa and kenaf.

Two experiments were conducted to determine the dietary value of pellets containing kenaf (Hibiscus cannabinus cv. 'Everglade 41') hay. Averaged across both experiments, kenaf pellets contained 82.6% kenaf hay, 16.6% liquid molasses, and 0.8% mineral oil. The chemical composition of the kenaf pellet was 12.6% crude protein (CP), 41.2% neutral detergent fiber (NDF), and 14.4% acid detergent fiber (ADF). In Exp. 1 (digestion and N balance trial), 18 lambs (body weight [BW] = 36.4 kg) were blocked by BW. Lambs were randomly assigned within a block to Diet 1 (59.5% corn and 40.5% alfalfa pellet), Diet 2 (59.7% corn, 28.4% alfalfa pellets, and 11.9% kenaf pellets), or Diet 3 (59.6% corn, 16.5% alfalfa pellets, and 23.9% kenaf pellets). Diets were formulated so that CP was the first-limiting nutrient. Each diet was limit-fed at 2.4% of BW. Replacing alfalfa pellets with kenaf pellets tended to decrease (P = 0.10) CP and ADF intakes, but increased (P = 0.01) DM digestibility. Diet had no effect (P = 0.33) on N balance. In Exp. 2 (dry matter [DM] intake trial), 32 lambs (BW = 30.4 kg) were blocked by gender and BW. Within a block, lambs were randomly assigned to one of four diets in a 2 x 2 factorial arrangement. Main effects were hay (bermudagrass or fescue) and supplemental protein source (kenaf or alfalfa pellets). Lambs were housed in individual pens with ad libitum access to the assigned hay. Supplemental protein was fed (185 g of DM) once daily. Hay intake was measured weekly for 8 wk. Lambs consumed more (P = 0.002) fescue than bermudagrass hay (743 vs 621 g/ d). Lambs fed fescue hay gained weight more rapidly (P = 0.001) than lambs fed bermudagrass hay (120 vs 72 g/d). Hay intake and ADG were similar (P = 0.90) for lambs fed alfalfa or kenaf pellets. Kenaf hay mixed with molasses and mineral oil can be formed into a pellet. In the diets used in this experiments, kenaf pellets can replace alfalfa pellets in diets fed to lambs without altering forage intake, gain, or N retention.

Apparent ileal digestibility of amino acids in protein feedstuffs and diet formulation based on total vs digestible lysine for poultry

A digestibility experiment was carried out with 140 Ross-broiler chickens (age 24 days) to determine coefficient of ileal apparent digestibility (CIAD) of amino acids in meat and bone meal (MBM), full-fat soyabeans (FFSs), soyabean cake and meal, full-fat rapeseeds, and rapeseed cake and meal. The birds were fed semi-purified diets which contained protein feedstuffs as a sole protein source and chromium mordanted straw as an indigestible marker. The CIAD of nutrients were assessed using the slaughter technique. A 37-day growth experiment was carried out with 2880 Ross-broiler chickens to compare feed formulation systems based on apparent ileal digestible or total lysine content. Three barley based diets were formulated to be similar in total lysine content (9.5 g/kg feed). Diet 1 contained soyabean meal (SBM) (280 g/kg DM), Diet 2 SBM (180 g/kg DM) and rapeseed meal (RSM) (171 g/kg DM) and Diet 3 a combination of SBM (78 g/kg DM), RSM (172 g/kg DM) and MBM (87 g/kg DM). The composition of Diets 4 and 5 was similar to that of diets 3 and 4, respectively, except that they were supplemented with l-lysine–HCl to obtain a similar apparent ileal digestible lysine content as in Diet 1 (7.9 g/kg feed). The total lysine content of Diets 4 and 5 was 10 g/kg feed. Furthermore, Diet 1 was supplemented with l-lysine–HCl to obtain Diet 6, in which the total and apparent ileal lysine contents were 10 and 8.5 g/kg feed, respectively. CIAD of lysine, methionine, threonine and cystine were respectively 0.60, 0.66, 0.48 and 0.34 for MBM; respectively 0.81, 0.75, 0.68 and 0.67 for FFSs; respectively 0.86, 0.86, 0.76 and 0.62 for soyabean cake; respectively 0.85, 0.84, 0.74 and 0.63 for SBM; respectively 0.59, 0.59, 0.43 and 0.53 for full-fat rapeseeds; respectively 0.68, 0.81, 0.64 and 0.53 for rapeseed cake; and respectively 0.63, 0.75, 0.54 and 0.43 for RSM. Final weight and growth rate were highest when digestible lysine based feed formulation was used compared to that based on total lysine ( P<0.001). The increase in final weight was largest for diet containing MBM and formulated based on digestible lysine ( P<0.001). In addition, the proportion of breast muscle of total live-weight and weight of breast muscle increased ( P<0.05) in animals fed diets formulated on the basis of digestible compared to total lysine. However, diet formulation based on digestible lysine impaired feed conversion ratio compared to that of total lysine for birds fed SBM as the sole source of supplementary protein compared to diets containing rapeseed or MBM ( P<0.01). Growth rate and final weight were higher in birds fed diets containing SBM alone compared to those also containing RSM and MBM ( P<0.001). In addition, the effect of diet formulation based on digestible lysine on performance results of broilers was more obvious in males than females ( P<0.05). The results indicated that formulation of diets based on a digestible lysine was better than that based on total lysine when diets contained protein sources of low amino acid digestibility such as meat and bone and RSMs.

Utilização de Três Fontes de Nitrogênio Associadas à Palma Forrageira (Opuntia ficus-indica, Mill.) Cv. Gigante na Suplementação de Vacas Leiteiras Mantidas em Pasto Diferido

O fornecimento da palma forrageira como único alimento não atende as necessidades nutricionais do rebanho, notadamente em proteína e fibra. Nesta pesquisa avaliaram-se fontes de suplementação protéica sobre o desempenho de vacas leiteiras alimentadas com palma e pasto diferido, durante a estação seca, bem como a composição botânica da pastagem. Testaram-se três tratamentos: T1 = pasto diferido (PD) + palma + cama de aviário; T2 = PD + palma + farelo de soja e T3 = PD + palma + uréia/sulfato de amônio, em um delineamento de blocos casualizados. Utilizaram-se 12 vacas mestiças 5/8 Holando-Zebu, com produção média de leite de 5,6 kg/dia/vaca e peso vivo (PV) médio de 452 kg. O experimento teve duração de 121 dias, sendo 21 dias de período de adaptação. Os resultados para produção de leite in natura (3,38, 5,33 e 3,38 kg/vaca/dia), produção de leite corrigido para 4% de gordura (3,15, 4,98 e 3,11 kg/vaca/dia), variação de peso vivo (-351, 77 e -401 g/vaca/dia) e consumo in natura de palma (26,3, 37,8 e 26,3 kg/vaca/dia), para T1, T2 e T3, respectivamente, demonstraram a superioridade do farelo de soja como fonte protéica, em relação aos demais tratamentos. No pasto diferido foram identificados 18 famílias, 32 gêneros e 36 espécies. O capim-milhã (Brachiaria plantaginea (Link) Hitch) foi o componente de maior participação na composição botânica da pastagem (28,72%).

Production response of lactating dairy cows fed increasing amounts of ground rapeseed

Fat is often fed to lactating dairy cows to provide supplemental metabolizable energy and increase milk yield. Commercial fat sources are typically processed to render them more inert in the rumen, but whole oil seeds also represent an effective fat source for lactation rations. In a previous study (Reynolds et al., 1998), we fed lactating dairy cows a commercial rumen-inert fat, cotton seed or crushed rapeseed at 25 g added fat/kg ration DM in a grass silage-based total mixed ration (TMR). All 3 fat supplements increased milk yield to a similar extent, whilst the commercial fat source, but not the whole oil seeds, reduced milk protein concentration. As a UK grown source of supplemental fat and protein, crushed rapeseed offers an attractive alternative to commercial fat supplements for dairy rations. Therefore, our objective was to determine the incremental effects of supplemental ground rapeseed on intake and milk production response of dairy cows fed rations containing maize silage.

Comparison of Alfalfa Hay and Distillers Dried Grains with Solubles, Alone or in Combination with Cull Beans, as Protein Sources for Beef Cows Grazing Native Winter Range

<h2>Abstract</h2> A grazing study was conducted at the Eastern Colorado Research Center (ECRC) to evaluate the use of locally available protein sources as supplements for beef cows grazing native winter range. The four treatments were as follows: 1) alfalfa hay to supply 182 g/d CP (Alfalfa); 2) a mixture of alfalfa hay and cull Great Northern Beans to each supply 91 g/d CP (Alfalfa/Beans); 3) distillers dried grains to supply 182 g/d CP (DDG); and 4) a mixture of DDG and cull Great Northern Beans to each supply 91 g/d CP (DDG/Beans). Pregnant, multiparous, spring calving crossbred cows (n = 112; 566 ± 59 kg) were randomly assigned to one of four treatments within one of two replicates. Supplemental CP was increased to 273 g/d ca. 60 d before calving. Cow BW change was affected by treatment (P<0.05); cows fed the Alfalfa supplement gained BW during the trial, whereas cows fed the other three supplements lost BW. Cows in the Alfalfa group also lost less (P<0.05) body condition during the trial period compared with cows fed a DDG or cows in the DDG/Beans group. However, calf birth BW, calf weaning BW, and subsequent cow pregnancy rate were unaffected (P>0.05) by treatment. Feeding cull Great Northern Beans to supply one-half of the supplemental CP reduced feed costs with little effect on subsequent cow performance. In this study, DDG was a less desirable source of supplemental protein because of higher cost and a lower percentage of degradable intake protein (DIP).

Effects of the level and source of dietary protein on intake and milk yield in dairy cows

The objectives of this trial were to determine the effect of dietary protein content and the effect of the source of protein supplements on dry matter intake (DMI) and milk yield in dairy cows fed ad libitum. In addition, the interaction of protein supplement with the level of milk yield was stud- ied to test the hypothesis that the DMI response to protein supplement depends on the nutrient requirements of the cows. Two groups of six lactating cows differing in milk yield (45 kg .d -1 and 38 kg.d -1 pre-treatment) were assigned to a double 3 〈 3 Latin square design over periods of 3 weeks. The 3 treatments consisted of 3 complete diets (60% maize silage and 40% concentrate) with different protein sources and levels: low-protein supplement (LP) (5% soybean meal + 1.2% of urea in the diet), high-protein supplement containing soybean meal (HP-SB) (19% soybean meal) and high-protein supplement containing formaldehyde-treated soybean meal (HP-FTSB) (12% formalde- hyde-treated soybean meal + 1.2% of urea in the diet). HP treatments significantly increased ( P < 0.05) DMI (+1.2 kg.d -1 ), milk yield (+1.8 kg.d -1 ), 4% FCM (+2.5 kg.d -1 ) and fat content (+1.9 g .kg -1 ) com- pared to the LP treatment. These improvements were not related to the source of protein used or the level of milk yield. Compared to LP treatment, the HP-SB treatment increased milk protein content (+1.4 g.kg -1 ) (P < 0.05), whereas the HP-FTSB treatment had no significant effect. Intake and milk yield were increased by higher protein content in the diets independently of the source of protein used or the level of milk yield. dairy cow / intake / protein / milk yield

Biochemical and technological studies on the production of isolated guar protein.

Guar seeds contain 32% crude protein. Therefore, attempts were made to prepare protein isolates from guar seed flour (GSF) by extraction in different media (distilled water, salt solution, alkali solution alone or in combination) followed by a precipitation at acid pH. From the four technologies adopted, mixed salt-alkali solution was found to be the most satisfactory for extraction of protein from GSF. The highest amount of product was obtained in the mixed technology along with the highest amount of protein (87.5%). Protein isolates were also nutritionally evaluated following well-established rat bioassay procedures in a comparative study with casein as standard. The protein isolates are rich in lysine but poor in sulphur-containing amino acids such as methionine and cysteine. Protein isolates obtained by mixed salt-alkali solution showed high water and oil absorption as well as good emulsifying and foaming stability. The results indicate that protein isolates can be used as a supplementary source of protein in different food industries.

Effect of different protein sources on growth and carcass traits in growing-finishing pigs.

Crossbred gilts (n = 180) and barrows (n = 180) from the Louisiana State University (LSU) Agricultural Center and the University of Illinois (UI) were used to compare the effect of soybean meal in swine diets, relative to other protein sources, on growth performance and carcass traits of growing-finishing pigs. Four replications with five pigs each at each location were allotted to nine dietary treatments: soybean meal control (SBM), crystalline AA (corn-AA), extruded soybeans (ESB), canola meal (CAN), peanut meal (PNT), sunflower meal (SFLR), ground peas, meat and bone meal (MBM), and poultry by-product meal (PLTY). The diets were formulated to meet or exceed NRC nutrient requirements and to have equal Lys:ME according to dietary phase and sex. Corn was the grain source in all diets and the protein sources were the sole source of supplemental protein in all diets except when AA were added to meet the requirement. Pigs (three per pen at each location) were killed at an average final BW of 114 kg in the LSU or UI Meat Science Laboratories. Pigs fed SBM had greater (P < 0.05) ADG than pigs fed the corn-AA, CAN, SFLR, MBM, or PLTY and greater (P < 0.05) ADFI relative to pigs fed the corn-AA, ESB, MBM, or PLTY. Gain:feed was decreased (P < 0.05) in pigs fed corn-AA or SFLR but increased (P < 0.05) in pigs fed ESB compared with pigs fed the SBM diet. Loin muscle area was decreased (P < 0.05) in pigs fed the corn-AA or MBM diets compared with pigs fed the SBM diet. Tenth-rib backfat thickness was greater (P < 0.10) in pigs fed corn-AA, peas, or MBM than in those fed SBM. The NPPC percentage acceptable quality lean and kilograms of lean were decreased (P < 0.10) in pigs fed corn-AA, peas, or MBM compared with those fed SBM. Results from this experiment suggest that pigs fed SBM have equal or better growth performance and carcass traits than pigs fed other protein sources.

Effect of nitrogen source in high-concentrate, low-protein beef cattle diets on microbial fermentation studied in vivo and in vitro.

In Exp. 1, four Holstein heifers (112+/-5.5 kg BW) fitted with ruminal cannulas were used in a 4 x 4 Latin square to evaluate the effects of N source on ruminal fermentation and urinary excretion of purine derivatives. A 2 x 2 factorial arrangement of treatments was used; the factors were the type of protein source (soybean meal, SBM, vs a 50:50 mixture of fish meal and corn gluten meal, FMCGM) and the partial substitution of protein source by urea (with vs without). Heifers were allowed to consume concentrate and barley straw on an ad libitum basis. Barley straw:concentrate ratio (12:88) and average ruminal pH (6.25) were not affected (P > 0.05) by treatment. Ruminal NH3 N concentration and urinary excretion of purine derivatives were not affected (P > 0.05) by supplemental N source. In situ CP degradability of supplemented SBM was very low (50%). In Exp. 2, eight dual-flow continuous-culture fermenters were used to study diet effects on microbial fermentation and nutrient flow, using forage:concentrate ratio, solid and liquid passage rates, and pH fluctuation to simulate in vivo conditions. The treatment containing SBM without urea reached the greatest total VFA concentration (P < 0.01), molar percentage of acetate (P < 0.05), and NH3 N concentration (P < 0.05), followed by treatments with partial substitution of protein source by urea, and finally by the treatment containing FMCGM. True OM digestion tended to increase (P = 0.13) in treatments containing SBM. These results suggest that amino N from SBM and NH3 N concentration stimulated nutrient digestion. Microbial protein synthesis was lowest in treatments with FMCGM and without urea, indicating that rapidly available N limited microbial growth. The low CP degradability of SBM observed may have contributed to the limitation in N supply for microbial growth. Efficiency of microbial protein synthesis increased in treatments containing urea (P < 0.05). Protein source affected total (P < 0.05) and essential AA (P < 0.10) flows, which were greater in treatments containing FMCGM. Partial replacement of protein supplements by urea did not affect total and essential AA flows. Because mean dietary protein contribution to total N effluent was 46%, the AA profile of supplemental protein sources had a great impact on total AA flow and its profile.

Preovulatory follicular status and diet affect the insulin and glucose content of follicles in high-yielding dairy cows

Insulin and glucose may be limiting factors for ovarian function in dairy cows genetically selected for high milk yield. The effects of nutrition on the intrafollicular content of insulin and glucose were investigated in Israeli Holstein dairy cattle fed a basic total mixed ration and producing 34–39 kg of milk daily. In experiment 1, carried out in 11 oestrus-synchronised cows, little variation in insulin concentration was found in plasma sampled during the luteal phase, but high variation was found in plasma sampled during the follicular phase. Therefore, in order to prevent confounding the effects of diet and of phase in cycle in the following experiments, experimental diets were fed during the luteal phase of synchronised oestrus cycles. In experiment 2, designed as Latin-Square, six cows received sequentially diets containing 17.1 (control) or 19.7% of crude protein, using two sources of supplementary protein, i.e. soyabean meal (SBM) and corn gluten meal (CGM), differing in ruminal degradability and leucine content. When dry matter intake was used as covariant, plasma insulin on day 16 was 29.5 and 26.4% higher in cows fed diets containing SBM and CGM than in the control ( P<0.05). In experiment 3, 17 cows were individually fed the basic diet and then switched to isoenergetic diets containing SBM ( n=5), CGM ( n=6) or corn grain (CG, n=6) given from day 10 to 16 of the synchronised oestrus cycle. On the eve of day 16, and in the morning of day 17, they were administered PGF 2α and the content of 26 largest follicles was aspirated by using the transvaginal ovum pick-up technique. Follicles were sorted into two classes (preovulatory and subordinate) according to oestradiol concentration and the progesterone:oestradiol ratio in follicular fluid (FF). Higher concentrations of insulin (0.282 versus 0.127 ng/ml, P<0.0001) and of glucose (0.614 versus 0.386 g/l, P<0.002), were found in FF from preovulatory follicles. The insulin concentration in the FF of cows fed the CG diet was 26% higher than in their counterparts fed CGM ( P<0.04), SBM being intermediate. Dietary effects did not reach significance in subordinate follicles. The finding that preovulatory follicular status is associated with increased intrafollicular insulin and glucose suggests that insulin is involved in follicular maturation. The nutritional effect on intrafollicular glucose and insulin may have practical implications to optimise feeding in dairy cows during phases of the oestrus cycle.

Performance of growing-fattening lambs fed diets containing different proportions of cotton seed meal

A lamb feedlot study was conducted to evaluate the nutritional value of cotton seed meal (CSM) as compared with that of sunflower meal as protein supplements for growing lambs. Forty-five Karagouniko male lambs immediately after weaning, having an average liveweight of approximately 14.7 kg, were assigned randomly to one of three growing lamb rations. CSM substituted for sunflower meal in a growing–finishing feedlot diet at levels of 0, 10 and 20% to provide 0, 50 and 100% of supplemental protein requirement, respectively. Diets were fed ad libitum and water was offered freely. All diets were approximately isonitrogenous and isocaloric. After being fed for 61 days and having reached a liveweight of approximately 27.6 kg, five lambs from each treatment were slaughtered and carcass data were collected. No significant differences (P > 0.05) in feed intake or the weight increase of lambs were found among groups given the 0, 10 and 20% treatments, indicating that lambs utilized CSM as effectively as sunflower meal when fed on an equal crude protein and crude fibre basis. The dressing percentage of the cold carcass, but not the warm carcass, and intestinal content weight were significantly influenced (P < 0.05) by the diet. Cooler shrink and intestinal fat, and perirenal fat and the combined weight of intestinal and perirenal fat were significantly (P < 0.05) correlated. Feeding margin was highest for the control diet, intermediate for the 10% CSM diet and lowest for the 20% CSM diet. It was concluded that CSM is accepted readily by growing sheep and can be incorporated into diets as a source of supplemental protein for growing–fattening lambs. No evidence of gossypol toxicity was noted. © 1999 Society of Chemical Industry

Local e extensão da digestão em terneiros desmamados alimentados "Ad Libitum" com dietas ricas em concentrado contendo diferentes fontes de proteína suplementar

Foram utilizados nove terneiros da raça Holandesa (139 ± 2,4kg), fistulados no duodeno, em um delineamento experimental completamente casualizado para estudar o efeito da suplementação com diferentes fontes protéicas (2% de uréia ou 10% de farinha de carne na dieta total) de dietas ricas em concentrado (milho e farelo de soja) sobre o local e extensão da digestão do alimento, em condições de consumo ad libitum. A relação volumoso:concentrado das dietas foi de 30:70. A digestibilidade ruminal e total da matéria seca, matéria orgânica e nitrogênio, assim como o fluxo duodenal de nitrogênio microbiano e residual do alimento, e a eficiência da síntese protéica microbiana foram semelhantes nos dois tratamentos (P&gt;0,10). A digestibilidade ruminal do amido também foi semelhante, mas a digestibilidade total foi menor no tratamento com uréia (P&lt;0,10). No entanto, é provável que isso seja devido mais a limitações dos ruminantes em digerir amido no intestino delgado do que a uma influência do suplemento protéico. O uso de uréia ou de farinha de carne, como fontes de proteína suplementar de dietas à base de milho e farelo de soja, balanceadas para suprir a demanda de crescimento de terneiros jovens e fornecidas ad libitum, não influencia significativamente o processo de digestão nestes animais. Deste modo, a escolha por um outro suplemento depende mais de outros critérios do que dos nutricionais.