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The effect of undegradable crude protein supplementation on milk production and composition and reproduction of early-lactating cows
Abstract
One hundred and fifty six Israeli-Holstein cows were randomly allotted to two groups in a continuous design; of these, 59 cows entered the trial within 14 days postpartum. The trial lasted 75 days. Diet 1 (control group) contained 16.5% crude protein (CP), of which 11.0% was rumen-degradable (RDCP). Diet 2 (high-protein; HP) contained 17.8% CP; all the additional protein was planned to be rumen-undegradable. Cows were group-fed. Feed intake and milk yield were recorded daily and milk composition was analyzed every 2 weeks. Dry matter intake, milk, milk fat and protein yields (kg/d) of the control and HP treatments were 21.2 and 20.7 (P≤0.05), 34.3 and 35.5 (P≤0.05), 0.866 and 0.935 (P≤0.05), and 0.963 and 1.002 (P≤0.05), respectively. Average milk, milk fat and protein yields in the control and HP cows that entered the trial within 0-21 d after calving, were 37.0 and 39.6 (P≤0.05), 0.992 and 1.043, and 0.985 and 1.056 (P≤0.05) kg/d, respectively. Supplementation of additional undegradable CP at the beginning of lactation, tended to improve reproductive performance, which was attributed to the earlier recovery of body condition score of those cows.
... Recently, El-Shabrawy (2006) found lower (P < 0.05) values of urea-N in plasma of goats receiving formaldehyde soybean meal and heat soybean seed diets than those receiving untreated soybean meal diets. However, Guillaume et al. (1991), Bruckental et al. (1996), and Rodriguez et al. (1997) found a non-significant effect of protected dietary protein on the blood level of urea-N with dairy cows. ...
This investigation included two experiments. Experiment 1 was executed to study the effect of feeding different rations of protected protein of canola meal on digestibility and nutritive val-ues within sheep. Twenty male, healthy sheep were divided into five treatments according to the methods of protein protection (control, heat, sodium hydroxide, formaldehyde, and acetic acid treatments). Experiment 2 was carried out on developing lambs to investigate the effect of protected protein on growth performance and some blood metabolites. Animals in this ex-periment were also divided into the same treatments as Experiment 1. Animals in the first and second experiment were fed concentrate ration (80%) and wheat straw (20%) to cover the feed requirements. Nutritive values expressed as total digestible nutrients (TDN%) and di-gestible crude protein (DCP%) of the experi-mental rations was calculated. In the second experimental all animals were weighed biweekly and the amounts of rations were adjusted throughout the experimental period (120 days) according to their body weight change. Results indicated that in the first experimental protected protein by heat (HE) and sodium hy-droxide (NH) had positive (P < 0.05) effects on most of digestibility coefficients of different nu-trients. Protein protection methods also im-proved (P < 0.05) the nutritive values (TDN and DCP) in the HE treatment and NH treatment. In the second experiment body weight increased by 14% and 7% and also daily gain by 27% and14% in HE and NH, respectively, while FM and AC decreased body weight by 8% and 4.4%. Higher values (P < 0.01) in both thyroid hor-mones were observed in HE and NH than those other treatments. Also, higher values (P < 0.01) of total protein, albumin, and glucose were ob-served in HE and NH than other treatments. The control (CTL) group recorded higher concentra-tions of urea-N and creatinine at different peri-ods of the experiment in comparison with other treatments. Generally, from the present investi-gation it can be concluded that protected pro-tein of canola meal by heat or sodium hydroxide treatments were more efficient for productive performance and some blood metabolites of sheep.
... Recently, El-Shabrawy (2006) found lower (P < 0.05) values of urea-N in plasma of goats receiving formaldehyde soybean meal and heat soybean seed diets than those receiving untreated soybean meal diets. However, Guillaume et al. (1991), Bruckental et al. (1996), and Rodriguez et al. (1997) found a non-significant effect of protected dietary protein on the blood level of urea-N with dairy cows. ...
This investigation included two experiments. Experiment 1 was executed to study the effect of feeding different rations of protected protein of canola meal on digestibility and nutritive values within sheep. Twenty male, healthy sheep were divided into five treatments according to the methods of protein protection (control, heat, sodium hydroxide, formaldehyde, and acetic acid treatments). Experiment 2 was carried out on developing lambs to investigate the effect of protected protein on growth performance and some blood metabolites. Animals in this experiment were also divided into the same treatments as Experiment 1. Animals in the first and second experiment were fed concentrate ration (80%) and wheat straw (20%) to cover the feed requirements. Nutritive values expressed as total digestible nutrients (TDN%) and digestible crude protein (DCP%) of the experimental rations was calculated. In the second experimental all animals were weighed biweekly and the amounts of rations were adjusted throughout the experimental period (120 days) according to their body weight change. Results indicated that in the first experimental protected protein by heat (HE) and sodium hydroxide (NH) had positive (P < 0.05) effects on most of digestibility coefficients of different nutrients. Protein protection methods also improved (P < 0.05) the nutritive values (TDN and DCP) in the HE treatment and NH treatment. In the second experiment body weight increased by 14% and 7% and also daily gain by 27% and14% in HE and NH, respectively, while FM and AC decreased body weight by 8% and 4.4%. Higher values (P < 0.01) in both thyroid hormones were observed in HE and NH than those other treatments. Also, higher values (P < 0.01) of total protein, albumin, and glucose were observed in HE and NH than other treatments. The control (CTL) group recorded higher concentrations of urea-N and creatinine at different periods of the experiment in comparison with other treatments. Generally, from the present investigation it can be concluded that protected protein of canola meal by heat or sodium hydroxide treatments were more efficient for productive performance and some blood metabolites of sheep.
Twenty four lactating Zaraibi goats in mid lactation were used in a 2 x 2 factorial experimental design to evaluate two different sources of ruminally degradable non structural carbohydrates (high and low RDNSC) and two different sources of ruminally degradable protein (high and low RDP). Four experimental diets were formulated to study their effects on digestion coefficients, some blood constituents and milk production and its composition. The obtained results indicated that digestibility coefficients for DM, OM, CP and NFE and the nutritive value in terms of TDN and DCP% were significantly (P<0.05) higher for goats received low RDP and high RDNSC diets than those received high RDP and low RDNSC diets. The concentration of plasma urea-N was decreased (P<0.05) when goats were fed low RDP diets than those fed high RDP ones, whereas the concentrations of total protein, albumin and globulin were increased indicating once more better utilization of low RDP. Regardless the RDP, plasma urea-N was significantly (P<0.05) lower in goats fed high RDNSC diets than in those fed low RDNSC diets. Yields of milk, 4% fat-corrected milk (4%-FCM) and milk components were higher (P<0.05) when goats fed low RDP diets than those fed high RDP ones. Milk non-protein-nitrogen (NPN) was lower (P<0.05) with low RDP diets. On the other hand, yield of true protein nitrogen, casein nitrogen, whey nitrogen and unsaturated fatty acids in milk were higher (P<0.05) with goats fed low RDP than those fed high RDP. Regardless the RDP content of the tested diets, a slight improvement in milk yield and 4%-FCM detected for goats given high RDNSC diets compared to those given low RDNSC ones without significant differences. Goats received low RDP with high RDNSC (diet 4) were higher and more persistent for milk yield during the experimental period. On the other hand goats received diets contained high RDP with high RDNSC produced the lowest milk yield.
This trial was designed to investigate whether increasing the amount of ruminal undegradable crude protein (CP) content of rations given to high producing dairy cows, affected total non-structural carbohydrate (TNC) digestibility and milk production. A total of 36 Israeli-Holstein multiparous dairy cows were assigned to three treatments according to parity number, calving date, milk yield during the previous lactation and body weight (BW) 2 days after calving. Diets were formulated to contain (on a DM basis) 45% forage, 16.5% CP, 1.7 Mcal/kg net energy lactation (NE), and differed in dietary CP undegradability, as follows: (1) low undegradable CP (LUDCP)-UDCP, 36% of dietary CP; (2) medium UDCP (MUDCP)-UDCP, 41% of dietary CP; and (3) high UDCP (HUDCP)-UDCP, 46% of dietary CP. Dietary UDCP was increased by reducing concentrations of soybean meal and urea and increasing those of fish meal and gluten meal. The cows were maintained in the trial for 3 months. Average dry matter intakes of cows on LUDCP, MUDCP and HUDCP treatments were 25.0, 23.3 and 23.3 kg/day, respectively (P>0.1). Treatment averages of milk yield (kg/day), milk fat, protein and lactose (%) were 43.3, 3.01, 2.97 and 4.48, respectively, and no significant differences between diets were observed. Apparent digestibilities of dietary CP and TNC were increased by UDCP supplementation (P
This trial was designed to investigate effects of the amount of dietary undegradable crude protein (CP) and the ratio of degradable organic matter to degradable CP in the diets of high-yielding dairy cows on milk yield, energy balance and fertility during the first three months postpartum. Forty-five Israeli Holstein cows were assigned to three dietary treatments at 2 d postpartum. Dietary treatments were (1) 16.7% CP, of which 32% was undegradable (control); (2) 16.7% CP, of which 38% was undegradable; and (3) 18.0% CP, of which 35% was undegradable. Corn gluten meal (CGM) was added to diets 2 and 3 in order to increase undegradability. Cows were fed in groups, and diets were offered as a total mixed ration. Intakes of dry matter (DMI) and CP (kg/d) were 23.8 and 3.975, 21.4 and 3.574, and 20.4 and 3.672, for cows on diets 1, 2 and 3, respectively. No significant differences among the three treatments were found for milk yield, milk protein concentration, milk fat, or protein and lactose yields. Control cows lost 35.0 kg of body weight (BW) during the first 27.2 d postpartum, and then started gaining weight. At approximately day 70 the control cows attained their calving weight. Cows on diets 2 and 3 lost 55 kg of BW during 45 d postpartum and, by the end of the trial, these cows still had not attained their calving weight. Change in body condition score (BCS) during the experimental period revealed the same trends. Mean concentrations (mg/100 ml) of ammonia N in ruminal fluids and concentrations of plasma urea N were 14.0 and 20.3, 12.7 and 21.2, and 14.7 and 21.3 for cows on diets 1, 2 and 3, respectively. No significant differences among treatments were detected for any reproduction parameter. It was concluded that the differences between control cows and cows on diets 2 and 3 in DMI, BW and BCS during the first period postpartum cannot be attributed to the level of dietary undegradable CP only but to a more specific effect of CGM.
In two feeding experiments the effects of different sources of protein on nitrogen utilization were studied. Three protein sources were examined in both experiments; ( a ) soya-bean oil meal; ( b ) lucerne hay or vetch oat hay, and ( c ) a mixture of soyabean oil meal and hay. The first experiment was carried out with nine adult rams and the second with twelve growing rams.
The results of N balance experiments showed clearly the superiority of the hay ration over the soya-bean meal ration. N retention when the mixed ration was given was greater than on hay alone. No parallel trend was found between the protein digestibility of any of the diets and its efficiency for N retention.
With adult sheep a negative correlation between the extent of N retention and blood urea concentration was found; this agreed with our earlier findings. No such negative correlation was found with growing animals.
The highest concentrations of the various forms of soluble N compounds such as soluble a-amino N, diffusible N and diffusible peptide N were found in the rumen liquor taken from the sheep kept on the hay diet. The lowest amounts were observed when the soya-bean oil meal diet was given and intermediate amounts with the mixed diet. These trend sappeared to be related to the NPN (non-protein nitrogen) content of the diet, but the amounts of soluble N compounds present in rumen liquor were not directly correlated with the extent of N retention.
Concentrations of VFA present in rumen liquor depended primarily on the carbohydrate composition in the diet. The type of protein ingested exerted some influence, particularly on the concentrations of caproic and iso-caproic acid. The ratios of concentrations of the individual fatty acids in blood to the concentrations of the same acids in rumen liquor were found to increase with lengthening of the fatty acid chain.
In situ evaluation of the duodenal amino acid (AA) profile was attempted in a 4 × 4 Latin square study using four lactating Holstein cows fitted with ruminal and duodenal cannulas. Dietary supplemental crude protein (CP) sources, making up 40% of the dietary CP, were: soybean meal, cottonseed meal, corn gluten meal or urea. Duodenal flow of organic matter (OM) and CP was determined in vivo by means of constant infusion of ytterbium and chromium, and predicted in situ from rumen degradation. Purines were used as microbial markers. In situ calculation of the AA profile, expressed as g AA in 100 g of total AAs, was based on the composition of AA in feed and in isolated bacteria as well as on in situ rumen degradation of OM and CP. The AA profile in the duodenum when assessed in vivo was affected by the nature of the supplemental protein; in situ assessment of the AA profile resulted in comparable profiles. The data are interpreted to suggest that the in situ method enables prediction of the profile of AA (g AA/100 g total AA) flowing to the duodenum, and that the undegraded portion of supplemented protein affects that profile.
Feed intake, milk production and composition were determined in three experiments (a total of 131 multiparous dairy cows), to measure the effect of protein intake on animal performance. A range of 80 to 120% of the estimated requirement for intestinal digestible protein (DVE) relative to energy requirement was tested. Diet composition was checked by chemical analyses, in vitro digestibility and in-sacco degradation. The individual feed intake, milk production and composition and body weight changes were recorded for 16 to 20 weeks in early lactation for each animal. Means per week were used for statistical interpretation. Animal performance, milk, protein and lactose production, improved significantly on a higher level of feed intake. A higher DVE intake relative to energy intake also improved production. However, multiple regression analyses showed, that the effect of DVE supply in addition to energy intake was not significant. The small, marginal effect of extra DVE on protein yield resulted in a significant reduction of the efficiency of milk protein synthesis from 78% to almost 50%. Reasons for this reduction and the relationship with the genetic potential of the animals is discussed.
In situ evaluation of the amount and composition of duodenal crude protein flow was examined in a 4 x 4 Latin square study using four lactating Holstein cows fitted with ruminal and duodenal cannulas. Dietary supplemental CP sources, making up 40% of the dietary CP, were: soybean meal, cottonseed meal, com gluten meal or urea. Duodenal flow of organic matter (OM) and CP was determined in vivo by means of constant infusion of Yb and Cr, and was predicted in situ from rumen degradation. Purines were used as microbial markers. The two methods of estimating ruminally undegraded protein ranked the diets similarly. Microbial CP (1.9 to 2.1 kg/d) was estimated to make up 57% to 68% of the duodenal CP flow in the experimental diets. Efficiency of microbial protein synthesis were 201 (SEM 16) g CP/kg OM truly digested in the rumen, and 224 (SEM 18) g CP/kg OM disappearing in the rumen. Data are interpreted to suggest that the in situ method enables a prediction of total protein flow to the duodenum which is comparable to that obtained using the in vivo method. The added practicality of the former method renders it advantageous.
In a 3 X 2 factorial experiment 75 Holstein cows in first, second, or third lactation were fed rations containing either 12.2% or 16.2% crude protein in total ration dry matter. On the average, 26% of dry matter intake was from corn silage, 22% from alfalfa-grass hay, and 52% from a grain mix. Protein was controlled by feeding a 13.7% crude protein grain mix with 1.4% urea for the 12% ration and a 19.8% crude protein grain mix with natural protein for the 16% ration. Average daily milk production (kg/day) for wk 2 through 12 of lactation for 12% and 16% rations by lactations were: first, 21.6 and 21.9; second, 25.7 and 31.5; and third, 27.5 and 34.0. Dry matter intakes by lactations were .42, 1.18, and 2.05 kg/day higher for cows fed the high protein compared to low protein rations. Milk composition was not influenced by protein treatment. The markedly different response to protein supplementation in milk production between heifers in first lactation and more mature cows is unexplained.
1. In four feeding experiments with sheep the utilization of proteins contained in lucerne hay and of those in toasted soya-bean meal (SBM), representing a roughage and concentrate feed respectively, were examined. The ration of one group of animals contained lucerne hay as sole source of digestible protein and that of the other SBM.
2. Measurements of the nitrogen balance showed clearly the superiority of lucerne hay as protein source compared with soya-bean meal; this arose from the greater N retention found with the lucerne hay ration.
3. The influence of both rations on the metabolic pathways of the proteins was examined by following the changes of concentration of various metabolites in the rumen contents and of blood urea at different intervals after feeding.
4. Concentrations of urea found in the blood of the sheep given lucerne hay were lower than those of the other group, a finding which is in agreement with the results of the balance experiments.
5. The concentrations of NH 2 -N and of aminoacids in the rumen liquor were higher in sheep given lucerne hay than in those given SBM. These concentrations appeared to be related to the differences between the soluble non-protein N contents of the two feeds.
6. The results agree with the finding from in vitro experiments that rumen liquor from sheep receiving lucerne hay promoted greater synthesis of protein than rumen liquor from sheep receiving SBM.
7. Total bacterial activity as measured by the reduction of triphenyltetrazolium chloride (dehydrogenase activity) was much higher in the rumen liquor of sheep given lucerne hay than when SBM was given.
8. The concentrations of volatile fatty acids (C 2 -C 6 ) were much higher in the rumen liquor in sheep on the lucerne hay diet than in those on the SBM diet. After meals of the lucerne hay diet, the concentrations of acids higher than C 2 , particularly those of valeric acid, exceeded those present in the rumen liquor of the animals kept on the SBM diet.
9. Proline and alanine appeared in relatively higher concentrations in the rumen liquor than the other amino acids determined, and these two acids together with valine disappeared very rapidly. The possible conversion of these amino acids into valeric acid is considered. It is suggested that valeric acid found in relatively high concentrations in rumen liquor of sheep given lucerne hay may be due in part to the deamination of proline, which likewise disappeared very rapidly together with alanine and valine.
The effect of variable degradability of both OM and CP, incorporated at a constant ratio in diets of high yielding dairy cows (35 kg/d), was studied under commercial dairy herd conditions. Two diets containing 17% CP were formulated, including high (70%) and low (65%) protein degradability. The ratio of rumen-degradable OM to degradable protein was adjusted to 5:1 in both diets. Cows were assigned to treatments based on equal milk yield prior to trial, parity, and DIM. The trial lasted 7 wk: a reference week (wk 0), in which both groups were fed the high degradability diet, was followed by 6 experimental wk, in which group 1 was fed the high degradability diet and group 2 the low degradability diet. Cows on the low degradability diet consumed 1.2 kg more DM and yielded 1.5 kg/d more milk, .055 kg/d more milk protein, and .196 kg/d more milk fat. Percentages of milk protein (3.06 and 3.03) were similar, but fat (3.67 and 3.28) was higher for cows fed the low degradability diet. The results suggest that, when diets were formulated to balance rumen degradability of both OM and CP, 65% rather than 70% degradability of CP was advantageous for yields of milk and milk components.