Responses in urea and true protein of milk to different protein feeding schemes for dairy cows.
ABSTRACT Four multiparous Holstein cows were used in a 4 x 4 Latin square to investigate the effects of protein concentration, degradability, and quality on plasma urea concentration and milk N constituents. Diets varied in the amount and proportion of RDP and RUP relative to NRC requirements: diet 1, excessive RDP, deficient RUP; diets 2 and 3, balanced for RDP and RUP; and diet 4, excessive RDP, balanced for RUP. Diet 3 was formulated for optimal AA balance as predicted by the Cornell Net Carbohydrate and Protein System. Diets contained 34% corn silage, 19% alfalfa haylage, and 49% concentrate (DM basis). Concentrates varied in amounts of urea and soybean, corn gluten, and fish and blood meals. Concentrations of urea N and NPN in milk varied among diets: diet 1, 19 and 34 mg/dl; diet 2, 16 and 31 mg/dl; diet 3, 15 and 30 mg/dl; and diet 4, 23 and 39 mg/dl, respectively. Increases in NPN concentration were attributed to increases in the urea fraction of NPN. Intake of RUP and AA balance influenced milk true protein content; diet 1, 2.89%; diet 2, 2.90%; diet 3, 3.01%; and diet 4, 2.95%. the proportions of true protein and urea in milk are influenced by CP concentration, protein type, and protein quality.
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ABSTRACT: A total of twenty four primiparous lactating cows (8 Baladi (B), 8 Baladi x Abondance (B x A) and 8 Baladi x Tarentaise (B x T)) were used to compare their potential in milk production. Production data (milk yield, days in milk) were recorded. Fortnightly milk and blood samples were collected starting two weeks postpartum till drying off to analyze the gross chemical composition of milk and quantify IGF-1 and leptin in blood. Baladi cows were the lowest (P<0.0001) in milk yield 727.7 kg in 156.3 days in milk. No significant differences were detected in milk yield between the two examined crossbred cows (1322.3 and 1656.6 kg milk in 191.5 and 236.0 days in milk for B x A and B X T, respectively). Data of the gross chemical composition of milk (fat, protein, lactose, total solids and solids not fat percentages) showed non significant differences among the examined genotypes. Slight increase in milk protein, lactose, total solids and solids not fat were noticed in B x A crossbred compared to the other genotypes. Values of milk urea nitrogen (mg/dl) were in the normal range without any significant differences among the studied genotypes. Values of IGF-1 (ng/ml) were lower (P< 0.05) in B cows (143.3) than B x A (195.8 ng/ml) and B x T (239.2 ng/ml) crossbreds. The values of leptin (ng/ml) were higher in B x A (14.7) than B x T (13.4) than B (12.27). Upgrading Baladi cows with either French Abondance or French Tarentaise improved significantly milk yield with longer days in milk without any noticeable change in the studied milk constituents. Also, the measured blood parameters may add some explanations to the superiority of Baladi x Abondance, Baladi x Tarentaise over Baladi cows in milk production. More research is needed to investigate the impact of the upgrading of Baladi cows with European genotypes concerning reproductive performance.
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ABSTRACT: To investigate the effects of inclusion of palm kernel cake (PKC) in the diets on intake, digestibility, rumen ferment-ation characteristics, nitrogen balance and microbial N supply, five goats (initial BW = 20±1 kg) were randomly assigned to a 55 Latin square design to receive five diets, T 1 = concentrate with 15% PKC, T 2 = 25% PKC, T 3 = 35% PKC, T 4 = 45% PKC and T 5 = 55% PKC, of dietary dry matter, respectively. Plicatulum hay was offered ad libitum as the roughage. A metabolism trial lasted for 21 days during which live weight changes and feed intakes were measured. Based on this experiment, there were no significant differences (p>0.05) among treatment groups regarding dry matter (DM) intake and digestion coefficients of DM, organic matter, crude protein, neutral detergent fiber and acid detergent fiber, except in T 4 and T 5 (45 and 55% PKC) which had lower (p<0.01) than other treatments. Rumen parameters: temperature, pH, NH 3 -N, blood urea nitrogen and blood glucose, packed cell volume, volatile fatty acids, rumen microorganism populations and N retention were similar among treatments (p>0.05), however the concentration of total volatile fatty acids and protozoal populations were slightly lower for goats fed inclusion of 45-55% PKC as compared with other treatments. Based on this experiment, it could be concluded that the optimal level of PKC in concentrate should be 15-35% for goats fed with plicatulum hay and that it may be an effective means of exploiting the use of local feed resources for goat production.
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ABSTRACT: This study estimated the effect of levels of rubber seed kernel (RSK) in concentrate on feed intake, rumen fermentation, and blood metabolites in goats. Four, Thai Native × Anglo Nubian crossbred growing male goats with an average body weight of 21 ± 1 kg were housed in metabolism crates and randomly assigned according to a 4 × 4 Latin square design with four consecutive 21-d periods which consisted of 14-d adaptation and 7-d data collection. The dietary treatments were as follows: T 1 = RSK at 0% (control), T 2 = RSK at 10%, T 3 = RSK at 20%, and T 4 = RSK at 30% of DM basis, respectively. Signal hay was offered on an ad libitum basis as the roughage. Based on this experiment, there were no significant differences (p>0.05) among treatment groups regarding roughage intake whereas overall means for daily DMI (total DMI, % BW and g/kg BW 0.75) were significantly affected (p<0.05) by levels of RSK and DMI were increased quadratically with increasing level of RSK in diets. T 4 (30% RSK) had lower (p<0.05) than other treatments. The ruminal pH, NH 3 -N, BUN, blood glucose, and packed cell volume (PCV) were similar among treatments (p>0.05). In conclusion, RSK levels were up to 20% in concentrate could be efficiently utilized for goats fed on signal hay.The 15th AAAP Animal Science Congress, Thammasat University (Rangsit Campus), Bangkok/Pathum Thani, Thailand.; 11/2012