• Asian-Australasian Journal of Animal Sciences
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• 제28권10호
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• pp.1419-1426
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• 2015

This study aimed to investigate the effect of the ratio of non-fibrous carbohydrates to neutral detergent fibre (NFC/NDF) and undegraded dietary protein (UDP) on rumen fermentation and nitrogen metabolism in lambs. Four $Dorper{\times}thin-tailed$ Han crossbred lambs, averaging $62.3{\pm}1.9kg$ of body weight and 10 mo of age, were randomly assigned to four dietary treatments of combinations of two levels of NFC/NDF (1.0 and 1.7) and two levels of UDP (35% and 50% of crude protein [CP]). Duodenal nutrient flows were measured with dual markers of Yb and Co, and microbial N (MN) synthesis was estimated using $^{15}N$. High UDP decreased organic matter (OM) intake (p = 0.002) and CP intake (p = 0.005). Ruminal pH (p<0.001), ammonia nitrogen ($NH_3-N$; p = 0.008), and total volatile fatty acids (p<0.001) were affected by dietary NFC/NDF. The ruminal concentration of $NH_3-N$ was also affected by UDP (p<0.001). The duodenal flow of total MN (p = 0.007) was greater for lambs fed the high NFC/NDF diet. The amount of metabolisable N increased with increasing dietary NFC:NDF (p = 0.02) or UDP (p = 0.04). In conclusion, the diets with high NFC/NDF (1.7) and UDP (50% of CP) improved metabolisable N supply to lambs.

• Asian-Australasian Journal of Animal Sciences
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• 제27권2호
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• pp.161-168
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• 2014

This study aimed to investigate dietary concentrate:forage ratios (C:F) and undegraded dietary protein (UDP) on nitrogen balance and urinary excretion of purine derivatives (PD) in lambs. Four Dorper${\times}$thin-tailed Han crossbred castrated lambs with $62.3{\pm}1.9$ kg body weight at 10 months of age were randomly assigned to four dietary treatments in a $2{\times}2$ factorial arrangement of two levels of C:F (40:60 and 60:40) and two levels of UDP (35% and 50% of CP), according to a complete $4{\times}4$ Latin-square design. Each experimental period lasted for 19 d. After a 7-d adaptation period, lambs were moved into individual metabolism crates for 12 d including 7 d of adaption and 5 d of metabolism trial. During the metabolism trial, total urine was collected for 24 h and spot urine samples were also collected at different times. Urinary PD was measured using a colorimetric method and creatinine was measured using an automated analyzer. Intake of dry matter (DM) (p<0.01) and organic matter (OM) (p<0.01) increased as the level of UDP decreased. Fecal N was not affected by dietary treatment (p>0.05) while urinary N increased as the level of UDP decreased (p<0.05), but decreased as dietary C:F increased (p<0.05). Nitrogen retention increased as dietary C:F increased (p<0.05). As dietary C:F increased, urinary excretion of PD increased (p<0.05), but was not affected by dietary UDP (p>0.05) or interaction between dietary treatments (p>0.05). Daily excretion of creatinine was not affected by dietary treatments (p<0.05), with an average value of $0.334{\times}0.005$ mmol/kg $BW^{0.75}$. A linear correlation was found between total PD excretion and PDC index ($R^2$ = 0.93). Concentrations of creatinine and PDC index in spot urine were unaffected by sampling time (p>0.05) and a good correlation was found between the PDC index (average value of three times) of spot urine and daily excretion of PD ($R^2$ = 0.88). These results suggest that for animals fed ad libitum, the PDC index in spot urine is effective to predict daily excretion of PD. In order to improve the accuracy of the spot sampling technique, an appropriate lag phase between the time of feeding and sampling should be determined so that the sampling time can coincide with the peak concentration of PD in the urine.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.637-642
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• 2005

The objective of this study was to evaluate the effect of dietary undegradable protein (UP) level on body weight change, nutrient intake, milk production and postpartum reproductive performance of Awassi ewes. Twenty-seven multiparous Awassi ewes (initial body weight = 53.3${\pm}$1.6 kg) were randomly assigned to three dietary treatments (9 ewes/treatment) for 62 days using a completely randomized design. Experimental diets were isonitrogenous (15.5% CP), isocaloric, and were formulated to contain 17.9 (LUP), 27.1 (MUP), and 34.0% (HUP) of the dietary CP as UP. On day 10${\pm}$3 (day 0 = parturition) ewes were housed in individual pens for 5 weeks. Feed offered and refused was recorded daily. At the end of this period, animals were removed from their pens and combined into 3 separate groups (LUP, MUP and HUP). One fertile, harnessed ram was allowed with each group for 34 days. Rams were rotated every 2 days among the three groups. Each group was offered the corresponding experimental diet. Organic matter, CP, UP and metabolizable energy intakes were higher (p<0.05) for ewes fed the HUP diet compared with ewes fed the LUP and MUP diets. Ewes fed the HUP diet gained more (p<0.05) weight compared with ewes fed the MUP diet (7.3 vs. 2.1 kg), while ewes fed the LUP diet lost an average of 2.1 kg. Pregnancy rate of ewes fed the HUP diet was 100%, compared with 66 and 33% for ewes fed the MUP and LUP diets, respectively. Lambing rate was greater (p<0.05) for ewes fed HUP (8/9) diet compared with ewes fed the MUP (4/9) and LUP (3/9) diets. These results indicate that Awassi ewes receiving adequate dietary UP level consume more feed and are capable of returning to estrus shortly after parturition and are capable of producing two lamb crops per year.

• Asian-Australasian Journal of Animal Sciences
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• 제14권3호
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• pp.321-325
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• 2001

Two experiments were conducted to examine the degradation rates of 4 tropical legume forages in rumen and intestine of Kedah-Kelantan (KK) cattle. Three KK cattle, averaging $173{\pm}17.15kg$ each fitted with a permanent ruminal and a T-shaped duodenal cannulae were used. The cattle were fed a maintenance diet (1% DM of their body weight) composing of 60% oil palm frond (OPF) pellet and 40% of a legume mixture of Arachis pintoi (AP) and Leucaena throughout the study. The overall DM and CP degradabilities in the rumen for Gliricidia sepium (GS) and AP were significantly higher than those for Leucaena leucocephala-Bahru (LB) and Leucaena leucocephala-Rendang (LR). This implies that LB and LR would have higher dietary protein flows into the intestine for the more efficient enzymatic digestion. However, the results of the present study suggested only limited proportions of the ruminal undegraded protein in the Leucaenas were digested in the intestine.

• Asian-Australasian Journal of Animal Sciences
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• 제14권8호
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• pp.1118-1124
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• 2001

Fifteen lactating crossbred cows were randomly allotted to three groups of 5 each, and fed three isoproteinous concentrate mixture varying in RDP and UDP ratios, viz. 71: 29 (T1) and 58: 42 (T2) and 44: 56 (T3), along with green maize and wheat straw given as 2/3 and 1/3 of total roughage respectively, for a period of 120 days. The DM intake (kg/d) differed significantly (p<0.01) among the treatments as well as among the fortnights over a period of 120 days. DMI (kg/d) progressively increased from first to eighth fortnight in all the treatments. The daily DMI (% BW) was significantly (p<0.01) lower in T1 (2.37) than those of T2 (2.82) and T3 (2.67). The body weights of cows decreased up to 4th fortnight in T1 and up to 3rd fortnight in T2 and T3, then it showed an increasing trend till the end of the experiment in all the treatments. Cows in T1 lost 10 kg body weight but cows in T2 and T3 gained 23 and 12 kg the body weight, respectively. Both the milk and FCM yield differed significantly (p<0.01) among the fortnights. The FCM yield increased up to 2nd fortnight in all the treatments and thereafter, the FCM yield declined gradually as the lactation advanced. The FCM yield (kg/d) was significantly (p<0.05) higher in T3 (10.47) than in T2 (9.81) and T1 (9.68), however, milk yield, SCM yield and milk energy yield did not differ among the treatments as well as among the fortnights. Fat and protein % in milk increased as the lactation advanced. However, fortnightly SNF % in milk showed an irregular trend. The % fat, protein, SNF and total solids in milk differed significantly (p<0.01) among the fortnights. The % fat and protein in milk varied significantly (p<0.01) among the treatments, being lowest in T1 and highest in T3. The feed efficiency for milk production showed a non-significant variation among the treatments as well as among the fortnights, but increased with the increase in UDP level. It is concluded that by increasing the UDP level from 29 to 56 per cent of CP in the diet of medium producing cows, the milk production increases and cost of milk production reduces.

• Asian-Australasian Journal of Animal Sciences
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• 제16권4호
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• pp.609-624
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• 2003

The genesis of methods for defining the nutritional value of feeds and the nutrient requirements of animals, and their development in the late 19th and early 20th centuries in Europe and the USA are outlined. Current energy and protein feeding systems for ruminants are described. Particular reference is made to the Australian systems which are applicable to grazing animals as well as to those given prepared feeds, and enable the effective nutritional management of a imals at pasture by means of the decision support tool GrazFeed. The scheme for predicting intakes by cattle and sheep from pastures allows for the effects of selective grazing on the composition of the feed eaten, and for reduction in herbage intake when a supplementary feed is consumed. For herbage of any given concentration of metabolizable energy (ME) in the feed dry matter the changes with season of year in the net efficiency of use of the ME for growth and fattening and in the yield of microbial crude protein, g/MJ ME, which both vary with latitude, are defined. An equation to predict the energy requirements for maintenance (MEm) of both cattle and sheep includes predictions of the additional energy costs incurred by grazing compared with housed animals and the cost, if any, of cold stress. The equation allows for the change in MEm with feed intake. A flexible procedure predicts the composition of liveweight gain made by any given breed or sex of cattle and sheep at any stage of growth, and the variation with rate of gain. Protein requirements for maintenance, production including wool growth, and reproduction, are related to the quantities of microbial true protein and undegraded dietary protein truly digested in the small intestine.

• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1634-1641
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• 2003

In vivo digestion and metabolism trials were conducted with 10 wethers equipped with ruminal, abomasal, and ileal cannulae to evaluate digestion of ensiled broiler litter (EBL), deepstacked broiler litter (DBL), and composted broiler litter (CBL). Wethers were fed a low protein (6.3% CP) basal diet alone or supplemented to 10.3% CP with EBL, DBL, CBL or soybean meal (SBM). All diets were formulated to be isoenergetic (56% TDN, DM basis). Apparent digestibilities of DM, OM, and ADF were not affected (p<0.05) by diet, but digestibility of CP was improved (p<0.05) by N supplementation. Apparent digestibility of CP was lower (p<0.05) for diets supplemented with CBL and DBL than for diets supplemented with SBM and EBL. Ruminal $NH_3$ concentration was 20 to 24 mg/dl at 2 h after feeding litter-supplemented diets compared with 13 mg/dl for SBM. Abomasal N, $NH_3$ N, and nonammonia N flows were increased (p<0.05) by N supplementation, whereas microbial N flow was not influenced (p<0.05) by diet. Compared with SBM and EBL, undegraded dietary CP flow to the abomasum tended to be greater (p<0.1) when wethers were fed DBL and CBLsupplemented diets. Retention of N (g/d) also was greater (p<0.05) due to greater (p<0.05) N intake and lower (p<0.05) urinary N excretion when wethers were fed diets supplemented with litter (especially EBL) vs. SBM. Overall, characteristics of ruminal fermentation and digestion indicated that broiler litter N was utilized efficiently by wethers, but ensiling may be preferable to deepstacking or composting.