Effects of maize and citrus-pulp supplementation of urea-treated wheat straw on intake and productivity in female lambs

Abstract

Two experiments with lambs given food indoors and individually penned were designed to study the effects of different levels of ground maize and citrus pulp as supplements of a diet based on urea-treated straw (5 kg urea per 100 kg straw) offered ad libitum over a period of 16 weeks (experiment 1) or 10 weeks (experiment 2). The voluntary intake, live-weight gain (LWG), organic matter digestibility (OMD), urinary allantoin-nitrogen (UAN) excretion and acetate clearance rate were measured. The lambs were blocked on weight and randomly assigned to the treatments described below. Ruminal outflow rate of the solid and liquid phases from the rumen were also measured in experiment 2.In experiment 1, 20 female lambs from the Ile-de-France breed, with an initial live weight (LW) of 43 (s.e. 3·3) kg were used. Wheat straw (WS) was supplemented with 50 g/kg of fish meal (FM) and with 0, 100, 200 or 300 g/kg of ground maize on a dry-matter (DM) basis (M0, M1, M2 and M3, respectively). In experiment 2, 25 female lambs from the Portuguese breed Churra-da-Terra-Quente, with an initial LW of 24·2 (s.e. 4·3) kg were used. The straw was offered ad libitum during 10 weeks and supplemented with 50 g/kg of FM and 0, 100, 200, 300, or 400 g/kg of dried citrus pulp on a DM basis (CP0, CP1, CP2, CP3 and CP4, respectively).During the experiments, all animals were moved to metabolism cages to measure OMD and UAN excretion. Two additional incubation studies were carried out with rumen fistulated rams (experiment 1) or cows (experiment 2) given the diets described above close to the maintenance feeding level.In experiment 1 daily straw DM intake linearly decreased (P < 0·05) from 21·6 to 17·7 g/kg LW and LWG linearly increased (P < 0·05) from 51 to 154 g/day for treatments M0, M1, M2 and M3, respectively. The rate of straw DM degradation was significantly decreased (P < 0·01) by maize supplementation. Straw OMD (kg/kg) was 0·562, 0·583, 0·547 and 0·520 and UAN (mg/day) was 620, 790, 854 and 859 for treatments M0, M1, M2 and M3, respectively. Acetate clearance rate, increased (P < 0·05) as the level of maize inclusion increased.In experiment 2 daily straw DM intake was 23·3, 25·8, 24·7, 23·5 and 18·6 g/kg LW per day and LWG was –9, 28, 44, 64 and 67 g/day for treatments CP0, CP1, CP2, CP3 and CP4, respectively. Supplementation significantly increased LWG (P < 0·001) but at the 400 g/kg level depressed straw DM intake. Straw OMD linearly decreased (P < 0·05) from 0·484 (CP0) to 0·428 (CP4) g/kg and UAN (mg/day) was 181, 303, 363, 384 and 392 for treatments CP0, CP1, CP2, CP3 and CP4, respectively. Rumen outflow rate of fibre particles was unaffected by supplementation while the outflow of liquid phase tended to be increased (P < 0·10). The rate of DM degradation was significantly reduced (P < 0·01) by citrus-pulp inclusion. Acetate clearance rate was unaffected (P > 0·05) by citrus-pulp supplementation.The results of these experiments demonstrate that supplementation of urea-treated straw with ground maize up to 200 g/kg or with citrus pulp up to 300 g/kg of the diet DM increased or did not depress straw intake, increased the supply of microbial protein and have no significant effect on straw digestibility. The efficiency of utilization of absorbed energy was apparently improved by maize but not by citrus-pulp supplementation.

Developmental changes in clearance of intravenous doses of glucose, acetate and β-hydroxybutyrate from plasma of calves

“…Clearance of glucose has previously been shown to become less efficient during the first few weeks of a calf's life (Bunting et al, 2000). The acetate clearance test was first used by Pugh and Scarisbrick (1952) and has been used since to characterize effects of diet on acetate supply to growing lambs (Cronjé et al, 1991;Fonseca et al, 2001;Chakeredza et al, 2002). To our knowledge, the BHB clearance test has not been attempted.…”

Short communication: Growth performance, nutrient digestibility and blood parameters of fattening lambs fed diet replacing corn with orange pulp

“…Higher DMI in lambs fed 33 and 66% of OP compared to control group might be due to increase in rumen out flow rate. Fonseca et al (2001) reported that increasing the amount of OP in diets of fattening lambs led to increase in rumen out flow rate. Also, in agreement with our results, Ammerman et al (1963) observed that the inclusion of OP in the diets increased DMI and stated that rations containing OP are more palatable than those containing corn.…”

The Effects of Replacement of Dried Orange Pulp with Ground Corn in Concentrate Feed on Dairy Goats’ Performance, Milk Somatic Cell Counts and Blood Parameters

“…In this case, it is thought that volatile fatty acids, which play an active role in shaping milk yield, are not sufficiently released in the rumen and sufficient resources cannot be sent to the liver to raise blood glucose levels. The low level of volatile fatty acid production in the rumen may cause by the orange pulp's increasing the ruminal flow rate (Fonseca et al, 2001), the suppressing of the rumen microorganisms by enteric oils in the pulp (Barrios-Urdanetat et al, 2003;Nam et al, 2006) or the rapid digestion of sugar and causing a sudden drop in pH and disrupting rumen dynamics.…”

“…Even though orange pulp has similar amounts of energy (about 2980 kcal/kg DM) with cereals (Bampidis and Robinson, 2006), there are studies reporting that performance decreases by affecting rumen dynamics negatively or neutrally. Dried citrus pulp increases ruminal fluid flow and reduces dry matter digestion in the rumen (Fonseca et al, 2001), the use of dried citrus pulp instead of barley suppresses rumen bacteria (Barrios-Urdanetat et al, 2003), and citrus essential oils also have antimicrobial effects (Nam et al, 2006). Due to these reasons, it can be thought that a decrease in milk yield and a deterioration in feed efficiency rate occur, since enough volatile fatty acids will not be released in the rumen.…”