Diets containing processed barley grain as a potential rumen bypass starch source enhance productive responses of lactating Holstein dairy cows.

Effect of diets containing untreated or processed barley grain [treated with sugar beet pulp extract (SBPE) or double sulphate of aluminium and potassium (ALUM)] and different levels of rumen undegradable crude protein (RUP) on production, rumen fermentation and blood metabolites of lactating Holstein cows were investigated. Untreated soybean meal (SBM) or xylose protected 'Yasminomax soy® (YAS)' was included to represent a low (LR, 4.2% DM) and high (HR, 5.4% DM) RUP diets, respectively. Experimental diet was as follows: (a) untreated barley grains with high RUP (HRCON); (b) untreated barley grains with low RUP (LRCON); (c) ALUM-treated barley grain with high RUP (HRAL; (d) ALUM-treated barley grain with low RUP (LRAL); (e) SBPE-treated barley grain with high RUP (HRSE); and (f) SBPE-treated barley grain with low RUP (LRSE). The experiment was conducted as a completely randomized design with lactating dairy cows (n = 36) averaging 215 ± 18 days in milk, milk yield 31.7 ± 5.8 kg/day, 620 ± 61 kg body weight. Diets containing processed barley grain increased feed intake, while decreased both rumination and eating (p < 0.001). Feed intake of dairy cows on Low RUP and High RUP were 23 and 24 kg/day, respectively (p < 0.01). Daily production of milk fat, protein, lactose and total solids was improved when the processed barley grain was included in the diets (p < 0.05). Present study pinpointed that the inclusion of the processed barley grain in diets might improve production indices of dairy cows.

Effect of treating recycled poultry bedding with tannin extracted from pomegranate peel on rumen fermentation parameters and cellulolytic bacterial population in Arabian fattening lambs.

This study was conducted to investigate the effects of recycled poultry bedding (RPB) treated with different levels of pomegranate peel extract (PPE) as a tannin source on cellulolytic bacterial population and rumen fermentation parameters of fattening lambs. For this purpose, twenty-eight Arabian lambs (19.70 ± 2.45 kg body weight, 90 ± 12 days of age) were randomly assigned to four dietary treatments. Recycled poultry bedding was treated with PPE at four levels of 0 (control), 20.00, 25.00 and 30.00% on DM basis. Bacterial populations were enumerated by DNA extraction of samples of rumen liquor followed by real-time polymerase chain reaction analysis. Also, rumen samples were evaluated for pH, volatile fatty acid (VFA) and ammonia nitrogen (AN) concentrations. The populations of total bacteria, Ruminococcus albus and Fibrobacter succinogenes were decreased significantly as the level of PPE in the diet increased, however, the population of Ruminococcus flavefaciens was not affected. Dietary treatments did not have effect on ruminal pH, while AN concentration was decreased in the diets containing RPB treated with PPE compared to the control. Concentrations of total VFA and individual VFA remained unchanged by PPE-treated RPB inclusion in the diet. In conclusion, supplementing RPB with PPE improved nitrogen metabolism of fattening lambs, however, it decreased population of rumen cellulolytic bacteria R. flavefaciens.

The effect of adding ethanolic saffron petal extract (SPE) and vitamin E on growth performance, blood metabolites and antioxidant status in Baluchi male lambs.

OBJECTIVE: This study investigated the effects of the administration of ethanolic saffron petal extract (SPE) and vitamin E on growth performance, blood metabolites and antioxidant status in Baluchi lambs. METHODS: Thirty-two Baluchi male lambs (35.22±5.75 kg) were randomly divided into 4 groups. The 1st (control), 2nd (ISPE) and 3rd (Vit. E) groups were respectively injected subcutaneously with either physiological saline (5 ml), SPE (25 mg/kg BW) or DL-α-tocopheryl acetate (225 IU) once a week. An oral dose of SPE (500 mg/kg BW) was also administered to the 4th group (OSPE). Feed intake and body weight were measured for 42 days and blood samples were taken on days 1, 14, 28 and 42. The lambs were slaughtered and tissue samples were taken. RESULTS: Growth performance and many blood metabolites were not affected (p&gt;0.05) by the treatments. Cholesterol of plasma in the ISPE and Vit. E groups was similar and less (p&lt;0.01) than both the OSPE and control groups. Although there was no significant difference between the control and other groups for plasma triglyceride, the ISPE group showed lower (p&lt;0.05) triglyceride than the OSPE and Vit. E groups. The highest (p&lt;0.01) plasma glutathione peroxidase (GPx) was detected in the OSPE group, while the ISPE and Vit. E groups showed higher (p&lt;0.01) superoxide dismutase (SOD) of plasma than the control. Malondialdehyde of plasma in the ISPE group was lower (p&lt;0.05) than the OSPE. No differences (p&gt;0.05) were observed among the groups for antioxidant status of both of the longissimus dorsi muscle and liver. However, the activity of GPx in the kidney and heart, as well as SOD activity in the kidney, were influenced (p≤0.01) by the treatments. CONCLUSION: Adding ethanolic SPE improved antioxidant status and lowered lipids oxidation in lambs. The SPE and vitamin E demonstrated similar effects on antioxidant status in lambs.

Truly Absorbed Microbial Protein Synthesis, Rumen Bypass Protein, Endogenous Protein, and Total Metabolizable Protein from Starchy and Protein-Rich Raw Materials: Model Comparison and Predictions.

This study was carried out to measure truly absorbed microbial protein synthesis, rumen bypass protein, and endogenous protein loss, as well as total metabolizable protein, from starchy and protein-rich raw feed materials with model comparisons. Predictions by the DVE2010 system as a more mechanistic model were compared with those of two other models, DVE1994 and NRC-2001, that are frequently used in common international feeding practice. DVE1994 predictions for intestinally digestible rumen undegradable protein (ARUP) for starchy concentrates were higher (27 vs 18 g/kg DM, p < 0.05, SEM = 1.2) than predictions by the NRC-2001, whereas there was no difference in predictions for ARUP from protein concentrates among the three models. DVE2010 and NRC-2001 had highest estimations of intestinally digestible microbial protein for starchy (92 g/kg DM in DVE2010 vs 46 g/kg DM in NRC-2001 and 67 g/kg DM in DVE1994, p < 0.05 SEM = 4) and protein concentrates (69 g/kg DM in NRC-2001 vs 31 g/kg DM in DVE1994 and 49 g/kg DM in DVE2010, p < 0.05 SEM = 4), respectively. Potential protein supplies predicted by tested models from starchy and protein concentrates are widely different, and comparable direct measurements are needed to evaluate the actual ability of different models to predict the potential protein supply to dairy cows from different feedstuffs.