The aim of this study was to compare the nutritional value of sunflower meal (SFM) and soybean meal (SBM) protein by determining both its ruminal degradability and intestinal digestibility. Three non lactating Jersey cows fitted with a rumen and T-type duodenal cannulas were used to estimate rumen degradability and intestinal digestibility of SFM and SBM dry matter (DM) and crude protein (CP). Samples of SFM were collected from seven sunflower processing plants (SFM1 to SFM7). Six different samples of SBM were collected from three main suppliers (SBM1 to SBM6). Both protein feeds were incubated in the rumen of the cows for 0, 2, 4, 8, 16, 24 and 48 h in 6 replications. The rapidly degradable fraction of DM averaged 24. 8% for SFM which was lower (P<0. 01) than that observed for SBM (29. 2%). The effective DM degrad-ability of SFM (56. 2 %/h), at mean rumen outflow rate of 0. 06/h, was lower (P<0. 01) compared with SBM samples (67. 3 %/h). The washable fraction a of CP was higher (P<0. 01) for SFM samples (26. 3%) in com-parison to all batches of SBM (16. 5%). The effective degradability of SFM CP (67. 7 %/h) at rumen passage rate of 0. 06/h was higher (P<0. 01) than in SBM (63. 0 %/h). The DM intestinal digestibility of SFM samples (42. 6%) measured by the mobile bag technique was lower (P<0. 01) compared to SBM samples (71. 9%). The intestinal digestibility of SFM CP (89. 9%) was also lower (P<0. 01) than in SBM (94. 6%). Results of this study indicate that SBM samples were more resistant to ruminal degradation than SFM. The data sug-gest that changing the toasting parameters can decrease degradability of SFM to improve protein quality.

This study was conducted to identify the nutritive and anti-nutritive composition, in situ rumen degradability, and the kinetics of in vitro gas production of Persian oak (Quercus persica) leaves harvested at three growth stages during the spring season. A tannin bioassay was also performed using polyethylene glycol (PEG 6000) as a tannin-complexing agent in a gas production test. Leaves were harvested in monthly intervals in spring, starting on April when leaves were at the early vegetative stage, and then May and June. As the leaf maturity progressed, crude protein decreased but total phenols, total tannins, and hydrolysable tannins increased. Condensed tannin concentration was not affected by maturity stage (Average=13. 0 mg leucocyanidin equivalent/g dry matter (DM)). As leaf maturity increased, the rapidly degradable A fraction of DM increased. In vitro gas production, metabolizable energy, in vitro DM degradability, ruminal NH3-N, and short-chain fatty acid concentrations were greatest in leaves harvested at the early vegetative stage (April) compared with other months. Application of PEG increased in vitro gas production, metabolizable energy, in vitro DM degradability, and NH3-N and short-chain fatty acid production in the rumen fluid compared with no addition of PEG. Overall, oak leaves harvested at the early vegetative stage appeared to be a good source of forage for ruminants. However, as leaf maturity increased, ruminal fermentability decreased, which was improved with PEG addition.

The productivity of Holstein dairy cattle herds is significantly influenced by prevailing climatic conditions. Given the potential variability in climates within a single province, this study aimed to investigate the impact of different climates across the country on the productive characteristics of these herds. The study examined average milk production, fat content, protein content, fat percentage, and protein percentage, analyzing data from 325,040 heifers belonging to 270 herds for the period between 2006 and 2021. The regions of the country were classified into five distinct climates, namely BSh, BSk, BWk, Csa, and Dsa, based on the Köppen classification system, which characterizes climates by varying temperature and humidity levels. The study found that the BWk climate, characterized by cold and dry conditions, exhibited the highest milk production levels despite the unfavorable climatic conditions. This outcome can be attributed to effective herd management practices implemented in cities such as Isfahan, which fall under this climate category. The Dsa climate, characterized by a continental climate with hot and dry summers, demonstrated the third-highest milk production levels and was found to be relatively suitable for livestock rearing, particularly during seasons other than summer. Additionally, the Dsa climate was highly conducive to the growth of fodder for livestock and exhibited the best performance in terms of both the quantity and percentage of fat and protein. Despite having the lowest number of herds among the different climates, the Dsa climate outperformed the other climates in terms of production traits. Moreover, in the period from 2007 to 2021, when increasing economic problems, such as the increase in inflation and currency rates, as well as the removal of livestock input subsidies, made it difficult for livestock farmers to cover the costs of providing animal feed, all regions except Dsa region experienced a decrease in the number of herds. From the findings of this research, it can be concluded that the climatic effect in terms of heat stress for livestock and in terms of the suitability of weather conditions for planting fodder and providing livestock feed can have a decisive effect on the productive traits of livestock.

Background and objectives: Whole barley kernel because of its intact pericarp is resistant to bacterial attachment in the rumen and digestion by ruminants. Therfore, barley processing is required to make its endosperm, encased within indigestible pericarp and hull layers, accessible to the microbial population in the rumen. This study was carried out to evaluate the effects of processing method (grinding vs. steam flaking) using completely randomized design and to investigate the impacts of steaming duration, roller setting, and interaction between steaming duration and roller setting on ruminal degradability of barley grain dry and organic matter in a 3 x 2 completely randomized factorial design.Materials and methods: Five grams (DM basis) of processed barley, ground barley using a hammer mill with a standard screen size of 3 mm (GB) or steam-flaked barley (SFB) using 3 steaming times including of 35, 45 or 55 min. and 2 roller setting distances of 0.3 or 0.4 mm for each steaming time, were weighed into bags (10×20 cm) made of polyester (pore size, 50 m). Triplicate nylon bags were placed in the rumen of a non-lactating Holstein dairy cow for 0, 2, 4, 8, 16, 24, and 48 h, respectively, for each sample. The incubation was repeated three times. Residues of dry matter (DM) and organic matter (OM) per incubation time were analyzed using SAS software.Results: Processing method changed the density of GB (616 g/L), SFB (285 g/L on average) compared to whole barley grain density (684 g/L). Increasing the extent of barley flaking decreased the density from 390 to 180 g/L, and kernel thickness from 1.5 to 1.0 mm. Grinding of barley versus steam-flaking on average increased DM and OM disappearance (%) and raised (P<0.01) the washable fraction (28.6 vs. 21.6%), degradation rate of potentially degradable fraction (0.10 vs. 0.05/h), and effective degradability (60.4 vs. 47.5%); whereas it reduced (P<0.01) the potentially degradable fraction (51.7 vs. 56.0%), and undergrad able fraction (19.7 vs. 22.5%) of DM and increased (P<0.01) the washable fraction (28.3 vs. 21.4%), degradation rate of potentially degradable fraction (0.10 vs. 0.05/h), and effective degradability (60.6 vs. 47.6%); whereas it reduced (P<0.01) the potentially degradable fraction (52.6 vs. 56.5%), and undegradable fraction (19.1 vs. 22.1%) of OM (P<0.01). Increasing the steaming time and decreasing the distance of roller setting (to comparison the distance of rollers, 0.4 vs.0.3 mm) on average increased DM and OM disappearance (%) but decreased the potentially degradable fraction (62.6 vs. 49.4%), and increased the washable fraction (17.8 vs. 25.3%), undegradable fraction (19.7 vs. 25.3%), degradation rate of potentially degradable fraction (0.05 vs. 0.06/h), and effective degradability (44.1 vs. 50.9%) of DM and decreased the potentially degradable fraction (62.9 vs. 50.1%), and increased the washable fraction (17.7 vs. 25.1%), undegradable fraction (19.5 vs. 24.9%), degradation rate of potentially degradable fraction (0.05 vs. 0.06/h), and effective degradability (44.2 vs. 51.0%) of OM for SFB (P<0.05).Conclusion: Results of this study showed that processing method could change barley grain density, particle size and its distribution on sieves. Grinding versus flaking increased the effective degradability of grain DM and OM. Ruminal DM and OM degradability of barley grain could be manipulated by varying the duration of steaming and the distance of roller setting.

Feed evaluation provides essential information’s to animal nutritionists for better feed formulation on the basis of physiological and economical view of point to improve animal performance. There are various feed evaluation method at present time and In situ technique (nylon bag or in sacco method) is commonly used in this way. In this study, ruminal degradability of dry matter, organic matter, crude protein and ADF was measured. Four different oil seed meals consist of canola meal, cotton seed meal, soybean meal and sunflower meal was studied using in situ method. Results of this experiment indicated that degradability (a+b) and effective degradation (EP) in soybean meal, canola meal and cotton seed meal produced in Behpak oil plant was (98.5, 98.7 and 56.8%) and (55.8, 62.0 and 48.3%) and for soybean meal, canola meal and sunflower meal produced in kesht-o-sanat oil plant was (81.7, 90.1 and 90.5%) and (47.1, 52.5 and 45.2%) respectively.

Rumen degradability was determined for six wheat, three corn and three millet cultivars in six ruminally cannulated sheep. The sheep were fed a ration containing 55% alfalfa and 45% ground barley. All grains were incubated for 2, 4, 8, 12, 24 and 48 h in dacron bags (50-llm pore size). The mean soluble and degradable portions, rate of degradation and effective degradability of dry matter ranged from 3.3 to 8.2%, 80.9 to 92.8%, 5.4 to 27.5% and 44;.8 to 74.2% for wheat, corn and millet, respectively. Corresponding values for crude protein of wheat corn and millet ranged from 5.7 to 9.6%, 4$.7 to 83%, 5.3 to 28.9% and 35.1 to 78.4%, respectively. It was concluded that grains varied widely in their ruminal degradability and this information may aid in synchronizing degradation of protein and starch in the rumen to improve lactation performance.

The aim of this study was to evaluate the effect of Gamma Ray irradiation (GR) at doses of 20 and 40 kGy and Microwaving (MW) at 800W for 3 and 5 minutes on ruminal degradation kinetics and in vitro digestibility of Sesame Seal (SSM). Degradability parameters of irradiated samples were measured by nylon bag technique. The amount of histidine, threonine, valine, alanine, arginine, glutamine, glycine, and serine were lower, but the amount of methionine and phenylalanine were higher in GR and MW treated samples compared to untreated ones. Irradiation reduced the fiber content of SSM and altered its chemical composition compared to the untreated SSM. Ruminal degradability of DM (Dry Matter) and CP (Crude Protein) was diminished in the treated SSM. Effective Degradability (ED) of DM and CP was found to be lower in the GR irradiated SSM compared to the MW irradiated SSM and the control. After 16 hours of ruminal incubation of the treated SSM, the degradability of isoleucine, methionine, phenylalanine, and threonine were lower, but those of glycine and serine were higher. The in vitro Digestibility of DM (DMD) and Organic Matter (OMD), as well as the Organic Matter in the Dry matter (DOMD) were lower and higher in GR and MW irradiated SSM, respectively, compared to unirradiated SSM. It can be concluded that irradiation of sesame meal by gamma ray irradiation was effective in protecting crude protein and some amino acids, including methionine and phenylalanine, from ruminal degradation.