Profitability of different grouping criteria was simulated in a dairy farm with 153 lactating cows that were divided into three groups of high (79), medium (40) and low (34) cows based on the milk records. Animals were reassigned to the new groups based on the following criteria using a decision support tool and the same three groups scenario: fat corrected milk 4%, days in milk (DIM), dairy merit (fat-corrected milk (FCM)/body weight (BW)0.75), and cluster (cow’s energy and protein requirements). Four total mixed ration (TMR) were formulated for feeding three simulated groups in which group 2 (medium producing animals) could consume either concentrate type I or concentrate type II, whereas groups 1 and 3 always had their specific concentrate mixture. The number of animals in the high, medium and low producing groups altered following the re-grouping and the highest number of cows fell in either the new medium (FCM and dairy merit) or low (DIM and cluster) producing groups. Cluster and dairy merit grouping criteria resulted the most income over feed costs (IOFC) and maximum profitability compared to the milk records and other simulated scenarios. In all of the grouping criteria, when the second group consumed concentrate type II, the amount of IOFC was higher than situations where this group utilized concentrate type I. Overall, profitability and economic efficiency of the herd increased when a more precise grouping method was used. Furthermore, cluster method provided a liberty for choosing the type of concentrate for medium producing animals with a negligible effect on the calculated IOFC from the simulated data. تفاصيل المقالة

Swiss Saanen goat is a widespread breed frequently found in commercial herds across the world. The present study aimed to identify the rumen microbial community of exotic Saanen goats adapted to a fibrous diet using barcoded pyrosequencing. Rumen content samples were collected from the four animals via a stomach tube after the morning graze and freeze-dried for DNA extraction. Bacterial and archaeal 16S rRNA and protozoal 18S rRNA genes were sequenced by 454 titanium pyrosequencing and analyzed using the quantitative insights into microbial ecology (QIIME) software package. Obtained results indicated that at the genus level, Prevotella (Bacteroidetes phylum) dominated the assigned sequence, with the relative abundance accounting for 29.41 ± 4.27% of the total bacteria. The second most abundant bacteria in the rumen of Saanen goats was an unclassified Bacteroidales (Bacteroidetes phylum) (11.01±0.94%). In addition, Firmicutes phylum was recorded as the second most frequent phylum and three unclassified genera, which belonged to the order Clostridiales, constituted21.42% of the total bacteria. Entodinium was the most abundant protozoal genus, comprising 46.78 ± 9.13% of the protozoal community, followed by Epidinium and Ophryoscolex (12.37±0.06 and 11.92±7.7, respectively). Almost half the archaeal community (43.71±1.57%) was composed of Methanoplasmatales- related sequences and Methanobrevibacter gottschalkii clade (35.79±4.84%) and Methanobrevibacter ruminantium clade (13.36±6.34%) were the second and third most dominant archaea, respectively. Overall, further efforts should be made to apply culture-based methods for the identification of remarkable number of unclassified bacteria in the rumen of goats. تفاصيل المقالة

Micronization of grains is an energy-consuming heat-based process and reducing treatment time in this method might be economically desirable. Different operational conditions including duration of the process (s), grain surface temperature at the end of the process (˚C), and distance between grain and burner (cm) in a micronizer machine were examined to assess the possibility of reducing processing time using in vitro gas production, in situ and enzymatic dry matter digestibility of corn grains. Treatments which were made by altering the above operational conditions in order included: Mic 1 (120 s, 155 ˚C, and 35 cm), Mic 2 (60 s, 155 ˚C, and 15 cm), Mic 3 (90 s, 165 ˚C, and 15 cm) and Mic 4 (120 s, 175 ˚C, and 15 cm). There were two batches of raw corn which were included Raw 1 and Raw 2 as the control for micronized corn grains (Mic 1, and Mic 2-Mic 4), respectively. Enzymatic dry matter (DM) digestibility in micronized corn grains (Mic 1=26.46 and Mic 3=29.27) was significantly (P<0.001) greater than their representative controls (Raw 1=22.17 and Raw 2=25.68) but increasing severity of the process, enhanced ruminal disappearance of dry matter (66.27 vs. 59.32 in Mic 4 and Raw 2, respectively. Out of 11 non-linear tested models, logistic-exponential without lag (LE0) showed the best performance for fitting gas production results indicated that the extent of gas production may decrease or increase by micronization depending upon the operational conditions. Overall, if the surface temperature of radiated grains at exiting (as a major indicator) is fixed and could be achieved by changing micronizer structure within a shorter time, similar in vitro and in situ performance in radiated corn grains can be obtained however, overheating may increase risk of ruminal acidosis. تفاصيل المقالة