No abstract

No abstract

EL-SHAZLY, K. (University of California, Davis), AND R. E. HUNGATE. Fermentation capacity as a measure of net growth of rumen microorganisms. Appl. Microbiol. 13:62-69. 1965.-A simple technique for measuring the rate of fermentation of rumen microorganisms is described. It allows quick preparation and handling of the rumen sample immediately after collection. The average rate of fermentation of rumen samples collected from a lactating cow fed on alfalfa hay and concentrate in the ratio of 2:1 was very similar to the rate obtained by other methods. On the assumption that when substrate is in excess, the fermentation rate is proportional to the total microbial cells, the method was used to estimate the net growth of rumen microorganisms. The maximal fermentation rate of subsamples, taken at the beginning and after 1 hr of incubation of a sample, was measured. The results indicate a net average growth of 8% per hr, or 192% per day, in approximate agreement with rumen turnover time. The highest net growth does not necessarily coincide with the highest gas-production rate in the rumen, in part because the bicarbonate concentration in the rumen contents varies. In a cow fed on hay and concentrate, the net growth was lowest before feeding and immediately after feeding.

Egypt), AND K. EL-SHAZLY. Effect of absence of ciliate protozoa from the rumen on microbial activity and growth of lambs. Appl. Microbiol. 12:384-390. 1964.-A survey of the components of the rumen ciliate population in a series of adult sheep, raised in the Faculty of Agriculture, University of Alexandria, has shown that a mixture of Entodinium, Isotricha, Ophryoscolex, Diplodinium, and Polyplastron species was found in the rumen contents of Egyptian sheep; no Epidinium and a negligible number of Dasytricha ruminantium were also observed. The microbial population, reducing sugars, ammonia, volatile fatty acids (VFA) production, and growth rate of 14 lambs inoculated with whole rumen contents from a mature sheep were compared over a 6-month period with those of 13 lambs maintained under the same conditions, except that they were strictly isolated from other ruminants. Certain large oval organisms and large numbers of flagellates and Oscillospira were frequently observed in the rumen contents of the isolated lambs. The reducing sugars, ammonia, and VFA levels, measured before and at intervals after feeding, in the inoculated lambs showed a pronounced rise above the values found in the ciliate-free animals. The propionic acid-acetic acid ratio in the rumen contents of the faunated lambs was considerably higher than in the nonfaunated controls. The inoculated lambs grew faster than the isolated lambs.

Nile tilapia, Tilapia nilotica (L.), were fed eight isonitrogenous diets in two laboratory experiments at the Faculty of Agriculture (Saba Basha), Alexandria University, Alexandria, Egypt. The diets were: (A) mixture containing 28% protein from both animal protein (fish meal) and plant protein (soybean meal and cotton seed meal) as a source of protein; (B) mixture free of animal protein; (C) mixture B supplemented with essential amino acids (EAA) (methionine and lysine); (D and E) composed of diet C supplemented with 5% and 3 5% oil respectively; (F and G) composed of diet C supplemented with emulsified or saponified 3-5% oil respectively and (H) mixture composed of diet C plus non-extracted rice bran instead of wheat flour as a source of energy without adding oil.Growth performance (energy and protein retention and protein efficiency ratio) decreased with the animal protein free diet B. Supplementation of methionine and lysine to diet C improved growth performance and feed utilization as well as addition of oil and treated oil but 5% oil and 3-5% saponified oil increased mortality of the tingeriings by 46-27% and 20% respectively. Diet F gave the lowest mortality and the highest growth, energy and protein retention and protein efficiency ratio.

This study was conducted to investigate the impacts of exogenous fibrolytic enzymes (Fibrozyme, Alltech inc company, USA) supplementation for 12 weeks on milk production and composition as well as blood metabolites in early lactating dairy cows. Total of 120 multiparous Holstein dairy cows at early lactation (57±4.2 days in milk) were randomly assigned into two groups according to lactation period "stage of lactation" and lactation season. The first group (control, n=60) were fed total mixed ration (TMR) without a supplement of exogenous fibrolytic enzymes. The second group (treatment, n=60) were fed TMR supplemented with a commercial exogenous fibrolytic enzymes at the rate of 15 g/cow/d for 12 weeks. Each group was placed in a shaded pen equipped with free stalls. An exogenous fibrolytic enzymes was added to the TMR at the time of feeding once per day at 10 am. Cows were fed as a group open feed, with free access to water.The results of this experiment on dairy cows showed that there were not significant changes in dry matter intake of lactating dairy cows with or without a supplement of exogenous fibrolytic enzymes at early lactation. Exogenous fibrolytic enzymes supplementd to lactating dairy cows improved (P<0.003) milk yield (41.0 vs. 39.5 kg/cow/d) compared to untreated dairy cows. Also, the fat corrected milk was increased (P<0.025) as a response to exogenous fibrolytic enzymes supplementation to lactating dairy cows compared to un-supplemented dairy cows. In addition, the supplementation of exogenous fibrolytic enzymes enhanced (P<0.006) the energy corrected milk (40.6 vs. 39.4 kg) and feed efficiency in early lactating dairy cows compared to the control group. The results revealed that supplementation of exogenous fibrolytic enzymes had no significant effect on milk fat, protein lactose and solid not fat (SNF) percentage compared to the control group of dairy cows. While, the quantities of milk protein (1.36 vs. 1.30kg), lactose (2.0 vs. 1.92kg) and SNF (3.47 vs. 3.31kg) in supplemented-dairy cows were improved significantly compared to the control group except quantity of milk fat (P<0.096). Serum glucose, albumin, urea and triglycerides were not affected (P>0.05) but total protein, globulin and cholesterol were declined (P<0.05) due to fibrozyme inclusion compared to control group of dairy cows. The supplementation of exogenous fibrolytic enzymes to early lactating dairy cows achieved higher net profit by 0.93 US$ per cow than control group. It is concluded that exogenous fibrolytic enzymes supplementation to early lactating dairy cows improved significantly milk production, SNF and energy corrected milk.

No abstract

1. Ten successive trials with two Rahmany adult ewes were carried out with the aim of comparing the nutritive values of the nitrogenous constituents of some concentrates used in Egypt as supplements in summer rations (decorticated cottonseed cake, linseed-oil meal and beans (Vicia faba)) and of animal proteins (meat meal, fish meal and casein) and of barseem (Trifolium alexandrinum). Wheat straw was employed as the main roughage in the ration. Nitrogen intake for all supplements was 10·16 g./day.2. Apparent digestion coefficients for crude protein were estimated. Casein had the highest digestibility coefficient while meat meal was the least digestible.3. Nitrogen retention and ruminal ammonia curves are given for each period. Only three proteins, namely, barseem, cottonseed cake and linseed meal gave positive nitrogen balance at the critical level of nitrogen intake used throughout the trials. Fish meal improved nitrogen retention significantly. Meat meal and beans did not improve nitrogen retention. The addition of 70 g. starch to beans improved nitrogen retention significantly.