1.
Effect Of Yeast Supplementation On Growth Performance In Non-Descript Male Cattle Calves In Summer
by Muhammad Tariq Iqbal (2006-VA-209) | Prof. Dr.Khalid Javed | Dr. Muhammad Qamer Shahid | Dr.Saeed Ahmad.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Livestock plays an important role in the economy of Pakistan. There are about 72 million heads of large ruminants, playing a vital role in rural economy of country,providing meat and milk to the masses. Withthe increase in human population, meat and milk demands are increasing. Thereis a majorcontribution of beef in total meat productionand cattle have a major share in total beef production. The meager feed resources are major factor for compromised growth performance of our livestock. Feed additives are feed ingredients of non-nutritive nature that stimulate growth, improve efficiency of feed utilization, and also beneficial for health. Products that improve feed efficiency are particularly important because feed costs are a major expense in animal production.
Yeast is aunicellular eukaryotic organism much different from bacteria. Among yeast Saccharomyces cerevisiaespecies are important and currently well accepted in ruminant feed. Incorporation of yeast (Saccharomyces cervesiae) culture to animal feed has become a common practice in ruminant feed. Many yeast culture based products have been shown to affect dry matter intake, stabilizing rumen pH and digestibility of different nutrients (Callaway and Martin, 1997).
The main purpose of suchadditives in ruminant feed is to prevent rumen flora disorders and disturbances. The inclusion of yeast increases consumption of dry matter, utilization of fiber, increase in average daily gain and yeast cells, and also increases absorption of phosphorus, magnesium, calcium, copper, potassium, zinc and manganese.
Due to the greaterconcerns with antibiotics and other growth stimulants in the animal feed industry, research of other feed additives, such as direct-fed microbial (DFM), has increased.DFMs are naturally occurring living microorganisms which are supplemented to enhance microbial population of rumen, and to stabilize rumen PH. DFMare frequently used in milk replacers for gastrointestinal health, welfare, as well as improving average daily gain, daily dry matter intake, and feed efficiency. Practice of these supplements in calves as a preventative measure has increased from 13.1% to 20% from 1996 to 2007 in USA (USDA, 2008).
Basic rumen studies shows that yeast apparently does not affect the digestibility, it only alters the degradation curve causing reduction in lag phase before digestion commences, thereby increasing the rate of degradation (Williams et al. 1991). It was also observed that inclusion of yeast may increase cellulolytic microorganisms in rumen. Birkelo and Berg (1994) observed that a yeast culture additive improved performance of yearling cattle fed corn-based finishing diets containing less than 10% roughage.Similarly, yeast addition was found to improve rumen fermentation by enhancing the bacterial population, soultimately increase the growth of ruminants (Beauchemin et al. 2003).Yeast culture addition increasedaily dry matter intake and average daily gain (Cole et al. 1992; Mir and Mir, 1994).
According to Blake et al. (1993) and Girard et al. (1997) yeast culture noticeably increase the cellulolytic activities of rumen microorganisms in such a way that they increase their total numbers, improve fiber digestion, decrease lactate accumulation, lessen the concentration of oxygen in rumen fluid and improve utilization of starch supplied in the feeding ration. In this way they influence (inhibit) the rate of volatile fatty acids production and, thus, increase the permanency of rumen environment and improve the intensity of digestion. Yeast culture has also directly enhanced rumen fungi, which may improve fiber digestion (Chaucheryaset al. 1995).
Yeast culture addition impact on ruminal lactic acid metabolism; prevent the accumulation of lactic acid in the rumen when they are fed on yeast supplementation. Sullivan and Martin (1999) described that yeast culture supplementation improved the utilization of lactate and digestion of cellulose. Yeast culture may improve ruminal fermentation because they are able to diminish excess oxygen (Newbold, 1996).So they provide optimal environment for fermentation. They amplified the number of rumen protozoa and NDF digestion in calves fed straw-based diets (Plata et al. 1994). Yeast culture has also been revealed to encourage acetogenic bacteria in the occurrence of methanogens (Chaucheryaset al. 1995), which may result in more effective ruminal fermentation.
The effect of altered doses of yeast (S. cerevisiae) (0, 3, 6 and 12 g of yeast/day respectively) on the lactating performance of Holstein dairy cows was described by Nikkhah et al. (2004). They concluded that the live yeast(LY) had a favorable effect on the rumen health. Other available data indicated that in the rumen fluid of animals receiving supplements of LY the total content of volatile fatty acids , the percentage of propionic acid (Sullivan and Martin, 1999), acetic acid were enhanced (Nursoy and Baytok, 2003) and the total numbers of ruminal bacteria were also significantly increased (Sune, 1998; Alshaikh et al. 2002; Kamra et al. 2002).
The positive effect of yeast may be due to increased dry matter intake reported byWohlt et al. (1991) and Williams et al. (1991).The increase in average daily gain and other productive parameters can be the function of increased dry matter intake and outflow rate of digested material from rumen. The dietary supplementation of yeast culture showed significant increase in degradability of roughage in 6 h (P<0.05) after live yeast addition(Ando et al. (2004).Moreover it is stated that yeast also contribute in maintaining rumen pH, reducing the risk of acidosis, improve rumen metabolism by stabilizing anaerobic rumen environment. It also regulates the digestibility approach, a positive influence on feed efficiency. It also maintains balance of ruminal ammonia concentration,improve feed efficiency in young calves and ultimately increase daily gain in cattle calves. The yeast supplementation in ruminant diets is being practiced at commercial herds both beef and dairy, especially where high concentrate rations are in use.
Based on the existing knowledge of live yeast supplementation and the inadequateinformation on the supplemental use of yeast in calves feedand effects on growth performance, under local conditions, the objective of present study was to determine the effects of yeast supplementation in non-descript male cattle calves on growth.
Availability: Items available for loan: UVAS Library [Call number: 2214,T] (1).
2.
Effect Of Feeding Two Levels Of Non Fiber Carbohydrate On Production Performance Of Lactating Nilli Ravi Buffaloes
by Nadeem Haider Hammad (2007-VA-065) | Prof. Dr. Anjum Khalique | Dr. Muhammad Afzal Rashid | Dr. Muhammad Qamer Shahid.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: In Pakistan during the past decade, milk production has been increased from 27.811MT to 49.512MT.Nili-Ravi buffalo is one of the best dairy breed of water buffalo; with an average milk yield per lactation 2,430 liters (Bilal et al. 2006).Buffalo population of Pakistan is considered as valuable asset comprising the best dairy breeds of the world. Buffalo’s milk contributes approximately 68% to the total milk production in the country.
The research in dairy cattle indicated that milk production is associated directly to the type of carbohydrates fed in the diet. Carbohydrate fraction contributes approximately 70% of dry matter in the diets for lactating dairy cows. NFC is a major source of energy for lactating dairy animals. According to NRC a typical dairy ration should contain NFC between 35 to 40 % of the total dietary DM to support optimal milk production. Studies in cattle have shown positive correlation of NFC with milk production.High NFC diets have shown improved production performance in cattleTherefore aim of current experiment was to evaluate the optimal level of straw based non fiber carbohydrate TMR on production performance of lactating Nili-Ravi buffalo.
The experiment was carried out at Buffalo Research Institute (BRI), Pattokito evaluate the effect of two levels of NFC on; dry matter intake, body weight, body score, fecal score, milk production, changes in milk composition, milk production efficiency. In this experiment twelve lactating Nili Ravi buffaloes of same parity and comparable milk production were selected. Animals were housed on concrete floor and were fed individually. The shed was well ventilated.
The duration of experiment was 50 days. Animals were given adaptability period of 10 days and remaining 40 days for data recording and sample collection. Animals were randomly assigned into two dietary treatments: Treatment 1: Straw based low NFC (32%) TMR as a control and Treatment 2: Straw based high NFC (40%) TMR with n=6 animals per treatment. Diets formulated were iso-nitrogenous. At the start of experiment animals were weighed and then weekly during experimental period. Hand milking was carried out twice daily in the morning and evening at 7.00 and 19.00, respectively. Milk let down was done by calf suckling. During the entire experimental period, ad libitum availability of fresh and clean water to individual animal was ensured. The animals were fed on straw based non-fiber carbohydrate TMR once daily in the morning after milking. TMR offered and refusal was recorded daily.
The effect of treatments on milk yield, milk composition, dry matter intake and other variables was analyzed by two independent sample t-tests using Procttest procedure of SAS ( release 9.1; SAS Institute, Inc, Cary, NC).
Conclusion
In present research animals were given two levels of straw based non-fiber carbohydrate TMR and it was observed that by giving straw based low NFC (32%) TMR the production performance of Nili-Ravi buffaloes were better than NFC (40%). The results of current study should be used cautiously due to the limitations of the trail.
Availability: Items available for loan: UVAS Library [Call number: 2352-T] (1).
3.
Evaluation Of Different Strategies To Improve The Dietary Nitrogen Efficiency In Lactating Dairy Cows In Pakistan
by Muhammad Imran (2005-VA-09) | Prof. Dr. Talat Naseer Pasha | Dr. Muhammad Naveed ul Haque | Dr. Muhammad Qamer Shahid.
Material type: ; Literary form:
not fiction
Publisher: 2017Dissertation note: The objectives of this study were to optimize the protein supplies and replacement of SBM with locally available ingredients in the rations of high producing Holstein Friesian cows at mid lactation. On the basis of these objectives, three experiments were conducted. Multiparous cows in mid-lactation received three treatments in a 3×3 Latin square design with a period length of 20 d. Number of animals used were nine in 1st and 3rd experiments and 12 in 2nd experiment (Table 6.1). The trials were conducted at a corporate dairy farm. When we compare the initial and final values of milk yield, milk fat and milk protein contents, there is not a big difference of our diets with that currently being practiced in Pakistan (Table 6.1). This also reveals that the experimental milk production was close to pre-experimental milk production indicating that a successful dietary transition was achieved. Table 6.1: Demonstration of parameters before and during the experiments Exp.
Cows
No.
Initial Parameters During Experiment Parameters
DIM Milk
yield (kg)
Milk
fat (%)
Milk
protein (%)
Milk
yield (kg)
Milk fat
(%)
Milk
protein (%)
1 9 113±25 32±4.1 3.65 3.25 29.7±3.1 3.70 3.27
2 12 153±44 23.3±2.1 3.99 3.34 24.7±1.8 3.98 3.31
3 9 109±19 34±3.7 3.71 3.19 30.7±2.5 3.64 3.21
Exp., experiment; DIM, days in milk In the 1st experiment, three dietary treatments were designed to provide similar energy and increasing supply of MP (g/d)—2371 (low), 2561 (medium), and 2711 (high). Increasing the MP supplies did not modify DMI; however, it increased milk protein, fat, and lactose yield linearly. Similarly, FCM increased (9.3%) linearly due to an increase in both milk yield (5.2%) and milk fat content (7.8%). Milk nitrogen efficiency decreased from 0.26 to 0.20, whereas, the
Summary
102
metabolic efficiency of MP decreased from 0.70 to 0.60 at low to high MP supplies and it average value across the treatments was 0.64 (Table 6.2). In conclusion, increasing the MP supplies resulted in increased milk protein yield; however, a higher BUN and low MNE indicated an efficient utilization of dietary protein in low MP supplies. Milk nitrogen efficiency ranges from 20 to 30% in dairy cows at mid stage of lactation. Milk nitrogen efficiency increases slightly but linearly with the increase of dietary protein up to a certain level of supply of protein. At high protein levels of dietary protein MNE is low and vice versa. In the 2nd experiment, the response of balancing metabolizable Lys to Met ratio (3:1) in low protein diets was investigated. Three experimental diets; 1) LP−: low protein diet (13.6% CP) with imbalanced Lys to Met ratio (3.33), 2) LP+: low protein diet (13.5% CP) with balanced Lys to Met ratio (2.94) through HMBi; and 3) HP−: high protein diet (14.7% CP) without balancing Lys to Met ratio (3.39) in a 3×3 Latin square design were designed. Milk yield of LP- was 0.85 kg/d less as compared with the average milk yield of LP+ and HP-. Dry matter intake decreased by 0.7 kg/d in LP+ compared to HP- treatment whereas milk yield tended to be higher by 0.7 kg/d and protein yield by 23 g/d. Balancing the Lys to Met ratio by supplementing HMBi through feed increased feed, N, and MP conversion efficiencies to milk by 4.4, 1.6, and 13.1% respectively compared to the HP- diet. Similarly, 4% FCM was increased by 4.4% in LP+ diet as compared to HP- diet. Moreover, plasma urea concentration was numerically less in LP+ compared to LP- and HP- treatments whereas no effect was observed on plasma glucose and TG concentrations. In the 3rd experiment, three diets 1) Control: with low protein with SMB as a protein source, 2) SBMD: high protein diet with SBM as a major protein source and 3) CGMD: high
Summary
103
protein diet with CGM as a major protein source. Increasing the protein supplies did not affect DMI, milk fat yield, and milk fat and lactose contents in SBMD and CGMD diets compared to the control diet. Similarly, MP balance and MP/NEL increased by 31.5 and 9.1%, respectively. Increasing the protein supplies tended to increase milk yield. Similarly, milk protein and lactose yield increased by 3.5 and 3.3%, respectively. Milk protein contents tended to increase by 1.5% in SBMD and CGMD treatments compared to the control. Increasing the dietary protein supplies increased FE in SBMD and CGMD treatments compared to control, whereas, MNE decreased by 10.9%. No effect was observed on DM, N and NEL intakes when SBM was partially replaced with CGM. Consequently, milk yield, milk components’ yield, milk composition and feed efficiency remained unaffected. Contrary to this, MNE decreased by 5% in CGM treatment compared to SBM. There were no dietary treatment effects on blood metabolites including BUN, glucose and TG concentrations, which means neither replacement of SBM nor concentration of protein in the diet affected the blood metabolites profile. There was no change in lactation performance of cows by the partial replacement of SBM with CGM. Therefore, SMB could be partially replaced with CGM with urea without affecting animal performance, and saving the feed cost. Table 6.2: Effects of experimental diets on different parameters Exp.
MP
efficiencies
Δ MP
efficiencies (%)
Δ MY
(kg)
Δ DMI
(kg)
Δ milk
fat (%)
Δ milk
protein (%)
1 0.64 14.3 5.20 0.10 7.80 5.30
2 0.65 11.6 1.20 0.70 3.93 1.50
3 0.68 9.85 1.10 0.20 2.18 1.10
Exp., experiment; MP, metabolizable protein; MY, milk yield; DMI, dry matter intake
Summary
104
In conclusion, balancing Lys to Met ratio at low protein diets and partial replacement of SMB with CGM is a mean to improve the MNE and reduce feed costs. 6.1 Conclusion and Recommendations Diets with low MP supply result in high MNE and better utilization with low levels of BUN. Although there was less milk yield in low protein diets but utilizing efficiency was high. Low protein corn-soy-based diets supplemented with rumen protected Met (HMBi) result in increased utilization of protein and low levels of BUN. Partial replacement of SBM with CGM plus urea showed no change in DMI, milk yield. Milk nitrogen efficiency was slightly decreased in CGM diet as compared to SBM diet. Feed cost could be saved by replacing 35% SBM with CGM provided that RDP is balanced by using NPN sources. Diets should be given with possible lowest protein levels having balanced AA particularly Lys and Met, which should be 3:1. High levels of protein could result into increased emission of gases to the environment. Soybean meal replacement with CGM along with some NPN source results in similar outcomes. First strategy is the best out of three currently tested and it can save money. 6.2 Future Perspectives Studies must be conducted to investigate the effects of further lowering the dietary protein levels without affecting milk production in Holstein cows. It will help to improve the dietary N utilization for milk synthesis. The above-mentioned strategies can also be tried simultaneously for improved protein/N utilization in dairy cows. Lysine can also be tried along with Met to balance the low protein corn-soy-based diets. On the basis of RDP and RUP values, other ingredients can also be tried to partially replace SMB. Availability: Items available for loan: UVAS Library [Call number: 2920-T] (1).
