C. Johnston
Department of Animal Sciences
Research was completed using 10- to 24-hour-old suckled lambs to evaluate both the preweaning and postweaning performance of artificially reared lambs fed milk replacer (MR) ad libitum in which 39.75% of the milk protein was provided by modified soyflour/wheat flour (MSWF). Modified soyflour/wheat flour was prepared by gelatinizing a mixture of soyflour (SF) with a lesser amount of wheat flour (WF), followed by treatment of the mixture with malted barley (MB) flour and yeast (S. cerevisiae). The acidified MR containing MSWF was readily accepted when introduced to 10- to 24-hour-old lambs when bottle fed to 3 days of age and then from a lam-bar ad libitum feeder until they were weaned at 28 days of age. While the benefits of introducing MSWF at birth or 1 day of age were inconclusive, results indicated that MR containing MSWF may be introduced by at least as early as 5 days of age. The acidified MR formulation containing MSWF was of good consistency, stable when fed ad libitum in lam-bar feeders, and remained fresh for up to 3 days.
To maximize the economic returns of the commercial sheep enterprise, it is important to market the largest possible number of quality lambs from each ewe every year. With improvements in management, reproduction, nutrition, and disease control, substantial progress in this area has been made; however, the cost of lamb milk replacer (MR) for those lambs which cannot be suckled is an impediment to future progress. Increases in the cost for MR have been associated primarily with the increases in the cost of dried skim milk. Although progress has been made toward checking additional cost increases by replacing dried skim milk with less expensive whey and whey protein concentrate, alternative low cost protein sources are needed if future costs are to remain stable or reduced. Attempts have been made to develop alternate protein sources of plant or animal origin for use in MR; however, the physical requirement that the formulation remain stable in an ad libitum feeding system for a considerable length of time has been difficult to overcome (Heaney and Shrestha, 1987; Tomkins, 1992). It was the objective of this research to develop a less expensive MR for lambs in which a major portion of the protein would be supplied by non-milk ingredients. The results from studies to evaluate MR formulations are reported here.
Lambs of predominantly Polypay, with a few Targhee of either sex, with birth weights of at least 7 pounds were included in the trial. Following birth, the navels of the lambs were sprayed with iodine, and they were injected s.c. with 1 ml of BO-SE (Schering-Plough Animal Health Corp., Kenilworth, NJ). The lambs were permitted to suckle for not less than 10 hours or longer than 24 hours before separation from their dams. They then were weighed, injected with Cl. perfringens C and D antitoxin (Bio-Centic, St. Joseph, MO), and assigned in birth order to three treatment groups of ten lambs each in separate pens. Lambs in each treatment group were within 3 days of the same age. They were hand fed for 2 days, and on the third day their tails were docked (White's emasculator), the males castrated, and trained to eat MR ad libitum from a lam-bar nipple feeder. The lambs in Group A were fed commercial MR from days 1 to 28, those in Group B MSWF diet from days 1 to 28, and those in Group C commercial MR for days 1 to 5, followed by MSWF containing MR from days 5 to 28. All lambs were fed MR until the average age of the lambs in each pen reached 28 days. Composition and calculated analyses of the MR formulations and the dry pelleted diets (DM basis), including the guaranteed analysis of the commercial MR, are shown in Table 1. Milk replacer diets were prepared according to the manufacturer's recommendation for the commercial MR to have a solids concentration of 19.36%. Diets were prepared in 200-pound quantities and refrigerated in four gallon pails before feeding. The lam-bars were refilled twice daily until the lambs ate satisfactorily, then once daily until this amount was no longer sufficient to provide adequate feed for the 24-hour period. Additional feed was then added as needed. The lam-bars were cleaned and fresh feed added every third day. On day 10, lambs were given a second injection of Cl. perfringens C and D antitoxin and injected s.c. with Cl. perfringens types C and D with tetanus toxoid (Bio-Centric, St. Joseph, MO). They were given a second injection of Cl. perfringens types C and D with tetanus toxoid 14 days later. On day 28, the lam-bars were removed from the pens and the lambs abruptly weaned to a dry pelleted (3.6 mm) commercial lamb starter diet for 1 week, then changed to a pelleted lamb grower (4.8 mm) for the remaining week. The lambs were not fed pelleted feed before weaning. Pelleted feed was supplied ad libitum by hanging feeders in each pen. Water was provided fresh daily from pails placed in each pen for the first 3 weeks, then from automatic fountains. Each pen of lambs was weighed individually at 7-day intervals. All diets were prepared in a double-walled stainless steel mixing vessel with a variable speed mixer.
The MSWF was prepared by placing 161.28 pounds of water into the mixing vessel and heating it to 122F. One percent of the MSWF DM weight was added as matted barley flour (Archer Daniels Midland Co., Inc., Decatur, IL) and stirred until suspended. The required amounts of Sapphire wheat flour (Con Agra, Inc., Omaha, NE) and toasted SF (Archer Daniels Midland Co., Inc., Decatur, IL) to provide 39.75% of the protein to the finished diet were then added and the mixture stirred for 5 minutes. The temperature was increased to 180F for one hour, then reduced to 95F, and the pH adjusted to 5.2 to 5.5 by adding granular citric acid. An additional 1% MB was added and the mixture stirred for 2 hours. The temperature of the mixture was increased to 139F over 30 minutes and the mixture stirred for 1 hour. The temperature was then reduced to 90F, and 1% of dried bakers yeast (Saccharomyces cerevisiae) was added. The mixture was stirred for 1 hour and let stand for 3 hours without stirring. With mixing, the temperature was rapidly increased to 150F for 15 minutes. The remainder of the ingredients needed to complete the feed were added. Feeds were prepared fresh at least weekly.
There were no differences in initial weights or average daily gains (ADGs) on days 1 to 7 and days 7 to 14 among the three groups of lambs (Table 2). The MSWF diet readily was accepted by groups C and D when it was introduced on days 1 and 5, respectively. However, after it was fed to Group B for 2 days, it was concluded that the formulation was too thick for optimum ease of consumption by newborn or day-old lambs. Subsequent determination of the solids/liquid content of the diet indicated that 1% of the water had been lost from the formulation by evaporation during preparation. This resulted in the diet having a solids concentration of 20.38% rather than the anticipated concentration. The addition of this lost water back to the diet markedly reduced its viscosity and the ease with which it was consumed by the lambs. However, because of the possible influence which this loss of water from the formulation could have had on the ability of the newborn or day-old lamb to consume it, its use for lambs of this age group should await additional evaluation. The addition of the water which was lost to evaporation was made prior to the initial feeding of the diet to Group C on day 5.
| Table 1. Composition of milk replacer1 and dry pelleted2 diets. | ||
| Percentage, DM basis | ||
| Ingredient | MSWF | Pelleted grower |
| Wheat flour | 5.33 | . . . |
| Soyflour | 16.00 | . . . |
| Whey protein | 19.25 | . . . |
| 13/603 | 48.5 | . . . |
| Lactose | 4.25 | . . . |
| Dicalcium phosphate | 0.70 | . . . |
| Calcium carbonate | 1.74 | . . . |
| Citric acid | 1.56 | . . . |
| Potassium sorbate | 0.625 | . . . |
| Vitamin, trace mineral premix4 | 0.56 | . . . |
| Lysine | 1.62 | . . . |
| Methionine | 0.49 | . . . |
| Alfalfa meal, 17% | . . . | 29.00 |
| Soybean meal, 44% | . . . | 16.00 |
| Ground shelled corn | . . . | 48.61 |
| Urea | . . . | 0.50 |
| Biofos | . . . | 1.10 |
| Limestone | . . . | 0.55 |
| Selenium premix5 | . . . | 0.10 |
| Trace mineralized salt6 | . . . | 0.50 |
| Ammonium chloride | . . . | 0.50 |
| Zinc oxide | . . . | 0.01 |
| Chlortetracycline (50
g/pound) |
. . . | 0.02 |
| Propionic acid | . . . | 1.00 |
| Vitamins7 | . . . | 0.11 |
| 100 | 100 | |
| Proximate analysis | ||
| Protein, % | 24.3 | 20.23 |
| Metabolizable energy,
kcal/pound |
2,135 | 1,244 |
| Fat, % | 29.73 | . |
| Lactose, % | 23.38 | . |
| Lysine, % | 2.76 | . |
| Methionine, % | 0.82 | . |
| Calcium, % | 0.93 | 0 |
| Phosphorous, % | 0.36 | 0 |
| Ether extract, % | . . . | 1 |
| Ash, % | . . . | 5 |
| Crude fiber, % | . . . | 10.26 |
| 1
Commercial milk replacer
guaranteed analysis (as fed
basis): protein, min. 23%; fat, min. 30%; crude
fiber, not more than 0.2%; vitamin A, not less than 20,000
IU/pound; vitamin D3, not less than 5,000 IU/pound;
vitamin E, not less than 5 IU/pound.
2 Commercial pelleted lamb starter guaranteed analysis (as fed basis): protein, min. 21%; fat, min. 3%, crude fiber, max. 11.5%; calcium, 0.89%; phosphorous, 0.7%; potassium, 1.45%; TDN, 69%. 3 Commercial dry fat product contains: protein, 13.25% (from whey protein concentrate); fat, 60% (32.5% lard, 32.5% tallow, 25% coconut oil, 8% emulsifiers, 2% lecithin). 4 Commercial premix contains: calcium, 0.32%; iron, 1.78%; cobalt, 0.02%, copper, 0.00004%; manganese, 0.69%; zinc, 1.78%; selenium, 0.005%; iodine, 0.08%; thiamine, 0.09%, riboflavin, 0.15%, vitamin B12, 0.00024%; pantothenic acid, 0.24%, niacin, 0.73%; folic acid, 0.05%; choline, 2.78%. | ||
| Table 2. Average daily gain (ADG) of lambs fed modified soyflour/wheat flour (MSWF) milk replacers. | ||||||||||
| Lamb group1,2 | Treatment3 | Average beginning weight, pound4 | Time intervals, days | Average final weight., pound | ||||||
| 1 to 7 | 7 to 14 | 14 to 21 | 21 to 28 | 28 to 35 | 35 to 42 | |||||
| (Average daily gain, pound + SEM5) | ||||||||||
| A | Commercial
MR,
days 1 to 28 |
8.73 + 0.47 | 0.38 + 0.04 | 0.63 + 0.06 | 0.834 + 0.26 | 0.71 + 0.03 | -0.47 + 0.05 | 0.63 + 0.05 | 27.68 + 0.54 | |
| B | MSWF,
days 1 to 28 |
8.73 + 0.34 | 0.29 + 0.03 | 0.49 + 0.05 | 0.634 + 0.05 | 0.66 + 0 .05 | -0.29 + 0.07 | 0.57 + 0.11 | 25.18 + 0.94 | |
| C | MSWF,
days 5 to 28 |
9.78 + 0.65 | 0.41 + 0.05 | 0.49 + 0.05 | 0.594 + 0.06 | 0.834 + 0.06 | -0.50 + 0.06 | 0.65 + 0.06 | 26.6 0 + 1.47 | |
| 1 Ten lambs per treatment group.
2 Milk replacers contained 19.36% solids. Lambs hand fed days 1 and 2 before introduction to lam-bar self-feeder on day 3. 3 Milk replacers fed from days 1 to 28, then pelleted solid fed to day 42. 4 Beginning weights, weekly ADG for days 1 to 42, and final weights analyzed separately. Means within a column lacking a common superscript differ (P < 0.10). 5 Standard error of the mean. | ||||||||||
For days 14 to 21, the ADG for the commercial milk replacer diet was improved when compared to that of the MSWF diet. However, by the end of the next weigh period (days 21 to 28), the results were reversed with the MSWF diet having the greater ADG (P < 0.05). There were no differences in the ADGs among the groups of
lambs (groups A to C) receiving the two diets for the two weekly periods following weaning (days 28 to 35 and days 35 to 42) or for the final weight of the lambs when the experiment was terminated on day 42.
Visual evaluation of the diets in the feeders, both when the milk replacer was added or the feeders were cleaned, indicated that there was very little, if any, residue in the feed reservoir, the tubes leading from the reservoir to the nipples, or the nipples. Daily assessment by smell and taste of the quality of the feed remaining in the reservoir of the feeders containing each of the three diets indicated that the quality of the diets remained about the same and that the feeders should be cleaned, as recommended by the manufacturer of the commercial milk replacer, at 3-day intervals.
Heany, D.P., and J.N.B. Shrestha. 1987. Effects of soyflour in milk replacer on the performance of artificially reared lambs. Can. J. Anim. Sci. 67:757.
SAS. 1991. SAS/STAT User's Guide (Version 6.04 Ed.). SAS Inst. Inc., Cary, NC.
Tomkins, T. 1992. Growing uses of milk replacers. Feed Management 43:6.