Performance of Dairy Goats Fed Soybean Mealor Meat and Bone Meal with or Without Urea During Early Lactation 1 ,2 C. D. LU, M. J. POTCHOIBA, T. SAHLU, and J. R. KAWAS3 American Institute lor Goat Research Langston University Langston, OK 73050 ABSTRACT

Meat and bone meal may be utilized efficiently by lactating does as a protein less degradable in the rumen, Ca, and P source; and may be beneficial for higher milk production during early lactation. (Key words: meat and bone meal, lactation, goat)

Use of meat and bone meal for early lactation rations was studied. In Experiment 1, 18 Alpine goats were used in a 15-wk lactation trial. Isonitrogenous and isoenergetic diets were fed (15% CP and 2.3 Mcallkg metabolizable energy) containing soybean meal, meat and bone meal with urea, or meat and bone meal without urea. Dry matter intake was 2.21, 2.30. and 2.34 kg/d for does fed soybean meal, meat and bone meal with urea, and meat and bone meal without urea, respectively. Milk production was 2.50, 2.67, and 2.66 kg/d in the same sequence. Rumen ammonia N (mg/dl) and total VFA (roM) were 12.9 and 81.5, 21.4 and 76.3, and 12.2 and 81.6 for does fed soybean meal, meat and bone meal with urea, and meat and bone meal, respectively. Serum urea N was higher in does fed meat and bone meal with urea, and no differences were observed in serum total protein and plasma glucose concentrations. In Experiment 2. 4 mature, castrated male goats were used to estimate digestibilities and retention of nutrients in three diets. Digestibilities of NDF and P and retention of P were higher in goats fed the meat and bone meal diet. Allowance of absorbed protein for milk production was calculated to be 81 to 83 g/kg 4% FCM.

INTRODUCTION

Received March 13. 1989. ~ccepted September 7, 1989. . This research was paniaIly supported by Office of Internwona! Cooperation and Development. USDA. Project Number IR-BR-OK-145 and Fats and Protein Research Foundation, Inc.. Des Plaines, n.. 60018. 2Sciemific Paper Number OKLP-l13, Agricultural Research and Extension Programs. 3Current address: Universidad Autonoma de Nuevo Leon. Facultad de Medicina Veterinaria y Zootecnia. Monterrey. N.L., Mexico. 1990 J Dairy Sci 73:726-734

Meat and bone meal (MBM) is a source of N, Ca, and P for livestock. Growing steers fed isonitrogenous diets containing soybean meal (SBM) or MBM perfonned equally (14). Average daily gain of steers fed 11% CP diet containing MBM was equivalent to those fed 12% CP diet containing soybean meal (14). Apparent protein digestibility in the small intestine was lower in pigs fed MBM than in pigs fed SBM (13), implying heat damage in MBM. Fecal and urinary N were higher from pigs fed MBM than those fed SBM (21). Heat treatment during the processing of MBM did not reduce the content or the availability of amino acids because of low carbohydrate content in MBM (27). A recent study suggested that lysine availability of MBM was reduced by high temperature treatment when MBM was utilized by monogastric animals, and species differences were notable (3). Heat treatment has been recognized ~ ~ effective way to reduce protein degradanon 10 the rumen (26). Feeding of heat-treated SBM. incre~d milk yield of high producing Jactabng dairy cows during early lactation (24). Appli~ation of heat to MBM during the dry ~endenng process may be beneficial in providmg a low rumen-degradable protein to ruminants. Little infonnation is available on the utilization and nutritional value of MBM by lactating dairy animals. The objectives of this study were to determine the nutritional values of MBM for milk production and to investigate the feasibility of integration of MBM with urea in lactation rations.

726

MEAT AND BONE MEAL

MATERIALS AND METHODS

Lactation Trial

Animals and Diets. Eighteen primiparous Alpine does (48 ± 3 kg BW, 14 ± 2 mo of age) during early lactation were used. Animals were fed a standard ration [11 % CP and 2.46 Meal! metabolizable energy (ME)) for dry does at 2 wk prepartum. The experiment consisted of a 3-wk adjustment phase and a 12-wk experimental phase. The adjustment phase was initiated immediately after parturition. Animals were blocked according to milk production, BW, and feed intake at the end of the adjustment phase and randomly assigned to one of the treatments. Treatments were isonitrogenous and isoenergetic diets containing SBM, MBM with urea (MBM-U), or MBM only. Soybean meal was solvent-extracted and contained 50.5% CP and 10% ADF (DM basis). The MBM was steamcooked and contained 54.9% CP, 11 % Ca, and 5.5% P (OM basis). In test proteins. soluble and degradable protein content (percentage of total protein) was 25.0 and 71.0 for SBM and 13.0 and 55.6 for MBM, respectively. Fifty percent of the dietary nitrogen was provided by test protein. In the MBM-U diet, MBM and urea each provided 25% of the dietary N. Diets containing only ground cottonseed hulls and alfalfa meal as roughage sources were fonnu1ated to contain 15% CP and 2.4 Mcal/kg ME (OM basis) according to the requirements for maintenance, growth, and lactation (18). Diets were completely mixed to minimize particle size differences and to prevent sorting by animals. Animals were fed once daily for ad libitum intake with at least 10% orts and milked twice daily. A Calan goat feeding system (American Calan Inc., Northwood, NH) was used to allow maximum freedom of animal activity and to monitor individual feed intake simultaneously. Animals were housed in a closed bam equipped with infrared heating and forced air ventilation. Composition and nutrient content of experimental diets are in Table 1. Design and Sampling. A completely randomized block design with covariance was employed. Rumen samples were taken via stomach tubes 4 h postprandial during wk 3. 5, 10, and 15. The first 20 to 30 m1 of rumen fluid were discarded to prevent salivary contamination. pH was detennined immediately after sampling.

727

Feed samples were obtained via jugular venipuncture 4 h postprandial during wk 2 and 3 and biweekly thereafter. Composited p.m. to a.m. milk samples were taken weekly during adjustment and biweekly during experiment. Milk production was recorded at each milking using a computerized volumetric flow measuring device (Westfalia Systemat. Elk Grove, IL). Body weight was measured on 2 consecutive d weekly). Chemical and Statistical Analysis. Weekly composited feed samples for each of the three diets were analyzed for OM, Kjeldahl N, ash, Ca, and P (2). However, Ca and P of feed were detennined by plasma emission spectroscopy (Applied Research Laboratories. Inc., Sunland, CA) instead of atomic absorption spectroscopy. Contents of AOF and NOF according to Goering and Van Soest (11) were detennined in each diet. Gross energy was detennined (1) using an adiabatic oxygen bomb calorimeter (Parr Instrument Co., Moline, IL). Metabolizable energy of each diet was calculated from tabular values (9). Burroughs' mineral solution and ficin protease assays were utilized to determine the protein solubility and protein degradability of test proteins and three dietary treatments (SMB, MBM-U, and MBM) (24). Plasma glucose (10), serum total protein (7), and serum urea N (16) were detennined with the use of a Technicon Autoanalyzer II continuous flow spectrophotometer (Technicon Instruments Corp., Tarrytown, NY). Composite milk samples were analyzed for fat, total solids, N, CP (N x 6.38), and ash (2). Total solids-corrected milk (12.5%) and milk energy were calculated from total solids (8). Casein N and true protein N of milk were determined by Rowland's methods (23). Ruminal fluid samples were preserved with 1.0 ml of a saturated HgCl2 solution and stored at -20T until analysis. The VFA were analyzed by adding 1 ml of 25% metaphosphoric acid to 5 ml of ruminal fluid. This solution was allowed to stand for 30 min and then centrifuged for 20 min at 10,000 x g. Aliquots of the supernatant fraction were subjected to gas chromatography (HewlettPackard Co., Avondale, PA) utilizing a 1.98 x 4 mm Ld. glass column packed with 15% SP1200 plus 1% H~4 on 100/120 Chromosorb W AW (Supelco Inc., Bellefonte, PA). Ruminal ammonia N (NH3N) was determined using a phenol-hypochlorite colorimetric procedure (5). Journal of Dairy Science Vol. 73,

No.3. \990

728

LU ET AL.

TABLE 1. Composition of experimental diets. 1 Treatment2 Item Ingredient Alfalfa meal Cottonseed hull Ground com Oats Soybean meal Meat and bone meal Urea Dicalcium phosphate Calcium carbonate Trace-mineral salt 3 Vitamin A, D, and E" Chemical composition5

SBM

MBM-U

MBM

8.0 32.8 22.0 16.0 15.0

5.0 39.3 43.9

6.0 39.2 35.0 5.0

6.8

13.6

1.3

Crude protein, % Soluble protein, % of total protein Degradable protein, % of total protein Acid detergent fiber, % Neutral detergent fi ber, % Calcium, % Phosphorus, % Gross energy, Mcal/ki Metabolizable energy. Mcal/kg

3.0 2.0 1.0 .2

1.5 1.0 1.0 .2

1.0 .2

15.1

15.0

14.8

23.8

31.1

21.1

43.1 28.3 47.4 1.7

40.8 31.5 48.9 1.6 .8 4.4 2.3

36.2 26.5 49.2 1.7

.8 4.2 2.3

.9 4.4 2.4

I Dry matter basis.

2S8M

= Soybean

meal; MBM-U

= meat

and bone meal with urea; MBM

= meat

and bone meal.

3Containing (%) NaCI. 94 to 95; Mn>.20; ferrous Fe. >.16; ferric Fe, >.14; Cu, >.033; Zn, >.10; I. >.007; Co. >.005. 4Each gram contained 2200 IV vitamin A. 2200 IV vitamin D, and .2

ru

vitamin E.

5Average of individually detennined weekly samples; 8BM, n = 15; MBM-U and MBM. n = 12. 6Calculated (9).

Rumen influx protein was calculated as intake CP x .15 (19). Rumen-available protein (RAP) was calculated as degradable intake protein + rumen influx protein. Bacterial crude protein (BCP) was calculated as RAP x .90 (19). Absorbed protein (AP) was calculated as digestible BCP + digestible undegraded intake protein, assuming a digestibility of .9 (19). Maintenance protein and fecal protein in absorbed protein units (maintenance or fecal protein absorbed) were calculated according to NRC (20). Retained protein in absorbed protein units (retained protein absorbed) was calculated as (body weight change x .15)/.65. Absorbed lactation protein was calculated as milk protein yield/.70. Data were subjected to analysis of covariance using the general linear models procedure (25). The model was: Journal of Dairy Science Vol. 73,

No.3, 1990

where Yij was the value of variable for the block j of treatment i; Il was the overall mean; (Xi was the effect of treatment i; Pj was the effect of block j; Xij was the value of variable before treatment, X.. was the mean of Xij; and eij was the random residual. Differences in treatment means were further analyzed by the new Duncan's multiple range test at P.05) among treatments (Table 2). Dry matter intake (OMI) averaged 4.5. 4.8, and 4.8% BW for goats fed SBM. MBM-U, and MBM, respectively. There was no depression in OMI i'ssociated with feeding MBM or MBM with urea. The average BW during wk 4 to 15 was 48.6 kg and was not different (P>.05) among treatments. Body weight changes (gld) of the entire experimental phase were positive for all treatments and were not different (P>.05) among treatments. Dry matter intake and BW curves are presented in Figures 1 and 2. respectively. Dry matter intake of does fed SBM was lower than those fed MBM-U or MBM during wk 5 to 9. Oietary changes at the end of adjustment phase did not affect OMI of does fed MBM-U but decreased DMI of those fed MBM. During the adjustment phase. average OMI was similar among blocks. Peak OMI occurred during wk 5 and 6 in does fed MBM and MBM-U. respectively. Although differences were not significant, does fed SBM had consistently higher BW except during wk 5 and 8. Does fed MBM-U diet had the lowest BW throughout the entire experimental phase. Ruminal NH3N (mg/dl) was higher (P-

"0

0

1/ 0

m i i i

5

I

i

I

10

47 46

I

15

Weeks Postpartum Figure I. Dry matter intake of lactating dairy goats fed soybean meal (0), meat and bone meal with mea (0), or meat and bone meal (Il.) in periods (Per.) with 1 and 2.

45

10

i i i

5

i

10

15

Weeks Postpartum Figure 2. Body weight changes of lactating dairy goats fed soybean meal (0), meat and bone meal with urea (0), or meat and bone meal (Il.) in periods (Per.) I and 2.

degradation of urea by urease in the rumen. Ruminal pH, concentration, and distribution of VFA were not different among treatments (Table 3); however, a trend toward a slightly lower total VFA was observed in does fed MBM-U. Acetate to propionate ratio was slightly, but not significantly (P>.05), higher in does fed the SBM diet. Serum urea N (mg/d!) was higher (P.05) among treatments (Table 4). Nevertheless, average milk production increased 7% (an 11 % increase in 4% FCM yield) in does fed diets containing MBM. The trend was apparent when the lactation curves were examined (FigJownal of Dairy Science Vol. 73.

No.3. 1990

UTe 3). Except for wk 11, milk production was consistently higher from does fed MBM-U or MBM diet than from those fed the SBM diet. From wk 12 to 15, does fed MBM produced the highest amount of milk among treatments. These trends suggested that MBM might be beneficial for higher milk production than from SBM, particularly during early lactation, and that integration of MBM and urea could be an effective alternative in support of milk production (12). No differences (P>.05) were observed in milk composition and yields of fat, protein, lactose, or total solids. These variables tended to be higher in does fed MBM-U or MBM diet. Milk true protein and casein protein did not differ (P>.05) among treatments; however, there was a trend toward higher true protein and casein protein in the milk of does fed MBM. Apparent digestion coefficients and retention of nutrients detennined in castrated male goats are presented in Table 5. Intake, BW, and live weight changes were not different among treatments (P>.05). Animals fed MBM gained 50 g/ d, whereas those fed SBM or MBM-U lost III and 50 g/d, respectively. Digestibilities of DM, OM, energy, N, and Ca were not different among treatments (P>.OS). However, goats fed the MBM diet were highest in these measure-

731

MEAT AND BONE MEAL

TABLE 3. Rumen and blood components of lactating goats fed soybean meal (SBM), meat and bone meal with urea (MBM-U), or meat and bone meal (MBM).I Item

SBM X

SE

MBM-U

MBM

X

SE

X

SE

.1 3.5 3.3 1.2 1.2 .8 .2

6.3 12.2 a 81.6 64.1 21.5 11.9 3.1

.1 3.2

Rumen pH NH3N, mg/dl TOlal YFA, mM Acetate (A), mol/IOO mol Propionate (P), mol/l00 mol Butyrate, mol/100 mol A:P

6.2 0 12.9"- 1.2 81.5 3.2 67.0 .8 18.7 .9 12.1 .4 3.8 .2

6.3 21.4 b 76.3 65.1 22.2 10.6 3.1

Blood Serum total protein, g/dl Serum urea N, mg/dl Plasma glucose, mg/dl

7.49 .26 I3.8a l.l G6.8 1.9

7.51 .36 17.6b .6 68.3 1.4

1.3 1.3 l.l l.l

.2

7.01 .18 13.3 a .5 70.4 1.4

a,bMeans in the same row without a common superscript differ (P

Performance of dairy goats fed soybean meal or meat and bone meal with or without urea during early lactation.

Use of meat and bone meal for early lactation rations was studied. In Experiment 1, 18 Alpine goats were used in a 15-wk lactation trial. Isonitrogeno...
714KB Sizes 0 Downloads 0 Views