Technical Bulletin 149 ISSN 0070-2315

THE EFFECT OF FEEDING PROTEKR ON THE PERFORMANCE OF LACTATING DAMASCUS GOATS AND THE IN SITU DEGRADABILITY

OF PROTEIN SUPPLEMENTS

M. Hadjipanayiotou

(May 1993)

TECHNICAL BULLETIN

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AGRICULTURAL RESEARCH INSTITUTE

MINISTRY OF AGRICULTURE AND NATURAL RESOURCES

NICOSIA CYPRUS

Technical Bulletin 149 ISSN 0070-2315

THE EFFECT OF FEEDING PROTEKR ON THE PERFORMANCE OF LACTATING DAMASCUS GOATS AND THE IN SITU DEGRADABILITY

OF PROTEIN SUPPLEMENTS

M. Hadjipanayiotou

(May 1993)

SUMMARY

Two experiments were conducted using lactating Damascus goats. In experiment 1, 69 goats were offered concentrate mixtures with either 140 or 174 g CP/kg DM; the concentrate mixture with 140 g CP/kg DM was either with (Pr) or without (LP) "Pro­Tek"R. In a second experiment 32 Damascus goats were paired on the basis of milk yield, and in a two-period change-over design were fed two diets ( LP , Pr ). In another experiment using four dry, mature, rumen fistulated Damascus goats offered a concen­trate with (Pr) or without (LP) ProTek, the in situ degradation of soybean meal (SB), heat-treated (149 °C for 2h) SB (HSB), dried (60 0c) brewers grain (BGr) and heat­treated BGr (HBGr) in the rumen was measured. There were no differences between diets in food intake. In both experiments, milk yield, milk fat content and initial and fi­nal body weight of goats on the different diets were similar. In trial 1, goats on the LP diet produced milk of lower CP, ash and total solids content than those on the C (con­centrate mixture with 174 g CP/ kg DM, without ProTek) diet. Effective DM and CP de­gradability of SB was greater than that of BGr. Heat treatment reduced degradability in SB to a greater extent than BGr. Feeding ProTek however, did not affect the degradabil­ity of feedstuffs.

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~tT] !!EAE'tT] ami] XQT]OL!!OreOLi]8T]XE 'to ProTek OE OL'tT]Q£OLa yaAaxtocp6Qwv ~a!!a­• OXTlVWV aLYwv xm ESE'tuotTlXE XaLU re600v !!Jl:OQEL va ErcLCP£QEL ESOLXOv6!!T]OT] reQwtEL­

VT]~ xm va EAattWoEL 'tTl OLUOreaoT] 'tT]~ reQW'te'CVT]~ areo 06yLa i] ureoreQo'(6vtWV l,:ueO~LO­!!T]xaVLa~ (~Qao!!£vwv otou~ 149°C yLa 6uo WQEe; i] 6XL). ~to reQti:l'to reELQa!!a to OALX6 OLtT]Q£OLO !!E ProTek reou reEQLELXE 115 YQa!!. aXaL£Qyao'tT]~ reQwtE'CvT]~ OUYXQL8T]xE !!E O'IJO uAAa OLtT]Q£OLa to Eva !!E oXEMv L6La (118 YQa!!.) xm to UAAO !!E 139 YQa!!. axa­tEQyaotT]~ reQwtE"CVT]~ avu XAy. ST]QOu tEALXOU OLtT]QWLOU. ~to OEUtEQO nELQa!!a 'to OL­tT]QEOLO !!E ProTek nEQLELXE 97 YQa!!. OE oUyxQWT] !!E 120 YOU!!. aXaL£QyaotT]~ reQwte"C­VT]~ avu xLM sT]QOu !!Ly!!atoe; reou reEQLELXE 0 wlQ'tuQa~. Km ota O'IJO reELQU!!aLa T] reQ60AT]'\jJT] reQw'tE"CvT]~ areo n~ aLyEe; oto !!uQ'tuQa xm 010 OL'tT]Q£OLO !!E xa!!T]Ai] nEQL-

ProTekR, a product marketed by Central Soya Co., Inc., Ft. Wayne, Indianapolis, USA.

1

IxtLXOtrrtU JtQWtEtVTje; (JtdQUl.lu 1) i]tUV XUI.lTjA.OtE­Qll ano tLe; uvaYXEe; Jtou ouoti]vOvtaL ano ta NRC (1981) yLU ULYEe; tlle; LOLUe; JtUQUYWYLxotrrtue;. TIUQa tU1Jtu, II I.l6vn otutLotLxa Olll.lUvtLxi] owcpoQa Jtou JtuQUtTjQi]8llXE i]tuv II XUl.lllA.OtEQll JtEQLEXnxotlltu tau yaAuxtoe; tWV aLywv Ota OLtllQEOLa XUl.lllA.i]e; JtEQLExtLXotlltUe; 01' JtQwtEtvll (JtdQUI.lU I, OLtllQE­OLa I.lE 118 YQul.l. JtQ<.otEtvll/XAy. I.lLYI.lUtae;) 01' JtQw­tE'CVll, tEqJQU XaL oALxa otEQEa, 01' OUyxQWll I.lE tOY l.laQtuQU (139 YQul.l. JtQwtEtvnc;!XAy. I.lLYI.lGtOe;). AvtL8Etu, XaL otu 61)0 JtELQal.lUtu OEV UJti]QXE XUI.l­I.lLU oLucpoQa I.lEtal;u twv OLtllQEOLWV ooov uqJOQa tllv Jtoootlltu tau JtUQUyal.lEVOU yaAUxtae;, ta ALJtOe; taU yaAuxtoe; XaL to UQXLXO i] tEALXO l36.QOe; twv aLYwv. H XQi]oll tou PIaTek OEV EJtllQEUOE tllv owoJtuotLXotlltU otll I.lEyaAll XOLALU tlle; oOyLue; i] tWV 'UJtOJtQO'LOvtwv tlle; tueo~Lal.lllXUVLUe;. AVtL8E­tu II 8EQI.lUVOll, LOLULtEQU otll OOyLU, EAanwoE Oll­I.lUvtLXa tllv OLuoJtuonXotlltU otll I.lEyaAll XOLUU. H OLuoJtuotLxotlltu tlle; oOyLue; i)tuv 'WllA.OtEQll ano UUti]v twv uJtOJtQO'LOvtWV tlle; tu80~Lal.lllXUVLUe;, yEyovoe; Jtou odxvEL tTJV UsLU twv OEUtEQWV yLU E'U­

QUtEQll XQi]oll otll OLGtQOqJi) twwv 'WllA.i]e; JtuQUYw­YLxotlltue;.

INTRODUCTION

In fast growing or dairy ruminants in ear­ly lactation production may be limited by a low dietary undergradable protein (UDP). Microbial protein synthesized in the rumen is not sufficient to meet the animal's protein re­quirement. Dietary protein in excess of that required by rumen microbes is most effi­ciently supplied in the form of slowly de­graded protein (ARC, 1980). Increased UDP may be provided by inclusion in the diet of protein sources such as corn gluten meal, dried brewers grains, fish meal and dehydrat­ed alfalfa (Deacon, De Boer and Kennelly, 1~98). Provision of a higher "by-pass" pro­tem level has been attained via heating of protein supplements and/or chemical treat­ment (Chalupa, 1975). However, high tem­peratures and extended heating times render protein less digestible (Stern, 1981), thus lowering postruminal utilization of amino ac­ids. The use of formaldehyde is the most common and effective chemical treatment (Kaufmann and Lupping, 1982). However, many objections have been raised against its use because it is said to cause cancer.

Finally, production studies using either chemically or heat-treated protein supple­ments have often failed to reveal any detecta­ble change in milk yield (Kaufmann and Lupping, 1982; Hadjipanayiotou, 1992).

Central Soya Co., Inc., (Ft. Wayne, India­napolis, U.S.A), has been granted U.S. pat­ents on its ProTek process, a treatment de­veloped by the company to enhance the level of available bypass in feed ingredients. Re­search carried out at Central Soya's dairy re­search farm, and at various universities, has demonstrated that with ProTek-treated feeds dairymen can reduce the protein in their grain mixture by 15 to 20%, while at the same time maintaining the production of milk (Muirhead, 1987).

The objective of the present studies was to study the effect of ProTek on the lactation performance of Damascus goats and the in situ degradability in the rumen of selected protein sources.

MATERIALS AND METHODS

Production Studies Two experiments, one with 69 Damascus

goats in early lactation, and another one with 32 Damascus goats in mid lactation were used to study the effect of ProTek on milk yield and milk composition. In experiment 1, goats were divided into three uniform groups based on their daily milk yield. Groups were randomly allocated to one of the three treat­ment diets (Table 1). In experiment 2, goats were paired on the basis of milk yield, and in a two-period change-over design (Seeger, 1980) were fed two diets (Control and Pro­tek, Table 1) for two 21- day periods. For­mulation of the concentrate mixtures and chemical analyses of the mixtures, the barley hay and straw used in these studies are shown in Table 1.

The composition of ProTek as given by the manufacturers was: crude protein 3.2%, digestible crude protein 2.5%, crude fat 2.0%, crude fibre 8.5%, ash 60.0%, Ca 10.0%, P 1.6%, NaCl 20.0%, Mg 40 g/kg, Fe 1,200 mg/kg, Cu 250 mg/kg, Mn 775 mg/kg, Zn 1,200 mg/kg, Co 16 mg/kg, I 20 mg/kg, Se 2.3 mg/kg, Vitamin A 200,000 IU/kg, vi­tamin D3 50,000 IU/kg and vitamin E 250 mg/kg. A vitamin trace element mixture was prepared and added to diets LP and C to pro­vide the same amounts of minerals and vita­mins.

In experiment 1, feed allowance was ad­justed once a week. Animals were offered roughage (0.4 kg/kg finished diet) and a con­centrate mixture (0.6 kg/kg finished diet) to

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Table 1. Formulation (kglt) of the concentrate mix­tures (as fed basis) and analyses (g/kg DM) of the concentrates and of roughages used

Concentratea Barley

C PR LP Hay Straw

Ingredients Barley grain 549.4 621.0 642.4 Com grain 200.0 195.0 202.0 Soybean meal 170.0 78.0 75.0 ProTek - 50.0 Wheat bran 50.0 50.0 50.0 Limestone 11.6 11.6 Dical. Phos. 5.0 5.0 NaCI 10.0 10.0 Vitatrace 4 6 4

Analysis Crude protein 174 138 142 120.1 29.3 Organic matter 939 928 946 911.3 926.0 ADF - 285 463 NDF - 534 750 ADL 19 45 D(%) 62.1 36.6

ac= concentrate mixture high in crude protein without ProTek; PR= concentrate mixture low in crude protein with ProTek; LP= concentrate mixture low in crude protein without ProTek.

meet their maintenance (0040 MJ MElKg WO.73/kg) and production energy require­ments [Y=(1.64+oA2X)/0.62] (where X=fat percentage and 0.62 is the efficiency of utili­zation of ME for milk production). The roughage was straw and barley hay (1: 1) in experiment 1 and only straw in experiment 2. In experiment 2, feed allowance was kept constant throughout each 21-day experimen­tal period.

Animals in each experiment were housed by treatment in adjacent pens and were given concentrates (9 mm cubes) and roughages (Tables 2 and 3) from separate food troughs. Animals had free access to water. Food sam­ples were collected routinely for chemical analyses. The analytical methods for milk

- and food samples were those outlined by MAFF (1973) and Harris (1970), respectively.

Goats were hand milked twice daily. Indi­vidual milk yields were recorded twice a week. Representative samples from morning and afternoon milking were taken once a week. The two samples were bulked and an­alysed for protein, fat, ash and total solids. Animals were weighed at the beginning and at the end of the trial and at the beginning and at the end of each period (trial 2).

Rumen degradation studies Four mature Damascus goats, weighing

on average 60 kg and fitted with permanent rumen cannulae, were used for measuring the effective crude protein and dry matter degradability of soybean meal (SB), heat treated (149 °C for 2 h) SB (HSB), dried (65 OC) brewers grain (BGr) and heat treated BGr (RBr). All four feedstuffs were incubat­ed (2,5,8, 24 and 48 h) in nylon bags (three bags/incubation interval) in the rumen of all four animals. The rumen fistulated animals were divided in two pairs. Animals within each pair were randonly assigned to the con­centrate mixtures LP or Pro After the incuba­tion of all four feedstuffs, animals changed over to the other diet and the feedstuffs were incubated again. All goats were individually offered, in approximately two equal por­tions, 600g of the concentrate mixture (LP or Pr) and 400g of barley hay. The mean of the three bags per incubation interval was used for calculations. Processing and analysis of samples before and after incubation were as outlined by Hadjipanayiotou et at. (1988). Samples of incubated feedstuffs were ana­lysed for DM and CP before and after incu­bation. Loss of DM and CP at various incu.> bation intervals was fitted to the non-linear equation [Orskov and McDonald, 1979; P=a+b(l-e-ct)], where P is the amount de­graded at time t, a is the rapidly degradable fraction, b is the potential degradability at in­finite time and c is the fractional rate con­stant at which the fraction b will degrade per h. Data collected (a,b,c and P) were analysed by one-way analysis of variance (Steel and Tome, 1960).

RESULTS

There were no differences between diets in food intake (Tables 2 and 3). In both ex­periments, milk yield, fat-corrected milk yield, milk fat content, initial and/or final bodyweight of goats on the different diets were similar (Tables 2 and 3). In experiment 1, goats on the LP diet produced milk of lower CP, ash and total solids content (P<0.05) than those on the C diet. Differenc­es between C and Pr diets for CP, ash and to­tal solids content were not significant (P>0.05). The total solids content of milk on the C and Pr diets was significantly higher

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Table 2. Performance of lactating Damascus goats offered three different diets (Experiment I)

Di e t*

LP C PR S.E.

No of animals 23 23 23

Intake (g/head/day) Concentrate Barley hay Straw Crude Protein

1200 1200 1200 323 323 323 323 323 323 194.2 227.6 189.9

Milk yield (g/day) FCMt (kg/day) Fat content (g/kg)

1804 1753 1734 2043 1981 1993

44.9 48.6 49.1

95 103 1.08

Protein content (g/kg) 40.4b 43.8a 41.8ab Ash (g/kg) 7.8b 8.4a 8.3a Total solids (g/kg) 132.6b 138.18 139.5a

1.02 0.10 1.80

Initial weight (kg) Final weight (kg)

65.5 64.1

66.3 65.4

65.3 64.2

1.98 1.90

Means in the same row with different letters differ sig­nificantly at P<0.05. *LP=concentrate mixture low in crude protein without ProTek; C=concentrate mixture high in crude protein without ProTek; PR=concentrate mixture low in crude protein with ProTek. tMilk yield corrected at 4% fat.

than that of LP diet. The experimental period had a significant

effect on milk yield (P<O.Ol) and weight loss (P<0.05). Milk yield was greater in the first compared to the second period, whereas ani­mals gained weight in the second period as opposed to weight loss in the first period.

Table 3. Performance of lactating Damascus goats of­fered two diets (Experiment 2)

Control Protek S.E.

No. of animals 32 32 Initial weight (kg) 63.4 63.8 0.27** Final weight (kg) 63.2 63.1 0.24 Weight loss (kg) 0.2 0.8 0.43*

Milk yield (kg/day) 1.47 1.41 0.028** FCMt (kg/day) 1.61 1.52 0.031* Fat content (g/kg) 46.9 45.9 0.96 Protein" " 41.3 41.0 0.33* Ash 8.2 8.2 0.06

Intake( kg/head/day) Concentrate 1.22 1.22 Straw 0.70 0.70

*Period effect significant at P<0.05; ** period effect significant at P<O.OI; tMilk yield corrected at 4% fat.

Percent disappearance of CP and DM ob­tained from nylon bags incubated in the ru­men of goats fed either the LP or the Pr diet were fitted to the non-linear equation of Ors­kov and McDonald (1979). Estimated par­ameters are in Table 4. There were no signif­icant differences between diets for a, band c constants of the equation. Furthermore, ef­fective CP and DM degradability was simi­lar for the two diets. On the other hand, there were significant differences among feed­stuffs. SB was more degradable than BGr; heat treatment reduced (P<O.OOl) the DM and CP degradability of SB, but its effect on BGr was marginal with the LP diet, but sig­nificant with the ProTek diet.

DISCUSSION

The manufacturers of ProTek claim that their product contains rumen stabilizers which improve the rumen activity, resulting in higher milk fat content, it contains fla­vours to increase palatability, it increases the amount of by-pass protein in the ration and energy efficiency. In the present studies, we were unable to measure its effect on palata­bility, but certainly it did not affect energy efficiency, milk fat content or degradability _ of protein, and eventually, by-pass protein.

The CP concentration (g CP/kg DM of the finished diet) was: LP 118, C 139, Pr 115 - experiment 1 and C 120, Pr 97 - exper­iment 2. These values were lower than those recommended for lactating Damascus goats to attain maximum milk yields (Hadjipanayi­otou, 1987). Furthermore, the CP intake by goats on the LP and C diets in experiment 1 and of the C diet in experiment 2 was lower than those recommended by NRC (1981) (lactating goats - medium activity, live­weight 65 kg and producing 1.76 kg milk! day of 4.75 % fat: CP requirements equal to 252 g/goat/day). It should be expected there­fore, that any potential of ProTek in improv­ing efficiency of protein utilization could be exerted through higher milk yields, but even in the case of lack of a potential for higher yields decreased degradability of protein in the rumen would be expected. Levels of pro­tein that are below standards lead to a de­cline in milk protein concentration (Arm­strong and Prescott, 1971). This being the explanation for the lower milk protein con­tent of goats on the LP and Pr diets.

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Table 4. Estimates of DM and CP disappearance of feedstuffs incubated in the rumen of fistulated Damascus goats offered different diets

Die t

Control ProTek

Item Constant SB HSB BGr HBGr SB HSB BGr HBGr SD

Crude protein

a b c PO.05 PO.08

17.4 77.8 8.1

64.3 55.5

2.6 43.5

1.7 12.5 9.5

3.2 58.7

5.7 34.1 27.3

-4.7 58.6 6.2

37.6 31.2

15.9 70.5 9.5

61.9 54.0

2.7 35.4 2.0

12.7 9.7

3.9 58.1

5.7 33.8 27.1

0.2 45.7

3.4 17.9 13.1

4.18** 10.08** 2.10** 9.91** 9.22**

Dry matter

a b c PO.05 PO.08

32 51.5 12.3 63.3 57.6

22.0 40.8

2.9 37.2 33.0

9.5 47.9

6.1 35.7 30.2

4.7 43.8

5.1 25.9 21.1

32.0 62.6

6.3 66.8 60.2

21.6 48.4

3.4 39.8 34.9

10.3 48.8

6.4 36.4 30.8

5.2 45.0

4.4 26.0 21.0

1.67** 10.76 3.65 5.12** 4.03**

a=the rapidly degradable fraction; b=the potential degradability at infinite time; c=fractional rate constant at which the fraction b will degrade per h; PO.05 and PO.08 effective degradability values at 0.05 and 0.08 outflow rate!h respectively. ** feedstuff effect significant at P< 0.01.

The reduction in the in situ DM and CP degradability observed in this study as a re­sult of heating, has also been observed in other studies (Lindberg et aI., 1982; Mir et aI., 1984; Deacon et ai., 1988; McKinnon et ai., 1991). In line with McKinnon et ai. (1991), the effect of heat in reducing the CP degradability was greater than that seen with the DM fraction.

The effective CP degradability of soybean meal was significantly higher than that of brewers grain. Our findings regarding SB are relatively close to those reported by ARC (1984). In contrast, our data with brewers grain were significantly lower than the re­spective ARC (1984) values ( P.OS , 0.70 ; P.08 , 0.64 ), but close to those reported by Cronje (1983) and Weakley et ai.(1983).

It can be concluded that ProTek was not effective in improving the lactation perfor­mance of Damascus goats and in reducing the degradability of protein supplements in the rumen, while heat treatment decreased degradability in the rumen. Brewers grain is a product of low degradability and of satis­factory CP content (30 % CP/kg DM) and can make an important contribution as partial replacement of imported and expensive soybean meal.

ACKNOWLEDGEMENTS

The author is grateful to Mr. L. Hadjipa­raskevas, Mr. A. Photiou, Mrs. M. Theodori­dou, Mrs. M. Karavia and the staff of the Central Chemistry Laboratory for skilled technical assistance, and Provimi B.V., Hol­land, for donating the ProTek.

REFERENCES

ARC. 1980. The Nutrient Requirements of Ruminant Livestock. Commonwealth Agricultural Bu­reaux, Agriccultural Research Council, Slough, U.K. pp 351.

ARC. 1984. The Nutrient Requirements of Ruminant Livestock. Supplement No. 1. Common­wealth Agricultural Bureaux, Agricultural Research Council, Slough, U.K.

Armstrong, D.G., and J.H.D. Prescott. 1971. Amount physical form and composition of feed and milk secretion in the dairy cow. In Lacta­tion. Proceedings of an International Sym­posium. forming the 17th Easter School in Agricultural Science (LR. Falconer, Ed.). : Butterworths, London.

Chalupa, W. 1975. Rumen by pass and protection of proteins and aminoacids. Journal of Dairy Science 58: 1198-1218.

Cronje, P.B. 1983. Protein degradability of several South African feedstuffs by the artificial fi­bre bag technique. South African Journal of Animal Science 13:225-228.

Deacon, M.A., G. DeBoer, and U. Kennelly. 1988. Influence of jet-sploding and extrusion on

5

ruminal and intestinal disappearance of ca­nola and soybeans. Journal ofDairy Science 71:745-753.

Hadjipanayiotou, M. 1987. Studies on the response of lactating Damascus goats to dietary protein. Journal of Animal Physiology and Animal Nutrition 87: 41-52.

Hadjipanayiotou, M. 1992. Effect of protein source and formaldehyde treatment on lactation per­formance of Chios ewes and Damascus goats. Small Ruminant Research 8: 185-197.

Hadjipanayiotou, M., E. Georghiades, and A. Kou­mas. 1988. The effect of protein source on the performance of suckling Chios ewes and Damascus goats. Animal Production 46:249­255.

Harris, L.E. 1970. Nutrition Research Techniques for Domestic and Wild Animals. Vol. 1. An In­ternational Record System and Procedures for Analysing Samples, Logan, Utah.

Kaufmann, W., and W. Lupping. 1982. Protected pro­teins and protected aminoacids for rumi­nants. In Protein Contribution of Feedstuffs for Ruminants: Application to Feed Formu­lation (Miller E.L., J.H. Pike and AJ.H. Van Es, Eds.), pp 36-75. Butterworth, London.

Lindberg, J.E., H.S. Soliman, and S. Sanne. 1982. A study of the rumen degradability of untreat­ed and heat-treated rape seed meal and of whole rape seed, including a comparison be­tween two nylon bag techniques. Swedish Journal ofAgricultural Research 12:83-88.

MAFF. 1973. The Analysis of Agricultural Materials. Technical Bulletin 27. Ministry of Agricul­ture, Fisheries and Food, London.

McKinnon, ].J., J.A. Olubobokun, D.A. Christensen, and RD.H. Cohen. 1991. The influence of heat and chemical treatment on ruminal dis­appearance of canola meal. Canadian Jour­nal ofAnimal Science 71 :773-780.

Mir, Z., G.K. Macleod, J.G. Buchannan-Smith, D.G. Grieve, and W.L. Grown. 1984. Methods for protecting soybean and canola proteins from degradation in the rumen. Canadian Journal ofAnimal Science 64:853-865.

Muirhead, Sarah. 1987. Treatment of protein ingre­dients adds new dimension to feeding. Feed­stuffs 59(33): 12.

NRC. 1981. Nutrient requirements of Domestic ani­mals. No.15, Nutrient Requirements of Goats: Angora, Dairy and Meat Goats in Temperate and Tropical Countries. National Academic Press, Washington, D.C.

Orskov, E.R., and I. McDonald. 1979. The estimation of protein degradability in the rumen from

incubation measurements weighted accord­ing to rate of passage. Journal of Agricultu­ral Science 92:499-503.

Seeger, P. 1980. The two-period change-over design applied to dairy cows. Swedish Journal of Agricultural Research 10: 175-180.

Steel, RG.D., and J.R. Torrie. 1960. Principles and Procedures of Statistics. McGraw - Hill, New York.

Stem, M.D. 1981. Effect of heat on protein utilization by ruminants. Feedstuffs 53 (46):24.

Tilley, T.M.A., and RA. Terry. 1963. A two stage technique for the in vitro digestion of forage crops. Journal of the British Grassland Soci­ety 18: 104-111.

Weakley, D.C., M.D. Stem, and L.D. Satter. 1983. Factors affecting disappearance of feedstuffs from bags suspended in the rumen. Journal ofAnimal Science 56: 493-507.

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