Twenty Sardinian lactating ewes were divided in four groups (A, B, C, D) and fed with four diets,

obtained mixing a pelleted fibre integrator (PFI) and a normal pelleted concentrate (NPC) in different

proportions (NPC/PFI: A = 27/73; B = 42/58; C = 58/42; D = 73/27). The intake was 123,

122, 114 and 135 g of DM per kg of metabolic weight. The ewes were able to choose between the

two type of pellets. The chewing time per kg of DM decreased with the reduction of PFI content

in the diet. The ewes were always able to maintain a regular ruminal activity. There were no significant

differences in the milk yield, milk fat content, SCC and body weight variations, while the

milk protein content was higher in the group B

Brandano, Paolo

Cannas, Antonello

Pulina, Giuseppe

Rassu, Salvatore Pier Giacomo

Rossi, Giancarlo

Serra, Antonio

UnissResearch

ANNAbl 
DELLA FACOLTÀ DI AGRARIA DELL'UNIVERSITÀ 
____________ SASSARI __________ __ 
DIRETTORE: P. BULLITTA 
COMITATO DI REDAZIONE: P. BRANDANO - P. BULLITTA - P. DEIDDA 
M. GREPPI - L. IDDA - F. MARRAS - G. PALMIERI - A. VODRET 
studi sassaresl 
ORGANO UFFICIALE 
DELLA SOCIETÀ SASSARESE DI SCIENZE MEDICHE E NATURALI 
Ann. Fac. Agr. Univo Sassari (I): 1993, 35 (lO): 27-34 
THE EFFECT OF THE UTILIZATION OF A HIGH FIBRE PELLETED FEED 
ON MILK YIELD AND COMPOSITION IN DAIRY SHEEP (1) 
Giuseppe PULINA(2), Giancarlo ROSSI(3), Antonello CANNAS (4), 
Paolo BRANDANO(3), Salvatore P. G. RASSU(4), Antonio SERRA(4). 
SUMMARY 
Twenty Sardinian lactating ewes were divided in four groups (A, B, C, D) and fed with four diets, 
obtained mixing a pelleted fibre integrator (PFI) and a normal pelleted concentrate (NPe) in diffe-
rent proportions (NPeIPFI: A == 27/73; B == 42/58; C == 58/42; D == 73/27). Tbe intake was 123, 
122, 114 and 135 g of DM per kg of metabolic weight. Tbe ewes were able to choose between the 
two type of pellets. Tbe chewing time per kg of DM decreased with the reduction of PFI content 
in tbe diet. Tbe ewes were always ab le to maintain a regular ruminaI activity. Tbere were no signi-
ficant differences in the milk yield, milk fat contento see and body weight variations, while the 
milk protein content was higher in the group B. 
Key words: dairy sheep, milk production, fibrous feed. 
RIASSUNTO 
L'effetto dell'utilizzazione di un alimento pellettato ad elevato contenuto fibroso 
nella produzione quanti-qualitativa di latte in pecore da latte. 
Venti pecore di razza Sarda in lattazione sono state suddivise in quattro gruppi (A.B,e,D) ed ali-
mentate con altrettante razioni costituite da un pellettato ad alto contenuto in fibra e da un concen-
trato normale nelle seguenti proporzioni: A == 27/73; B == 42/58; C == 58/42; D == 73/27). L'ingestio-
ne di sostanza secca è stata di 123, 122, 114, e 135 g/kg di peso metabolico. Gli animali hanno 
mostrato capacità selettiva sugli alimenti somministrati. L'attività ruminale è stata regolare in 
tutti i gruppi; il tempo di masticazione per kg di s.s. è diminuito nei gruppi alimentati con le diete a 
minore concentrazione fibrosa. Non sono state evidenziate differenze significative nella produzio-
ne di latte. nel suo contenuto in lipidi ed in cellule somatiche, mentre il contenuto in proteine è 
stato più alto nel gruppo B. 
Parole chiave: pecore da latte, produzione di latte, alimento fibroso. 
(1) Financial support of the Assessorato alla Programmazione of the Regione Autonoma della Sardegna and 
Silos e Mangimi Martini S.p.A., S. Giusta, (OR). Paper presented at the 43rd meeting of the E.A.A,P., 
Madrid,14-17/9/1992. 
(2) Associate professor. Istituto di Zootecnica - Università di Sassari - Via E. De Nicola - 07100 Sassari. 
Phone 079/229300. 
(3) Full professor, ibidem. 
(4) Researcher, ibidem. 
28 
INTRODUCTION 
One of the most important problems of dairy ewe feeding in the Mediterranean area is 
the shortage of pasture during the winter and the summer (4). In these periods feeding is 
based on the supply of hay and concentrates; the quality of hay, however, is usually poor 
and this leads to its low intake (2). To increase the milk production with low quality hay 
the shepherds usually increase the supply of concentrates (lO); this technique, however, 
often causes digestive disorders (acidosis) due to the low fibre content of the diet (6,7). 
To avoid this problem we have produced a pelleted feed with high NDF content and long 
fibre inside; this feed should be mixed with normal pelleted concentrates to increase the 
total chewing activity without affecting the intake of the other feeds. It has been thought 
as "long fibre integrator" to be used in different amounts, depending on the quantity and 
quality of the fibre content in the di et (8,9). An experimental trial, therefore, has been 
carried out on Sardinian dairy ewes to study the use of this pelleted fibre integrator feed 
at different levels of utilization and its effects on milk production, intake and feeding 
behaviour. 
MATERIALS AND METHODS 
Twenty multiparous ewes in the last two months of lactation (Iune and July) were divi-
ded in 4 groups (A, B, C, D), similar for milk production, of 5 ewes each one. The ewes 
were housed and kept in individuaI pens during both the preliminary (2 weeks) and the 
experimental period (6 weeks). They were fed only with pelleted fibre integrator (PFI) 
and normal pelleted concentrate (NPC). 
The PFI was produced using: whole cottonseeds with lint (15%); wheat straw (45%); 
beet molasses (5%); dehydrated sugar beet pulp (24.5%); ligninesulfonate (0.5%); midd-
lings (10%). The wheat straw was put in the pelletting machine as wafers of chopped 
straw; the straw and the cottonseeds with lints were included in the PFI to work as stimu-
lators of the chewing activity of the ewes. The chemical composition of the PFI is repor-
ted in Table 1. 
The NPC was a normal pelletted concentrate for dairy ewes, whose chemical composi-
tion is reported in Table 1. 
Both feeds were produced in pellets of the same diameter (6 mm), to reduce the possibi-
lity of choice by sheep, and then mixed in different proportions to obtain four diets with 
different levels of NDF. 
The following diets were used. 
- Preliminary period, alI groups: PFI = 50% NPC = 50% 
- Experimental period: 
- GroupA PFI = 73% NPC = 27% 
- Group B PFI = 58% NPC = 42% 
- Group C PFI =42% NPC = 58% 
- GroupD PFI = 27% NPC = 73% 
29 
Each di et was given ad libitum to the same group of ewes, following a monofactorial 
experiment with four different levels. 
The individuaI ffiilk yield, intake and body weight were measured every week during the 
trial. The percentage of PFI and NPC pellets in the orts was measured to estimate the 
diet actually eaten by the ewes. IndividuaI milk samples were collected and then analy-
zed for the ffiilk fat, protein and lactose content with the IRMA method (Milkoscan 605) 
and for the somatic cell count with the automatic instrument Fossomatic 306 (1). 
At the end of the trial eating and ruminating time were measured on 3 ewes per group 
during 24 hours with continuous manual measurement. 
The data were submitted to the analysis of the variance and the differences among grou-
ps were checked with the Turkey test, after doing logarithmic transformation of the data 
in the case of the somatic cell count. 
Table l - Chemical composition (% on DM) of feeds and diets supplied. 
FEEDS DM CP EE NDF ADF ADL ASH 
PelIeted fiber integrator (PFI) 92.21 12.51 3.19 44.32 30.53 8.03 8.63 
Normal pelleted concentrate (NPC) 92.04 16.85 3.00 24.84 10.95 3.56 9.08 
Diets supplied PFI NPC 
(%) (%) 
Group A 73 27 13.68 3.14 39.06 25.24 6.82 8.75 
GroupB 58 42 14.33 3.11 36.14 22.31 6.15 8.82 
Group C 42 58 15.03 3.08 33.02 19.17 5.44 8.89 
GroupD 27 73 15.68 3.05 30.10 16.24 4.77 8.96 
RESULTS AND DISCUSSION 
The chemical composition of the feeds and of the diets supplied is reported in table 1. 
The different proportion of PFI and NPC in the four diets resulted in a range of NDF 
from 39.06% to 30.1%. The long fibre of the diet came only from the PFI, which the-
refore was the main chewing activity stimulator. 
The mean intake of feed (Table 2) was high in alI groups and there were no statisticaI 
differences among groups, probably as result of the high variability within each group. 
In the second week of trial the group C had very low intake, due to the anomalous beha-
viour of some animaIs of this group. The intake data of the first week of the experimen-
tal period were not collected. 
30 
Table 2 - Intake of feed. 
GroupA Group B Group C GroupD 
Periods Mean SD Mean SD Mean SD Mean SD 
As fed intake (glday * head) 
2 2780a 319 2410a 810 1400b 757 2400a 423 
3 2280 760 2500 567 1998 407 2274 292 
4 2750 429 2540 640 2290 773 2110 383 
5 2230 552 2310 241 2590 451 2420 448 
6 2410 700 2610 826 2530 368 2920 266 
Mean 2490 260 2474 117 2162 485 2425 303 
Dry matter intake (glday * kg of bw A 0.75) 
2 138 19 125 40 85 53 134 18 
3 113 40 131 27 102 15 127 14 
4 137 25 133 28 119 33 118 18 
5 111 27 122 11 133 21 135 21 
6 117 31 98 59 129 22 159 17 
Mean 123 23 122 15 114 11 135 8 
Initial 48.50 4.81 44.86 3.16 46.05 5.28 40.45 3.53 
Final 50.14 3.97 46.10 5.54 47.64 6.46 43.56 4.18 
Variation 1.64 4.89 1.24 4.97 1.59 4.72 3.11 1.23 
Different suffix letters show significant differences at 0.05 
SD = standard deviation 
The animals were able to make a choice between the two feeds supplied (Table 3 and 
Figures 1 and 2). In the groups A and B, which had the highest percentage of PFI in thè 
diet, the choice of the ewes was directed to increase the intake of NPC, while in the other 
two groups (C and D) the choice was directed to increase the intake of PFI. This kind of 
behaviour was clearer in the intermediate groups ( B and C), where the choice done by 
the ewes resulted in the fact that both groups ate very similar diets. It seems that the 
ewes have chosen the feeds to have 34-35% of NDF in their diet (Tabie 3 and Figure 2). 
The ability of sheep to satisfy their requirements by selecting their diet has been aIready 
showed by Forbes (3). 
The total chewing ti me (Table 4) was similar in the groups A, Band D and Iower in the 
group C. The chewing activities per kg or dry matter (Tabie 4) decreased from the 
group A (highest content of PFI) to the group D (lowest content of PFI). In any case this 
parameter was high enough to maintain normai ruminai fermentation in alI groups. The 
manuai survey of the chewing time, however, may have influenced the behaviour of the 
animals, above alI during the night. 
The milk yield (Tabie 5) was high in alI groups; there were no statistical differences 
among the groups, due to the high variability; this variability may be an effect of the 
variability in the feeding behaviour and in the intake. The milk yieId, in any case, 
decreased reguIarIy during the trial in the groups B and D, while the groups A and C 
showed an irreguiar paUern in the 1st (group A) and in the 2nd (group C) week of trial. 
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33 
Table 4 - Chewing activity af the ewes. 
GroupA GroupB GroupC GroupD 
Mean SD Mean SD Mean SD Mean SD 
Chewing time 
min/day 
- eating 110 19 91 9 87 72 96 35 
- rumination 155 48 174 72 99 57 167 56 
- totai 265 67 265 63 186 17 263 67 
Intake 1.749 0.470 1.959 0.200 1.661 0.499 2.371 0.298 
(kg/d ofDM) 
Chewing activities 152 18 137 40 115 29 114 45 
(min/kg ofDM) 
Table 5 - Milk yield and campasitian. 
GroupA GroupB Group C GroupD 
Periods Mean SD Mean SD Mean SD Mean SD 
Mi/k yield (g/d) 
Pre-expe 1311 141 1336 201 1327 161 1332 190 
rimental 
l 957 148 1234 278 1112 208 1206 144 
2 1095 194 927 343 590 265 1087 389 
3 1005 225 914 314 926 256 964 255 
4 976 193 774 267 874 188 989 170 
5 856 299 712 180 932 243 852 242 
6 721 261 619 413 774 186 974 253 
Mean 935 130 863 217 868 175 1012 121 
Milk faI (o/c) 
1 5.88 0.85 6.02 0.23 5.72 0.40 6.01 0.50 
2 7.40 1.24 8.66 1.29 9.08 2.05 7.35 1.46 
3 8.12 1.76 8.57 0.87 7.19 0.84 7.05 1.26 
4 8.39 2.14 8.28 0.50 6.74 0.63 7.63 0.86 
5 7.81 2.70 8.16 0.99 7.06 1.10 7.48 0.48 
6 8.24 2.35 8.11 1.81 8.21 2.21 7.78 0.77 
Mean 7.64 0.95 7.97 1.00 7.33 1.19 7.22 0.66 
Milk protein (%) 
1 5.90a 0.21 6.23b 0.38 5.91a 0.33 5.95a 0.33 
2 5.89 0.48 6.50 0.69 6.48 0.79 6.22 0.74 
3 5.99 0.74 6.69 0.84 5.90 0.41 6.23 0.54 
4 5.65 0.58 6.43 0.40 5.80 0.31 5.94 0.45 
5 5.52a 0.53 6.48b 0.51 5.66a 0.22 6.20ab 0.46 
6 6.01 0.68 6.72 1.08 6.10 0.84 5.83 0.43 
Mean 5.83a 0.20 6.51b 0.18 5.98a 0.29 6.06ab 0.18 
. 
SCC (n/mi) in thousands 
1 2616 3264 855 736 282 154 836 1389 
2 743 730 1672 2899 375 163 514 445 
3 1078 1348 282 210 187 43 1254 2109 
4 2069 2186 2021 2671 183 25 2908 3871 
5 918 1127 352 151 172 21 2747 5244 
6 793 1158 412 279 180 34 539 515 
Mean 1370 798 932 760 230 84 1466 1111 
Different suffix letters show significant difference at 0.05 
SD = standard deviation. 
34 
The milk fat content (Table 5) was high enough (and sometimes very high) in aH grou-
ps. This indicates that even the group fed with the highest content of NPC had an ade-
quate ruminaI activity. 
The milk protein content (Table 5) was statistically higher in the group B than in the 
other groups, both as average and in the 1st and 5th week of trial; this, however, is pro-
bably the effect of pre-existing differences, since the group C ate a very similar diet to 
that eaten by the group B. 
The somatic celi count (Table 5) of the milk did not show any significant difference, 
even if the values of the group C were much lower than those of the other groups. 
The body weight variations (Table 2) were always positive but not statistically different 
among groups. 
CONCLUSIONS 
The pelleted fibre integrator (PFI) was able to maintain normal ruminal fermentation in 
alI the doses used. This feed can allow, therefore, the correct feeding of lactating ewes 
even when there is shortage of long fibre in the diet. The effects of the PFI on feeding 
behaviour and on milk production, however, require more investigations to understand 
which level of PFI and NDF is able to maximize milk production. 
LITERATURE CITED 
l) ANDERSEN T., BREMS N., BORGLUM M.M., KOLD-CHRISTENSEN S., HANSEN E., JORGENSEN 
H. J., NIGAARD L. (1986). - Modern laboratory practice: Chemical analyses - In "Modern Dairy 
Terminology, vo1.2", R.K. Robinson (ed.). Elsevier, London: 307-343. 
2) BOCQUIER F., DELMAS G., THERIEZ M. (1983) - Alimentation de la brebis laitiere: capacitè d'inge-
stion et phenomenes de substitution chez la brebis lacaune. Bull. Tech. CRZV, 52:19. 
3) FORBES J.M. (1986) - The Voluntary Food Intake of Farm AnimaI - Butterworths & Co. (Publisher) Ltd, 
London. 
4) LUCIFERO M., BRANDANO P., CONGIU E, DATTILO M., ROSSI G., VALSECCHI F. (1973) -
Ricerche pluriennali per una razionale utilizzazione dei pascoli della Sardegna - Risultati di un quadriennio 
di sperimentazione sui pascoli di Foresta Burgos - Studi Sassaresi Sez. III - Ann. della Fac. di Agraria 
dell'Università di Sassari, Vol.XXI 2:1-128. 
5) MARTILLOm F., ANTONGIOVANNI M., RIZZI L., SANTI E., BITTANTE G.(1987) - Metodi di ana-
lisi per la valutazione degli alimenti di impiego zootecnico. Quaderni metodologici n.8. IPRA. 
6) KINSER A R., FAHEY G. c., BERGER L. L., MERKEN N. R.,(1988) - Low-quality roughage in high 
concentrate pelleted diets for sheep: digestion and metabolism of nitrogen and energy as affected by dietary 
fiber concentration. J. of Anim. Sci., 66: 487-500. 
7) ROSSI G., PULINA G., CANNAS A. (1988). - L'alimentazione delle pecore da latte ed il problema della 
formulazione della razione con animali al pascolo - L'Informatore zootecnico n.24. anno XXXVI: 41-44. 
8) ROSSI G., SERRA A:, PULINA G., CANNAS A, BRANDANO P. (1991) - L'utilizzazione di un alimen-
to unico pellettato ( Unipellet) nell'alimentazione delle pecore da latte. 1 - Influenza della grassatura e del 
livello proteico sulla produzione quanti-qualitativa di latte in pecore di razza Sarda. Zoot. e Nutr. Anim. 
Anno XVII- n. 1:23-34. Febbraio 1991. 
9) CANNAS A, ROSSI G., BRANDANO P., PULINA G. (1991) - Effect of feeding method of a complete 
pelleted feed (Unipellet) as supplement of grazing in dairy ewes. 42nd Congr. EAAP 9-12 September 1991, 
Berlin. 
lO) TRIMARCHI G., ROSSI G., SECCHIARI P., FERRUZZI G. (1981) - Influence de la concentration ener-
getique sur les performances des brebis laitieres. Int. Symp. Past. Sheep Farm. Int. Ec. Env., Tel Aviv 8-13 
March 1981. 
Lavoro pervenuto in redazione il 30-9-1992 
For reprints apply to: 
Gli estratti possono essere richiesti a: Prof. Giuseppe Pulina, Istituto di Zootecnica - Facoltà di Agraria 
Via E. De Nicola - 07100 Sassari - Phone 079/229305 


The Effect of the utilization of a high fibre pelleted feed on milk yield and composition in dairy sheep

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