Abstract:
Daily excretion of purine derivatives (PD) and creatinine by lactating cows fed four
different rations were examined in a small farm at Kamburupitiya area during the
period of six months. The four diets used were 1) mixture of natural forages -farm
diet (FD) 2) FD + 675g DM /head/d low cost concentrate supplement -Gava Triposha
(GT) 3) FD + 216g DM /head/d Gliricidia sepium tree fodder (TF) 4) FD+GT+TF
respectively. In addition, effect of four diets on milk yield and composition were also
studied. A Latin square design was used with four lactating cows (cross-bred Frisian
cows,, live weight 250±12,; 150-160 days of 3rd lactation ) and four feeding periods.
The intake of organic matter and nitrogen increased with supplementation in
association with higher dry matter intake. Milk yield was not increased due to
supplementation but fat and total solids were slightly changed due to supplementation
of GT+TF. The level of allantoin, uric acid, total PD and creatinine (mmol/1) in urine
responded positively towards supplementation in response to higher nitrogen status of
supplemented diets. The highest response was observed when farm diet was
supplemented with GT+TF. The PD: Creatinine index (PDC Index) and estimated daily
PD excretion (mmol/d) also responded significantly towards supplementation. The
PDC index was lowest with farm diet (19) and increased with supplementation and
reached the highest value of 32 with TF+GT diet. The estimated digestible organic
matter intake (DOMI) was 0.69, 0.83, 0.98 and 1.17 kg/head/d respectively for FD,
FD+GT, FD+TF and FD+GT+TF diets. According to the banding system based on
PDC index and estimated microbial nitrogen production, under feeding condition was
observed when only farm diet was fed to lactating cows. However, supplementation
with TF or GT could enhance the microbial nitrogen production to reach the
maintenance level of feeding. Supplementation both with GT and TF could boost the
microbial nitrogen production to reach a satisfactory level of feeding.
The findings of this study suggest that supplementation of tree fodder and low cost
concentrate mix (Gave Triposha) have a greater potential to improve the nutritional
status of milking cows particularly under small farmer conditions.
