Seaweed formulations (AF-KWP and AFRD-5) were higher in total ash and insoluble ash content (Table 2). Total ash, which mainly represents mineral content, in the present experiment was higher than the values reported by
Cabrita et al. (2016) with
Ulva sp. and
G.
vermiculophylla. EE content was in agreement with many studies
(Khairy and El-Shafay 2013; Mouritsen et al., 2013). The CP content of concentrate mixture was almost similar. The chemical composition of maize fodder and wheat straw was within the normal range reported by
Ranjhan, 1988. Our results are also similar to
Abdoun et al., (2013) who reported that NDF and ADF were less in seaweed (
Ulva lactuca) supplemented group than control.
The intake and digestibility of DM, OM, CP, EE, total carbohydrate, ADF and NDF was comparable in all three groups (Table 3). Therefore it is evident that supplementation of seaweed formulations has no adverse impact on overall rumen microbial and digestive efficiency of the animals. This corroborates well with the findings of
Berry and Turk (1944) who have reported no influence of brown seaweed supplementation on DMI. Our findings were in contrary to
Antaya et al., (2016) who have reported increased digestibility of OM and NDF due to supplementation of
Ascophyllum nodosum.
The results showed that all the experimental calves were in positive Ca, P and N balance (Table 4). The Ca intake (g/d) was significatly (P<0.001) higher in the seaweed supplemental group than control. However, P intake (g/d) was significatly lower (P<0.001) in the seaweed supplemental group than control. The N intake was similar in all 3 groups. The retention (% intake) of Ca and P was significant (P<0.05) among the different groups.
Munde (2018) reported that intake (g/d), retention (% intake) of Ca and P were similar among the groups by feeding
Kappaphycus and
Gracilaria.
Munde (2018) also reported that retention of N (% intake) did not differ significantly among the group by feeding
Kappaphycus and
Gracilaria. Similarly,
Venketeswaran (2018) reported that daily intake and retention of N were statistically similar in 3 groups by feeding 2% and 4%
Turbinaria conoides.
Non-significant effect was observed in total gain in body weight, ADG, total DMI and FCR among the 3 treatment groups (Table 5). Our results were in agreement with
Anderson et al., (2006) who did not observed any influence of
Ascophyllum nodosum supplementation on growth performance of crossbred cattle. Our results are in contarary with many studies who observed that seaweed supplementation improved body weight gain
(Al-Shorepy et al., 2001; Turner et al., 2002).
The level of different antioxidant parameters were presented in Table 6. In the present study, seaweed formulations supplementation increased the activity of SOD, catalase, MDA and GPx. Our findings were similar to
Allen et al., (2001) and
Saker et al., (2004) who reported that inclusion of
Ascophyllum nodosum improved antioxidant status in cattle. The seaweed formulation AFRD-5 used in the present experiment contained a brown seaweed thrashed powder (
Turbinaria conoides) which contain phlorotannin, has antioxidant activities. Moreove extracts of
Kappaphycus sp. showed higher reducing power and- OH radical scavenging activity than other antioxidants
(Holdt and Kraan 2011). Sulfated polysaccharide from
Gracilaria sp. exhibited moderate effect in inhibits the formation of free radicals.
Kapaphycus alvarezii contains β-carotene, vitamin C and vitamin E which have antioxidant activity
(Mantajun et al., 2010). Our result is in contradiction with
Abdoun et al., (2013) who reported that seaweed inclusion did not alter the blood antioxidant activity. Similarly,
Venketeswaran (2018) reported non-significant effect in serum SOD and GPx concentrations by supplemementation of
Turbinaria conoides in crossbred calves.
The mean values for skin thickness differed significantly (P<0.001) among different groups and significantly (P<0.001) maximum skin thickness was observed in group T
2 followed by T
1 and T0 groups (Fig 1). Maximum average thickness was observed after 24 h and then gradually reduced. Our results are in agreement with
Allen et al., (2001) who have observed that
Ascophyllum nodosum improved immune response in mammals.
Kuznetsova et al., (2015) also observed that fucoidans are agonists for receptors of innate immunity and potent inducers of the cell-mediated immune response. In the present experiment, increased GPx and SOD activity was observed which might contributed to increased cellular immunity. This is similar with the finding of
Fike et al., (2001) who have reported increased SOD in ruminants with supplementation of brown seaweed.
Kappaphycus and
Gracilaria are rich in Se and vitamin E which were positively linked to cellular immunity
(Fike et al. 2001). Our results are in agreement with
Venketeswaran (2018) and
Munde (2018) who reported that cell mediated immune response was significantly higher seaweed supplemented groups.