THESIS Submitted in partial fulfilment of the requirement for the degree

Transcription

1 COMPARATIVE FEED EFFICIENCY OF 'CROSSBRED JERSEY AND CROSSBRED BROWN SWISS CATTLE P.A. By DEVASIA THESIS Submitted in partial fulfilment of the requirement for the degree DOCTOR OF PHILOSOPHY Faculty of Veterinary and Animal Sciences Kerala Agricultural University Department of Nutrition COLLEGE OF VETERINARY AND ANIMAL SCIENCES MANNUTHY: TRICHUR 1989

2 CER TIFICA TE Certified that this thesis, entitled COMPARATIVE FEED EFFICI- ENCY OF CROSSBRED JERSEY AND CROSSBRED BROWN SWISS CATTLE is a record of research work done independently by Sri. P.A. Devasia under my guidance and supervision and that it has not previously formed the basis for the award of any degree, fellowship, or associateship to him. Mannuthy, ~--~~~ Dr.CR. Ananthasubramaniam, (Chairman, Advisory Board) Professor & Project Co-ordinator, Cattle & Buffaloe, College of Veterinary & Animal Sciences.

3 "., ' ABSTRACT A comparative evaluation of the feed conversion efficiencies of crossbred Jersey and crossbred Brown Swiss cattle of Kerala involving a growth study and a lactation study using 'eight heifer calves and six milch cows each for 28 and 14 fortnights respectively were carried out. While records of 'daily feed intake, water consumption, fortnightly data on body. weight, body measurements and monthly data on haematologkal values were maintained during the growth study, data on daily feed intake, milk yield, fortnightly data on composition of mill<, body weight and haematological values were gathered during the lactation study. Dige,s t ion -cum -balance trials were carried out during the 14th and 28th fortnights respectively under gro\\.'th study and during the 11th fortnight under lactation study... There were no significant differences between crossbred Jersey and crossbred Brown Swiss heifer calves in respect of; their average daily dry matter and water consumptions; various body measurements, haematological values and digestion coefficients of various nutrients in their feed throughout the experimental period of 28 fortnights except that the average digestion coefficients of crude fibre in crossbred Brown Swiss heifer calves during digestion trial I was 'significantly higher (P 10.01) than that of crossbred Jersey. BOTh the groups of heifer calves did not differ significantly in respect of their average daily consumptions of dry matter, gross energy. total digestible nutrients, digestible energy, crude protein and digestible

4 crude protein per unit metabolic body size (WO~5). Tt")e feed converslon efficiency values as adjudged in terms ofquan-tities of dry matter, gross energy, total digestible nutrients, digestible energy, crude protein and digestible crude protein needed per kg body weight gain in crossbred Jersey were :!:.1.01kg, :!:.3.13Mcal, 8.09.:!:.0.46kg, :!:.2.09Mcal, 1.83.:!: kg and 1.10.:!:.0.06kg respectively and,the same were not significantly different from the average values of :!:.1.06kg, :!:.4.47 Mcal, 9.17.:!:.0.68kg, :!:.3.00Mcal, 2.03.:!:.0.14kg and 1.24.:!:.0.08kg respectively observ.ed in the case of crossbred Brown Swiss heifer calves. Both the groups did not differ significantly in respect of average daily nitrogen retention of :!:.0.61and :!:.1.02g respectively during trial I and and :!:.1.15g respectively during trial II. Milch cows belonging to both the genetic groups of crossbred Jersey and' crossbred Brown Swiss not only maintained their body weight but also showed an overall average fortnightly weight gain of 1.44.:!:.0.14and kg respectively without any significant diuerence between them in this regard. They also failed to show any significant difference in respect of feed consumption, digestion coefficients of nutrients and nitrogen retention, the marginally positive nitrogen balance together with normal haematological values obtained in respect of both the groups indicated that all the animals were in good nutritional status. The average daily milk yields of 7.28, 7.06 and 6.43 kg respectively during the 1st, 7th and 13th fortnights in the case of 'crossbred Jersey cows were not significantly different from those of 7.07, 7.08 and 6.80 kg respectively in the case of crossbred Brown Swiss cows. There was no significant difference between cows belonging to the two genetic

5 groups In respect of their average daily consumption of OM, gross energy, TON, crude protein and OCP per unit metabolic body size. The overall average consumptions of :..23 Mcal, :..03 kg, :..13 Mc.al,and :.4.60 g respectively of gross energy, total digestible nutrients, digestible energyand OCP per kg of FCM produced by crossbred Jersey cows including their maintenance requirements were' not significantly different from :..25 Mcal, :..03 kg, :..14 Mcal and :.4.60 g respectively of the same by crossbred Brown Swiss cows. The two crossbred groups of milch cows failed to show any significant difference 'in respect of their economic efficiency in terms of dairy merit as well as income over feed cost, the average values being :..88 and Rs per day for crossbred Jersey and :..89 and Rs per day for crossbred Brown Swiss cows respectively. No significant differences were observed in the performances of crossbred Jersey and crossbred Brown Swiss cattle in respect of their growth and milk production when reared in the same locality under identical conditions of feeding and management.