Environmental influences on hogget lambing performance and the relationship between hogget and two-tooth lambing performance

Effects of hogget oestrus and the lambing and milking of hoggets on the subsequent milk composition and yields of 2-year-old Dorset ewes, Abstract One-hundred-and-ninety Poll Dorset hoggets were used in an experiment to determine the effects of hogget oestrus, and the lambing and milking of hoggets on subsequent milk composition and yields of the ewes as 2-year-olds. Seventy hoggets were mated to vasectomised rams and the rest to entire Dorset rams. Twenty-eight of the 83 hoggets which lambed reared their lambs, while 55 hoggets were milked twice a day. At lambing as 2-year-olds there were four groups: ewes that had reared lambs as hoggets (14); ewes that had been milked as hoggets (43); ewes that had exhibited hogget oestrus to vasectomised rams (34); and ewes that had not exhibited hogget oestrus (25). The 2-year-old ewes had a mean lambing date of 4 August and were milked twice a day until 17 November. Daily milk yields were measured every 7-14 days and the concentrations of fat, protein, lactose, and solids in the milk were measured every 7-28 days. Lambing or milking as a hogget had no effects on subsequent milk yields or milk composition as 2-year-olds. Two-year-old ewes which exhibited hogget oestrus, had lower (P < 0.001) concentrations of protein in their milk, and higher (P < 0.05) liveweights, total and mean daily milk yields, and yields of fat and lactose than 2-year-old ewes which had not exhibited hogget oestrus. Including the liveweight as 2-year-olds as A94075 a covariate in the analyses removed the effect of hogget oestrus on yields of milk, fat, and lactose but not protein concentration. Milk composition and yields of 2-year-olds were positively correlated with the milk composition and yields as hoggets. There were no beneficial effects of the lambing or milking of hoggets on subsequent milk yields as 2-year-olds but there were direct benefits of milking hoggets through the volume of milk produced and the ability to cull low-producing ewes early in their life.

contrasting

confidence: 66%

Section: Introductionmentioning

confidence: 96%

Effects of hogget oestrus and the lambing and milking of hoggets on the subsequent milk composition and yields of 2‐year‐old Dorset ewes

Knight¹,

Gosling²,

Dick³

1995

“…Overseas, the practice has been shown to increase lifetime reproductive performance in several breeds (Dyrmundsson 1973). An improvement in the 2-year-old reproductive performance of previously lambed Waihora Romney ewes has been reported (McCall & Hight 1981), but the effects of hogget lambing per se could not be determined because ' no control ewes remained unjoined. Hogget lambing under North Island hill country conditions had no effect on 2-year-old lambing (R. L. Baker, pers.…”

Section: Introductionmentioning

confidence: 97%

Reproduction in ewe lambs and its effect on 2-year-old performance

McMillan

McDonald

1983

Reproductive performance was studied in 1-and 2-year-old Romney and Border Leicester x Romney ewes. Control lambs were joined with vasectomised rams, and the remainder were joined with entire rams for 5 weeks. Fertility, growth rate, and weaning rate were higher in crossbred ewe lambs, and birth rank effects were small. Conception rate to first service was negatively related to liveweight gain over joining. Weaning rate (57070 lambs weaned/ewe joined) was lower than normally expected from adult ewes. Lamb survival was improved in previously lambed 2-year-old ewes, whereas oestrous and ovarian activity, fertility, fecundity, and lamb growth were unaffected. Ewe liveweight and fleece weights were temporarily reduced. It is concluded that lambing in l-year-old ewes can enhance their reproductive performance as 2-year-olds.

“…In contrast, in the mature ewe the aim is generally not to increase conceptus-free liveweight. It is likely that the affects of poor nutrition in pregnancy would be more pronounced in the hogget than in the mature ewe, as hoggets tend to give birth to relatively lightweight lambs (McMillan 1983;McMillan & McDonald 1983) which display low survival rates (McCall & Hight 1981;Craig 1982;McMillan 1983;McMillan & McDonald 1983;Moore et al 1989). Interestingly, Wallace et al (1996Wallace et al ( , 1997 and Wallace (2000) reported that a very high level of hogget nutrition using concentrates increased foetal loss via spontaneous non-infectious abortion, decreased lamb birthweight and colostrum production, and increased neonatal losses.…”

Section: Introductionmentioning

confidence: 99%

“…In the present study, hoggets were not weaned until January, which would have limited the time available for "low" group hoggets to achieve adequate two-tooth mating weights. Interestingly, field studies to date have not reported decreased two-tooth reproductive performance from hogget lambing (McCall & Hight 1981 ;Craig 1982;McMillan & McDonald 1983;Moore et al 1989).…”

mentioning

confidence: 99%

Effect of hogget nutrition in pregnancy on lamb birthweight and survival to weaning

Morris

Kenyon

West

2005

The effect of hogget nutrition during pregnancy on birthweight and survival of lambs has not been thoroughly examined under pastoral conditions in New Zealand. The aims of the present study were to examine the effect of three hogget nutrition levels during pregnancy on both lamb birthweight and lamb survival, and hogget performance. Hoggets were offered either a "low", "medium" or "high" level of nutrition of herbage during pregnancy, which resulted in total liveweight increases of 12, 21, and 30 kg, respectively over the period from 13 days after the average day of mating to average day 130 of pregnancy. Hogget nutritional treatment failed to affect either lamb birthweight or lamb survival. Nutritional treatment also failed to consistently affect ewe metabolic status. However, "low" group hoggets weaned significantly (P < 0.05) lighter lambs and were themselves significantly (P < 0.05) lighter at weaning and produced significantly (P < 0.05) less wool. The results of this study indicate that offering pregnant hoggets a level of nutrition that increases their liveweight gain above that of the expected conceptus growth will not benefit lamb birthweight or survival rate to weaning, but will increase hogget fleece weight and lamb weight at weaning. On the other hand, and in contrast to some earlier research, an even higher level of nutrition in pregnancy did not reduce birthweight or survival rate to weaning. This suggests that when farmers are aiming to achieve heavy lamb weaning weights and two-tooth mating weights, they need not avoid offering hoggets a high level of nutrition in pregnancy.