Reproductive and productive response to suckling restriction and dietary flushing in primiparous grazing beef cows

Abstract

The objectives of the present experiment were to analyse the reproductive and productive responses to suckling-restriction treatments and flushing in primiparous grazing beef cows. During 3 years, 153 primiparous anoestrus cows were assigned randomly to one of four treatments in a 2 by 2 factorial arrangement of suckling-management treatments and flushing. Suckling-restriction treatments started at 61 ± 10 days postpartum and consisted of applying nose plates to calves for 12 days (i.e. TS treatment) or 5 days of isolation of the calf from the cow followed by applying nose plates to calves for 7 days as calves were reunited with their mothers (i.e. IS treatment). Nutritional treatments (flushing v. control) started at the beginning of the breeding season, immediately after the suckling-restriction treatments were finished (73 ± 10 days postpartum), with cows receiving or not receiving 2 kg/day of whole-rice middling for 22 days. Cow body condition score (BCS) was recorded every 20 days from calving until 120 days postpartum. Duration of postpartum anoestrus (PPA) and probability of cyclicity were estimated by plasma progesterone concentrations analysed in weekly samples. Pregnant cows were determined by ultrasound 42 days after bull introduction (early pregnancy; EP) and 30 days after the end of the breeding season (total pregnancy; TP). BCS at calving and changes in BCS from calving to the day of BCS nadir (ΔBCS) varied among years depending on forage availability and weather conditions. Increased cow BCS at calving decreased PPA (b = –41 days, P < 0.0001) and, in interaction with ΔBCS, increased EP (P < 0.008) and TP (P < 0.003). Calf weights at weaning and average daily gain were not affected by suckling-restriction or flushing treatments. Isolated temporary suckling control reduced PPA by 11 days when compared with temporary suckling control (P < 0.004). Flushing increased EP by 40%, which was also affected by BCS at calving and was greater in cows that gained, than in those that maintained or lost BCS. We conclude that flushing was useful in improving early pregnancy rates of primiparous beef cows with ‘suboptimal’ body condition (lower than 4.5) at calving and grazing native pasture.

Supplementation with a mixture of whole rice bran and crude glycerin on metabolic responses and performance of primiparous beef cows

“…The effect of the pre-mating supplementation on BCS is not consistent and seems to depend, at least partially, on the supplement used. Astessiano et al (2013) and Soca et al (2013) used a supplement based on whole rice bran and reported no effect on BCS. However, cows grazing on pasture improved with Lotus subbiflorus cv.…”

“…Short-term supplementations before or during the mating period, with or without association with temporary weaning, are alternatives to increase pregnancy rates in cows with sub-optimal BCS (Pérez-Clariget et al, 2007;Soca et al, 2013). The supplement most frequently used in these studies has been whole rice bran, an energy nutrient with 130-180 g kg −1 of crude protein (CP) (Wang et al, 2012).…”

Influences of nutrition and metabolism on reproduction of the female ruminant

“…Indeed, in grazing production systems dairy and beef cows with better BCS during the pre and postpartum periods, or with better BCS at calving, had an earlier first postpartum ovulation (Meikle et al, 2004a;Quintans et al, 2010;Soca et al, 2013b). Soca et al (2013b) determined that the length from calving to first ovulation in beef cows decreased by 49 days for each incremental unit of improvement of BCS at calving (scale 1 to 8). Stagg et al (1995) reported a prolonged period of anestrus in cows with poor body condition.…”

Liver functional genomics in beef cows on grazing systems: novel genes and pathways revealed

“…Extensive beef cow-calf production systems depend on the quantity and quality of grazed forages to meet their nutritional demands throughout the year. In temperate environments, nutrient availability of grazed forages fluctuates during seasons (13, 42), and often, in spring-calved beef cows, the lowest nutrient availability occurs during pregnancy in winter, and cows lose body tissue to support conceptus growth (13,37,42).…”

“…Extensive beef cow-calf production systems depend on the quantity and quality of grazed forages to meet their nutritional demands throughout the year. In temperate environments, nutrient availability of grazed forages fluctuates during seasons (13, 42), and often, in spring-calved beef cows, the lowest nutrient availability occurs during pregnancy in winter, and cows lose body tissue to support conceptus growth (13,37,42).Microarray technology has been used to evaluate hepatic metabolic adaptations to pregnancy (19), transition period, early and midlactation (1, 25, 28), negative energy balance (NEB) or dietary restriction (1,26,29), and transition-related metabolic diseases (27) in dairy cows. In is well known that dairy and beef cows have been selected for different purposes and consequently, they have developed different metabolic adaptation strategies (47, 51).…”