The effect of supplementary grass silage and standard concentrate on milk fat fatty acid composition and iodine value when cows are fed a whole rapeseed-based concentrate at pasture

peer-reviewedThe use of grass silage and concentrates to supplement fresh grass intake is commonly practised in dairy systems. However, the effects of such supplementation within a dietary regime designed to produce a spreadable butter are unknown. Sixteen Holstein Friesian cows were used in an incomplete changeover design to investigate the effect on milk fat of supplementation with grass silage (GS) or standard concentrate (SC) when offering a concentrate based on whole rapeseed at pasture (RC+G). A control diet of fresh grass and standard concentrate (SC+G) was also included. Diet had no effect (P > 0.05) on milk yield or on the lactose concentration of milk. The iodine value (IV; grams of iodine per 100 g milk fat) of milk fat with the RC+G diet was greater (43.9, P < 0.05) than with the SC+G diet (39.9). The iodine value of milk fat was reduced (P < 0.05) when RC+G+GS was offered (41.5 g/100g), but not when RC+G+SC was offered (43.1 g/100g), compared with when RC+G was offered. The proportion of unsaturated fatty acids in milk fat was higher (P < 0.05) when the RC+G diet was offered compared with either RC+G+GS or RC+G+SC. If supplementary feedstuffs are to be used in combination with a wholerapeseed- based concentrate and pasture, then inclusion of standard concentrate would be preferred over grass silage because the negative impact on the iodine value of milk fat was less. However, further research is required to investigate the effect on IV of milk fat when a standard concentrate supplement is offered at levels that increase milk yield

The Effect of Dietary Oil Type and Energy Intake in Lactating Sows on the Fatty Acid Profile of Colostrum and Milk, and Piglet Growth to Weaning

peer-reviewedThis study investigated the effect of salmon oil in lactating sow diets and offering these diets in a phased dietary regimen to increase the energy density of the diet in late lactation. Sow and piglet productivity to weaning, the fatty acid profile of milk, piglet blood and tissues at weaning were the main parameters measured. Multiparous sows (n = 100) (Landrace × Large White) were offered dietary treatments from day 105 of gestation until weaning. Dietary treatments (2 × 2 factorial) included oil type (soya or salmon oil) and dietary regimen (Flat 14.5 MJ/kg DE diet offered until weaning or Phased 14.5 MJ/kg DE diet offered to day 14 of lactation then a second diet containing 15.5 MJ/kg DE offered from day 15 until weaning). Salmon oil inclusion increased the total proportion of n-3 fatty acids in colostrum (p < 0.001), milk (p < 0.001), piglet plasma (p < 0.01), adipose (p < 0.001), liver (p < 0.001) and muscle (p < 0.001). Increasing sow dietary energy level in late lactation increased the total n-3 fatty acids in milk (p < 0.001), piglet adipose (p < 0.01) and piglet muscle (p < 0.05). However, piglet growth to weaning did not improve

The effect of creep feed intake and starter diet allowance on piglets’ gut structure and growth performance after weaning

Publication history: Accepted - 18 June 2018; Published - 7 September 2018.Diets offered to lactating and weaned piglets are the most expensive diets within pig production; however, the effect of these diets on lifetime pig performance is inconsistent. The objective of the current study was to investigate the impact of creep feed consumption during lactation and different starter diet allowances on piglets' gut structure and lifetime growth performance. In total, 320 pigs and 80 pigs (Landrace × Large White) were used after weaning in a 2 × 2 factorial arrangement to study growth performance and gut structure, respectively. At weaning, piglets that ate creep feed and piglets that were not offered creep feed during lactation were allocated to 2 kg/pig [low level (LL)] or 6 kg/pig [high level (HL)] of starter 1 diet (16.5 MJ DE/kg, 22.5% CP, and 1.7% total Lys) allowance. At weaning and at 1 and 3 wk after weaning, 8 piglets per treatment were sacrificed, and their small intestine morphology was evaluated (villus height and crypt depth). Piglets that ate creep feed had increased feed intake during the first week after weaning (P 0.05). Piglets that were fed HL after weaning had higher ADG and BW from weaning to 16 wk after weaning (both P < 0.05) and had lower feed conversion ratio (FCR) from weaning to 6 wk after weaning (P < 0.05). Piglets fed HL after weaning also had higher villi height and greater crypt depth than LL piglets at 3 wk after weaning (both P < 0.05). Creep feed consumption during lactation increases feed intake early after weaning, suggesting an improved capacity of piglets to cope with weaning, but did not influence their growth performance. Offering piglets 6 kg of starter diet enhances piglets' growth performance during the growing and finishing phase, probably by improving gut structure after weaning

What is the current significance of low birthweight pigs on commercial farms in Northern Ireland in terms of impaired growth and mortality?

Publication history: Accepted - 25 July 2020; Published - 31 July 2020.There is little modern data addressing the differential lifetime growth of commercially reared low and average birthweight pigs born into large litters (>14 piglets). As such, the main aim of this study was to quantify the lifetime growth and mortality rate of low and average birthweight pigs on commercial farms in Northern Ireland. It was also aimed to analyse the level, stage and cause of mortality within each birthweight category. A total of 328 low birthweight (LOW BW; 0.05). The alimentary tract (27%) and respiratory tract (27%) were the most commonly implicated body systems following post-mortem examination of post-weaning deaths. In conclusion, this study quantified the inferior weight, growth rate and mortality of Low BW pigs, identifying the lactation and immediate post-weaning periods as having greatest potential in reducing this birthweight associated growth differential

Extended nursing and/or increased starter diet allowances for low weaning weight pigs

Publication history: Accepted - 3 October 2019; Published online - 21 October 2019.Objective: To evaluate the use of nurse sows and post-weaning nutrition strategies for low wean weight (WW) pigs on lifetime growth and efficiency. Methods: Animals (n = 270) were assigned to one of five treatments at 28 d. Low WW pigs (<6 kg) were either weaned and offered a special dietary regime recommended for low WW pigs (WEAN) or placed on a nurse sow (NURSE) and weaned at 49 d. Normal WW pigs (9 kg) (NORM) were also weaned at 28 d. After weaning, NORM and NURSE pigs were offered either a ‘high’ (4 kg/pig of starter 1 diet followed by 8 kg/pig of starter 2 diet) or ‘low’ (8 kg/pig of starter 2 diet) starter diet allowance in a 2×2 factorial arrangement. A typical grower diet was then offered, followed by a typical finisher diet until 147 d of age. Results: NORM pigs where heavier throughout their life compared to NURSE pigs (91.4 kg vs 76.2 kg at 147 d; p<0.001). WEAN pigs were heavier at 70 d compared to NURSE pigs (23.9 kg vs 21.0 kg; p<0.001), but there was no significant difference at 147 d between NURSE and WEAN treatments. NURSE pigs had reduced feed intake throughout the finishing period (1.6 kg/d; p<0.001) compared to WEAN (2.0 kg/d) and NORM (1.9 kg/d) pigs. Feed conversion ratio (FCR) of NURSE (2.20) was lower than NORM and WEAN during the finishing period (2.40 and 2.79, respectively). Conclusion: Extended (up to 49 d) nursing for low WW pigs resulted in improved FCR during the finishing period, but no overall improvement in growth rate compared to low WW pigs weaned at 28 d and offered a specialised starter regime. Normal WW pigs where significantly heavier than low WW pigs throughout the study.This work was part of a PhD project sponsored by DARD and Pig Regen Ltd. The authors gratefully acknowledge the funders and the technical and farm staff at AFBI Hillsborough

Impact of sow lactation feed intake on the growth and suckling behavior of low and average birthweight pigs to 10 weeks of age

Publication history: Accepted - 2 May 2020; Published online - 9 May 2020.Improved genetics in commercial pig production have resulted in larger litter sizes. However this has increased the prevalence of compromised pigs exhibiting inferior birthweights, weaning weights, and lifetime performance. This study aimed to determine the effects of increased sow lactation feed intake on growth of low and average birthweight piglets until 10 wk of age. Low (Low BW; <1 kg) and average (Av BW; 1.3–1.7 kg) birthweight animals were reared in uniformly weighted litters comprising 14 piglets on a foster mother offered either a low (Low FA; max 7.5 kg/d) or high (High FA; max 11 kg/d) feed allowance over a 28- ± 1-d lactation. Piglet performance was monitored from birth until 10 wk of age. Sows offered a High FA consumed 42.4 kg more feed on average than those offered Low FA, resulting in a greater derived milk yield (P < 0.05). Animals of Av BW remained heavier than Low BW pigs throughout the trial (P < 0.05). Piglets reared by High FA sows were heavier at weeks 3, 4, 5, and 7 (P < 0.05) but not week 10 (P > 0.05). Growth rate of piglets relative to their birthweight was significantly greater for Low BW piglets than those of Av BW during lactation (P < 0.001). Piglets reared by sows offered a High FA expressed greater relative growth preweaning (P < 0.05); however, postweaning relative growth for piglets reared on sows offered a Low FA was greater (P < 0.05) suggesting compensatory growth. Neither birthweight nor sow feed allowance significantly affected preweaning mortality (P > 0.05). However, Low BW animals on sows with a High FA recorded half the preweaning mortality of Low BW pigs on sows with a Low FA. During week 1 of lactation, Av BW litters recorded a greater total suckling duration compared to Low BW litters (P < 0.05) but there was no difference in suckling frequency (P > 0.05). During week 3 of lactation, High FA litters displayed a significantly lower suckling frequency (P < 0.05) yet a greater total suckling duration (P < 0.001). Average daily gain was greater for Av BW pigs during weeks 4–7 (P < 0.001) but no difference was recorded between weeks 7 and 10 (P > 0.05). Average daily feed intake was greater for Av BW pigs throughout the nursery period (P < 0.05) but feed–conversion ratio did not differ compared to Low BW pens (P>0.05). In conclusion, offering sows a High FA increased weaning weight of all animals; however, birthweight was the major determinant of postweaning performance

Strategies towards Improved Feed Efficiency in Pigs Comprise Molecular Shifts in Hepatic Lipid and Carbohydrate Metabolism

Publication history: Accepted - 28 July 2017; Published online - 1 August 2017Due to the central role of liver tissue in partitioning and metabolizing of nutrients, molecular liver-specific alterations are of considerable interest to characterize an efficient conversion and usage of feed in livestock. To deduce tissue-specific and systemic effects on nutrient metabolism and feed efficiency (FE) twenty-four animals with extreme phenotypes regarding residual feed intake (RFI) were analyzed. Transcriptome and fatty acid profiles of liver tissue were complemented with measurements on blood parameters and thyroid hormone levels. Based on 803 differentially-abundant probe sets between low- and high-FE animals, canonical pathways like integrin signaling and lipid and carbohydrate metabolism, were shown to be affected. Molecular alterations of lipid metabolism show a pattern of a reduced hepatic usage of fatty acids in high-FE animals. Complementary analyses at the systemic level exclusively pointed to increased circulating triglycerides which were, however, accompanied by considerably lower concentrations of saturated and polyunsaturated fatty acids in the liver of high-FE pigs. These results are in accordance with altered muscle-to-fat ratios usually ascribed to FE animals. It is concluded that strategies to improve FE might favor a metabolic shift from energy storage towards energy utilization and mobilization.This work was funded by the European Union Seventh Framework Programme (FP7/2007–2013) as part of the ECO-FCE project under grant agreement No. 311794. The Leibniz Institute for Farm Animal Biology provided its own matched fundin

Impact of feeding low and average birthweight pigs on a weight basis post-weaning on growth performance and body composition

Publication history: Accepted - 28 August 2020; Published online - 29 August 2020This study aimed to investigate the effectiveness of employing a targeted nutritional regime until slaughter to maintain performance in animals recording high weaning weights. Low birthweight (Low BW; <1 kg) and average birthweight (Av BW; 1.3kg-1.7 kg) pigs were reared on sows exhibiting a high lactation feed intake and, as a result, weaning weights were 7.9 kg and 8.9 kg respectively. Pens containing either Low BW or Av BW animals were then offered either a ‘standard’ (STAND) or ‘feed-to-weight’ (FTW) regime from weaning until slaughter. The STAND regime was reflective of commercial production, where diet transitions were implemented after pre-determined feed levels or time intervals had been reached. In contrast, diet transitions in the FTW regime were carried out when target pen average weights of 12 kg, 18 kg, 22 kg, 45 kg and 75 kg respectively were met. Animal growth, feeding performance and body composition were monitored from weaning until slaughter. As expected, Av BW pigs were heavier than Low BW animals throughout (P<0.001), recording a superior average daily gain (ADG) (P<0.01) and average daily feed intake (ADFI) (P<0.001) at each stage of growth. This resulted in Av BW animals recording a greater carcass weight (P<0.001) and kill-out percentage (P<0.01). DEXA scan analysis showed Low BW animals to exhibit a greater percentage fat (P<0.001) and lower percentage lean (P0.05). Feeding regime did not affect age or weight at diet transition for Av BW animals for most transitions (P>0.05). However Low BW animals offered the FTW regime were significantly older and heavier than those offered the STAND regime at each transition (P<0.05). The FTW regime increased animal ADG and ADFI compared to STAND pigs from weeks 4 to 10 of age (P<0.05), whilst providing a greater average daily intake of energy and lysine from week 4 to 10 (P<0.05) and week 10 to 17 (P<0.05). This facilitated a greater liveweight in FTW animals from 7 weeks of age through to slaughter (P<0.05). Feeding regime had no effect on kill-out percentage or back-fat depth (P>0.05). Furthermore, DEXA scan results showed total or percentage lean and fat did not differ for FTW or STAND pigs at 10 or 21 weeks of age (P>0.05). In conclusion, feeding Low BW animals on a ‘feed to weight’ basis improved nutrient intake and animal liveweight, likely due to a greater time allowance for digestive development between diet transitions. As such, this approach should be considered for commercial adoption.DAER

An association analysis of sow parity, live-weight and back-fat depth as indicators of sow productivity

Publication history: Accepted - 4 June 2018; Published online - 18 July 2018; Published - March 2019.Understanding how critical sow live-weight and back-fat depth during gestation are in ensuring optimum sow productivity is important. The objective of this study was to quantify the association between sow parity, live-weight and back-fat depth during gestation with subsequent sow reproductive performance. Records of 1058 sows and 13 827 piglets from 10 trials on two research farms between the years 2005 and 2015 were analysed. Sows ranged from parity 1 to 6 with the number of sows per parity distributed as follows: 232, 277, 180, 131, 132 and 106, respectively. Variables that were analysed included total born (TB), born alive (BA), piglet birth weight (BtWT), pre-weaning mortality (PWM), piglet wean weight (WnWT), number of piglets weaned (Wn), wean to service interval (WSI), piglets born alive in subsequent farrowing and sow lactation feed intake. Calculated variables included the within-litter CV in birth weight (LtV), pre-weaning growth rate per litter (PWG), total litter gain (TLG), lactation efficiency and litter size reared after cross-fostering. Data were analysed using linear mixed models accounting for covariance among records. Third and fourth parity sows had more (P<0.05) TB, BA and heavier BtWT compared with gilts and parity 6 sow contemporaries. Parities 2 and 3 sows weaned more (P<0.05) piglets than older sows. These piglets had heavier (P<0.05) birth weights than those from gilt litters. LtV and PWM were greater (P<0.01) in litters born to parity 5 sows than those born to younger sows. Sow live-weight and back-fat depth at service, days 25 and 50 of gestation were not associated with TB, BA, BtWT, LtV, PWG, WnWT or lactation efficiency (P>0.05). Heavier sow live-weight throughout gestation was associated with an increase in PWM (P<0.01) and reduced Wn and lactation feed intake (P<0.05). Deeper back-fat in late gestation was associated with fewer (P<0.05) BA but heavier (P<0.05) BtWT, whereas deeper back-fat depth throughout gestation was associated with reduced (P<0.01) lactation feed intake. Sow back-fat depth was not associated with LtV, PWG, TLG, WSI or piglets born alive in subsequent farrowing (P>0.05). In conclusion, this study showed that sow parity, live-weight and back-fat depth can be used as indicators of reproductive performance. In addition, this study also provides validation for future development of a benchmarking tool to monitor and improve the productivity of modern sow herd.Department of Agriculture, Food and the Marine, Ireland (DAFM), University of Leeds